Regulations Concerning Naturally Occurring Asbestos (NOA) in Germany—Testing Procedures for Asbestos

STEFAN PIERDZIG* CRB Analyse Service GmbH, Bahnhofstrasse 14, D-37181 Hardegsen, Germany

Key Terms: NOA, Asbestos, Analysis, Regulations, Germany, TRGS 517

ABSTRACT

In Germany, potential asbestos-containing rocks are used as raw materials for a number of engineering applications. These rocks are ultrabasites (dunite, harzburgite), igneous rocks (basalt, gabbro, norite), and metasomatic or metamorphic rocks like talcum, greenschist and amphibolite. Based on the German Gefahrstoffverordung (Hazardous Substances Ordinance), regulatory statutes exist for operations using these rocks and resultant composites and products. The authorities state that in Germany no natural rocks exist with more than 0.1 mass-% of one of the six regulated asbestos minerals. But it is well known that there are rocks with a high modal concentration of these minerals with a nonasbestiform, columnar to prismatic habitus. Under mechanical stress during handling, they can lead to fibrous cleavage fragments, which conform to the World Health Organization (WHO) “respirable asbestos fiber” definition. In view of this fact, the regulations changed in 2009, with revision of the Technical Rules for Hazardous Substances (TRGS) 517: any fibrous asbestos particles, regardless of whether or not they represent naturally occurring asbestos or are of cleavage origin, are evaluated for potential hazards associated with handling of these rocks. If the WHO fiber concentration is <0.1 mass-%, rocks and products can be used and re-used under protective measures. At concentrations >0.1 mass-%, the material is considered hazardous waste. These regulations apply to many industrial sectors that exploit and process rocks, using them in road building and track construction and when they are recycled. Analysis (by scanning electron microscopy, SEM/energy dispersive x-ray spectroscopy, EDS) to determine the asbestos concentration of rocks, gravels, or dusts is carried out in the <100-µm, grain-size fraction produced by sieving or grinding. The results provide a representation of a worst-case examination of the air quality during mechanical treatment of these materials. Workplace monitoring is done by air sampling to survey an exposure limit of 10,000 fibers/m 3 of air (0.01 f/cc).

*Corresponding author email: pierdzig@crb-gmbh.de

INTRODUCTION

Compiled by Germany’s Committee on Hazardous Substances (AGS), Technical Rules for Hazardous Substances (TRGS) reflect the state of the art and the state of occupational health and occupational hygiene, as well as other sound scientific knowledge relating to activities involving hazardous substances, including their classification and labeling.

In compliance with the requirements of the Gefahrstoffverordnung (Hazardous Substances Ordinance; GefStoffV, 2017), TRGS 517 (2013) applies to activities with potentially asbestos-containing mineral raw materials and mixtures and products produced from them and describes the protective measures to be applied to these activities. It applies especially to the following: the extraction and purification of naturally occurring mineral raw materials containing asbestos in quarries (e.g., gravel, grit, crushed sand, filler); the further processing of asbestos-containing mineral raw materials and mixtures and products manufactured from them in construction and civil engineering (e.g., road and rail construction, concrete, asphalt); the re-processing (recycling) and re-use in road construction (e.g., the treatment and reincorporation of recycled materials, the manufacture of asphalt); and the processing of natural stone (e.g., soapstone in construction furnaces) and cold milling machines in traffic areas. Following the GefStoffV, the extraction, preparation, further processing, and re-use of mineral raw materials that occur naturally and preparations and articles manufactured therefrom that contain asbestos with a mass content of more than 0.1 percent are prohibited.

INFORMATION GATHERING AND RISK ASSESSMENT

To assess working conditions according to GefStoffV section 6, the employer must, before commencing activities with potentially asbestos-containing materials, competently determine by means of

Figure 1. Diabase quarry in the Harz Mountains, Hercynian Forest.

appropriate measures whether asbestos exposure for employees should be expected and to what extent.

Potentially Asbestos-Containing Rocks

In the mineral deposits found when mining in the Federal Republic of Germany, for particular types of rock, the occurrence of asbestos minerals chrysotile, tremolite, actinolite, amosite, and, to a lesser extent, anthophyllite needs to be taken into account. Above all, basic magmatites are affected. Figure 1 shows a Diabase quarry in the Harz Mountains, where one million tons of gravel for road and railroad construction are produced per year.

The following rock types are particularly considered to contain asbestos (TRGS, 2013): Ultrabasite/peridotite (e.g., dunite, lherzolite, harzburgite); Basic effusives (e.g., basalt, diabase, spilite, basanite, tephrite, phonolite); Basic intrusives (e.g., gabbro, norite); and Metamorphic and metasomatically influenced rocks (e.g., metasomatic talc occurrences, green schist, chlorite and amphibole schist/bedrock [e.g., nephrite], serpentinite, amphibolite).

Procedures for Determining the Mass Content of Asbestos

When processing asbestos-containing technical products, respirable asbestos fibers are released, which predominantly display an aspect ratio of >10:1 and mostly exhibit a small diameter of <1 μm. Elongated particles from an asbestos mineral, released in the processing of mineral raw materials, differ morphologically. The majority of these particles have an aspect ratio of <5:1 and a larger diameter, as displayed on Figure 2.

Asbestos is defined as six regulated minerals (chrysotile, amosite, tremolite, actinolite, crocidolite, anthophyllite, compare TRGS 517) that exhibit dimensions determined by the World Health Organization (WHO, 1986): length > 5 µm, diameter < 3 µm, with an aspect ratio >3:1). The regulation applies regardless of whether an asbestos fiber has been released from a primary fibrous deposit or from a non-fibrous, rockforming mineral, which belongs to the category of regulated asbestos minerals.

Analysis and quantification of asbestos content is carried out according to BIA/IFA Code 7487 (BIA/IFA, 1989) by suspension in water and filtration through a 0.2-µm membrane filter. Quantification of asbestos with a limit of detection (LOD) of 0.008 percent is performed to estimate the potential of exposure to asbestos. In addition to the determination of the mass percentage of asbestos, the number of asbestos fibers per milligram of material examined should also be determined. This information is gathered when determining the mass percentage. If asbestos is detected in the material, asbestos exposure must be determined (TRGS, 2010) by a scanning electron microscopy (SEM)/energy dispersive x-ray spectroscopy (EDS) method designed for the monitoring of workplaces.

Risk Assessment

The risk assessment calculation for workplace and work activities is required to be performed by a competent person (DGUV Information 213–546, 2014). When performing the risk assessment, the following aspects should be taken into account: The extent and duration of the inhalation exposure; Working conditions and work practices, including work equipment; and Required protective measures, based on exposure potential. When a change in the operating conditions occurs, which can lead to a major change to the hazard, the risk assessment must be performed again and the results of the risk assessment documented.

Event-Related Advice

The employer is required to obtain event-related advice on protective measures to be taken to minimize the risks related to exposure to asbestos. If the employer’s own expertise is non-existent, advice may be provided through a qualified employee or subcontracted supervisor. If custom recommendations are not obtained, the procedures within “Dust-free ablation of

Figure 2. Asbestos cleavage fragment of actinolite, released from a primary non-fibrous deposit of an asbestos mineral under physical stress, such as that involved in crushing and milling.

asphalt pavements with cold milling machines” (BG Bau, 2011) can be followed. When a change to the operating conditions occurs, which can lead to a major change to the hazard situation, the event-related risk assessment should be carried out again.

Notification to Local Mining Authorities

If the investigation has revealed that workers are or may be exposed to asbestos during their activities, the employer must notify the local mining authorities of these activities. The notification to authority must be carried out by the employer before the start of the activity and must contain the following information: The location of the work site; The activities and procedures; The number of workers concerned; The beginning and duration of the activities; and Measures to limit asbestos exposure for workers. For activities and procedures of a similar nature, a single enterprise-related notification is acceptable. The notification must be repeated when there is a significant change in the working conditions. After notification has been completed the protective measures should be selected and documented according to the result of the risk assessment. The effectiveness of the protective measures should be reviewed by subsequent exposure measurements after implementing the measures and then at regular intervals, at least once per year.

PROTECTIVE MEASURES

General Protective Measures

For activities involving asbestos-containing materials, the breathing air at the workplace must, as much as possible using state-of-the-art controls, be free from asbestos fibers. Where the asbestos fiber concentration falls below 10,000 F/m³, minimum basic measures to protect workers must be carried out (TRGS, 2008).

Where the asbestos fiber concentration exceeds 10,000 F/m³, the following ranking of protective measures must be complied with to minimize risk:

1. Use of low-emission work procedures and work equipment; 2. Implementation of collective protection measures at the hazard source, such as extraction, aeration and ventilation, and appropriate organizational measures; and 3. Use of personal protective equipment if a risk cannot be prevented by the measures referred to in points 1 and 2 above.

The general protective measures describe, among others, the following: the use of machinery and equipment, the design of work spaces, ventilation measures,

air return, hygienic facilities, material storage and handling, cleaning procedures, and handling of wastes and residues. Protective measures also include definitions of responsibilities and supervision, limiting of the number of persons exposed, procedures for minimizing exposure, and information and training of workers.

Complementary Protective Measures

In addition to the general protection measures, complementary protective measures exist for the following work areas and activities: Extraction and processing in quarries; Reprocessing and recycling; Processing of natural stone; Release agents and lubricants; Fillers and aggregates; Tunneling; and Cold milling of road surfaces.

OCCUPATIONAL HEALTH PREVENTION AND CARE

In the case of activities with potentially asbestoscontaining raw materials and mixtures, and products derived therefrom, occupational medicine prevention generally comprises the participation of the occupational physician in the risk assessment, general medical advice, and occupational health care. The focus here is on imparting knowledge about carcinogenic and other chronically damaging properties of asbestos, as well as information regarding the necessity of wearing personal protective equipment. The workload must be included in the assessment of the inhalation burden.

Occupational medicine toxicological advice is used to inform endangered employees, for example, within the framework of a briefing. Instruction is to be provided if possible, with the participation of the company’s physician, and is also intended to provide information on the uses and scope of occupational health care examinations. Information is presented in a manner to motivate workers to participate.

Occupational health care includes assessing the individual interrelation between work, physical and mental health, and early detection of work-related health problems. An additional purpose is to assess whether there is an increased health risk associated with a particular work activity. If this is this case, advice for employees on exposure and resulting hazards to their health is the focus. If physical or clinical investigation are not required by the physician’s assessment or are rejected by the worker, occupational health care may be limited to a consultation.

Figure 3. Flowchart showing the sequence of the survey of potentially asbestos-containing mineral raw materials and their products.

Occupational health care must be arranged for the workers by the employer prior to the activity and then at regular intervals when repeated exposure to asbestos in the workplace cannot be ruled out. The whole process of surveying potentially asbestos-containing raw materials is shown in Figure 3.

SUMMARY

In Germany, the Hazardous Substances Ordinance (GefStoffV, 2017) and the Technical Rule for Hazardous Substances, TRGS 517 (2013), provide extensive regulatory statutes for the examination of potentially asbestos-containing materials. The use and re-use of asbestos-containing materials with an asbestos content of <0.1 percent is allowed. For risk assessment, both naturally occurring asbestos and cleavage (elongated) fragments of asbestos minerals are taken into account. The determination of asbestos concentration follows BIA/IFA Code 7487 (1989) and is conducted using SEM/energy dispersive x-ray spectroscopy (EDS) after grinding of material, suspension, and filtration at the grain-fraction of<100 µm and reflects a worst-case-examination of the health hazard. Extensive general and complementary protective measures are required for activities with asbestoscontaining materials.

REFERENCES

DGUV Information 213-546 (previously ZH 1/120.46, BGI 505-46), 2004, Verfahren zur getrennten Bestimmung der Konzentrationen von lungengängigen anorganischen Fasern in

Arbeitsbereichen—Rasterelektronenmikroskopisches Verfahren [Procedure for the Separate Determination of the Concentration of Inorganic Fibers in Work Areas—Scanning Electron Microscopy Procedures]. Analytical Methods Recognized by the Professional Associations for Determining the Concentration of Carcinogenic Substances in the Air at the Workplace]: Deutsche Gesetzliche Unfallversicherung (DGUV), Federation of Professional and Trade Associations in Industry, Sankt Augustin/Carl Heymanns Verlag, Cologne. BIA/IFA Code 7487, 1989, Verfahren zur Bestimmung geringer Massengehalte von Asbestfasern in Pulvern, Pudern und Stäuben mit REM/EDX (Kennzahl 7487) [Procedure for Analytically Determining Low Mass Concentrations of Asbestos Fibers in Flours, Powders and Dusts with SEM/EDX (Code 7487)]. In: IFA-Arbeitsmappe Messung von Gefahrstoffen [IFA Work Folder on the Measurement of Hazardous Substances], 18, Supplement IV/97: Professional Association for Industrial Safety (BIA), Sankt Augustin/Erich Schmidt, Bielefeld–Losebl.-Ausg. Bundesgesetzblatt (BGBI) IS 626, 2017, Verordnung zum Schutz vor Gefahrstoffen, [Regulation on the Protection Against Hazardous Substances] Hazardous Substances Ordinance— GefStoffV”. BG BAU, 2011, Branchenlösung “Asphaltbeläge staubarm abtragen mit Kaltfräsen” [branch solution Dust-free ablation of asphalt pavements with cold milling machines]: http://www.bgbau.de, Webcode 3096458. TRGS 402, 2010, Ermitteln und Beurteilen der Gefährdungen bei Tätigkeiten mit Gefahrstoffen: Inhalative Exposition [Identifying and Assessing the Risks in Activities Involving Hazardous Substances: Inhalation Exposure]: Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (BAuA), Berlin. TRGS 500, 2008, Schutzmaßnahmen [Protective Measures]: Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (BAuA), Berlin. TRGS 517, 2013, Tätigkeiten mit potenziell asbesthaltigen mineralischen Rohstoffen und daraus hergestellten Gemischen und Erzeugnissen [Activities with Potentially Asbestos Containing Minerals and Mixtures and Products Manufactured from Same]: Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (BAuA), Berlin. World Health Orhanization (WHO), International Programme on Chemical Safety & WHO Task Group on Asbestos and other Natural Mineral Fibres, 1986, Asbestos and other natural mineral fibres: Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organisation, and the World Health Organization.