FREQUENTLY ASKED QUESTIONS 123

What are the most commonly used BFRs and in what products are they used?

The two most commonly used BFRs are Tetrabromobisphenol A (TBBPA) and Decabromodiphenyl ether (Deca-BDE). These 2 products make up approximately 50% of all BFRs produced and used. TBBPA is the main flame retardant used in circuit boards in computers and other electronic products. TBBPA is also used in the housings of computer monitors. Deca-BDE is commonly used to flame retard plastics in electrical and electronic equipment such as television set casings and the insulation around wire and cable.

What are some of the other products that use BFRs as flame retardants?

The foams for thermal insulation used in building and home construction are typically flame retarded with Hexabromocyclododecane (HBCD). Upholstered fabrics for commercial furniture, cars, and residential furniture in some parts of the world are flame retarded with either Deca-BDE or HBCD. Some roofing materials and coatings are also flame retarded with a BFR.

Is my TV or computer exposing me or my family to BFRs?

It is highly unlikely. The plastics used in TV and computer housings are hard and dense so that substances used in their construction have little opportunity to be released. Also, the BFRs commonly used in these applications do not tend to move from their solid state into a gas form, and so are unlikely to be released into the air around the computer or TV. Monitoring studies have confirmed that TVs and computers are not significant emission sources.

Chemicals called PBDEs have been in the news lately. What are they?

The term PBDEs is an abbreviation for polybrominated diphenyl ethers. Another term for these chemicals is polybrominated diphenyl oxides. PBDEs represent one particular family of BFRs. There are three commercial PBDE products (Octa-BDE, Penta-BDE and Deca-BDE) and the three products differ in their composition, uses, manufactured volume, toxicology, and environmental distribution. Of the three PBDEs, only Deca-BDE remains in widespread commercial use. Because of this, we believe that rather than referring to all PBDEs as if they all had the same properties, it is preferable to state the specific commercial product or the specific identity of the molecule.

What PBDEs have been found in breast milk? Are the levels going up, down or staying the same in various regions around the world?

The PBDEs detected in breast milk are similar to those detected in fish caught in the wild. About 50-70% of the total amount is commonly made up of one specific molecule: 2,2’,4,4’-TetraBDE. The next most common is 2,2’,4,4’,5-Penta-BDE. These specific molecules are major components of one PBDE product: “Penta-BDE”. It’s been reported that total PBDE levels in breast milk collected in Sweden increased during the 1990s’, and peaked in 1997, but this is based on a small number of samples. Time trend data doesn’t exist for other countries in Europe, in the U.S. or Asia. Penta-BDE has since been removed from markets and detection levels are expected to decrease.

How did these compounds get in breast milk?

At this point, we can’t answer this question with any degree of certainty. There simply has not been enough research to positively identify how the women in the studies were exposed. For other environmental compounds, diet is typically the major source. Recent work measuring levels in a typical “market basket” tends to indicate this is also true with regard to “PBDEs”, but at this point it is too early to be certain.

Do the levels in breast milk pose a risk to babies?

Our best information indicates that the levels found in breast milk are hundreds or thousands of times below that which might cause a harmful effect. Leading authorities in the field continue to recommend breast milk as the best source of nutrition for babies.

A number of publications report detecting various BFRs in sediments, fish, birds and other species. What do the levels reported mean?

BFRs detected in the environment include Deca-BDE, TBBPA, HBCD, and various tetra-, penta-, and hexa-BDEs. The amounts and locations of each vary, and depend on the molecule’s properties and the products use. For example, when Deca-BDE is detected, it is usually in sediments near point sources of manufacture or industrial use. This is because Deca-BDE is either not taken up at all by animals, or taken up very sparingly and so does not tend to move in the environment far from its point of release. HBCD, on the other hand, is taken up more efficiently and has been detected in fish and birds. Generally, levels in environmental samples are very low and in the parts-per-billion or parts-per-trillion range.

There’s a lot of speculation in the news about the kind of health or environmental effects that could be caused by BFRs. What effects have actually been found in humans or in animals in the environment?

It’s easy to raise questions in the media and speculate on what might happen. Those raising questions aren’t required to have any particular expertise or to have demonstrated knowledge about the existing database. To date, no human health or environmental effects have been associated with the BFRs detected.

Are BFRs persistent in the environment?

Some BFRs seem to be persistent; others do not. For example, Deca-BDE seems resistant to degradation in sediments, but studies have shown that both TBBPA and HBCD can be degraded in sediments and/or soils. Other BFRs have not been studied to the extent of these products.

Do BFRs accumulate in tissues?

There seems to be a common misperception that BFRs, as a group, accumulate in animal and human tissues. However, studies have shown that this is not the case. Neither Deca-BDE nor TBBPA, which make up 50% of all BFRs sold, accumulate.

Do BFRs affect the endocrine system of humans or animals?

The endocrine system has become an active area of toxicology research in recent years. It is composed of several organs: pituitary, thyroid, parathyroid, pancreas, adrenals, ovaries and testicles, all of which produce hormones that act on other parts of the body to integrate their various functions. No BFR has been shown to affect the endocrine system of humans. Changes in thyroid hormone blood levels in response to the Penta-BDE , HBCD and TBBPA have been shown in rats. However, there was no associated harmful effect in the whole animal, and the mechanism by which the thyroid hormone level was lowered is not believed applicable to humans.

Are BFRs toxic to the nervous system?

Exposure to large, repeated doses of Deca-BDE, TBBPA, or HBCD over either the entire or a substantial portion of the animals’ lifetime has had no effect on their nervous systems. Similarly, no effect on the fetal nervous system was seen when the pregnant females were treated. One group of researchers has reported that 2,2’,4,4’-Tetra-BDE, 2,2’,4,4’,5-Penta-BDE and Deca-BDE can cause behavioral or learning effects when given to 10 or 3 day old mice. Neither mice nor the study design are those typically used to study neurotoxicity. Further, the reported effects could not be reproduced in rats.

Why do people use the term BFRs when the individual BFRs are so different from one another? Can you really talk about them as one homogeneous group?

It is really not correct to imply that all BFRs are alike, because they come in many different types. About the only thing they have in common is that they are all used as flame retardants and all contain bromine as active flame retarding mechanism. Other than Deca-BDE, which is a general purpose FR and used in many different applications, most BFRs have fairly narrow applications due to their different chemical properties. Their different properties in turn lead to differences in toxicology and environmental behavior. As a result, we believe that each BFR should be evaluated and discussed individually.