Brominated Flame Retardants: Cause for Concern?
The European Union (EU) established the REACH system (Registration, Evaluation, Authorization and Restriction of Chemicals) and the Restriction of Hazardous Substances (RoHS) an integrated system for Registration, Evaluation and Authorisation of Chemicals and establishing a European agency for these products. This system requires companies that manufacture and import chemicals to assess the risks arising from their use and take the necessary measures to manage any risk to be identified.
The burden of proof with regard to the safety of chemicals manufactured or sold is on the industry. The regulation aims to ensure a high level of protection of human health and the environment, as well as to strengthen the competitiveness of chemical innovation.
My focus was on flame retardants.
What are flame retardants?
Flame retardants are added to certain components, printed circuit boards (PCB), plastic containers and cables, to reduce their flammability for example, they prevent or reduce the possibility of a fire starting and spreading flame.
There are several types of flame retardants, they are divided between those containing chlorine and bromine compounds (also known as halogenated flame retardants), those containing phosphorus and nitrogen compounds and inorganic flame retardants.
The halogenated flame retardants Brominated Flame Retardants (BFRs) are found in many household products, such as furniture, computers and other electrical equipment. They are designed to protect homes and offices from the effects of fires by slowing the rate at which objects burn.
Some types of brominated flame retardants are:
Why ban flame retardants?
These compounds accumulate in the food chain (bio-accumulation) and so are eventually consumed by humans. Exposure can also occur via skin contact or inhalation. Some of these compounds are considered harmful to certain organs and DNA, as well as causes of degenerative diseases and cancer.
Some PBDE compounds decompose in the environment forming, thus, more toxic compounds. The PBDEs can be transferred from materials treated with flame retardants and their environmental effects be long lasting. The PBBs can particularly affect the endocrine (hormonal) system in animals. Similarly, some kinds of chlorinated flame retardants, normally used in plastics, are considered toxic.
The substitution of brominated flame retardants (BFRs)
The BFRs are used in a wide range of consumer products: electronics, textiles, foam for upholstery, carpets and building materials – all jobs where the risk of fire requires attention. The increase in the use of plastic and synthetic combustible materials has contributed to growth in the use of flame retardants.
With increasing evidence of the dangers of flame retardants in the late ’80s, particularly PBBs (polybrominated biphenyls) and PBDEs (polybrominated diphenyl ethers), Germany, Denmark, Holland and Sweden have begun to restrict and prohibit their use. In a mission statement in 1989, the chemical and plastics manufacturers in Germany stated that they would not produce or use PBDEs.
Has the electronics industry found alternatives to BFRs?
The electronics industry has begun to find alternatives, ranging from material substitution (replacement of halogenated flame retardants with non-halogen) to exchange functional (replacing plastic cases with metal).
Apple does not use RFB in the plastic cases of its products.
Sony Europe has begun to find safer substitutes for halogenated flame retardants. Sony has developed halogen-circuit boards used in television sets, VCRs and DVD players in Europe. The printed circuit boards use a resin material that is itself flammable. Sony’s engineers have adopted a structure containing a resin with nitrogen to increase resistance to heat.
Samsung Electronics Co. has developed a “green” semiconductor that does not use halogen compounds or toxic substances like lead, chlorine and bromine. The company was the first to develop a packaging and a form that does not contain lead or halogens. The alternative has improved the quality of the product and has saved 960 million won (684,000 euros). Samsung has publicized its efforts on the replacement to increase its image as an environmentally friendly company.
National / Panasonic (Matsushita) has joined forces with other major manufacturers to develop alternative electric cables and plastic compounds that contain no halogens. In September 1999, they began to market the first wide screen TV without halogen compounds.
NEC, a leading manufacturer of mobile phones, office equipment and personal computers, aims to abandon the use of halogenated flame retardants by 2011.
IKEA prohibits a large number of hazardous materials in its product lines, including azo dyes in textiles and has totally banned the RFB in their products and PVC. IKEA chooses textiles and materials which by their nature are difficult to ignite and can often completely avoid the use of chemical protection from the flames thanks to new materials, such as linings of non-woven materials that are inherently flame retardant.
Matsushita website: http://www.semicon.panasonic.co.jp/lead-free/eindex.html ENDS Report 270, Chemical Firms Move to block shift to bromine-free PCs ENDS Report 308, September 2000. NEC unveils circuit boards free of halogen or phosphorus compounds Personal meeting with Magnus Bjork, IKEA, the Brominated Flame Retardants and Foam Furniture Conference and Roundtable: EPA 9. San Francisco, April 2003
Assess the safety of chemical alternatives to BFR
The German Environment Protection Agency (UBA) has examined the toxicity to humans and the environment of 13 flame retardants, with the objective to assess the feasibility of substitution with less hazardous compounds. They selected red phosphorus, ammonium polyphosphate and aluminum trihydroxide as alternatives less problematic for the environment. Red phosphorus can technically be used in a variety of polymers to meet even the most stringent fire safety standards, although it might not work for all applications.
The LU has emphasized that “it is encouraging that there is a general trend towards abandoning the use of halogenated flame retardants in products, replacing them with less hazardous compounds or through the redesign of systems flame retardants, for example by creating more distances from potential sources of heat. “
The results of these surveys are summarized in Table 1.
I. Ban recommended
- Decabromodiphenyl ether
- Tetrabromobisphenol A (additive)
- Tetrabromobisfeneolo A (reactive)
- Tri (chloropropyl) phosphate
III. Property issues:
- Sodium borate decahydrate
- Antimony trioxide
IV. No advice possible because of gaps inknowledge of phosphate:
- Bis (pentabromofenil) ethane
- Pirovatex new CP
- Melamine cyanurate
V. Unproblematic use :
- red phosphorus
- Ammonium polyphospha
- aluminum trihydroxide
UBA (2003). Precautionary Risk Assessment and Risk Management of Chemicals. Part 1: New Strategies for the Ecological Risk Assessment and Risk Management of Substances. http://www.umweltbundesamt.de/index-e.htm
The BFRs represent major industrial chemicals which use has increased dramatically over the past few decades. They are produced to prevent fires and thus can have a direct and obvious benefit.
However, concerns are being raised because of their persistence, bioaccumulation, and potential for toxicity, both in animals and in humans. Production and use patterns are different in various parts of the world. There is clearly a need for more systematic environmental and human monitoring to understand how and where these chemicals are being released into the environment, and what is happening to them once they enter the environment.
What fate and transport processes are involved in their entrance into the environment?
Are the commercial products breaking down in the environment or in biota?
Is food the major pathway, as is true for many other POPs, or are there other potential sources?
Once we understand what the exposure levels are in both people and wildlife, what should be our level of concern?
Our toxicology database is inadequate to truly understand the risk. Many of the studies that do exist involve the commercial mixtures, which do not represent human exposure.We need studies that focus on the congeners, and potentially their metabolites and/or breakdown products, present in people and wildlife in order to understand the risk from exposure to BFRs.