What is it?
Flame retardants are a broad class of chemicals added to furniture foam, electronics, mattresses and textiles to slow the spread of fire. The most studied class, polybrominated diphenyl ethers (PBDEs), were phased out in Europe and the US after evidence of widespread bioaccumulation and harm, but remain in millions of items of older furniture and mattresses. They were largely replaced with alternative compounds, many of which are now showing similar toxicity profiles. The problem is not just the chemicals but the regulatory pattern: one harmful flame retardant is restricted, another takes its place.
What it does to your body
Thyroid disruption
PBDEs structurally mimic thyroid hormones and interfere with thyroid function at very low doses, affecting metabolism, energy and cognitive function.
Neurodevelopmental harm
Prenatal PBDE exposure is linked to lower IQ, attention deficits and hyperactivity in children in multiple epidemiological studies.
Reproductive harm
Endocrine-disrupting effects on sex hormones have been observed in both animal and human epidemiological studies of PBDE exposure.
Cancer
Several PBDE congeners are classified as possible carcinogens by IARC, and thyroid cancer risk has been associated with occupational PBDE exposure.
Immune disruption
PBDEs alter immune cell function and inflammatory pathways, reducing the effectiveness of immune responses.
How widespread is the problem?
PBDEs are found in the blood of virtually all Americans tested in CDC biomonitoring. US levels are 10 to 40 times higher than European levels, reflecting historical differences in flammability standards. A 2021 study found PBDEs in the breast milk of women across 7 countries, including those who had never lived in the US.
Where it hides in your home
Key research
NTP PBDE Toxicology Report
National Toxicology Program concluded that PBDEs are reasonably anticipated to be human carcinogens, with thyroid disruption and neurodevelopmental harm as established effects.
Silent Spring Institute PBDE Breast Milk Study
Found PBDEs in breast milk samples from women in 7 countries, demonstrating that these banned chemicals continue to circulate globally through biological systems.
EPA PBDEs Action Plan
EPA action plan leading to the voluntary phase-out of penta- and octa-BDE formulations, acknowledging widespread bioaccumulation and toxicity.
PBDEs are extremely persistent. They accumulate in fatty tissue and have been found in human breast milk at levels that have increased decade on decade. Eliminating old foam furniture and mattresses is the most important step. Regular vacuuming with a HEPA filter removes settled dust, which is the primary indoor exposure route.