When I was pregnant with my first child in 2008, the nurse who taught our pregnancy class recommended that we use Dreft detergent. One of her reasons was that they don’t strip clothes of their flame retardants. At which point, I raised my hand and asked, “but don’t we want to avoid flame-retardant exposures?” Consider this a 12-year overdue answer to my own question.
What are flame retardants?
Flame retardants are chemicals that are added to manufactured goods to prevent the start or slow the spread of fire. They are common in many types of consumer and industrial products and have been in global use since the 1970s.
Hundreds of chemicals can act as flame retardants, and they can be divided into categories based on their chemical structure and physical properties. There are two primary classes in current use:
- brominated flame retardants
- polybrominated biphenyls (PBBs)
- polybrominated diphenyl ethers (PBDEs)
- organophosphate flame retardants (OPFRs)
Both brominated and organophosphate flame retardants are part of a group of chemicals called persistent organic pollutants (POPs). (These also include other chemicals of current concern known as PFAS.) These chemicals have been called “forever chemicals” because they are persistent and bioaccumulate. This means they stay in the environment and our bodies for a very long time.
PBBs were introduced in the 1970s and 1980s to replace other flame retardants when their effects on human health and the environmental impacts became known. Similarly, PBDEs replaced PBBs when PBBs were phased out after the PBB accident in St. Louis, Michigan made it clear that these chemicals also posed a major health risk. In 1973, the Michigan Chemical Company (owned by Velsicol chemical) accidentally mixed Firemaster (a PBB flame retardant) into cattle feed. As a result, almost all of the population of Michigan’s lower peninsula consumed meat, milk, and eggs that were highly contaminated with PBBs. This has been called “the most costly and disastrous accidental contamination ever to occur in United States agriculture.”
Since the voluntary phase-out of brominated flame retardants started in 2004, OPFRs have been adopted as replacements, but are not necessarily safer. These chemicals have similar profiles for persistence, bioaccumulation and toxicity. This is a case of regrettable substitutions where toxic chemicals are replaced but the replacement is as toxic or more toxic than what it replaced. For example, when manufacturers removed BPA from baby products, they replaced it with BPS which unfortunately may have similar properties and similar toxicity. The replacement of PBBs with PBDEs and then the replacement of PBDEs with OPFRs highlights why decisions about which chemicals we ban AND their replacements need to be guided by evidence.
With a lack of federal action, in 2018, California passed a ban on most flame retardants in children’s products, mattress foam and upholstered furniture, above 1000 ppm. This overdue change identified classes of chemicals, rather than individual chemicals, which may finally help to end the game of flame retardant whack-a-mole. Other states have passed varying levels of restrictions. However, not all states have adopted these bans yet. Fortunately, a focus on these chemicals in the 2000s and 2010s has resulted in decreased new exposures, but manufacturing of brominated flame retardants has been fairly stable.
To me, one of the most shocking things about these replacements is that some of them bear the brand name Firemaster. One would think that this brand name would be retired, but companies continue to use this name.
What are the benefits of flame retardants?
Flame retardants are used to meet flammability standards in a wide range of products including building materials, electronics, furniture, and children’s clothing. The fire safety benefit of these chemicals is unclear at best, and many scientists feel the data supporting their use is flawed or misinterpreted. In short, the need for these chemicals may have been exaggerated by industry lobbyists.
Flame retardants have the added problem of producing toxic gases when there is a fire, making fires more dangerous. As a result, the International Association Of Fire Fighters “believes there is a need for modern fire safety that is toxic free and does not expose our members to the carcinogens that are contributing to the high rates of cancers in the fire service.”
Since the benefits are unclear, we should have a lower risk tolerance for the use of these chemicals and should question whether they are necessary for each application.
I find it useful to think about reducing exposure to potentially toxic chemical hazards in two categories.
- Applications that are unnecessary and could be stopped. This may be the case for many uses of flame retardants in consumer products.
- Applications that are necessary but should be limited and heavily regulated to ensure chemicals are contained and contamination of surrounding areas is limited. For these applications, safe alternatives should be developed wherever possible. This may apply to certain manufacturing uses of flame retardants.
In this case, it seems that in many current applications, these flame retardant chemicals are not as necessary as the manufacturers claim. And when they are needed, we should be working to develop less toxic options.
Who is exposed to flame retardants?
As a reminder, a hazard is anything with the potential to cause harm and risk measures the likelihood of harm occurring. Hazards only become risks when there is exposure. In this section, I will focus on exposure levels and in the next, I will go over the risks of those exposures.
The groups with the highest exposure levels are those exposed occupationally and those who live near manufacturing sites. For example, as a result of the PBB contamination in Michigan, 60% of Michiganders have PBB levels above the 95th percentile of the general population as measured in the CDC’s National Health and Nutrition Examination Survey (NHANES). (The 95th percentile level represents the exposure level that 95% of people are below; the 50th percentile level is the level that 50% of people are below). Fortunately, new exposures to PBBs are low, but the effects in this community will be seen for decades.
Flame retardant exposure in the general population is widespread but at lower levels than it is for those who are exposed occupationally or who live near manufacturing sites. Thus, the risk to the general population is lower. For example, according to the most recent results of the National Health and Nutrition Examination Surveys, nearly all samples analyzed contained detectable levels of least 1 of the PDBEs measured. PBBs were not measured in the most recent NHANES.
It is important to remember that these levels alone only measure exposure and they do not tell us what the health effects of these exposures are. By measuring exposure levels through biomonitoring studies such as NHANES and the PBB registry, scientists establish reference values to determine what exposure levels pose a minimal health risk. These studies are also important for labs like mine to identify doses to use in our studies in animal and cellular models that are relevant to human exposures. However, with these chemicals, based on their similarity to other chemicals, it seems backward that we only look for harm after people are exposed. We do not need to continue this decades-long game of whack-a-mole with each individual chemical if we know that this entire group behaves similarly.
What are the risks of exposure to flame retardants?
In highly exposed communities like those in the PBB registry, health effects are clear, as summarized on the PBB registry research page (with citations listed there).
- Some women with high exposure to PBB had fewer days between menstrual periods, more days of bleeding and lower estrogen levels. However, there was no evidence that these women had reduced fertility.
- There were a few more breast cancer cases among women with high exposure to PBB than expected.
- Chemical workers were more likely to have abnormal thyroid hormone levels.
- PBB was transferred to children in the womb and through breast milk. Children who were born after contaminated products were removed from farms had PBB detected in their blood, and those who were breastfed were much more likely to have PBB in their blood.
- On average, breastfed daughters of women with high PBB exposure started menstruating a year earlier than unexposed girls.
- Daughters of women with high exposure to PBB were more likely to experience a miscarriage.
- Sons of women with high exposure to PBB were more likely to report a genital or urinary condition.
Human health effects from PDBEs at lower levels are unclear, but animal studies suggest that they may have effects on the thyroid, neurodevelopment, the liver, and the reproductive system (summarized in the NHANES Fourth Report). In addition, given that these are persistent chemicals, there are significant concerns about toxicity, even at these lower doses, during critical periods of development – mainly during pregnancy and early childhood – when sensitivity to toxic exposures may be higher.
Am I worried?
I am not particularly worried about my family’s risk from these chemicals. That said, since we moved to Michigan, with its history of PCB and PBB contamination and the current PFAS contamination a few miles up the road, we did install a reverse osmosis filter system on our kitchen sink to filter most of the water that we use for cooking and drinking.
I try to take a broad view as an individual and consider this one low-level exposure within the entire landscape of our exposures. We can mitigate the effects of many exposures by eating lots of fruits and vegetables, not smoking, and getting regular exercise. We are privileged to be able to afford a reverse osmosis filter, to purchase lots of produce, to belong to a gym and take our kids to activities to keep us moving and active, to replace and buy new products without flame retardants, and to live in a place without a lot of air pollution.
However, just because I am not worried about my own exposure to these chemicals does not mean I am not worried. I am worried about the exposure of the people who work directly with these chemicals. I am worried about the communities near these plants with very high levels of exposure. I am worried about the persistence in the environment and the ongoing exposures in areas like St. Louis, MI and other communities around chemical plants. I am worried about exposure in groups that do not have access to the same things that I do. This is not about me as an individual, it is about the health of everyone. Everyone deserves a safe environment, not just those who can afford to create one.
What can you do?
- Avoid children’s clothes with flame retardants. These are often labeled with a big tag. Natural fibers like cotton are more likely to have flame retardants added. Some artificial fibers are naturally flame retardant and don’t require the addition of these chemicals.
- I definitely did not use Dreft! Also, I wanted unscented detergent anyway.
- Buy products (electronics and furniture) that do not contain flame retardants. A quick Google search can help you identify brands that do not use any flame retardants, not just those that have removed and replaced PBDEs.
- Install an activated carbon filtration system or reverse osmosis system in your house, especially if you are on well water. You can also get your water tested first to see if this is necessary. (Note: Charcoal filters do not remove all PFAS chemicals from your water – these are related chemicals)
- Clean your air ducts regularly to reduce indoor dust levels. Vacuum often.
- Wash your hands and your children’s hand often (also helpful for flu, colds, and coronavirus)
Reducing my exposure to flame retardants can reduce risks from this specific exposure, but I can also do a wide range of other things that will also mitigate risks of many exposures (see all those big trees in the risk landscape graphic). This includes eating a diet rich in fruits and vegetables, avoiding exposure to cigarette smoke (and vaping), and exercising regularly.
How can I help protect at-risk populations?
However, this is less about people like me and more about vulnerable populations. To reduce exposure to those most at risk:
- Avoid products that contain any flame retardant to reduce demand. As long as there is a demand for production, there will be communities that are exposed at very high levels due to geography alone.
- Push for regulations to reinstate the Superfund tax. The Superfund program is designed to investigate and clean up contaminated sites. It was originally funded primarily by a tax on “potentially responsible parties”. However, in 1995, Congress did not renew this tax. Now the cost of cleanup is borne by taxpayers and not the companies who contaminated these sites. As a result of this and extreme budget cuts to the EPA in recent years, the number of cleanups has dropped drastically.
- Support politicians who supported reform of the Toxic Substances Control Act, and continue to support science-based policy and a strong and well-funded EPA and CDC. Regulatory measures are particularly important since we are seeing the same patterns emerge in how we are responding to PFAS contamination.
- Support environmental justice reforms that address the lack of access to mitigating exposures and the increased levels of harmful exposures in at-risk communities. If you are able, join local organizations to help these communities based on their specific needs.