The scientific community has long believed that polymers—very large molecules—are too big to migrate out of products into people and therefore pose no health risks. As a result, polymers have largely evaded regulation. For example, polymers are exempt from the major toxics acts: Toxic Substances Control Act in the U.S. and REACH in the E.U.

However, a study published today demonstrates that polymers used as flame retardants can break down into smaller harmful chemicals.

The chemical producers and their trade groups promote polyBFRs as environmentally friendly and non-hazardous substitutes for banned monomeric flame retardants (e.g., hexabromocyclododecane and decabromodiphenyl ether) to meet flammability standards for electronics, building materials, and vehicles. However, real-world fire-safety benefits for many of these standards have not been demonstrated.

The study also has implications for other types of polymers used in consumer products, such as per- and polyfluoroalkyl substances (PFAS). PFAS polymers have been put into textiles, including children’s uniforms, food packaging, and cosmetics, to name a few uses.