Yes, flame retardants are toxic. These chemicals, added to furniture foam, electronics, and building materials to slow the spread of fire, are linked to hormone disruption, lower IQ in children, reproductive harm, and potential cancer risk. The troubling part is that exposure doesn’t require direct contact with a burning product. Flame retardants leach out of everyday items and accumulate in household dust, where you breathe and ingest them daily.
What Flame Retardants Do in the Body
Flame retardants don’t stay locked inside the products they’re added to. They migrate into air and dust, enter the body through ingestion, inhalation, and skin contact, and then interfere with some of the body’s most important signaling systems. The primary concern is endocrine disruption: these chemicals mimic or block hormones that regulate growth, metabolism, reproduction, and brain development.
One major class, polybrominated diphenyl ethers (PBDEs), looks structurally similar to thyroid hormones. Their breakdown products bind to thyroid transport proteins and thyroid receptors, essentially hijacking the system your body uses to regulate metabolism and brain development. Some also bind to estrogen receptors, adding reproductive disruption to the list. The newer organophosphate flame retardants (OPFRs), introduced as “safer” replacements after PBDEs were phased out in 2005, affect hormone levels and reproductive function through similar pathways. Because they share a chemical backbone with organophosphate pesticides, they also carry potential for neurotoxicity.
Some flame retardants also activate fat cell development pathways, which has raised concerns about a possible link to obesity, though research on that connection is still developing.
Effects on Children’s Brain Development
The strongest and most alarming evidence involves children exposed before birth. Flame retardants cross the placenta, accumulate in placental tissue, and alter how the placenta produces and transports serotonin, a chemical critical for early brain wiring. In animal studies, organophosphate flame retardants disrupted serotonin-related gene activity in the placenta and caused abnormal serotonin nerve growth in the fetal brain, with male offspring particularly affected.
In human studies, the cognitive effects are measurable. In a New York City cohort, prenatal PBDE exposure was significantly associated with lower IQ scores in children at age 4. A California study (the CHAMACOS cohort) found that a tenfold increase in combined PBDE levels corresponded to a 4.7-point drop in full-scale IQ at age 7. Similar patterns emerged for PCBs, a related class of persistent chemicals: each 1 nanogram-per-gram increase in placental PCB concentration was associated with a 3-point IQ reduction.
Beyond cognition, exposed children show more behavioral problems. Higher prenatal levels of certain PBDEs are associated with increased externalizing behaviors, things like aggression and attention difficulties, measured at ages ranging from 13 months to 8 years. The newer organophosphate replacements show suggestive evidence of reduced cognition and behavioral issues as well, meaning the switch away from PBDEs hasn’t necessarily solved the problem.
The “Safer” Replacements Aren’t Safe
After PBDEs were phased out due to their persistence in the environment and accumulation in human tissue, manufacturers turned to organophosphate flame retardants. These chemicals break down faster in the environment, which sounds like an improvement. But in toxicity comparisons, organophosphate flame retardants affect development and reproduction at concentrations similar to the older PBDEs. The main difference is that PBDEs appear worse for neuromuscular function specifically, while the newer chemicals carry their own neurotoxic and reproductive risks.
This pattern of replacing one harmful chemical with a slightly different but still harmful one is sometimes called “regrettable substitution.” The core problem isn’t any single chemical. It’s that the entire approach of embedding biologically active chemicals into consumer products creates ongoing, low-level exposure for everyone in the household.
How Long They Stay in Your Body
Some flame retardants leave the body relatively quickly. Others do not. Polybrominated biphenyls (PBBs), a related class of brominated flame retardants, have an estimated half-life in human blood of 10.8 years. That means if you have a measurable level today, half of it will still be circulating a decade from now. For someone with a moderate initial exposure, it could take more than 60 years for blood levels to drop below detectable limits. PBDEs, while somewhat shorter-lived, still persist in fat tissue for years. The organophosphate replacements leave the body faster, typically within days, but because exposure is continuous through household dust, your body is constantly being re-exposed.
Cancer Risk
The cancer evidence is less definitive than the endocrine and neurodevelopmental data, but some flame retardants have drawn concern. The International Agency for Research on Cancer has evaluated several flame retardants. Tris(2-chloroethyl) phosphate and chlorendic acid, both used as flame retardants, are classified as possibly carcinogenic to humans. Several others evaluated by IARC could not be definitively classified due to insufficient evidence, which means they haven’t been cleared of cancer risk either.
The EPA has taken regulatory action based on the combined toxicity picture. In 2021, it prohibited the manufacture, import, and distribution of decaBDE (a widely used brominated flame retardant) for most uses, with additional restrictions and water-release prohibitions added in 2024. Another chemical, PIP (3:1), an organophosphate flame retardant found in plastics and electronics, was similarly restricted.
Where Exposure Happens
Household dust is the primary route of exposure for most people. Flame retardants slowly off-gas from polyurethane foam in couches, mattresses, and carpet padding, then bind to dust particles that settle on floors, furniture, and hands. PBDEs are among the most commonly detected chemicals in house dust, alongside lead and phthalates. Young children face the highest exposure because they spend more time on floors and put their hands in their mouths frequently, which is particularly concerning given the neurodevelopmental risks.
You also encounter flame retardants through food and water, as these chemicals make their way into the broader environment, but for most people the dust pathway contributes a substantial share of total exposure.
Reducing Your Exposure
You can meaningfully lower flame retardant levels in your home and body through a few practical steps. Frequent hand washing reduces body burdens of PBDEs. Vacuuming with a HEPA filter makes a measurable difference: one study found that a single week of enhanced cleaning, including HEPA vacuuming, lowered urinary levels of organophosphate flame retardant metabolites in home occupants. Replacing old foam furniture is also effective, as older couches and chairs manufactured before 2014 are more likely to contain flame retardants.
When buying new upholstered furniture, look for the TB117-2013 label, which indicates the foam does not require flame retardant treatment to meet fire safety standards. Avoid products with the older TB117 label, which typically means flame retardants were added to the foam. This labeling distinction applies primarily to furniture sold in the United States, where California’s flammability standards historically drove manufacturers to add these chemicals to products sold nationwide.
Keeping dust levels low through regular wet mopping and dusting with a damp cloth, rather than dry dusting that sends particles airborne, also helps. These aren’t dramatic interventions, but given that exposure is continuous and cumulative, consistent small reductions add up over time.