Peer-Reviewed Publication: Flame Retardants in Children’s Car Seats

Published on September 10, 2019

"Children’s Car Seats Contain Legacy and Novel Flame Retardants"

Environmental Science & Technology Letters 2019, vol. 6, no. 1, 14-20

Authors: Yan Wu, Gillian Z. Miller, Jeff Gearhart, Kevin Romanak, Viorica Lopez-Avila, and Marta Venier

Full text available for purchase here

For this study, Ecology Center researchers teamed up with Dr. Marta Venier's group at Indiana University to test children's car seats purchased in 2018. (Our consumer guide and companion report on this testing can be found here.) Together, we confirmed the presence of a flame retardant chemical never before reported in a product in North America. The study also found trace levels of multiple "legacy" flame retardant chemicals, meaning those that haven't been in use for years due to toxicity concerns. The fact that legacy flame retardants are still showing up at low levels in new products underscores the difficulty of ridding our environment of persistent substances, once introduced.   


Brominated and phosphorus-based flame retardants (PFRs) were measured in foam and fabric samples from 18 newly marketed children’s car seats. The concentrations of two cyclic phosphonates {PMMMPs, 5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphinan-5-yl)methyl methyl methylphosphonate and bis[(5-ethyl-2-methyl-1,3,2-dioxaphosphorinan-5-yl)methyl] methyl phosphonate p,p′-dioxide} were quantitatively measured for the first time in the North American environment and were much higher than those of other flame retardants. Median PMMMP concentrations were 73.6 μg/g, accounting on average for 52% of the total FR concentrations, indicating an intentional addition of PMMMPs during the manufacturing process of these car seats. Two other emerging PFRs [tris(2,4-di-Hi Katie,t-butylphenyl) phosphate (TDTBPP) and resorcinol bis(diphenyl phosphate) (RDP)] were detected for the first time in baby products at median levels of 1.11 and 6.15 μg/g, respectively. Other frequently detected PFRs included triethyl phosphate (TEP), triphenyl phosphate (TPHP), and tris(2-butoxyethyl) phosphate (TBOEP). Among the brominated flame retardants monitored, decabromodiphenyl ethane (DBDPE), with a median concentration of 128 μg/g, was the only halogenated FR measured at levels suggesting intentional use. Other brominated FRs such as hexabromobenzene (HBB) and 2,3-dibromo 2,4,6-tribromophenyl ether (DPTE) were sporadically detected with median concentrations of 0.23 and 0.18 μg/g, respectively. Despite being phased out in the United States starting in 2013, polybrominated diphenyl ethers (PBDEs) were still observed in 75% of our samples, although at modest levels (median total PBDE levels of 0.24 μg/g). Trace PBDE levels suggest background contamination rather than intentional use. The high levels of FRs measured in these children’s car seats together with the negative health effects associated with some of these compounds are a cause for concern for children’s health.