Children's Exposure to the Flame Retardant TDCPP in Indoor Environments: A Risk Assessment

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is an organophosphate additive flame retardant used in consumer products. Due to the phase out of the persistent and endocrine disrupting polybrominated diphenyl ether (PBDE) flame retardant commercial mixtures in 2005, the use of TDCPP has increased. However TDCPP is considered a suspected human carcinogen by the Consumer Product Safety Commission (CPSC, 2006), and it has recently been detected in both infant products, residential furniture, and in indoor air and dust particles at levels that are equivalent to, and in some cases higher than, levels of PBDEs (Kolpin et al, 2002 and Stapleton et al, 2009). Levels of TDCPP in indoor dust are particularly worrisome as children are known to have greater exposure to dust relative to adults, and therefore greater exposure to chemicals found in dust, including flame retardants, lead and pesticides (Xue et al, 2007). Due to these facts, more research is necessary to understand the magnitude of exposure that children are receiving to TDCPP in indoor environments and from contact with consumer products. With this in mind, the goal of this research study was to investigate children' exposure to TDCPP in indoor environments, and quantify exposure from both hand to mouth contact and exposure to house dust to compare with exposure limits set by the CPSC and the state of California. In the spring of 2012, a cohort of toddlers and young children residing in and around Durham, North Carolina were recruited into this research study. In every home, a research team collected house dust samples (n=30) and handwipe samples from toddlers. Handwipes and house dust samples were analyzed in the laboratory for several organophosphate flame retardants (OPFRs), including TDCPP, tris (2-chloroethyl) phosphate (TCEP), and tris (1-chloro-isopropyl) phosphate (TCPP), using gas chromatography mass spectrometry (GC/MS). Detection frequencies for TCEP, TCPP and TDCPP were 48.8%, 70.5% and 95.3% in handwipes, and 97.0%, 97.0% and 100% in house dust. Based on levels of TDCPP in house dust, the estimated daily dose for children' median exposure to TDCPP was 273 ng/day, and 1242 ng/day for children residing in homes with very high TDCPP dust levels (i.e. 99th percentile). Using levels of TDCPP measured in the handwipes, the estimated daily dose for children' median exposure to TDCPP was 833 ng/day, and 5242 ng/day for children with high levels of TDCPP on their hands (e.g. 99th percentile). California' acceptable daily dose of TDCPP is listed as 5.4 micrograms/day. Therefore, based on our estimates of children' exposure to TDCPP from hand to mouth contact measured here, a small percentage of children may be at an increased risk for cancer.