Rubber Journal Asia Materials
Detoxifying latex for safer work and play applications Studies say that latex-based products
The FDA said that aside from medical gloves, a wide range of latexbased products, from adhesive bandages a n d catheters to sanitary napkins and blood pressure monitoring cuffs, can potentially trigger allergies and may Dr Ranjit K Matthan of Vystar is at cause anaphylactic the helm of developing aluminium shock. Any user may hydroxide-treated latex be at risk, it added. To minimise the risk, the agency suggested using powderfree gloves with reduced protein content. Making latex products safer, a new technology product is offered. The Ultra Low Protein Lattices (ULPL) is developed by US-based Vystar Corporation, the exclusive creator of Vytex natural rubber latex (NRL), a raw material that features significantly reduced levels of the proteins inherent to NR latex. Recently, a presentation was delivered by Dr Ranjit K. Matthan, an internationally renowned latex and rubber expert, who has joined Vystar’s Board of Directors and as Research & Development Director. Dr Matthan has been a consultant to Vystar since 2008 and has played a significant role in the manufacturing scale up of reduced-protein Vytex in Malaysia and refining the R&D of manufacturing processes for applications using Vytex NRL, such as latex foam, condoms, adhesives, medical devices. In the session titled “Advances in Environmentally Friendly Ultra Low Protein Natural Rubber Specialty Latices” during the International Latex Conference 2015 held in August in Akron, Ohio, Dr Matthan revealed ongoing developments in the formulation of ULPL with reduced or no ammonia and nitrosamines. He said that these advances in aluminium hydroxide-treated ULPL properties and applications address concerns on volatile organic content and nitrosamines for some critical latex products, such as balloons, catheters, condoms, and other medical devices. In formulating ULPL, Dr Matthan has pooled his expertise along with Joseph John, Director of the Polymer Consultancy Services in Chennai, India; and Bill Doyle, CEO of Vystar. The main man in ULPL’s R&D, Dr Matthan has been an important figure in South Asia’s rubber industry since the 1970s. He is also a key proponent for NR sustainability via the Bangkokbased Asia Pacific Elastomer Science and Technology (APEST).
like gloves, medical devices and balloons can result in users falling ill. Find out why and what advances have been made to prevent this, in this report by Angelica Buan.
T
he milky sap derived from the rubber tree (Hevea brasiliensis), latex, is about 30-40% rubber and the rest is made up of resins, ash, sugar, water, and more than 200 types of proteins. Of this number, 13 are known to be allergens according to the American Latex Allergy Association (ALAA). In the US healthcare environment, allergy from latex is comparatively low at 1% of the general population of about 3 million, states ALAA. Risk groups are further categorised as healthcare workers (8-17%), who are frequently using latex gloves or products, and individuals who have had multiple surgeries or children who have spina bifda-related surgeries (68%), all of which can be mitigated through avoidance of exposure. Solving the dilemma with low-protein latex or a long time, allergic reactions to latex proteins resulted in decreasing use of latex-based products. This is especially in the healthcare environment where latex gloves are important barrier devices and allergic reactions are major concerns.
F
“…allergic reactions to latex proteins resulted in decreasing use of latex-based products..” Last year, the US Food and Drug Administration (FDA) issued guidance on latex product labelling. The agency had been equivocal with latex-free labels in products, for lack of existing tests that could determine the total absence of allergy-inducing proteins in natural rubber latex, and thus latex-free claims were misleading. 5 N OV E M B E R / D E C E M B E R 2 015
www.rubberjournalasia.com
Rubber Journal Asia Materials Safety in the production chain – use of chemicals “In recent years, the latex industry has sought part from allergy reactions, the chemicals to reduce or eliminate the need for nitrosamines required in processing latex also raise and ammonia in natural rubber latex to remove safety concerns. During processing, latex is any potential health hazards for those with preserved by anticoagulants like ammonia or long term exposure in the production and in sodium sulphite to prevent deterioration. The the manufacture of products in several end kind of anticoagulant used is dependent upon the use applications,” stated Dr Matthan in a press production process. Sodium sulphite is preferred release of the company. This development enables if crepe or sheet broader range rubbers are to be “…the latex industry has sought to reduce applications made, but ammonia minus the threat or eliminate the need for nitrosamines is more suitable for from leachable latex concentrate. – a and ammonia in natural rubber latex..” extractables Latex-dipped rubber industry products, such as balloons, gloves and condoms, pipeline dream come true. contain the colourless, corrosive chemical ammonia. As explained in a study published Balloons: party friends or environmental foes? by the Wisconsin-headquartered World Allergy s harmless as it may seem but those party Organisation, about 12% of harvested latex balloons that breathe life to a festivity can is treated either with 0.7% ammonia (high also pose safety risks. Claims of health risks ammoniated latex) or with 0.2% of ammonia and associated with the latex that make up these thiuram combination (low ammoniated latex). colourful balls of fun say that they are not only On a broad manufacturing set-up, workers in potential choking hazards, since they contain this segment also face risks in chemical exposure. chemicals occurring naturally and during The National Institute for Occupational processing, but that human and environmental Safety and Health (NIOSH) has released a exposure to latex balloons can be devastating. hazard report for workers handling rubber Latex per se that is used in novelty items products. The latter would refer to vehicle tyres, like balloons, in sexual wellness products like automotive and appliance mouldings, rubber condoms, and in healthcare products like gloves, bands, rubber gloves, and other barrier devices. poses no direct harm to the environment. Because making these rubber products involves According to New Jersey-headquartered The application of heat, pressure and catalytic action Balloon Council (TBC), latex is 100% natural onto the chemical mixtures, with dust, gases, substance that degrades in sunlight and water. vapours, fumes, and chemical by-products (e.g. One sign that a balloon is starting to degrade is nitrosamines) that occur from the manufacturing when oxidation occurs, or also called frosting, processes may contaminate the work areas. Thus, that is when the balloon’s colour starts to workers may be exposed to these hazards through fade. Exposure to sunlight as well as to certain inhalation and skin absorption. microorganisms hastens the process. The International Agency for Research on TBC implies that latex balloons may have no Cancer (IARC) of the World Health Organisation major impact to the environment. A balloon that (WHO) came up with a study on exposure to is released into the air, which is “well-tied and rubber processing chemicals and found that has no structural flaws”, can potentially ascend to workers in the rubber manufacturing industry an altitude of about 5 miles where it freezes and are primarily vulnerable to dust and fumes is shred into pieces, TBC explained. The pieces from processing rubber and vulcanisation. The that would drop to the ground (or into a body of chemicals identified for potential exposure water) can sometimes be ingested by land or sea include nitrosamines, polycyclic aromatic animals, TBC said, adding that evidence showed hydrocarbons, solvents, and phthalates. rubber pieces that passed through the digestive “Inhalation is the main route of exposure, tracts of animals have not harmed them. TBC also although workers may have dermal exposure cited that latex balloons “biodegrade at about the as well, such as from cyclohexane-soluble same rate as a leaf from an oak tree.” compounds,” IARC said. While the US organisation of retailers, Barring chemicals, Vystar’s aluminium manufacturers and distributors of balloons aver hydroxide-treated ULPL is formulated with that balloons are not found to be a significant reduced or no ammonia and nitrosamines, two of litter problem, based on beach clean-up the chemicals that are found to cause health risks observations, it strongly recommends proper on exposure. waste disposal of the latex product.
A
A
6 N OV E M B E R / D E C E M B E R 2 015
www.rubberjournalasia.com
Rubber Journal Asia Materials Vystar makes a case for its NRL eanwhile, Vystar’s Vytex NRL has been used by Pioneer Balloon Company, the largest US producer of balloons. It has upgraded to using treated NRL for use in the high-end, jewel-tone colour balloons. It adds, “Treated NRL produces a very high quality, more translucent balloon that has better barrier properties than ordinary NRL. No doubt this is due to removal of the lutoids and Frey-Wyssling particles to reduce discolouring by removing the opportunity of PPO browning, higher rubber to nonrubber ratio, and reduction of odourous low molecular weight acids.” Vytex NRL is biodegradable, stated Vystar. “The latex grade, when used in balloons, can return to nature in as little as six months,” says the US firm. Vystar also says that several adhesive and foam manufacturers have also upgraded to the use of treated NRL, including Islatex, which launched high-end foam pillows made from aluminium hydroxide-treated latex. The company says it continues to work with manufacturers across a broad range of consumer and medical products, such as Tamicare and their Cosyflex product. Vystar adds, “Glove manufacturers continue to differentiate their products and upgrade to Vytex due to the softness/low modulus and are able to increase filler loading due to the absence of non-rubbers, reduce leaching processes and cost.” Other benefits of Vytex are that the aluminium hydroxide-treated NRL has a longer “pot life”, compared to regular NRL, which benefits glove manufacturers in terms of longer shelf life of the compound allowing for more dipping flexibility. “These attributes are attractive in other applications, such as foam, where less rubber odour and a whiter colour are highly desirable. Aluminium hydroxide treatedNRL has a low non-rubber content compared to regular NRL and is virtually free of the 14kD and 30kD polypeptide proteins reported to be known Type 1 latex allergens. These characteristics make it the material of choice for applications seeking high-quality, safer end products,” says Dr Matthan in his presentation. Additionally, Vytex NRL contains no known or suspected human carcinogens, said Dr Matthan, concluding that the 100% renewable resource latex grade provides a “safer and healthier environment for consumers, workers and the planet.”
T h e “ b i o de g rad able” c laim for latex balloons i s sl a m me d b y Balloon s Blow, a non-p ro fit o r g a n i sa t i o n b as ed in Florid a, U S, an d which c a m p a i g n s a g a inst balloons being released into t h e e n vi r o n m e nt. It s aid th at wh ile N R l at ex may b e b i o d e g r a d a ble, the chemicals, plasticisers and a r t i f i c i a l d y e s added into the material shrivel l a t e x ’s b i o de g r ad ability fac tor.
M
Latex balloon pollution is a growing problem says US-based group, Balloons Blow
M o r e o v e r , l i kening latex’s biodegradability t o a n o a k l e a f i s “m is lead in g”, s tated B a lloons B l o w o n i t s w e b s ite. It ex p lained , “Oak leaves a r e v e r y d u r a b l e. They can take four years to d e c o m p o s e a n d that means balloons have plenty o f t i m e t o i n j u r e or kill.” I t a l s o a d d e d that the remaining shreds from a bu r st b a l l o o n c ould be m is taken by animals f o r f o o d – a g a ffe that could potentially block t h e d i g e s t i v e t ract of the animal, leading to s t ar v a t i o n o r d eath, or both.
“…likening latex’s biodegradability to an oak leaf is misleading..” I t sa i d t h a t s ea tu rtles p artic u larly are p r o n e t o t h i s f atal ingestion. “They naturally p r e y o n j e l l y f i sh, which balloons can easily be m i st a k e n f o r, even with hum an eyes ,” t h e e n v i r o n m e ntal conservation group said. B a l l o o n s Bl o w s eeks to rais e awaren es s ab out p o l l u t i o n f r o m balloon s , whic h it s aid is a “ gro w i n g pr o b lem and one th at n eed s to b e a d dr e sse d. ” 7 N OV E M B E R / D E C E M B E R 2 015
www.rubberjournalasia.com