Are flame-retardant chemicals doing more harm than good?
Talk about a hot issue! Flame retardants in clothing, furniture and electrical equipment are supposed to protect us from fire, but according to some critics, they create more problems than they solve. The argument is that exposure to these chemicals may be linked with a variety of health problems that outweigh any benefit that may be provided by preventing fires.
The cost of fire to society, both in dollars and lives, is huge, so fire prevention should, of course, be on the front burner. Back in 1975, recognizing that every year about 6,000 lives were being lost in the United States to fire with damage about $10 billion in current dollars, the California legislature decided that something had to be done.
A law was introduced requiring certain furniture and some other products, such as children’s clothing, to comply with flammability standards. The basic requirement was that the materials used had to withstand a small open flame for 12 seconds without catching fire. In order to meet that standard, manufacturers began adding chemicals belonging to a family known as polybrominated diphenyl ethers (PBDEs) that prevented quick ignition.
The amounts were not trivial; some sofas contained as much as a kilo of the chemicals. Although the law applied only to California, manufacturers everywhere abided by it because of California’s large customer base. It would have been too expensive to manufacture items differently for California and the rest of the world.
According to statistics provided by the National Fire Prevention Association in the U.S., the total number of fires dropped from almost threequarters of a million in 1977 to fewer than half a million in 2004. The number of deaths was cut in half and property damage costs dropped by about 40 per cent. Just how big a role flame retardants played is hard to determine because smoke detectors were widely introduced and there were numerous changes in building codes. According to some studies, the protection provided by PBDEs was not a big factor.
The introduction of flame retardants was obviously well-intentioned, but as the proverb states, the road to hell is paved with good intentions. By 2004, flame retardants were feeling the heat not only from flames, but from scientific stud- ies. Researchers linked PBDEs to problems in the development of the nervous system, disruption of the endocrine system, fertility issues, behaviour problems and decreased birth weight.
In animals, PBDEs have been associated with decreased levels of circulating thyroid hormones and some human studies have linked blood levels of flame retardants with health problems, but such associations can never prove cause and effect. It may be that people with higher levels of flame retardants in their blood also were exposed to various other chemicals. No adverse effects have been noted in foam or electronic-equipment recyclers or in carpet installers despite these workers having higher blood levels of flame retardants than the average population.
Still, PBDEs raised concerns because they are persistent chemicals and show up in indoor dust, commercially available foods and breast milk. The most troublesome flame retardant seemed to be pentabromodiphenyl ether, which was banned by California in 2004, prompting its manufacturer to voluntarily cease production. Other PBDEs are now being phased out, but because of slow turnover of products that were formulated with them, their long half-life and their potential to bioaccumulate, exposure will continue for many years.
Since susceptibility to hormonedisrupting substances is greatest during infancy, there has been concern about exposure to flame retardants while children are restrained in car seats. Since the time spent in such seats may be considerable, there is the possibility of exposure from skin contact as well as from ingesting or inhaling contaminated dust emanating from the seats. Researchers in New Zealand investigated this issue by estimating exposure based on studies that measured flame-retardant concentration in the air and dust inside cars. On comparing the amounts that could be expected to be inhaled or ingested to animal studies that showed a risk, they concluded that flame retardants in car seats were not likely to cause adverse health effects.
Gymnasts also make for an inter- esting example of continued exposure to flame retardants. Gyms are equipped with foam landing mats and pits filled with pieces of foam to protect gymnasts from injuries, particularly when practising new moves. They commonly joke of “eating pit” after a less than perfect landing, which generally means being covered in dust after plunging into the pile of foam.
The most common foam is made of polyurethane, which is treated with flame retardants according to current fire-safety regulations. It takes a beating in gyms, causing it to slowly crumble and release dust that is laden with flame retardants. This dust may be inhaled or ingested if hands are not properly washed before eating. While no health effects have been noted in gymnasts, concern has been raised because in a study of 11 gymnasts, blood levels of brominated flame retardants were found to be three times higher than in the general population. Nobody is recommending that gymnasts should curtail their activities, but gyms should be emphasizing the importance of washing hands after practice.
The world of flame retardants is set to undergo a significant change because on Jan. 1, California eliminated the 12-second exposure to an open flame test in favour of a requirement that upholstered furniture must not continue to “smoulder” some 45 minutes after a lit cigarette is placed on it. Manufacturers can meet the requirement without the use of fire retardants by choosing appropriate fabrics and fillers.
As expected, the flame-retardant industry opposes this change vehemently, claiming that it will result in an erosion of safety. That’s debatable, as is whether a decrease in exposure to a few compounds with possible hormonal effects will have an impact on our health in a world where exposure to thousands of both synthetic and natural hormone mimics is common. Hopefully, with the elimination of brominated flame retardants, we won’t be going from the proverbial frying pan into the fire.