P#3

Textile Industries Hazard and control measure in textile/cotton Industries HAZARD NOISE noise induced hearing loss Tinnitus mental stress

DUST causes respiratory problems and causes Byssinosis, a disease caused by cotton dust LIGHT (eye strain and glaring)

FIRE HAZARDS

ELECTRICAL HAZARDS

ERGONOMICAL HAZARDS It includes Continuous work and improper workstations Heat & Humidity

Machinery hazards

CONTROLMEASURE • Isolation of the machine and silencer must be kept • Proper maintenance lubricating control noise • Use ear muff and ear plug PPE • Good regular maintenance by tightening loose guards and panels • Dust collector • Proper house keeping • Necessary PPE should wear by worker • Local exhaust ventilation provide • Proper lightening condition • Provide dust proof, flameproof, lightening • Firefighting arrangement consisting portable appliance, water hydrant and water sprinklers • Fire detection and Sound(Fire) alarm system • Inspection, Maintenance and training for fire protection • Proper earthling and double insulation • Use of approved insulated tools, rubber mats, shockproof gloves and boots • Air-Current breaks should be used • Employed qualified trained electrician • Good insulated and tasted wire • Safety tags and safety warning system • The work, work condition and plant and infrastructure should be designed that they best fitting for workers • Proper working procedure • By providing natural and mechanical ventilation • Reduce the exposure of time • Hot metal parts should b insulated • Limits of DBT & WBT Should be maintained • Machine guarding • Train person to know the hazard • Use the PPE

Hazards and safety measure in jute industries?

Hazards:

1. Machinery hazards are high as in case of cotton textile machinery.

2. Fire may occur due to friction and heat. Pesticides used in cultivation of jute may cause poisoning.

3. Dust is given off in bale opening and spinning 4. Dermatitis gives skin trouble due to dust, batching oil, dyes etc.

5. Excessive noise in weaving operation may cause hearing loss.

6. Carrying heavy loads may cause strains. Medical examination of workers is necessary.

7. Poor lightening.

Control Measure: 1. Main drives, gears, in-running nips of rollers or bowls, spindles and shafts, knives and cutters, flying shuttles etc. need efficient guarding.

2. Water hydrants are necessary.

3. Firefighting arrangement consisting portable appliance, water hydrant and water sprinklers 4. Fire detection and Sound(Fire) alarm system 5. Local exhaust ventilation is a must.

6. Ear protection is necessary.

7. Use the full sleeves clothing.

8. Maintain good housekeeping.

9. The work, work condition and plant and infrastructure should be designed that they best fitting for workers 10. Proper working procedure What is carding process in textile industries?

• • • •

Carding is a mechanical process that disentangles, cleans and intermixes fibres to produce a continuous web or sliver suitable for subsequent processing.

This is achieved by passing the fibres between differentially moving surfaces covered with card clothing.

It breaks up locks and unorganized clumps of fibre and then aligns the individual fibres to be parallel with each other.

In preparing wool fibre for spinning, carding is the step that comes after teasing.

Work environment related hazards and control measure Hazards 1.

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Noise and vibration Dust Poor illumination Bad ventilation Heat, humidity Material Handling Machinery hazards

Control Measure 1. Isolation of the machine and silencer must be kept 2. Proper maintenance lubricating control noise 3. Use ear muff and ear plug PPE

4. Good regular maintenance by tightening loose guards and panels 5. Dust collector system must be provided 6. Proper house keeping 7. Local exhaust ventilation provide 8. Proper lightening condition 9. Provide dust proof, flameproof, lightening 10. By providing natural and mechanical ventilation 11. Reduce the exposure of time 12. Hot metal parts should be insulated 13. Limits of DBT & WBT Should be maintained 14. Necessary PPE should wear by worker Hazard and control measure in sugar industries?

Hazards The nature of sugar mill machinery poses mostly 1. Mechanical hazards - crush injuries, packing machines and large size crushing gears.

2. Electrical Hazards- Electric Shock, electric burn, fire and explosion, static electricity 3. Toxic Hazards- Due to asbestosis, laboratory chemical, lead, welding and cutting fumes.

4. Falls or slipping from heights-falling into pit or hot sugar juice hurt by falling bodies or sugar bags, 5. Fumes and gases (SO , HCI, CO, CO,) 6. Heat & Humidity-steam at many places, During Evaporation for boiling of clarified juice 7. Sugar cane dust (may cause bagassosis) 8. Noise and vibration due to centrifuge machines and vibrating screens, 9. Ergonomically hazards-Handling of material in awkward position.

10. Poor lightening and housekeeping.

Control measure 1. Guarding of all machinery moving parts, drives, and shafting, gearing and cutting knives.

2. Nip guards to conveyors and rollers.

3. Good housekeeping and vacuum cleaning.

4. Isolation of the machine and silencer must be kept 5. Proper maintenance lubricating control noise 6. Use ear muff and ear plug PPE 7. Good regular maintenance by tightening loose guards and panels 8. Dust collector system must be provided 9. Proper house keeping 10. Local exhaust ventilation provide 11. Proper lightening condition 12. Provide dust proof, flameproof, lightening 13. By providing natural and mechanical ventilation 14. Reduce the exposure of time 15. Hot metal parts should be insulated 16. Limits of DBT & WBT Should be maintained 17. Necessary PPE should wear by worker

18. Good sanitary and washing facilities, personal, hygiene, protective clothing, dust masks and medical supervision.

Hazards associated with spinning operation in textile mill OR machine related hazards in spinning?

Main Hazards are due to nip points at fed and calendar roller of blow room machinery, carding machine, comber etc.

Other hazards include: 1. Physical Hazards- Noise, Dust, poor illumination, heat and humidity.

2. Electrical hazards- Shock, burn, fire and explosion.

3. Ergonomically hazards- Poor plant layout, lifting heavy weight, working in awkward position Control Measure: 1. All main drives, counter drives and reduction gears shall be securely guarded.

2. All beater covers or doors giving access to any dangerous part of the machine should be interlocked or be securely fenced.

3. All belt and chain drives should be guarded.

4. In Roving waste opener, cage-wheel and side shaft wheel should be guarded.

5. Inspection doors (covers) on trunkings should be properly situated and closed. If their location is dangerous, it should be changed or interlocked.

6. Safe means of access i.e. catwalk, guard-rails, steps, ladders, hand-rails etc., should be provided on top of the machine where a worker has to work.

7. The nip between the plate-wheel and the side shaft wheel of carding machine should be guarded.

8. Local Exhaust Ventilation: Modern card machines have built-in local exhaust system with dust collection chamber to extract the cotton dust generating in the machine and to prevent its exposure in the work environment. This system should be efficiently maintained 9. Proper earthling and double insulation, all the moving parts of machinery should b properly earthed, 10. Use of approved insulated tools, rubber mats, shockproof gloves and boots 11. Air-Current breaks should be used 12. Isolation of the machine and silencer must be kept 13. Proper maintenance lubricating control noise 14. Use ear muff and ear plug PPE and required PPE 15. Good regular maintenance by tightening loose guards and panels 16. The work, work condition and plant and infrastructure should be designed that they best fitting for workers 17. Proper working procedure Hazards associated with cotton pickers include 1.

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Machine stability when turning sharply.

Loaded with cotton, or crossing uneven ground, Large moving equipment with poor operator vision lines, Rotating shafts and belts, Shearing mechanical parts, hydraulic lines, blowers,

6. Noise exposure, airborne dust, and clogged spindles, chutes, grills and vents.

Control measure 1. Thoroughly review and understand safety information provided in the cotton picker operator’s manual 2. Always carried out inspection, including checking fluid levels, lights, tires, and guards and shields.

3. Inspect the cotton picker for loose hydraulic connections and worn or loose parts such as belts, gears, or lug nuts. If a cotton picker fails the pre-shift inspection, notify your supervisor and remove the machine from service by attaching a red tag that states “DO NOT USE.” 4. Always wear appropriate personal protective equipment, including hearing protection and if conditions warrant, a dust mask.

5. Before starting or beginning to drive a cotton picker, look for people or obstructions behind, alongside, or ahead of the cotton picker.

6. Maintain eye contact with others working around the cotton picker 7.

As the cotton picker begins to move, engage the clutch slowly and evenly – avoid jerky starts, turns, or stops.

8. Never carry passengers on a cotton picker.

9. Avoid operating a cotton picker within six feet of ditches, holes, depressions, and embankments.

10. Always look for overhead lines before operating a cotton picker or raising the basket.

11. Reduce speed when turning on roads or at row ends, crossing slopes, or driving on rough, slick, or muddy surfaces.

12. Do not operate cotton pickers on slopes too steep for safe operation.

13. Never adjust or unclog machine parts until the cotton picker is shut off 14. affected parts have stopped moving and are de-energized, and proper lockout/tag-out procedures have been implemented What is winding in textile industries?

Purpose is to wind weft on bobbins.

Types of machines used are: Barber-Coleman, Auto-comer, pirn winder etc.

Safety Measure 1. Guards should be provided on main drive, revolving drum, drum drive motor, timer drive, cam drive, traveller pulley and track nip and conveyor drive.

2. The gap between the moving parts of conveyor and fixed parts should be checked all along its length and reduced to the minimum by suitable covers/guards.

3. Bobbins/sleeves used on the m/c should be inspected for broken edges, burrs etc. as also for their proper fitment on driving spindles.

4. Haste in loading spindles with empty bobbins should be avoided. Also, dust and other extraneous materials on spindle and moving yarn should not be removed while they are in motion. Dust collecting blower and bag are useful.

5. Automatic winders like cone winder and spoolers prevent hands reaching near the rotating drum and are preferable.

Explain the hazards and control measure at process house in textile industries?

Process House Types of machines in use are: Shearing, singing, washing, bleaching, kiers, yarn and cloth dyeing, printing, polymerising, sanforising, stentering, padding, finishing, folding, bale (cloth) pressing machine etc.

Hazards: 1. Physical Hazards- Noise, Dust, poor illumination, heat and humidity.

2. Electrical hazards- Shock, burn, fire and explosion.

3. Chemical Hazards- Use of bleach agents during bleaching process, Splashes from chemical and Hot solution 4. Machinery hazards: Caught hand in moving objects 5. Material Handling- No training, - excessive weight lifting, improper or failure of lifting tackles, slings etc.

Control Measure: 1. The in-running nips between rollers and similar parts should be securely guarded with nip guards (bars) 2. Other machine parts such as main and counter drive, belts, pulleys, shafts, gears and flappers should be guarded.

3. Removing crease from die cloth on rollers should never be done when the machine is in motion.

4. Oiling, greasing, adjustment or repairing near dangerous parts should not be done with the machine running.

5. Splash guards should be provided for containing the likely splashes of chemicals and hot liquids at those parts of machine where- splashes generally occur.

6. Wherever risk of splashes from chemical or hot solutions exists, operators should be provided with PPE such as face shields or goggles, hand gloves, aprons and gum-boots.

7. Suitable means of access in the form of catwalks and platforms should be provided.

8. Acids, alkalis, bleach liquors or whitening agents, dyestuffs and solvents are used for process or cleaning purpose. Their storage should be kept away in a separate room. They should be handled in small containers with lids. Their spillage or leakage should be avoided and cleaned immediately.

9. Normally chlorine, sodium hypochlorite or hydrogen peroxide are used as bleach liquors. Their concentration should be within safe limits. They should be stored in minimum quantities.

10. Open bleaching tanks should have fencing to prevent fall inside.

11. Bleaching machine should have fume exhaust device. Bleaching range should have nip guard on rolls.

Agro/Sugar industries Hazard and control measure in Agro industries?

RESPIRATORY HAZARDS

1. Farming situations present several respiratory hazards to farm workers Exposure will produce to excessive coughing and congestion 1. Symptoms of chronic bronchitis were also observed 2. Organic Dust Toxic Syndrome (ODTS) is a common respiratory with fever, headache, and muscle aches and pains 3. Dust from mouldy hay, grain, and silage can also cause ODTS 4. Nuisance dusts and gases also are hazards. Suspended dust particles not containing spores from mouldy organic matter are considered nuisance dusts. Repeated exposure can turn portions of the lung into hardened, non-functioning tissue and cause chronic bronchitis and occupational asthma.

5. A variety of disabling gases, including nitrogen dioxide (NO 2), hydrogen sulphide (H2S), ammonia (NH3), Carbon dioxide (CO2), and methane (CH4), are produced during many routine operations. Exposure will produce lung and eye irritations, dizziness, drowsiness, and headaches Control measure 1. The best prevention of respiratory disease is to wear a respirator approved by the National Institute of Occupational Safety and Health (NIOSH).

NOISE 6. Prolonged exposure to excessive noise, such as that produced by tractors, combines, choppers, grain dryers, and chainsaws, can cause permanent hearing loss unless noise-control measures are taken.

Control measure 1. The two types of hearing protection available are ear muffs and ear plugs. Ear muffs are more effective 2. Control noise at source by providing silencer.

SKIN DISORDERS 7. Contact dermatitis is a skin disorder that occurs among agricultural workers. There are two general categories: irritant and allergic. Irritants act directly on the skin at the place of contact. Allergic sensitizers, however, cause changes in the immune system so that subsequent contact produces a reaction.

Control Measure 1. To know chemicals and other agents to which an individual has been exposed.

2. Wearing proper protective clothing, and washing frequently are the most effective means of prevention.

CANCERS 8. Skin cancer is a concern on the farm due to the long hours farmers spend in the sun.

Skin cancer is the most common form of cancer.

Control measure

1. wear protective clothing, such as long-sleeved shirts, pants 2. Conduct regular self-examinations for early detection.

CHEMICAL HAZARDS 9. Many agricultural workers are exposed to chemicals on a daily basis. If they do not observe proper precautions, illness or even death may ensue.

Control measure 1. To prevent dermal (skin) contact and inhalation of pesticides, applicators should wear personal protective clothing and equipment.

2. should wear chemical-resistant while using pesticides and chemical HEAT STRESS 10. Heat stress occurs when the body builds up more heat than it can handle. High temperatures, high humidity, sunlight, and heavy workloads increase the likelihood of heat stress.

Control measure 1. Drink water every 15 minutes, even if you are not thirsty.

2. Rest in the shade to cool down.

3. Wear a hat and light-coloured clothing.

4. Use fans, ventilation systems, and shade whenever possible.

OTHR HAZARDS 1. Ergonomically Hazards- repetitive, forceful, or prolonged exertions of the hands; frequent or heavy lifting, pushing, pulling, or carrying of heavy objects; and prolonged awkward postures.

2. Other Biological Hazards. These include vector-borne diseases, venomous wildlife and insects, and poisonous plants.

3. Extreme Cold.

4. Lightning.

5. Ultraviolet Radiation.

Explain retting activities of harvesting in agriculture sector?

1. Retting is the process of extracting fibre from the long lasting life stem or bast of the bast fibre plants.

2. The available retting processes are: mechanical retting (hammering), chemical retting (boiling & applying chemicals), steam/vapour/dew retting, and water or microbial retting.

3. Among them, the water or microbial retting is a century old but the most popular process in extracting fine bast fibres. However, selection of these retting processes depends on the availability of water and the cost of retting process.

4. To extract fine fibres from jute plant, a small stalk is harvested for pre-retting 5. If the fibre can easily be removed from the Jute hard or core, then the crop is ready for harvesting.

6. After harvesting, the jute stalks are tied into bundles and submerged in soft running water.

7. The stalk stays submerged in water for 20 days.

8. However, the retting process may require less time if the quality of the jute is better.

9.

In most cases, the fibre extraction process of bast fibres in water retting is done by the farmers while standing under water.

Explain Thrashing in agriculture sector?

1. Threshing is the process of loosening the edible part of cereal grain (or other crop) from the scaly, inedible chaff that surrounds it.

2. It is the step in grain preparation after harvesting and before winnowing, which separates the loosened chaff from the grain.

3. Threshing does not remove the fibre from the grain.

4. Threshing may be done by beating the grain using a flail on a threshing floor.

5. Hand threshing was difficult, with a bushel of wheat taking about an hour.

6. Industrialization of threshing began in 1786 with the invention of the threshing machine by Scotsman Andrew Meikles. Today, in developed areas, it is now mostly done by machine, usually by a combine harvester 7. The cereal may be stored in a threshing barn or silos.

Explain winnowing in agriculture sector?

1. Wind winnowing is an agricultural method developed by ancient cultures for separating grain from chaff.

2.

It is also used to remove weevils or other pests from stored grain.

3. Threshing, the loosening of grain or seeds from the husks and straw, is the step in the chaff-removal process that comes before winnowing.

4. In its simplest form it involves throwing the mixture into the air so that the wind blows away the lighter chaff, while the heavier grains fall back down for recovery.

5. Techniques included using a winnowing fan (a shaped basket shaken to raise the chaff) or using a tool (a winnowing fork or shovel) on a pile of harvested grain.

6. Winnowing can also describe the natural removal of fine material from a coarser sediment by wind or flowing water, analogous to the agricultural separation of wheat from chaff.

CONSTRUCTION INDUSTRIES:

Write down the hazards and safety measure in use of construction machinery?

Construction machinery can be classified into three categories as under 1 Lifting Appliances and Gear: Pulleys, chain pulley blocks, winches, hoists, derricks, gin poles, cranes (fixed and mobile), lifting ropes, slings etc.

2 Transport, Earth-moving and Material Handling Equipment: Power shovels (excavators), bulldozers, scrapers, pavers, road rollers, pile drivers, mobile asphalt layers and finishers.

3 Plant machinery, Equipment and Hand tools Concrete mixers and vibrators, pneumatic compressors, pneumatic tools, cartridge operated tools, electric tools, hand tools, conveyors, crusher plants, power generators, engines and silos.

The hazards: associated with the use of lifting equipment in construction are: 1. Hazards related to the loads, e.g. crushing due to impact of moving objects or loads falling from vehicles because they are not singed properly or the wrong type of slings were used 2. Hazards from moving vehicles or collapsing structures - i.e. cranes falling over because of improper fixation or strong wind, unsafe loads, loads exceeding the safe weight limits, falling from height , limbs or bodies caught in machinery 3. falling from lifting platforms or being crushed when the platform moves 4. musculoskeletal hazards related to force exertions, poor working postures and/or repetitive work 5. hazards related to poor environment that may interfere with communication between workers or concentration needed for the task (noise) or cause sweaty, slippery objects (heat, poor ventilation) 6. Contact with overhead electrical cables.

7. Cranes operated by unskilled person or without authority Possible causes of these hazards may be: 1. poor mechanical design (breaks in use, not powerful enough, components fracture or malfunction), 2. poor workplace design, 3. malfunction of the (manual, mechanical, electronic) signalling system, not using the proper equipment for the purpose or misuse (not using as designed, e.g. the load was too heavy), loads insecurely attached, 4. poor maintenance (breaks or emits noxious gases) or untidy workplace, 5. Human error when operating machines or erecting scaffolding.

Control measure

Lifting Appliances and Gear: Pulley 1. Select the pulleys as per requirement.

2. Steel and nylon rope should not be used together.

3. Sheaves should rotate freely on the shaft. The shaft should be free from any defect or crack.

Hoists: 1. Refer Sec. 28 of the Factories Act. Design should be as per standard code.

2. Hoist shaft (way) should be enclosed with rigid panels or fencing at all landing platforms, access or where any person is liable to be struck by any moving part.

Cranes (Fixed & Mobile): Refer Sec. 29 of the Factories Act 1. The crane capacity should be ascertained and brakes checked before lifting a load.

Mobile crane should be parked on hard soil and not near any pit or excavation.

2. The safe working load should be displayed in the crane 3. Devices should be provided to prevent load being moved to a point where the corresponding safe working load of the crane would be exceeded.

4. Standard signalling code, understood by the operator and trained signalman, should be followed.

5. Tag lines should be used while hoisting heavy and bulky load. The crane and its parts (brakes, boom, hook, wire ropes, pulleys etc.) should be checked regularly and maintained in good condition.

6. The load should not touch the boom and the boom should not touch any live electric line or structure. Quality of packing should be checked before lifting. Nobody should stand below the boom or load. The operator should be able to see the hook and the load, should keep his windshield clean for clear vision and deck clean of any oil, mud or dust.

Transport, Earth-moving and Material Handling Equipment: 7. All vehicles and earth-moving and material handling equipment should be of good design, sound material and construction, adequate strength and maintained in good working order. Principles of safety and ergonomics should be considered in design and operation.

8. Operators/drivers should be well trained, medically examined, physically fit and above 18 years of age.

9. All vehicles should be equipped with proper lights, horns, silencers, power and hand brakes and reversing alarm. Their motors, engines, brakes, gears, chassis, blades, tracks, wire ropes, sheaves, transmission parts and pneumatic, hydraulic systems should be checked daily before use.

Plant Machinery, Equipment and Hand Tools:

1. All such machinery, equipment and tools should be of good, ergonomic and safe design, maintained in good working order and operated .by trained operators with necessary personal protective equipment.

2. Safety instructions from manufacturer and safe operating procedure should be followed.

3. Power driven equipment should be properly earthed, stop switch provided in close proximity, adequately guarded, speed regulated and when not in use, switched off (de-energised) and isolated before any major adjustment.

Write the hazards and provision of safe guard of them at construction site?

Hazards at Construction: 1. Fall of Persons – 1. Fall from height, fall through opening, collapse of scaffold, structure failure, tripping.

2. Fall from height may be due to non-use or failure of safety belt, lack of proper access, non-use of proper ladder etc.

3. Fall through opening may be due to unguarded opening or poor guarding.

4. Collapse of scaffold may be due to its improper design, no toe board, and no means of access. Minimum dimensions are: Board width 6", thickness I" and guard rail height 30 to 36".

5. Tripping may be due to loose object/cables etc.

2. Fire- Due to welding, gas cutting, smoking, gas cylinders, scattered wooden material/ rubbish, paints/thinners, temporary shed etc.

3. Electrocution - Electric shock, burns, damaged cable, no earthling, no ELCB, no use of 3 pin plug/socket, work by non-qualified electrician etc.

4. Material Handling: No training, - excessive weight lifting, improper or failure of lifting tackles, slings etc.

5. Transport Accidents: Untrained driver, not obeying traffic rules, reversing without signalling, over-speed, speed-breakers, poor brakes, poor lighting etc.

6. PPE: Not using helmet, safety shoes, hand gloves, safety belt, respirators etc.

7. Others: Noise, vibration, dust, gas, fumes, cave in, night work, overtime, intoxication etc.

This suggests the direction of accident prevention work in construction activity.

1. The work, work condition and plant and infrastructure should be designed that they best fitting for workers First, 2. Plan for the whole and then for the detail. Plan site layout, plot layout and equipment layout as per requirement.

3. Each work should be subdivided in steps accounting for safety precautions and responsibilities.

4. All the electrical instrument should be properly earthed.

5. Facilities for water, firefighting, first-aid, tools and equipment availability, roads, vehicle movement, parking, smoking booths, sanitary blocks, canteen, control room, safe entry, exit and escape route etc. should be properly planned.

6. Special precautions should be encountered for working at heights or depths.

Systematic work permit system should be adopted before carrying any work.

7. hazard identification, risk and reliability assessment, strength and stability criteria, inventory reduction, process safety, fail-safe design, emergency shut-down procedure and emergency planning.

8. Appointment of safety and health personnel, trained supervisors and requirement of adequate first-aid and firefighting facilities and personal protective equipment should be considered at the stage of planning and budgeting for safety at work.

9. For the safety of workplaces and avoiding risk of injury to workers, safe means of access to and egress from all workplaces should be provided, maintained and indicated where necessary.

10. To prevent fall, fencing or other devices are required.

11. Means of access may be a ladder-portable or fixed, ramp, runway or stairway. They should conform to the code or standards prescribed.

12. All such machinery, equipment and tools should be of good, ergonomic and safe design, maintained in good working order and operated .by trained operators with necessary personal protective equipment.

13. All vehicles should be equipped with proper lights, horns, silencers, power and hand brakes and reversing alarm. Their motors, engines, brakes, gears, chassis, blades, tracks, wire ropes, sheaves, transmission parts and pneumatic, hydraulic systems should be checked daily before use.

14. All the noise creating machine has been properly lubricated to reduce noise 15. Maintain Good Housekeeping : 16. Cleaning of floors, passageways, stairs etc. to remove oil, water, dust etc. Sand, ash, sawdust and proper absorbers can be used.

Root Cause of Accident at construction site?

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Unsafe equipment Inoperative safety devices Using Equipment defect Unsafe condition Poor housekeeping Working at height without PPE Unsafe Act

8. Equipment and waste material arrangement 9. Slippery and muddy work surface 10. Excessive noise 11. Poor illumination 12. Poor ventilation 13. Not using PPE

14.

15. List out various safety equipment used in construction industries 1. PERSONAL PROTECTION EQUIPMENT- Safety helmet, gloves, shoes, safety jacket etc.

2. FALL PROTECTION EQUIPMENT- full body harness, Lanyard, Lifeline 3. COMMUNICATION EQUIPMENT- personal alert system 4. FIRE FIGHTNING EQUIPMENT- Fire extinguishers, water hydrants 5. RESPIRATORY PROTECTION EQUIPMENT 6. SAFETY EQUIPMENT – first aid kit, lockout tag-out system 7. LIFE SAVING EQUIPMENT – 8. INDUSTRIAL HYGIENE EQUIPMENT-Welding Blankets Personal and area heat stress monitors Sound level meters, Noise dosimeters Single gas monitors Personal sampling pumps 9. SMOKE DETECTION EQUIPMENT 10. EMERGENCY LIGHTING 16. Explain the electric Hazard in construction industries and its control measure?

17. Main electrical hazards are: 18.

1.

Electric Shock.

2.

Electric Burns.

3.

Fire and Explosion.

4.

Hazards due to Electric Welding and Cutting 5.

Hazards due to static electricity.

6.

Fall of lightening from the sky.

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20. Control Measure 1.

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Main protections are proper fuses, switchgears, circuit breakers, earthlings and bonding. Such electrical safety precautions are highly needed to prevent accidents .due to electrical hazards.

Use of approved insulated tools, rubber mats, shockproof gloves and boots, tester, fuse puller, wooden or insulated ladder and not wearing metal ring, chain etc.

Switches on the live line. Fused switches and air-current breaks should be used.

Avoid temporary wiring. Avoid hurry and chance taking. Avoid left hand touching.

Employ qualified and trained electrician.

Good insulated and tested wiring.

Isolation of machine/equipment before use.

Work permit system should be followed Safety tags and safety warning notices.

Use of machine/ equipment within their limits i.e. no overloading.

Precautions against thermal and mechanical stress, moisture, dust and overvoltage. Automatic voltage regulators and overvoltage relays to protect from overvoltage’s.

Use of electric shock guard (ELCB) and 3-pin plug and socket to have proper earth connection.

Use protective relays, circuit breakers and rated fuses to control the current and to isolate the faulty equipment speedily and automatically.

14.

15.

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17.

Record of ground resistance values and the physical condition of the grounding mat.

Temperature sensitive alarm and protective relays to make alert and disconnect equipment before overheating.

Interlocks to put into and out of service equipment correctly.

Testing for high voltage, timing, polarity and insulation resistance.

21. Explain various construction work activities / any four operations of construction industry and hazards associated to them and their controlling measure?

22. Excavation Activity 23. Foundation or underground support is required for most of the constructions and method of reaching earth or rock stratum for foundation is called excavation.

24. Hazards:1.

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3.

4.

5.

fall of persons, soil, material etc., Inrush of water, oil, gas etc., inadequate lighting and ventilation to supply fresh air inside, Gas, vapour, dust etc.

Fire- Due to welding, gas cutting, smoking, gas cylinders, scattered wooden material/ rubbish, paints/thinners, temporary shed etc.

6. Lack of proper means of access, 7. Stability of the ground, position of public utility services such as electric or telephone cables, water, gas or sewers line etc.

8. Material Handling: No training, - excessive weight lifting, improper or failure of lifting tackles, slings etc.

25. Control Measure 1. Chemical waste and contamination should be safely removed.

2. No load, vehicle or material should be moved or stacked near the edge of excavation unless shoring or piling is done to prevent the sides from collapsing.

3. Cutting shall be done from top to bottom 4. Erosion of soil over excavated pits, trenches etc. should be prevented from running water by dewatering pumps etc.

5. Helmets and gum-boots should be given to all workers working inside.

26. Drilling, Loading and Blasting: 27. Drilling and blasting was the only economical way of excavating long tunnels through hard rock, where digging is not possible. Drilling and loading are required before blasting.

28. Hazards 1.

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4.

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Electric Hazards- Electric shock, electric burn Fire and explosion- use of explosive and detonator for blasting Fall of material Flying object (Rock)- during drilling Noise and vibration- During Blasting and drilling Heavy Material Handling

29. Control Measure 1. Before starting drilling, any presence of unfired explosives should be carefully checked before drilling.

2. loose or disintegrated rock should be removed by hand tools or pneumatic jack 3. Compressed air hoses should have self-locking couplings.

4. Drillers should wear helmet, hand gloves and gumboots.

5. Transportation, storage, handling and use of explosives are governed by the Explosives Act and Rules.

6. No smoking or open flame is allowed in explosive loading area.

7. All the workers from this area are withdrawn to a safe place 8. Then follows the warning procedure. 'Warning' and 'All clear' signals should be established and made known to all concern 9. No other electric circuit should be allowed in that area or it should be de-energised 10. The blasting foreman, then, sounds a warning siren to drive away all persons from the danger area and not to allow anybody to enter in the blasting area.

30. Scaffolding 31. A scaffold is a temporary structure that provides support for workers, plant and materials used in building, construction, maintenance, repair and demolition work.

32. Hazards 1. Unsuitable or faulty material of construction.

2. Inadequately supported scaffold boards.

3. Improper platform width and thickness.

4. Non-securing or bracing scaffold to the structure. Damaged or wrong couplers.

5. Unsecured ladders slipping.

6. Omission of guard rails or toe-boards.

7. Overloading the scaffold.

8. Erected on uneven ground.

33. Control Measure 34.

1. The scaffolds should be of sound material, sufficient strength 2. Their erection, alteration and dismantling should be done under the supervision of a competent person.

3. In high wind or storm work on scaffold should be avoided.

4. No hot work should be carried out on wooden platform.

5. Firefighting facility should be kept nearby.

6. Warning notice should be displayed near incomplete or damaged scaffold.

7. Materials should not be thrown from heights and should not be left lying here and there.

8. Should be away from overhead electric lines.

35. Welding and Cutting Operations: 36. Welding and cutting operations are frequently used in construction, demolition, repair and maintenance works.

37. Hazards 1. Electric Shock, electric burn.

2. Fire and explosion 3. Radiant energy generated by cutting and welding

4. Fumes and gases 5. Noise, heat 38.

39. Control Measure 1. Remove all combustion material from the place of welding 2. Clear the work area and cover wooden floor with fire proof mats.

3. Erect fire resistance screen around the work.

4. All welding cables should be fully insulted 5. All welding mics shall be double earthed 6. Welding area should be dry and free from water 7. Keep the fire extinguisher / sand really 8. USE PPE and follow hot work permit system strictly 40. Write down the importance of site planning and layout in construction industries?

41.

42. Importance of Planning 43. Need of planning for safety and health and 'safety engineering approach in design, planning and construction of new plant or new alteration or addition' are basic and most essential, because: 1.

General efficiency and safety in industrial activities can be greatly increased thereby.

Accidents and occupational diseases can be prevented from the earliest days.

Efficient flow of work is maintained, and Safety and comfort of people are achieved by considering ergonomic aspects.

2.

3.

4.

44.

45. Importance of Layout 46.

1. To ensure enough work space should be provided for workers to work without restriction.

2. To provide Proper roads, walkways, tracks, alleys, catwalks etc. should be provided for free passage of men and materials to avoid delay and obstruction.

3. To provide Sufficient doors, windows, ventilators and open space must be provided for good ventilation and lighting.

4. To Installation of machinery, floors, stairs, lifting machines, electric wiring etc. must be done to ensure safety. Allow at least I’m space around each machine.

5. To keep the handling of materials to the minimum. Use mechanical means to reduce manual strain.

6. To provide safe means of access to all work places.

7. Provide safe transport facilities for men and materials.

8. Provide adequate emergency exits.

47.

48. Explain Housekeeping in construction industries 49.

1. Speedy removal of scrap, waste, debris, loose and unused materials at regular intervals.

2. Proper storage of materials, tools and equipment. Removal of nails from lumber before stacking.

3. Cleaning of floors, passageways, stairs etc. to remove oil, water, dust etc. Sand, ash, sawdust and proper absorbers can be used.

4. Containers should be provided for collection and separation of waste. Flammable/ hazardous waste should be covered and safely disposed off.

5. After completion of any job, excessive materials, tools and equipment should be lifted and placed in their proper place.

6. Piles of materials should be stable and properly supported.

7. Throwing of material should be avoided. If it is to be thrown, warning signals should be given. Proper painting and colour-coding should be followed.

50.

51. Automobile Industries: 52.

53. Write the hazards and control measure in automobile industries?

54. Hazards 1. Noise and vibration during casting, forging, machining 2. Fire hazards due to welding and soldering 3. Heat near furnaces 4. Dust Fumes and gases due to welding 5. Material handling- poor layout, awkward working position.

6. Machinery Hazards- Caught hand in between objects, defects in tools and equipment 7. Electrical Hazards- Shock, burn, fire, static electricity 8. Fall of material 9. Poor housekeeping, ventilation and illumination 10. Chemicals hazard- during painting.

55.

56. Preventive measure 1.

Noise and vibration control.

2.

Dust, fumes and gas emission control by 3.

High temperature control near furnaces by insulating material or heat reflective surfaces to heat source.

4.

Heat protective clothing, eye and face protection.

5.

Mechanical lifting.

6.

Guarding of drilling, reaming, grinding, milling machines, power presses, conveyor belt etc.

7.

Machine tools with splash guards.

8.

Barrier creams and oil-resistant aprons. .

9.

Welding and soldering precautions.

10.

Electroplating baths with special lip ventilation and anti-foaming surface tension agents.

11.

Solvent and spray controls with special booths in painting shop Paint dipping and electrostatic or electrophoretic painting requiring worker outside are more safe.

12.

Dryers with exhaust ventilation.

13.

Controls for chemicals which are toxic, flammable and explosive.

14.

Electrical safety.

15.

Precautions against silicosis, solvent poisoning, lead poisoning, skin diseases. Xrays for non-destructive testing etc.

57.

58.

59. Explain the various types of NDT test in automobile manufacturing industries?

Describe at least 2 in detail with neat diagram?

60.

61. Types of NDT test in automobile manufacturing industries 1. Ultrasonic Testing for Case Hardened Components 2. Laser-Welded Tailored Blanks 3. Computed Tomography 4. Magnetic Particle Testing 5. Eddy Current testing of sleeve of cylinder 6. Liquid Penetrant testing for castings, machined parts and all carbon steel materials 62.

63. Ultrasonic Testing for Case Hardened Components 1. Case hardened components used in automobiles, which include crankshafts, camshafts, roller bearing and ball bearings require tight tolerance limits.

2. Ultrasonic testing method can either be implemented as PINT (Process Integrated Non-destructive Testing) units or can be instigated in post-process testing systems.

3. This relatively inexpensive NDT method has been proved to cut the high cost of material and destructive testing expenditures and reduction of production line downtime involved in the testing processes.

4. It also accommodates instant manufacturing control, assuring high quality levels.

64. Advantages: 

UT is sensitive to subsurface and surface discontinuities



Gives instantaneous results



Superior to other techniques



Very less preparation time is required



Can also be used for thickness measurements



One-sided access is sufficient

65. Disadvantages: 

Surface must be accessible



Longer/steeper learning curve



Coupling medium required



Cannot detect linear defects parallel to the sound beam

66.

67.

5. Principle of ultrasonic testing.

LEFT: A probe sends a sound wave into a test material. There are two indications, one from the initial pulse of the probe, and the second due to the back wall echo.

RIGHT: A defect creates a third indication and simultaneously reduces the amplitude of the back wall indication.

68.

69. Hazards & Control Measure 70.

71. Biological effects have been noticed on workers72. Human body always generates new cells replacing dead or damaged cells. But when ionising radiation causes more damage than the body's repair capacity, biological damage takes place. Injury to individual .is called somatic effect and that being passed into future generations is called genetic effect. The Biological effect is the destruction of reproduction capacity of a cell or carcinogenic effect (cancer) which is difficult to cure.

73. Control measure 1. Shielding of electrical connection causing electromagnetic fields, 2. Sound isolated booth, 3. Use of cotton lined rubber gloves, absorbent lining to tools, ear muffs, noise & vibration control, and periodic medical examinations are necessary.

74.

75. Magnetic Particle Testing 76.

77. Electromagnetic Inspection Test of Bar of Torsion 78.

1. The inspection for surface defects of Bar of Torsion can be carried out by the electromagnetic inspection techniques.

2. The part is scrutinized for longitudinal slits using a semi-automatic test unit.

3. Defects as small as 0.005" can be detected by this technique.

79.

80. Magnetic Particle Testing for Synchronizing Hubs 81.

1. Synchronizing hubs, used in manual transmission gearboxes for automobiles, are mostly manufactured using powder metallurgy techniques and are case hardened.

2. Cracks (Keyway, Groove or Radial/Spline), that are bound to develop in this component, could prove detrimental to the functioning of the automobile.

3. Thus, it is important that crack-free products are used in automobiles.

4. The most optimal (non-destructive) method found for testing this particular component was found to be Magnetic Particle testing technique 82. Advantages: 

Rapid inspection of large surface areas



Surface and subsurface flaws can be detected



Equipment costs lower compared to other NDT techniques

83. Disadvantages: 

Can only be used for inspection of ferromagnetic materials.



A relatively smooth surface required for application of this method.



Non-magnetic materials like paints, coatings etc. affect the sensitivity of this testing technique.

84. Hazards & Control Measure 85. Hazards- Dust particle, Electric shock, burn, fire and explosion, Electrical arcing (caused by loose contact, excessive current or slipping of prods) can cause sparks or fire.

86. Control Measure 1. Local exhaust is necessary to control dust particles. If it is not possible, dust mask (respirator) and eye and skin protective equipment should be worn by the workers.

2. Smoking should not be permitted near wet bath process.

3. Filters should be used on the black light while testing with fluorescent particles, to protect skin or eyes.

4. Proper training is to be provided to know the causes of electrical arcing followed by burning.

87.

88. List Hazards associated with heat treatment operation in automobile industries and their control measure?

89. Hazards in heat-treatment are:

90.

1.

2.

3.

4.

5.

Burns due to high temperature heating (between 700 to 1100° C).

Hazards of chemicals like N2, NH3, NaCN, Na2CO3, NaCI. Contact of quenching media like brine, water, oils, air and solution of NaOH or H2SO4 in water etc.

Hazards of various types of furnaces and temperature measuring instruments and electrical apparatus.

Handling of machine parts viz. steel castings, forging (shafts, axles etc.) springs, gears, wires, drills, screw taps, hammer dies, die moulds, high speed cutting tools and speed etc. for heat treatment purposes.

Lifting and travelling mechanism and their unguarded agency parts.

Dust exposure.

Hot surfaces and high air temperatures.

High humidity and air velocities.

High voltages and electromagnetic radiation.

High noise levels.

Infra-red radiation.

Excessive brightness of illuminated surfaces etc.

6.

7.

8.

9.

10.

11.

12.

13.

91.

92. Control Measures are as under: 93.

1.

Exhaust ventilation to remove chemical vapours, fumes, gases, flammable or explosive dusts, vapours etc.

2.

Flameproof or non-sparking fans and motors should be utilised in flammable area.

3.

Monitoring of HCN or NaCN is necessary.

4.

Excessive heat should be removed away.

5.

Air supply to the furnaces should be uninterrupted and well controlled.

6.

Adequate methods of storage, handling and disposal are desired.

7.

Furnaces, ovens, dryers etc. should be gas fired or heated electrically. The use of solid or liquid fuel may be allowed in exceptional and justified cases.

8.

Hardening tanks, quenching and pickling baths, shaft furnaces etc. should be projected about I’m above the working level. If this is not possible, they should be fenced.

94. Manufacture of Basic Metals: Ferrous and Non Ferrous 95.

96. What is radiography Test?

97.

98. Radiography is a process of detecting discontinuities (defects) in test objects by passing ionising (short wavelength) radiation through them and recording the transmitted radiation pattern on X or Gamma ray films.

99. A simple radiography set-up consists of radiation source (shielded), test object and X-ray film between a pair of lead screens enclosed in a light proof cassette. The image on the film is converted into black or white pattern which indicates the structure of the test object.

100.

Radiographic examination should be conducted before final heat treatment.

101.

What is the meaning of NDT test and different types of NDT test

102.

By visual inspection, it is impossible to see under surface or inner defects, cracks, porosity, thickness reduction etc. Hydraulic test can check the overall integrity (soundness) of the vessel but it. Cannot show the above defects. Therefore nondestructive tests are developed to test boilers, pressure vessels and nuclear components.

103.

NDT can detect (1) Inherent metal defects like porosity, shrinkage, non-metallic inclusions (2) Processing defects like residual stresses, cracks caused by grinding of casting and forging, spring and (3) In-service defects like corrosion, erosion, change in section etc.

104.

105.

Types of NDT test 106.

1. Radiography Test 2. Ultrasonic Test 3. Magnetic particle test 4. Eddy current Or Electromagnetic Method 5. Dry penetration test 107.

108.

Importance of Ultrasonic Test 109.

1.

Ultrasonic is an inspection technique to test both metallic and non-metallic products such as welds, castings, forging, sheet, tubing, plastics and ceramics by using sound waves (vibrations).

2.

It discloses the soundness, thickness or physical property of the material or nature of discontinuities without impairing the material and by exposing its one side only.

3.

UT is sensitive to subsurface and surface discontinuities 4.

Gives instantaneous results

5.

Very less preparation time is required 110.

Importance of Magnetic particle Method

1. Rapid inspection of large surface areas 2. Surface and subsurface flaws can be detected 3. Equipment costs lower compared to other NDT techniques 111.

112.

113.

1.

2.

3.

4.

Importance of Eddy current OR Electromagnetic Method Contact with test probe not required Mostly forgings are tested by this method Part preparation requirement is minimal Surface or near surface defects can identified

114.

115.

116.

117.

118.

Q) Explain any two different type of NDT Method?

Ultrasonic Testing

1. Ultrasonic is an inspection technique to test both metallic and non-metallic products such as welds, castings, forging, sheet, tubing, plastics and ceramics by using sound waves (vibrations).

2. It discloses the soundness, thickness or physical property of the material or nature of discontinuities without impairing the material and by exposing its one side only.

3. Ultrasonic waves i.e. vibrations are created by an electronic generator and passed through a material due to its elastic properties.

4. Vibrations above the human hearing range (20000 Hz) are called ultrasonic vibrations.

5. Electrical energy is applied to a piezoelectric crystal also called transducer which causes material displacement within the specimen.

6. The transducer converts electrical energy into mechanical and vice versa.

7. Thus transducer can transmits or receives the energy.

8. Transmission of energy can be pulsed or continuous.

9. Steel, water and oil can transmit ultrasound very well but air is a poor transmitter because of its low particle density.

10. Therefore water, oil (grease) or steel is used as a coolant between the transducer and the test specimen.

11. The pulses (waves) return back (reflect) from discontinuities in their path or from any boundary (end) that they strike.

12. The received reflections are displayed on a cathode ray tube (CRT). The quality of the material is measured in terms of energy lost by a sound beam as it travels through the material.

13. Biological effects have been noticed on workers.

14. Shielding of electrical connection causing electromagnetic fields, sound isolated booth, use of cotton lined rubber gloves, absorbent lining to tools, ear muffs, noise & vibration control, and periodic medical examinations are necessary.

119. Magnetic Particle Method 1. Mostly forgings are tested by this method.

2. Finely ground ferromagnetic particles of different forms and colours are available.

Depending on the condition of surface to be inspected and type of indication to be located, form of particles and type of method - dry, wet or fluorescent - are selected.

3. Colour is selected to have full contrast with the surface.

4. Then magnetic field is applied by DC or AC (low volts) current.

5. This attracts and holds magnetic particles right on the surface.

6. Defects if any, interrupt the magnetic field and are clearly shown by the pattern formed by the particles.

7. Nature of discontinuities (defects) is disclosed and acceptable and unacceptable material can be separated in accordance with predetermined standards.

8. After the test is over, the part should be demagnetised by reversing and reducing the magnetic field.

9. Local exhaust is necessary to control dust particles. If it is not possible, dust mask (respirator) and eye and skin protective equipment should be worn by the workers.

120.

Q) List the job for which the work permit is required? Safety precautions for hot work and cold work?

121.

Types of Work Permit System

1. Hot and cold work permit- Welding, Cutting, grinding, in flammable area 2. Electrical work permit- power generation, distribution control

3.

4.

5.

6.

Vessel entry permit- To enter any confined space ( Chamber, Tank, pit, pipe, flue etc) Excavation Permit Chemical area work permit Working at height permit

122.

Safety precautions for hot work 123.

Hot working of metal includes foundry operations, forging operations and hot polling operations.

1. Good ventilation, lighting and housekeeping.

2. Efficient exhaust ventilation for removal of dusts, fumes, gases etc.

3. CO detectors should be used to ensure safety: Self breathing or airline respirators should be worn while doing this manually. Fixed CO detectors with alarm are desirable at crucial points.

4. Cold drinking water and salt to worker' working in very hot environment.

5. cold air showers at hot work places 6. Rest rooms protected against radiant heat should be provided and equipped with air and water showers etc.

7. Provide insulating screens for protection against radiant heat and hot air 8. Rotation of workers after short duration work in hot processes.

9. Ergonomic design of man-machine-environment relationship.

10. Pre-employment medical examination to select suitable persons for hard or hot work, TB disqualifies from work with refractory materials and heart diseases, obesity and chronic gastroenteritis disqualify from work in hot environment.

11. Periodical medical examination of worker; exposed to heat stress, dust and high noise.

12. First-aid centre with necessary medical facilities 13. safety programmes and workers' training is essential 14. Use of personal protective equipment by workers exposed to excessive heat, noise, dust and hot materials.

124.

Safety precautions for cold work 125.

The five functional methods of cold working of metals are pressing or punching, shearing or cutting, rolling, bending and hammering.

1.

2.

3.

4.

Design and construct tools so that the guards may not be needed.

Provide enclosures/covers and barricades Provide mechanical feeding device.

Provide device that prevents or interrupts the movement of tools when the operator is in the danger zone.

5. Provide remote control operating mechanism.

6. Provide device (guard) that removes the body part safely from the danger zone 7. Regular inspection and maintenance and 8. Good training and supervision.

9. Two hand control.

10. Photo cell device operating on interruption of light beam near the dangerous zone.

11. Good housekeeping and good illumination are also essential.

12. Hard hats, safety shoes, gaiters, gloves, goggles etc. should be worn.

13. Noise and vibration of Machine can be controlled by good engineering technique.

14. Sound proof and heat radiation proof cabins for operators increase safety as well as efficiency.

126.

Q) Explain Hazards and control measure in steel industry?

127.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

Main hazards in steel manufacture are as under: Burns due to molten metal, its splashes while tapping, pouring, tilting, and falling of ladle and sparks or spatters.

Explosion in metal or slag due to water insertion and spattering of hot material over a wide area.

Explosion risk in storage, transport and use of oxygen.

Accidents due to heavy transport of locomotives, wagons, bogies and rail mounted furnace chargers.

Breakage or failure of lifting machines, tackles, ladles, ingots, overhead travelling cranes and unsafe access.

Obstructed floors, platforms and stairs with materials and implements.

Accidents due to material handling.

Poisoning due to Carbon monoxide in fuel gases (converter gas 68-70%, blast furnace gas 20-30% and coke oven gas 5-10%) or its leakage from the furnace, pipelines, water-seal valves, repair work.

Excessive heat, heat-stroke and heat cramps (lack of salt due to excessive perspiration) to the workers.

Dust generation e.g. sintering near furnaces and in ingot-making.

Dense fumes while using oxygen lances or its use in open hearth furnaces.

Risk of silicosis to men engaged in lining, relining and repairing furnaces or ladles with refractory bricks which may contain 80% silica. Silicate content causes pneumoconiosis.

Eye and ear damage due to glare, high noise of blowers and electric furnaces.

128.

To protect the workers from above hazards, following safety measures are necessary: 1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

Engineering measures like guarding and fencing of dangerous machine parts, floors, stairs and platforms, lifting machines, tackles, transport vehicles and safe work practices.

Good ventilation, lighting and housekeeping.

Efficient exhaust ventilation for removal of dusts, fumes, gases etc.

CO detectors should be used to ensure safety: Self breathing or airline respirators should be worn while doing this manually. Fixed CO detectors with alarm are desirable at crucial points.

Cold drinking water and salt to worker' working in very hot environment.

Rotation of workers after short duration work in hot processes.

Ergonomic design of man-machine-environment relationship.

Pre-employment medical examination to select suitable persons for hard or hot work, crane work etc. TB disqualifies from work with refractory materials and heart diseases, obesity and chronic gastroenteritis disqualify from work in hot environment.

Periodical medical examination of worker; exposed to heat stress, dust and high noise.

First-aid centre with necessary medical facilities Safety organisation including safety committees accident investigation and discussion, safety programmes and workers' training is essential Use of personal protective equipment by workers exposed to excessive heat, noise, dust and hot materials.

129.

Q) Explain the hazards in process of melting in furnace and casting in manufacturing industries and their safety measure?

130.

Hazards and Safety Precautions in furnaces:

131.

Main hazards while working with furnaces, kilns and ovens are as under:

14.

15.

16.

17.

18.

19.

20.

132.

13.

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

Burns due to contact with hot surfaces.

Burns due to contact with hot product, fuel or electricity.

Splashing or bubbling of molten metal.

Contact of cooling water with the molten metal or slag (e.g. induction furnace) and explosion due to sudden steam generation.

Fire or explosion due to leakage of fuel.

Carbon monoxide from fuel gas or products of combustion.

Explosion due to hydrogen.

Precautions to be followed are as under: Good insulation over hot metal surfaces.

Protective clothing for head, face, hands and feet.

Respirators, safety eye glass (plain or tinted) for protection against dust, fumes, toxic gases and glare.

Exhaust hoods and fans to draw dusts, fumes, gases etc.

Good ventilation to vent off hazardous waste generated from scrap charged, alloys and fluxes.

Hot work permit before allowing any worker to enter any hot chamber. Insurance of cooling, fresh air ventilation and lighting necessary.

Interlocking to cut off fuel supply in case of flame failure.

Precautions while lighting fuel or burner to prevent flash back, fire or explosion.

Training and awareness programmes for workers.

Provisions of drinking water and shielding to avoid heat disorders.

Flameproof electric fitting with solvent drying ovens. PPE against eye and skin irritation or respiratory disorders.

Precautions against free silica, asbestos etc., while cleaning and maintaining furnaces. Area monitoring and medical surveillance of such hazardous exposures.

133.

Hazards and Safety Precautions in Casting:

134.

Hazards:

1. Poor ventilation 2. Dust, fumes, gaseous.

3. Air pollution due to burning of chemical flux of welding electrode and metal fumes of chromium, fluoride, magnesium, nitrogen oxide and carbon monoxide from furnace 4. Fire and explosion due to welding, hot sparks, combustion waste 5. Inadequate lightening 6. Production machinery and electric shock 7. Material handling 8. Bad housekeeping 9. Radiant heat 10. Hot metal burns 11. Noise and vibration

135.

Control Measure:

1. Good housekeeping, local exhausts system on mechanised plant, vacuum cleaning.

2. Fire retardant protective clothing, hand protection, ventilated booth to prevent organic vapour exposure. No smoking.

3. Avoidance of excessive weight and using mechanical lifting device.

4. Reduce the noise or use ear plugs or muffs.

5. Ample water for washing, FFE, hood extractor to remove fumes.

6. Eye protection and other PPE necessary.

7. Guarding and safe operation.

8. Electrical equipment I must be earthed and operated safely.

9. Periodical medical examination of worker; exposed to heat stress, dust and high noise.

10. First-aid centre with necessary medical facilities 11. Safety organisation including safety committees accident investigation and discussion, safety programmes and workers' training is essential 12. Use of personal protective equipment by workers exposed to excessive heat, noise, dust and hot materials.

13. Cold drinking water and salt to worker' working in very hot environment.

14. Rotation of workers after short duration work in hot processes.

136.

137.

Q) Explain the possible hazards and control measure in heat treatment for manufacturing of ferrous and nonferrous metal?

138.

Hazards in heat-treatment are: 139.

14.

Burns due to high temperature heating (between 700 to 1100° C).

15.

Hazards of chemicals like N2, NH3, NaCN, Na2CO3, and NaCI. 16.

Contact of quenching media like brine, water, oils, air and solution of NaOH or H2SO4 in water etc.

17.

Hazards of various types of furnaces and temperature measuring instruments and electrical apparatus.

18.

Handling of machine parts viz. steel castings, forging (shafts, axles etc.) springs, gears, wires, drills, screw taps, hammer dies, die moulds, high speed cutting tools and speed etc. for heat treatment purposes.

19.

Lifting and travelling mechanism and their unguarded agency parts.

20.

Dust exposure.

21.

Hot surfaces and high air temperatures.

22.

High humidity and air velocities.

23.

High voltages and electromagnetic radiation.

24.

High noise levels.

25.

Infra-red radiation.

26.

Excessive brightness of illuminated surfaces etc.

140.

141.

Control Measures are as under: 142.

9.

Exhaust ventilation to remove chemical vapours, fumes, gases, flammable or explosive dusts, vapours etc.

10.

Flameproof or non-sparking fans and motors should be utilised in flammable area.

11.

12.

13.

14.

15.

16.

Monitoring of HCN or NaCN is necessary.

Excessive heat should be removed away.

Air supply to the furnaces should be uninterrupted and well controlled.

Adequate methods of storage, handling and disposal are desired.

Furnaces, ovens, dryers etc. should be gas fired or heated electrically. The use of solid or liquid fuel may be allowed in exceptional and justified cases.

Hardening tanks, quenching and pickling baths, shaft furnaces etc. should be projected about I’m above the working level. If this is not possible, they should be fenced.

143.

144.

Q) Write down the hazards and control measure in hot and cold rolling mill operation?

145.

146.

Hazards in Hot rolling Operation 147.

1. Harmful gases- Harmful Gases from lead alloy rolling or cutting, gas cutters, or butt welding (ozone effect), pit furnace and reheating furnace 2. looping and lashing may cause burns 3. Material handling 4. Hot surfaces 5. Radiant Heat 6. Infrared radiation 7. Fire and explosion due to welding, hot sparks, combustion waste 8. Inadequate lightening 9. Production machinery and electric shock 10. Material handling 11. Bad housekeeping 12. Radiant heat 13. Hot metal burns 14. Noise and vibration 148.

Hazards in cold rolling Operation

1) Crushing, shearing, cutting, entanglement, drawing-in or trapping, impact stabbing or punctures, friction or abrasion, ejection of material from machine, contact with the moving parts, hot surface of sharp edges, and free fall of any material.

2) Noise and vibration 3) Dust 4) Poor housekeeping, and illumination 149.

****For prevention control, see above****

150.

Q) List out the hazards and control measure in the operation of forging hammer?

151.

152.

Hazards 1) heavy impact machine causes noise and vibration 2) Falling of object 3) Material defect- Parts that frequently fail are head bolts, cylinder bolts, guide bolts, cylinder bolt springs, column bolts and gland bolts.

4) Material handling- hammer parts are extremely heavy and bulk 5) Hammer equipment is usually hot and slippery

6) Burns and eye injury 153.

Control Measure

1) Treadle guard should be well designed to provide complete coverage and at the same time allow enough clearance for operator comfort and control of the treadle action.

2) Protective safety measures be taken to guard against the falling object hazard.

3) These parts (head bolts, cylinder bolts, guide bolts) should be retained and prevented from falling by installing safety cables or chains.

4) In the case of board drop hammers, all exposed power transmission parts be well guarded. This includes the flywheel, drive belts, motor pulley and drive coupling etc.

5) Portable shields should also be used when driving out die or some block keys to prevent injuries by a die key flying out into the working area.

6) All steam or air drop hammers should be equipped with a safely type cylinder head designed to cushion the impact blow if the piston breaks or pulls out of the ram.

7) Air or steam valve should be closed whenever the hammer will not be used.

8) Employees must be fully trained in heavy rigging and repair work.

9) Regularly inspection and maintenance.

154.

Q) Hazards and safety measure needed in foundry 155.

OR 156.

Q) What are the hazards associated with foundry operation and prevention of hazards in moulding and forging operation?

157.

158.

Hazards associated with foundry operation 1. Poor ventilation 2. Dust, fumes, gaseous.

3. Air pollution due to burning of chemical flux of welding electrode and metal fumes of chromium, fluoride, magnesium, nitrogen oxide and carbon monoxide from furnace 4. Fire and explosion due to welding, hot sparks, combustion waste 5. Inadequate lightening 6. Production machinery and electric shock 7. Material handling 8. Bad housekeeping 9. Radiant heat 10. Hot metal burns 11. Noise and vibration 159.

Hazards associated with moulding operation and preventive measure as follow 160.

1.

161.

Health hazard due to sand, free-silica, silicones and zircon. Silicosis.

Silica dust in sand handling, shakeout and slinging operation.

162.

Good housekeeping, local exhaust system on mechanised plant, vacuum cleaning.

163.

2.

164.

Irritation or dermatitis due to Phenolic resins in thermosetting process

165.

Washing with hot water, medical attention on ingestion.

166.

Barrier creams.

167.

3.

168.

Asthmatic symptoms due to Methylene biphenyl isocyanate (MBI) used in cold self-setting process.

169.

Protective goggles, local exhaust ventilation while dealing with hot sand resin mixture. Clean the storage vessel for 24 h with 5% sodium carbonate solution.

170.

4.

171.

Skin and eye irritation due to sodium silicate in the gas (CO2) hardened moulding process.

172.

Emergency shower, eye wash bottle, - barrier cream, precaution against CO2 cylinders.

173.

5.

174.

Fire risks due to isopropyl alcohol sprays on mould surface for better finish. Dermatitis due to such solvent.

175.

Fire retardant protective clothing, hand protection, ventilated booth to prevent organic vapour exposure.

No smoking.

176.

6.

177.

Strain due to lifting and shifting of heavy moulding boxes.

178.

Avoidance excessive weight using mechanical device.

of and lifting

179.

180.

Hazards associated with forging operation and preventive measure as follow 181.

Hazards 182.

1. Accidents in forge shops are generally due to hot and cold metal coming out, falls of the tup.

2. Accidental starting of the machine, crushing hazards, radiant heat, burns, high noise etc.

3. Forge workers may suffer chronic rheumatism, digestive disorders (enteritis), inflammatory skin disease, respiratory trouble and hearing loss due to high noise and vibration.

183.

Control measure 184.

1. Good plant layout, uncongested machine and process layout, good housekeeping and ventilation 2. good draft to furnace and efficient exhaust of gases, water curtains and reflective or insulating screens for protection against radiant heat and hot air, 3. Local exhaust systems at the furnaces, cold air showers at hot work places, noise absorbent panels and deep and massive foundations to suppress vibrations.

4. Rest rooms protected against radiant heat should be provided and equipped with air and water showers etc.

5. Comfortable conditions are 19° to 24°C (not exceeding 27°C) air temperature, 30 to 50% relative humidity and 0.5 m/ s air velocity.

6. Protective heat-resistant armlets, gaiters, aprons, safety footwear, eye and face shield, ear muffs or plugs to workers and 7. Pre-employment and periodical medical examinations and safety training are also necessary.

185.

Q) Health Hazards in Foundry?

186.

1. This may cause silicosis, a serious form of pneumoconiosis resulting in permanent lung damage. Asthmatic symptoms due to Methylene biphenyl isocyanate (MBI) 2. Pneumoconiosis due to dusting in handling finishing cores.

3. Health hazards due to acrolein, Aluminium, antimony, beryllium, chromium, fluorides, iron oxide fumes and dust, lead, magnesium, manganese, phosphorus, SO 2 resins, coal, silica 4. Noise induced hearing loss 5. Coal dust is generated at furnace, boiler and coal handling work and may cause anthracnosis i.e. coal workers' pneumoconiosis.

6. Siderosis is caused due to inhalation of such iron dust 187.

Q) Describe the type of ventilation required for hot process working in foundry and write the shorts notes on following?

188.

Types of ventilation 189.

Dilution (or general) ventilation 1. Dilution (or general) ventilation reduces the concentration of the contaminant by mixing the contaminated air with clean, uncontaminated air.

2. Dilution, or "general", ventilation supplies and exhausts large amounts of air to and from an area or building.

3. It usually involves large exhaust fans placed in the walls or roof of a room or building.

4. Dilution ventilation controls pollutants generated at a worksite by ventilating the entire workplace.

5. Dilution ventilation can be made more effective if the exhaust fan is located close to exposed workers and the makeup air is located behind the worker so that contaminated air is drawn away from the worker's breathing zone.

190.

191.

Local exhaust ventilation 192.

1. Local exhaust ventilation captures contaminates at or very near the source and exhausts them outside.

2. It is applied at the release point of the contaminant source to reduce the concentration of contaminant below the TLV level.

3. Local exhaust is generally a far more effective way of controlling highly toxic contaminants before they reach the workers' breathing zones.

193.

194.

Annealing 1. Annealing is a heat process whereby a metal is heated to a specific temperature /colour and then allowed to cool slowly. This softens the metal which means it can be

cut and shaped more easily. Mild steel, is heated to a red heat and allowed to cool slowly

2. Annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness

3.

It involves heating a material to above its recrystallization temperature, maintaining a suitable temperature, and then cooling.

4. In annealing, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to the change in ductility and hardness.

5. In the cases of copper, steel, silver, and brass, this process is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air.

195.

Heat Treatment

1. After hot or cold working of metal, stress and strain are produced in the metal.

Therefore heat treatment methods are required to remove these stresses.

2. Heat treatment can be defined as an operation of heating and cooling of metals in the solid state to induce certain desired properties into them.

3. It is generally employed to improve grain size, machinability, mechanical properties e.g. tensile strength, hardness, ductility, resistance to wear heat and corrosion, magnetic and electrical properties or to relieve stresses in the metal produced because of cold or hot working.

4. The common heat-treatment operations are annealing, normalising, hardening, tempering, carburising (case-hardening), cyaniding, nitriding, induction hardening and flame-hardening.

5. Heat treatment of rolled products are divided into two groups : 1.

Processes involving holding for a long time at a specified temperature and slow cooling i.e. annealing and tempering.

2.

Processes where metal is only heated in a furnace to a specified temperature and then cooled in air (normalising) or in liquid quenchers (hardening).

196.

Safety in IT Industry

197.

198.

199.

Q) Hazards in Computer/television manufacturing industry?

200.

Hazards 1. Fumes of lead, zinc, rosin etc.

2. Fire and Explosion- flammable or explosive mixtures of solvents 3. Chemical Hazards- due to use of organic peroxide, phenol compound, oxidising or self-reacting gases, contact with mercury, mixture of solvents 4. Toxic hazard- Use of acids , alkalis 5. Poor ventilation & Illumination 6. Material handling- heavy lifting of material cause stress and strain 7. Poor housekeeping 8. Airborne contamination of dust fumes gases mist 9. Electrical shock & fire hazards

201.

Q) Prevention control measure in computer/ television manufacturing industry?

202.

1. Exhaust ventilation for fumes of lead, zinc, rosin etc. and also for molten-solder tanks.

2. Eye protection for organic peroxide hardeners and respirators for quartz flour, epoxies with phenol compound and airborne concentrations.

3. Prevention of flammable or explosive mixtures of solvents and source of ignition.

4. Exhaust ventilation for printing process.

5. Acid resistant and non-slip flooring exhaust ventilation, eye bath and PPE in etching processes. Use closed containers for etching liquids.

6. Good industrial hygiene.

7. Protection from chemical hazards such as flammability, corrosive, self-reacting gases 8. Protection from toxicity and carcinogen asphyxia 9. Protection from exposure or contact to mercury used in electronic equipment and compact fluorescent lamp 10. Protection from compressed gases and extremely cold gases handled in liquid form 11. Control against irritant and toxic chemicals acids, alkalis, dust, gases, fumes and vapour of organic solvents.

203.

204.

Q) Hazards & Control Measure in manufacture of semiconductor industry?

205.

Semiconductor manufacturing includes four main operations: (1) substrate manufacture, (2) device fabrication, (3) metallization, and (4) non-fabrication processing.

206.

Hazards and control measure in substrate manufacture

1. Possible employee exposure to crystalline silica used as a raw material. Inhalation of silica can lead to chronic, accelerated or acute silicosis and is associated with bronchitis and tuberculosis.

2. Possible employee exposure to hydrogen chloride gas. Hydrogen chloride is irritating and corrosive to the eyes, skin, and mucous membranes.

3. Possible ignition of flammable gases, such as hydrogen and oxygen, resulting in fire and/or explosion 207.

Control measure

1. Provide appropriate ventilation to reduce silica concentration levels in the air.

2. Maintain adequate housekeeping to remove unwanted silica dust and reduce concentration levels.

3. Use respiratory protection when necessary to further reduce exposure and protect employees 208.

Hazards and control measure in Device fabrication

1. Flammable Gases, Fire 2. Toxic Exhaust Gases 3. Radiofrequency (RF) and Infrared (IR) Radiation 4. Solvents 5. Acids and Caustic Solutions 6. Possible thermal burns due to contact with hot equipment or exposure to high temperatures.

7. Machinery-related hazards during cutting, grinding, lapping, polishing, sanding, sorting, testing, and so fort 209.

Control measure

1. Provide PPE as appropriate to prevent eye and skin contact.

2. Use respiratory protection when necessary to further reduce exposure and protect employees.

3. Provide guarding and/or insulation to protect against accidental contact with hot surfaces.

4. Enclose operations involving RF and/or IR emissions; provide shielding as necessary.

5. Identify machinery hazards and provide adequate guarding.

6. Install appropriate emergency shut-offs and/or interlocks with the machinery.

210.

Hazards and control measure in metallization

1. Various hazards associated with the use of high-voltage electrical equipment, including electric shock, electrocution, fires, explosions, and so forth.

2. Exposure to nuisance dust during cutting, grinding, machining, polishing, sanding, and so forth.

211.

Control measure

1. Use wet operations when possible to reduce airborne dust concentrations.

2. Provide appropriate ventilation to reduce dust concentration levels in the air.

3. Use respiratory protection when necessary to further reduce exposure and protect employees.

4. Maintain adequate housekeeping concentration levels.

to

remove

unwanted

dust

and

reduce

212.

Q) What are the hazards present in electronic equipment manufacturing industries and what is the preventive measure?

213.

Hazards

1. Electrical waste contains hazardous material like Lead, mercury, cadmium, hexavalent chromium.

2. Dermatological hazards- These include exposure to irritants and allergens during common operations such as soldering, cleaning operations, materials handling, and procedures for control of static electricity and low humidity in the work environment.

3. Chemical Hazards- Chemicals may be explosive, toxic, or corrosive. Examples include gases such as arsine, phosphine, ammonia, chlorine; doping agents containing arsenic; strong acids such as hydrofluoric and hydrochloric acids; and numerous solvents.

4. Physical hazards- noise and radiation. Ionising and non-ionising radiation are used for testing, quality control, and curing operations, Noise may be emitted by machinery such as motors, cutting equipment, and packaging machines.

5. Soldering of polyurethane enamels can also produce occupational asthma 6. Skin problems can also arise from contact with rosin flux.

7. Many chemicals used in the electronics industry are hazardous to health and may cause harm if they are inhaled or are absorbed through the skin. Unwanted effects include dermatitis, eye irritation and asthma 8. Metal related hazards 9. Ignition of flammable solvent vapours 10. Corrosive fluxes - liquids and fume 11. Solvent handling - vapours, dermatitis, spillage procedures 12. Solder bath cleaning 13. Vapour phase soldering - toxic thermal decomposition products 14. Solder creams - solvent discharge, fumes 214.

215.

Control Measure: 1. Increasing environmental awareness has led to changes in electronics design to reduce or eliminate toxic materials 2. To control the exposure of individuals to solder fumes both in relation to the lead content of the solder and the problems related to the flux. Such control is achievable and can dramatically reduce the personal exposure to solder fumes.

3. Ensure that all health risks to employees - especially respiratory sensitizers/occupational asthma - have been properly identified and assessed 4. Ensure that, wherever practicable, exposure to hazardous fumes are prevented, or if not practicable, are adequately controlled, ideally via total or partial enclosure of the fume generating process 5. If adequate control cannot be achieved, decide what alternative control measures are needed - local exhaust ventilation, personal protective equipment - and decide how to provide them

6. Monitor occupational exposure levels and compare with published standards 7. Provide health surveillance, as required 8. Provide necessary information, instruction and training 9. Provide PPE as appropriate to prevent eye and skin contact.

10. Use respiratory protection when necessary to further reduce exposure and protect employees.

11. Other safety measures might include: 1. Acid resistant and non-slip flooring; 2. Exhaust ventilation in areas where toxic gases or fumes are given off; 3. Protection of electrical equipment and material from wet 4. Prohibition of eating, drinking, and smoking in work areas; 5. eye-bath and first aid equipment; 6. Standard procedures for manual handling, for example, handling of solid alkalis and dry acids with tongs or shovels.

216.

217.

Q) Hazards and Control measure in electroplating?

218.

Hazards 1. Workers at electroplating workplaces may be exposed to hazardous substances.

Such as fumes; vapours or mists; and metal dusts.

2. Other hazards in electroplating involve the use of: electricity; mechanical plant; and manual handling.

3. Electroplating produces substantial amounts of chemical waste such as metal salts, acids, alkalis and cyanides.

4. Electrical hazards in electroplating may be associated with: • pumps; • filters; • blowers; • centrifuges; • heaters; 5. Manual handling hazards in electroplating may include pushing, pulling, lifting or carrying heavy chemical containers, plant and items being electroplated.

6. Chemical Hazards1. solvents such as methylene chloride, phenol, cresylic acid 2. gases such as hydrogen cyanide; 3. acids such as chromic and dichromic acid, sulphuric acid and hydrochloric acid; 4. alkalis such as sodium hydroxide ( also known as caustic soda); 5. cyanides such as sodium and potassium cyanide; 219.

Control Measure 1. storing hazardous substances in a cool, lockable, enclosed area with adequate ventilation; 2. storing incompatible substances separately, such as cyanides away from acids, and avoiding risk of mixing or cross contamination; 3. ensuring all labels remain intact on containers and packaging; 4. limiting access to chemical storage areas to authorised people only; 5. ensuring flammable, explosive or toxic substances are stored away from possible sources of electrical spark, heat or flame, and that smoking in storage areas is prohibited; 6. checking all containers against leakage or seepage – keeping lids and caps tightly sealed; 7. ensuring there is a method to collect and treat any spilled chemicals, such as using pallets with bunds or concrete bunds;

8. ensuring forklift and other mobile plant operators are formally trained in safe procedures for chemical containers; 9. appropriate firefighting and emergency equipment; and 10. Monitoring atmospheric contamination and temperature levels in storage areas where a risk assessment indicates there could be a problem.

220.

221.

Q) What is computer Vision Syndrome? Explain preventive measure?

222.

Computer vision syndrome (CVS) is a condition, often temporary, resulting from focusing the eyes on a computer or other display device for protracted, uninterrupted periods of time. Some symptoms of CVS include headaches, blurred vision, neck pain, redness in the eyes, fatigue, eye strain, dry eyes, irritated eyes, double vision, vertigo/dizziness, polyopia, and difficulty refocusing the eyes 223.

Preventive measure

1. Monitor should be kept at 10 to 15° below the angle of eye level and 20 to 28 inch away from the face.

2. There should be a balance between monitor light and room light.

3. In darkness, computer should not be operated. Eyes should be turned aside and closed for a few seconds at the interval of half an hour.

4. A vision guard programme is available to remind this relaxation exercise. It should be loaded in the computer.

5. Hand below the elbow should remain parallel on computer-table, and fingers on keyboard.

6. Table and chair should be fully flexible so as to rearrange as requirement. Specially designed back rest necessary.

7. VDU should be so placed that the sight will fall on the correct place on the screen.

Computer screen should remain below the eyes so that the eyes and neck are not unnecessarily raised.

8. Key-board should be thin, easy to operate and move and separate from the display unit.

9. Noise from printer should not be more than 55 dB, otherwise hood is required.

10. Operators having sitting work and standing work should be interchanged by job rotation. This will relax the contracted muscles and maintain the body tone-up.

11. Eyes should be examined by Ophthalmologist for internal defects if any. After the age of 40, spectacles become necessary to see from a short distance. Considering the length between the eyes and the computer screen, the special spectacles (not bifocal) should be worn while working on computer.

12. Lighting, shining and colour have also some effects. They should not be excessive.

13. At every 15, to 30 minutes, eyes should be turned away from the screen to see aside or take rest raise-or move hands, press fingers etc. Legs should be freed from one position. They should have rest support.

14. Working hours on computer should be reduced with increasing age or difficulty.

224.

Safety in boiler

225.

Q) List the various accessories of boiler and their use? Explain the activity of external treatment of feed water boiler?

226.

The following accessories are given below.

227.

1. Air pre-heater- Air heater or air pre-heater is waste heat recovery device in which the air on its way to the furnace is raised in temperature by utilizing the heat of the exhaust gases.

228.

2. Economiser- The economizer is a device, which serves to recover some of the heat being carried by exhaust flue gases. The heat thus recovered is utilized in raised temperature in feed water being supplied to the boiler. If the water is raised and thus there is a saving in the consumption of fuel.

229.

3. Super heater- The steam generated by a simple boiler in generally wet or at the most dry saturated. Steam super heater is a surface heat exchanger in which the wet steam is first dried at the same temperature and pressure and then raised to temperature above the saturation temperature at constant pressure. Heat of flue gasses utilized in super heating the steam and as the super heater is placed in the path of the flue gasses, 230.

4. Feed pump-The pressure inside a steaming boiler is high and so the feed water has to be raised in pressure before its entry can be affected in the boiler. Feed pump is a device which raised the pressure of water and forces it into the boiler.

231.

Boiler water treatment

1. The treatment and conditioning of boiler feed water must satisfy three main objectives:   

Continuous heat exchange Corrosion protection Production of high quality steam

2. External treatment is the reduction or removal of impurities from water outside the boiler.

3. In general, external treatment is used when the amount of one or more of the feed water impurities is too high to be tolerated by the boiler system in question.

4. There are many types of external treatment (softening, evaporation, deaeration, membrane contractors etc.) which can be used to tailor make feed-water for a particular system.

5. The water treatment facilities purify and deaerate make-up water or feed water.

6. Water is sometimes pre-treated by evaporation to produce relatively pure vapour, which is then condensed and used for boiler feed purposes.

232.

Q) What are the different types of boiler and there mounting? What is the safety precaution needed in their operation 233.

Types of Boiler

1. Pot boiler or Haycock boiler/Haystack boiler 2. Water tube boiler 3. Fire tube boiler

4. Flash boiler 5. Fluid boiler 234.

Mounting on boiler 235.

SAFETY VALVE: The function of the safety valve is to permit the steam in the boiler to escape to atmosphere when pressure in the steam space in the boiler.

236.

Safety precaution

1. To assure that a valve's mechanism will operate properly, the try-lever should be lifted once a month and the valve set pressure tested annually.

2. If a valve will not operate or does not reseat properly when tested, the boiler must be shut down immediately and the valve repaired or replaced.

3. The safety or safety relief valve must be set to open at or below the maximum allowable working pressure established by the manufacturer.

4. It is not good practice to operate a boiler too close to the valve setting. Operating too close to the set pressure will cause these valves to leak slightly, resulting in an internal corrosion build up.

237.

WATER LEVEL INDICATOR: The function of the water level indicator is to ascertain constantly and exactly the level of water in the boiler shell. It is fitted in the front of the boiler from where it is easily visible to the operator.

238.

Safety precaution

239.

The water in the boiler evaporates, and the boiler must receive a supply of water to maintain the level. If the boiler operates with insufficient water, severe damage could occur and there is ultimately the risk of explosion.

240.

For this reason, controls are required which will:



Monitor and control the water level.



Detect if a low water level point is reached, and take appropriate action.

This action may include: Sounding an alarm, shutting down the feed water supply and shutting down the burner(s).

241.

242.

FUSIBLE PLUG: The function of the fusible plug is to extinguish the fire in the event of the boiler shell failing below a certain specified limit 243.

PRESSURE GAUGE: Each boiler has to be provided with a pressure gauge, which record the pressure at which the steam is being generated in the boiler.

244.

BLOW OFF COCK: The blow of cock serves to drain out the water from the boiler periodically 245.

FEED CHECK VALVE: The feed check valve has the following two functions to perform: 246.

1. To allow the feed water to pass into the boiler.

247.

2. To prevent the back flow of water from the boiler

248.

STOP VALVE: The function of the steam stop valve is to shut off or regulate the flow of steam from the boiler to the steam pipe or from the steam pipe to the engine.

249.

MAN HOLES: These are door to allow men to enter inside the boiler for the inspection and repair.

250.

Q) Causes of boiler explosion along with the control measure?

251.

"The principal causes of explosions, in fact the only causes, are

1. deficiency of strength in the shell or other parts of the boilers, 2. Over-pressure and over-heating.

3. Deficiency of strength in steam boilers may be due to original defects, 4. Bad workmanship, Poor maintenance 5. Deterioration from use or mismanagement.

6. Cause.-Boiler explosions are always due to the fact that some part of the boiler is, for some reason, too weak to withstand the pressure to which it is subjected.

7. Either the boiler is not strong enough to safely carry its proper working pressure, 8. else the pressure has been allowed to rise above the usual point by the sticking of the safety valves, or some similar cause 9. Low pressure of oil or gas. Not correctly positioned. The nozzle may be too small.

10. Lack of adequate air openings in the boiler room.

11. Lack of knowledge or poor operator training.

12. Defective valve. Foreign objects under valve seat.

252.

Control Measure

1. Periodic inspection of valves. Defective valves should be replaced promptly. Regular leak test and verification of valves’ operation.

2. Only authorized personnel should conduct maintenance. Operators should be properly trained in maintenance and operation procedure.

3. Ensure adequate air to boiler room. Combustion air fans should be clean and running properly.

4. Ensure adequate pilot. Light-off fuel/aeration. Pilot turndown test. Excessive restart attempts should be avoided.

5. Implement an extensive preventive maintenance program.

6. Gauge, control equipment pressure relief valves, pumps and valves, water quality and treatment methods, burner and fuel systems must be checked periodically to prevent hazards.

7. All pipes and fitting should be well-maintained and in good condition.

8. The boiler area has many heated surfaces causing risks of burns and other thermal hazards. Wherever possible, refractory and insulation should be used to reduce surface temperature.

9. Protect the water supply to the boiler by installing an approved back-flow stopper.

10. Promptly repair leaking steam, water, fuel and other boiler connections.

11. Periodically clean and inspect exhaust venting, breeching and chimney to remove combustion gases.

12. Conduct periodic boiler water analysis and chemical treatment to prevent corrosion, pitting and scale.

13. Safety or relief valves should be tested by lifting the test lever at least once a year 253.

Q) Safety Precaution to be taken while operation of the boiler?

254.

Location and access

1. The boiler should be housed in a separate room away from the general production area.

2. Ensure adequate ventilation in the boiler room.

3. Ensure that no flammable or combustible materials are stored in the boiler room or next to it.

4. Restrict the entry to the boiler area only to authorized personnel.

255.

Housekeeping

1. Ensure good housekeeping of the boiler room. Do not allow dumping of waste or unnecessary articles in the boiler room.

2. Keep floor drains clean, clear and unclogged.

256.

Safe operation

1. Do not leave the boiler operation to a person who is not trained or qualified. The operator should ideally have a formal qualification and training to run a boiler of given capacity.

2. Clear direction should be provided for start-up, running and shutdown procedures, and blow down, high and low water conditions, and emergency procedures.

3. If a boiler plant is started remotely and/or automatically without warning, workers must be alert to avoid that equipment which can be started remotely.

4. The water for the boiler should be treated for hardness before using.

5. Each boiler should have a temperature gauge.

6. Ensure easy access to ladders, runways and controls.

7. Ensure sound boiler piping support, foundation and settings for all equipment.

8. Piping systems including flow direction should be properly marked. Post piping diagram at the location.

9. A fire boiler utilizes flammable and potentially explosive fuel. Fuel-piping connection should be of high quality using the correct gasket, bolts, thread lubricants and tightening torque to prevent leaks.

257.

Maintenance and risk prevention

14. Implement an extensive preventive maintenance program.

15. Gauge, control equipment pressure relief valves, pumps and valves, water quality and treatment methods, burner and fuel systems must be checked periodically to prevent hazards.

16. All pipes and fitting should be well-maintained and in good condition.

17. The boiler area has many heated surfaces causing risks of burns and other thermal hazards. Wherever possible, refractory and insulation should be used to reduce surface temperature.

18. Protect the water supply to the boiler by installing an approved back-flow stopper.

19. Promptly repair leaking steam, water, fuel and other boiler connections.

20. Periodically clean and inspect exhaust venting, breeching and chimney to remove combustion gases.

21. Conduct periodic boiler water analysis and chemical treatment to prevent corrosion, pitting and scale.

22. Safety or relief valves should be tested by lifting the test lever at least once a year.

23. High voltages exist in control panels and control components. Power must be shut off before these components are serviced.

24. The boiler plant should have a documented lockout and tag-out procedure that is strictly enforced.

258.

Workers training and PPE

1. Workers must be trained in safe operation of the boiler equipment. The training should be a continuous process to emphasize the importance of safety.

2. Wearing loose clothing and jewellery should be avoided in the boiler plant.

Appropriate Personal Protective Equipment (PPE), such as respirators, ear plugs, guides, shields, or covers should be fitted in rotating equipment, mechanically automated devices, or electrically and pneumatically operated control components to prevent accidents.

259.

Fire Safety and First aid

1. Ensure safe exits in the boiler room.

2. Place an adequate number of suitable fire extinguishers in and outside the boiler room.

3. Link the boiler room with the fire alarm system of the factory by installing a fire alarm switch/box. • Place sand buckets near the boiler room to manage any spills.

4. Place “No Smoking” signs in the boiler room in the workers’ language as well as in English. • Place First aid kit just outside the boiler room.

260.

Q) What are the hazards in Boiler operation and their preventive measure?

261.

Hazards-

262.

Accidental Hazards1. Falls from ladders, stairs and elevated platforms 2. Slips and falls on the level, particularly on floors made slippery by water, fuel, oils, etc.

3. Struck by falling objects 4. Mechanical accidents when operating pulveriser and stoker in coal-fired boilers 5. Burns from hot surfaces, hot water and escaping steam

263.

Physical Hazards 1. Excessive continuous noise levels - as high as 94 dBA

2.

Heat stress caused by prolonged work at high temperatures and relative humilities 3. Potential exposure to radon 264.

Chemical Hazards 1. Irritation of eyes, respiratory tract and skin as a result of exposure to hydrazine and its derivatives 2. Irritation of the upper respiratory tract and coughing, as a result of inhalation of sulphur dioxide 3. Pneumoconiosis from exposure to vanadium-containing dust, and to asbestos from the insulation, particularly during maintenance and repair work, and from exposure to reparable fly ash 4. Dermatoses from exposure to fuels and to corrosion inhibitors (various organic or metal organic compounds) and other water additives 5. Asbestos may cause cancer; smoking strongly increases the risk

265.

Biological Hazard

1. Back pains and other musculoskeletal problems (including lesions of intervertebral discs) resulting from overexertion and wrong postures, during lifting and moving of sacks and heavy loads 266.

Prevention Measure 1. Wear safety shoes with non-skid soles 2. Periodically check and adjust burners operation to prevent carbon monoxide generation 3. To protect the integrity of the boiler and ensure it continues to produce good steam quality, it is important to properly treat the feed water, or the water going into the boiler.

4. Install effective exhaust ventilation to prevent air contamination; add local exhaust ventilation if necessary 5. Wear long-sleeve shirts and protect hands with chemical-resistant gloves; if impractical, use a barrier cream 6. Wear appropriate eye protection; consult a safety supervisor or a supplier 7. Arrange periodic inspection of boilers, to detect failure of components, metal cracking, etc.

8. Wear hearing protection appropriate for the noise levels and type of noise consult the supplier or an expert 9. Replace hydrazine with less-hazardous substitutes 10. Wear respiratory protection during maintenance or other work in which dust may be released into the atmosphere 11. Learn and use safe lifting and moving techniques for heavy or awkward loads; use mechanical aids to assist in lifting

267.

Q) State the hazards of using untreated water in boiler? List the boiler mounting and write the function of any two of them?

268.

Hazards of untreated water 1. Boiler Untreated water contains dissolved gases, such as carbon dioxide and oxygen that react in a boiler and lead to corrosion of the boiler internals and the

piping system. If these gases are not extracted from the water supply before entering the boiler, the corrosion will eventually eat through boiler tubes and cause leaks and equipment failure.

2. Boiler Untreated water also contains metal solids such as chlorides, magnesium, sulphur and calcium bicarbonates. If deposits of calcium and magnesium are not removed from boiler feed water, they will coat heating surfaces and eventually plug pipes and boiler tubes 3. Scale build-up and mud, sludge and contaminants can collect on the bottom of the boiler and on the tube sheet; it affects the heat distribution through the tubes and the boiler in general.

4. Microbiological Growth 5. Sedimentation / Fouling 269.

270.

List of Boiler mounting 271.

1. SAFETY VALVE: 2. WATER LEVEL INDICATOR: FUSIBLE PLUG: 3. PRESSURE GAUGE: 4. BLOW OFF COCK: 5. FEED CHECK VALVE: 6. STOP VALVE: 7. MAN HOLES: 272.

273.

SAFETY VALVE: 1. The function of the safety valve is to permit the steam in the boiler to escape to atmosp0here when pressure in the steam space in the boiler.

2. The safety valve operates in the principle that a valve is pressed against its seat through some agency such as strut, screw or spring by external weight or force, when the steam force due to boiler pressure acting under the valve exceeds the external force, the valve gets lifted off its seat and some of the steam rushes out until normal pressure is restored again.

3. The commonly used safety valves are given below: 274. ii) Lever safety valve 275. iii) Spring loaded safety valve 276. iv) High steam-low water safety valve 277.

278.

WATER LEVEL INDICATOR: 279.

1. The function of the water level indicator is to ascertain constantly and exactly the level of water in the boiler shell.

2. It is fitted in the front of the boiler from where it is easily visible to the operator.

280.

281.

Q) “Boiler nothing but the live bomb� explain why?

282.

283.

A boiler is a closed vessel in which water or other fluid is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in

various processes or heating applications. including water heating, central heating, boiler-based power generation, cooking, and sanitation.

284.

285.

There can be many different causes, such as failure of the pressure parts of the steam and water sides, failure of the safety valve, corrosion of critical parts of the boiler, or low water level. Corrosion along the edges of lap joints was a common cause of early boiler explosions can cause the death or injury to person and also damaged to property.

286.

287.

Hence we can say it’s a live bomb if we not take proper safety precaution during operation and periodic maintenance of boiler accessories and mounting including boiler shell thickness.

288.

Q) What are the precaution need to be taken when boiler not in use?

289.

1. Steam boiler when not in use are liable to deterioration from corrosion and unless well cared for and made rust proof.

2. They should be thoroughly drained 3. All value, cocks and opening closed so as to exclude moisture 4. Another method is to filled the boiler with water to which about 1/100 percent caustic soda has been added 5. Check of all components of the boiler including piping, valves, pumps, gaskets, refractory, etc.

6. Comprehensive cleaning, spot painting or re-painting and the replacement of expendable items should be planned.

7. Be prepared to perform any testing required by the inspector including hydrostatic testing of the equipment.

8. Clean metal surfaces where cover plate bears against shell plate or ring.

9. Check the condition of the refractory for significant damage or cracking.

10. Safety valve inspection and testing 11. Check and inspect all the accessories and mounting of boiler for any defects.

12. Check the thickness of boiler shell.

290.

291.

Work Permit, Welding & Gas cutting 292.

293.

What are the hazards in welding and gas cutting?

1. Eye injury 2. Burn injury Arc realization 3. Electrical shock Light arc radiation 4. Heat, light and radiation effect Heat fume 5. Poisonous gases Chipped price of weld metal 6. Fire 7. Explosion Scattering 8. Noise Sparking 9. Sparking 10. Flying sand 294.

295.

What are the pre cautions for welding?

1. Remove all combustion material from the place of welding

2. Clear the work area and cover wooden floor with fire proof mats. (Welding mechanic should be kept within the visibility of the welders.

3. Erect fire resistance screen around the work 4. All welding cables should be fully insulted 5. All welding mics shall be double earthed 6. Welding area should be dry and free from water 7. Keep the fire extinguisher / sand really 8. Use leather hand gloves, goggles and helmets 9. Switch off the power when welding is stopped 10. Do not allow the helper to do welding 11. Do not shift him welding cable unless the electric power is switched off.

12. Do not allow the helper to carry the welding. Terminal of the welding cables should be provided 3-cable with lugs and kept tight.

13. Oxygen hose in black and Acetylene hose in red in colour as per standard 14. NRV of the blow torches should be maintained properly avoid back fire 15. Welders should be trained properly 16. Cylinders should be stored in a cold dry place away bottom heat and direct sunlight 17. Proper housekeeping, good ventilation in the working area 18. Smoking should be avoided from welding area 19. Hose connection should be proper made 20. Barricade the work area and put a sign board 21. Rolling of cylinders should be avoided 296.

What is the precaution for gas cutting?

1. Keep fire extinguisher nearby 2. Keep fire watch near by 3. Remove all combustible from work area 4. Use all necessary PPE 5. Never put welding gas cylinder inside a confined space 6. Hoses shall not be laid in path ways 7. Gas cutting torch should have flash back arrestors 8. Gas test to be done to check for presence of flammable gas in site.

9. Good housekeeping and ventilation necessary in working area.

10. Hose connections should be made properly.

297.

Hazards and control measure in brazing and soldering operation?

298.

Hazards 1. Metal fumes because of heating 2. Lead oxides and chlorides are released when soldering 3. Spattering of solder or flux 4. Gases from fluxes, commonly fluorides and other halides 5. Metal dust while metalizing or burning of metal.

6. Fire 299.

300.

Control Measure

1. Inhalation of fumes (toxic or irritating) should be removed by local exhaust ventilation.

2. Hazardous contaminants should be measured by air sampling.

3. Lead solder particles should not be allowed to accumulate on the floor or work tables.

4. For protection against spattering of solder or flux, workers should wear face shield or do the work under a transparent shield.

5. Respirators are required to protect against metal dust or fume while metalizing or burning of metal.

6. Hand gloves can protect against burns. Insulated, non-combustible holders can protect against fire and burns. Table cover should be heat resistant.

7. Firefighting equipment must be keep ready 8. Follow the SOP. 9. Do not do hot work in or near rooms containing flammable or combustible vapors, liquids, or dusts.

301.

Hazards and control measure in Electric Arc welding?

302.

303.

Hazards: 1. Flying metallic sparks and molten metal. Some of these sparks consist of tiny shreds of extremely hot metal, sometimes molten, which may be hotter than 1000° F and may cause painful burns on exposed skin. These sparks are also source of fire or explosion hazard, in case flammable materials are nearby.

2. Hot surfaces of the work pieces after welding or cutting may cause harms to unsuspecting persons.

3. Flying materials while chipping the weld.

4. Enrichment of Oxygen (due to leakage from Oxygen cylinder) radically changes flammability.

5. Glare which comes when the arc is struck or the torch is lit. It affects the optic nerve at the back of the eye. Special eye glass (screen) is required.

6. Thermal heat radiation from welding can cause headache, fatigue and eye damage.

7. Infra-red radiation. Some of the IR is stopped by the upper layer of the skin but part of the radiation penetrates the exposed skin and may cause serious skin burns or pigmentation. Since eye has no absorbing layer, it can be severely damaged by this and may cause "heat cataract".

8. Ultra-violet radiation may cause skin burns and prolonged exposure may lead to skin tumours. Inert gas shielding is a strong source of UV radiation.

9. Workers on the shop floors may be exposed to noise due to welding, cutting or chipping operations.

10. Fall of materials and equipment’s during operation.

304.

Control Measure 305.

306.

Electrodes and Holders: 2. Electrode holders are used to connect the electrode to the welding cable supplying secondary current.

3. In order to prevent accidental striking of an arc they should be fully insulated.

4. Holders should be capable of handling the maximum current required by the electrode.

5. Dipping of hot electrode holders in water should be prohibited as it may expose the worker to electric shock.

307.

Electric Shock:

1. The work set up is such that the work is grounded and if the worker is not careful, he can receive electric shock.

2. The risk of shock can be reduced by providing an insulating barrier between the worker and the ground of nearby metal objects, while changing electrodes.

3. The welding cables should be of good quality to resist hard ware and inspected for insulation defects.

4. Joints between cables should be by insulated connectors of equivalent capacity.

5. The welding equipment must be safely earthed.

308.

309.

Personal Protection:

1. Ordinary clothing may be sufficient to protect against UV and IR radiation, but some exposed areas such as face, wrist, neck, hands etc. would be affected.

2. Asbestos/leather gloves may be useful to protect hands from electric shocks, heat and sparks.

3. Control measures have to be taken to stop flying particles, glare and the radiation.

4. If possible the welding operation in a shop floor be isolated and screened so that other workers engaged nearby are not affected.

5. To protect the workers from the toxic fumes, suitable respiratory protection should be provided.

6. Cotton apron if used by the workers may be treated with fire retarding chemicals.

310.

Explain Back fire and flash back in gas cutting? Explain there causes and the preventive measure?

311.

Backfires

312.

A backfire is when the flame burns back into the torch, often with a sharp bang. This may happen when the torch is held too close to the workpiece, or if the nozzle is partly blocked. The flame may go out or it may reignite at the nozzle.

Sometimes the flame burns back into the torch, and burning continues inside it.

Backfires do not usually cause injury or damage, but they can indicate a fault in the equipment.

313.

Causes

1. Backfires are typically caused by the tip overheating allowing the flame to regress back into the nozzle.

2. As well as getting the tip too close to object 3. or touching the tip to the work, a dirty/partially blocked tip can cause back fire 314.

If a backfire does occur:

1. Shut off the torch valves, oxygen first (usually coloured blue) and then the fuel gas (usually coloured red); 2. Shut off the oxygen and fuel gas cylinder valves; 3. Cool the blowpipe with water if necessary; 4. Check the equipment for damage or faults, particularly the nozzle.

315.

Flashbacks

316.

Flashbacks are commonly caused by a reverse flow of oxygen into the fuel gas hose (or fuel into the oxygen hose), producing an explosive mixture within the hose. The flame can then burn back through the torch, into the hose and may even reach the regulator and the cylinder. Flashbacks can result in damage or destruction of equipment, and could even cause the cylinder to explode.

317.

Causes

318.

A flashback is caused by the reverse flow of gases upstream into the hoses or other equipment.

319.

This reverse flow is usually the result of: 320.

1) Improper shutdown and/or start-up procedures; 321.

2) Allowing cylinder pressures to become too low; 322.

3) Check valve that is not working properly.

323.

324.

The following precautions will help to prevent flashbacks: 1. Use the correct lighting-up procedure. Purge the hoses before lighting the torch to remove any potentially explosive gas mixtures. Use a spark igniter and light the gas quickly after turning it on.

2. Make sure the blowpipe is fitted with spring-loaded non-return valves.

3. Use the correct gas pressures and nozzle size for the job.

4. Maintain the equipment in good condition.

5. Flashback arrestors are normally adequate in preventing reverse flow flashbacks.

325.

326.

What is Flash back arrester?

A flashback arrestor or flash arrestor is a special gas safety device most commonly used in oxy-fuel welding and cutting to stop the flame or reverse flow of gas back up into the equipment or supply line and it prevents the user and equipment from damage or explosions.

327.

Safety precaution required during working at height?

328.

1. Safe, sound and dry (non-slippery) surfaces for walking and working. Fencing, guarding and toe boards.

2. Safe helmet, safety belt, foot-wear, etc.

3. Safe practice in walking and working. No excessive load lifting.

4. Safe means of access while working at height or depth.

5. Use of crawling board, cat ladder, fall arrester net etc. while working on fragile roof.

6. Use of Safety work permit for working at height or depth.

7. Safe and sound stairs, ladders, scaffold etc. and safe use thereof.

8. Good lighting and supervision, cutting off power supply in overhead electric lines.

9. Safety cordon to disallow persons in the area where any object may fall from height.

10. Do Not Carrying too much load making it difficult to see 11. Do not work in Dusty, steamy or smoky atmosphere restricting vision.

12. Do not use Ladders, ramps, planks and platforms not rigid or safe for the job.

13. De-energies overhand electric lines, if any.

14. The stair landings should be protected by railings and toe-boards. Non-skid strips on stair treads can prevent slipping.

15. Adequate lighting on stairway should be provided to avoid accidents.

16. Stairways should be of fireproof material to give support for a longer time.

17. Runways are long with uniform slope as they are at arodram

18. Ladders should rest on firm ground and its top should extend at least 1 in above the place of landing.

19. The scaffolds should be of sound material, sufficient strength (4 times the expected load) and properly designed.

20. Pre-employment and periodic medical examination of workers to check their suitability for working at height. Workers suffering from balance disorders, vertigo, epilepsy, blackouts etc. should not be employed or continued to work at height.

21. Trained Workers: Safety belts, harnesses and lanyards are to be used in conjunction with permanent anchorage points. Workers should be trained to know how to check, wear and adjust before they start work and how to connect themselves to the structure or safety line.

329.

What is man by confined space and its hazards Safety precaution required during working in confined space?

330.

331.

'Confined space' as any space by reason of its construction as well as in relation to the nature of the work carried therein and where hazards to the persons entering into working inside exist or are likely to develop during working.

332.

Example- Work in vessels and tanks below ground in pits, cellars and basements or inside confined spaces such as silos, tanks, vats, vessels, boilers gutter etc.

333.

1.

2.

3.

4.

5.

6.

7.

8.

Hazards of Confined Space can be classified as-

Poor lighting and ventilation.

Oxygen deficiency.

Contamination of toxic and/or flammable gases.

Unexpected activation of machinery or flow.

No way or no time available for exit.

Engulfment (burying) in loose material.

Nonspecific work practices.

Other hazards are suffocation, burning, poisoning, explosion, drowning, freezing, crushing, entrapment, scalding, stroke, heat stress, radiation, physical trauma, injury by moving machinery, slipping or falling etc.

334.

Control Measure

1. Tanks, vats, pits, sumps, vessels, floor opening etc. should be protected by guard rails or cover.

2. Fixed ladder with handrail if possible, should be provided to step down safely.

3. Portable (rope) ladder may be used while working inside a tank or vessel for temporary work.

4. Check the concentration of toxic or flammable gas, dust, vapour etc., by a gas detector. Oxygen content should also be checked for safe proportion. It should be >18%.

5. Air line or self-contained breathing apparatus and safety belt are essential.

6. Sump pumps with flameproof electric or pneumatic motors and air extraction fans (spark proof) and exhaust ducting to remove heavy vapours is necessary.

7. Complete isolation of the vessel, cleaning, purging and ventilation of the vessel, inspection and testing, safety permit and all rescue arrangements must be done

before such work and only a trained worker will work under constant help and supervision.

8. Latest safety and rescue systems should be used. Winch arrangement connected with the worker's harness is useful to lower and pull out quickly.

9. Hand free communication system is available to keep the worker in the tank in constant touch with the supervisor outside. Hand operated clutch, cord and chair assembly can be used to lower the person while working at height or depth.

10. Bottom drain valve and other nozzles should be kept open to allow good ventilation and fresh air in a vessel or tank.

11. Wear helmet or hard hat, safety shoes and protective clothing necessary.

335.

336.

Precaution Need to be taken in the paint Booth?

337.

Things to do and not to do before painting

1. DO Post “No Smoking” and “No Welding” signs 2. DO Remove portable lamps and heaters from the area 3. DO Make sure painting is done away from naked flames, sparks, non-explosion proof motors or any other source of ignition.

4. DO Check the ventilation system to make sure it is on and working correctly.

5. DO Electrically ground all spraying equipment 6. DO Make sure approved respirator, eye goggles and any other protective equipment required for the job are worn 7. DON’T Smoke 8. DON’T Take more paint out of the store room than you can use in one day.

338.

Fire and explosion hazards

1. Because of the danger of fire and explosion where paints which contain flammable solvents are being used, care should be taken to remove all potential sources of ignition before starting work.

2. This means naked flames, cutting and welding torches, gas fired heaters and materials which may give off sparks, whether electrical, mechanical, friction or static, and there must be no smoking.

3. Make sure the correct types of fire extinguishers are available at the work site.

339.

Protective clothing 1. Some of the chemicals you work with can injure skin or cause dermatitis. Coveralls and gloves prevent these chemicals from coming into contact with your skin, reducing the risk of damage.

340.

Eye and Hearing Protection 2. Without good eyesight you cannot do your job properly — so why risk eye damage, or loss of eyesight from solvent spray or splashing.

3. Wear your SAFETY GOGGLES to protect your eyes from paint materials as well as the particulates created during sanding and grinding.

341.

Respirators 1. Two types of respirators, the air-purifying and the atmosphere supplying, are commonly used in spray painting 342.

When painting:

1. follow the equipment manufacturer’s instructions, 2. avoid using plastic drop cloths on the floor (slip hazard) 3. never point a spray gun at yourself or anyone else, 4. position yourself so the piece you are spraying is between you and the exhaust fan, 5. do not over spray, and 6. use appropriate personal protection 343.

What is work permit system?

344.

Permit to Work System: This is a formal written system document used to closely control certain types of activities, tasks, processes or work that have specific hazards or are potentially hazardous.

345.

Describe the work permit system and its advantage for hot work and cold work?

346.

DefinitionPermit to Work System: This is a formal written system document used to closely control certain types of activities, tasks, processes or work that have specific hazards or are potentially hazardous 347.

1.

2.

3.

4.

5.

6.

7.

8.

The elements of a permit to work system are:

Hazards of the plant, chemicals and work are fully explained to the workers involved.

Instructions are in details and fully understood by both the parties.

Work area should be clearly identified, made safe or the hazards highlighted.

In-charge of the area who issues the permit, should be competent and responsible and should sign the document stating that he is satisfied regarding necessary isolation, blanketing etc. completed and it is made safe for the workers to work in that area.

The in-charge of the team of workers, who receives the permit must sign the permit stating that he has fully understood the work to be carried out, the hazards potential, precautions, conditions and procedure and the PPE/FFE to be utilized.

Any monitoring including gas testing required before, during and after the work should be specified and the results noted on the document.

When the work is completed (after necessary extension of the permit if work continues), the work in-charge signs off the permit stating that the specified work has been completed and the plant is in a suitable state to return to operations.

The area in-charge signs to accept that the work has been completed and he now accepts the responsibility.

348.

Advantage

1. It describes procedures and guidelines on work permit system to carry out jobs of inspection, testing, maintenance, alternation, repair, and construction in safest possible manner.

2. The implementation of this system will help in bring down the risks at work sites to acceptable level, thereby reducing possibility of any accident, fire, explosion, property damage and adverse effect on environment.

3. Help in ensuring a safe working environment, thereby reducing possibility of injury to personnel, protect property, and avoid fire, explosion & adverse effect on environment.

349.

350.

Environmental Protection 351.

352.

Q) Explain the following term 353.

354.

Ozone layer depletion 355.

1. Ozone depletion describes a steady decline of about 4% in the total amoun of ozone in Earth's stratosphere (the ozone layer), and a much larger springtime decrease in stratospheric ozone around Earth's polar regions 2. Man-made causes of depletion of ozone layer: The main cause for the depletion of ozone is determined as excessive release of chlorine and bromine from man-made compounds such as chlorofluorocarbons (CFCs).

3. Natural causes of depletion of ozone layer: Ozone layer has been found to be affected by certain natural phenomena such as Sun-spots and stratospheric winds.

4. Main Ozone Depleting Substances (OCD)  Chlorofluorocarbons: Account for more than 80% of ozone depletion. Used in freezers, air cooling component, dry-cleaning agents, hospital sterilants.  Methyl Chloroform: Used for vapour degreasing, some aerosols, cold cleaning, adhesives and chemical processing.  Hydro chlorofluorocarbons: Substitutes for CFC’s but still play a vital role in ozone depletion.  Halons  Carbon Tetrachloride: Mainly used in fire extinguishers 5. Since the ozone layer absorbs UVB ultraviolet light from the sun, ozone layer depletion increases surface UVB levels (all else equal), which could lead to damage, including increase in skin cancer.

356.

Acid Rain 357.

1. "Acid rain" is a popular term referring to the deposition of a mixture from wet (rain, snow, sleet, fog, cloud water, and dew) and dry (acidifying particles and gases) acidic components 2. Causes of acid rain – 358.  Acid rain is caused by a chemical reaction that begins when compounds like sulphur dioxide and nitrogen oxides are released into the air.  Human activities are the main cause of acid rain. Over the past few decades, humans have released so many different chemicals into the air that they have changed the mix of gases in the atmosphere.  Power plants release the majority of sulphur dioxide and much of the nitrogen oxides when they burn fossil fuels, such as coal, to produce electricity.

In addition, the exhaust from cars, trucks, and buses releases nitrogen oxides and sulphur dioxide into the air. These pollutants cause acid rain.  The principal natural phenomena that contribute acid-producing gases to the atmosphere are emissions from volcanoes.

359.

3. Effects of acid rain 360.  Acid rain has been shown to have adverse impacts on forests, freshwaters and soils, killing insect and aquatic life-forms as well as causing damage to buildings and having impacts on human health  Many scientific studies have identified a relationship between elevated levels of fine particles and increased illness and premature death from heart and lung disorders, such as asthma and bronchitis.

361.

362.

Greenhouse Effect 363.

1. The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect 2. The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be in the absence of its atmosphere 3. The surface itself emits energy at the lower frequencies of infrared thermal radiation.

4. Infrared radiation is absorbed by greenhouse gases in the atmosphere.

5. By their percentage contribution to the greenhouse effect on Earth the four major gases are: water vapour, 36–70% , carbon dioxide, 9–26%, methane, 4–9%, ozone, 3–7% 6. The enhanced greenhouse effect is when the increasing the concentration of this gases are enhancing the natural greenhouse effects.

364.

Global Warming 365.

1. Global Warming is the increase of Earth's average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth.

2. Causes of global warming  Global warming is primarily a problem of too much carbon dioxide (CO2) in the atmosphere  As we burn fossil fuels like coal, oil and natural gas for energy  cut down and burn forests  Certain waste management and agricultural practices aggravate the problem by releasing other potent global warming gases, such as methane and nitrous oxide.

3. Potential to change rainfall and snow patterns, increase droughts and severe storms, reduce lake ice cover, melt glaciers, increase sea levels, and change plant and animal behaviour. 

366.

Solid Waste Management 367.

1. Solid waste is the unwanted or useless solid materials generated from combined residential, industrial and commercial activities in a given area.

2. It may be categorised according to its origin (domestic, industrial, commercial, construction or institutional); according to its contents (organic material, glass, metal, plastic paper etc); or according to hazard potential (toxic, non-toxin, flammable, radioactive, infectious etc).

3. Management of solid waste reduces or eliminates adverse impacts on the environment and human health and supports economic development and improved quality of life.

4. A number of processes are involved in effectively managing waste for a municipality.

These include monitoring, collection, transport, processing, recycling and disposal.

5. Methods of waste reduction, waste reuse and recycling are the preferred options when managing waste.

6. There are many environmental benefits that can be derived from the use of these methods.

7. They reduce or prevent greenhouse gas emissions, reduce the release of pollutants, conserve resources, save energy and reduce the demand for waste treatment technology and landfill space.

8. Therefore it is advisable that these methods be adopted and incorporated as part of the waste management plan.

9. Waste treatment techniques seek to transform the waste into a form that is more manageable, reduce the volume or reduce the toxicity of the waste thus making the waste easier to dispose of.

10. Treatment methods are selected based on the composition, quantity, and form of the waste material.

11. Waste treatment methods being used today include subjecting the waste to extremely high temperatures, dumping on land or land filling and use of biological processes to treat the waste.

368.

369.

Define Following 370.

371.

Environment- All the external factors, conditions and influences which effects an organism or a community. Also everything that surrounding an organism or a organism including both natural and human built element.

372.

Environment includes air water land and interrelationship which exists among and between the water air land human being other leaving creature, plants, microorganism and property.

373.

374.

Hazardous Waste- refuse that could present danger through the contamination and pollution of the environment. It requires special disposal technique to make it harmless or less dangerous.