On October 1, ISPA submitted a quantitative human health risk assessment (HHRA) of modacrylic fiber without antimony trioxide to the California Bureau of Household Goods and Services (BHGS). Modacrylic fibers are used in fire-retardant barriers inside mattresses to comply with federal mattress flammability requirements. ISPA was required to produce and submit the study pursuant to a law (CA AB 1059) enacted in 2023, which exempts the fiber from being banned or limited by statutory levels.  

The HHRA followed guidelines established by the U.S. Environmental Protection Agency (U.S. EPA) for conducting conservative and health-protective toxicological risk assessments. Testing determined that expected exposures to modacrylic fiber used in mattresses within a fire-retardant barrier in the normal course of consumer use do not confer a health risk to humans.