Flickering Flames, Lingering Threats

While the use of toxic PBDE flame retardants has declined, concerning levels still linger in our homes, offices, and vehicles. Now, new research raises questions about whether similar chemicals taking their place may leave a dangerous legacy for years to come.

PolyBrominated Diphenyl Ethers (PBDEs), once widely used in furniture foam, electronics, and textiles, have been phased out under international agreements like the 2004 Stockholm Convention. However, the United States still lacks a nationwide ban on their production. Only 13 states have set limitations on the products that can contain these substances. Despite the reduction in production, the lingering presence of these chemicals continues to pose significant health risks to the public.

A first-of-its-kind study by Buyun Liu and colleagues used data from the National Health and Nutrition Examination Survey (NHANES) and found that individuals with the highest blood levels of PBDEs had a staggering 300% increased risk of dying from cancer compared to those with lower exposures. The researchers warn these chemicals may be a hidden driver behind rising cancer rates in the U.S.

While some progress has been made, the patchwork of state-level policies leaves too many Americans at risk from hazardous flame retardants.

Alarmingly, the most common route of exposure is through the dust in our living spaces. Up to 90% of PBDE exposure for the general population comes from ingesting contaminated dust in homes and workplaces. Even as PBDE production wanes, these persistent pollutants continue to be shed from aging couches, electronics, and baby products, drifting through the air we breathe.

Other emerging evidence links flame retardants to a spectrum of health risks, from reduced fertility to intellectual disabilities in children. In a 2020 study, Gaylord and colleagues used data from previously published studies to model the effects of prenatal exposures to PBDE’s on children’s IQ scores. Their findings suggest that even low levels of exposure during pregnancy can have lasting impacts on cognitive development.

While PBDEs fade from use, a new generation of replacement flame retardants raises fresh concerns. A 2024 study by Hoehn and colleagues. found that organophosphorus flame retardants (OPFRs), a class of flame retardants used as a PBDE substitute, is frequently used in the polyurethane foam of newer vehicle seats. In summer temperatures, this chemical is released into cabin air at levels up to 9000 ng/m3—nearly 30 times higher than average concentrations found in homes.

Another study, a 2019 review by Blum and colleagues, raises alarming parallels between the health risks of phased-out PBDEs and their OPFR replacements. The authors found that OPFRs, like PBDEs, are environmentally persistent, accumulate in human tissues, and are increasingly prevalent in indoor dust and air. Several OPFRs show comparable developmental and neurodevelopmental toxicity to PBDEs in lab studies. The researchers caution this may yet become a regrettable case of substitution of one harmful chemical for another.

The researchers recommend more robust research efforts to scrutinize the chemicals we use to replace PBDEs and a more aggressive approach to regulation of these substances. While some progress has been made, the patchwork of state-level policies leaves too many Americans at risk from hazardous flame retardants.