Flame retardant biomarker changes with furniture replacement after flammability standard update

Upholstered furniture has been a major source of flame retardant (FR) exposures in the United States. However, the California update to furniture flammability standards has allowed compliance without relying on chemical additives. We investigated whether FR biomarkers would decrease in participants who replaced furniture foam or upholstered furniture with items manufactured after the policy change. Building off previous work demonstrating decreased dust FR concentrations after furniture replacement, we collected urine and blood from 25 participants prior to furniture replacement and approximately one year after and from a comparison group (n = 28) over a similar time frame. Serum was analyzed for 19 polybrominated diphenyl ethers (PBDEs) and urine for 3 metabolites of organophosphate FRs (OPFRs). For BDE-47, BDE-99, and BDE-100, time to decline by half was 1.9-3.9 times longer in the comparison group than the replacement group (equivalent to 1.4 years (median) in the replacement group versus 2.6-5.2 years in the comparison group). For BDE-153, times to decline by half were not significantly different. For OPFR metabolites, which are excreted within days after exposure, concentration changes were much more variable. Nonsignificant greater decreases were seen for bis(1,3-dichloroisopropyl) phosphate in the replacement group and for diphenyl phosphate in the comparison group, whereas concentrations remained level or increased for bis(2-chloroethyl) phosphate. Moderate positive correlations were observed for baseline PBDE concentrations with baseline dust concentrations (ρ = 0.58-0.60); OPFRs were less correlated. Magnitudes of change were mostly positively correlated between dust and biomarker concentrations but not significant. Overall, results indicate that updated flammability standards can reduce FR exposures.