Exposure to di-2-ethylhexyl terephthalate in the U.S. general population from the 2015–2016 National Health and Nutrition Examination Survey

Abstract Background Di-2-ethylhexyl terephthalate (DEHTP) is used as a replacement plasticizer for other phthalates, including di-2-ethylhexyl phthalate (DEHP). Use of consumer products containing DEHTP may result in human exposure to DEHTP. Objective To assess exposure to DEHTP in a nationally representative sample of the U.S. general population 3 years and older from the 2015–2016 National Health and Nutrition Examination Survey (NHANES). Method We quantified two DEHTP metabolites, mono-2-ethyl-5-hydroxyhexyl terephthalate (MEHHTP) and mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) in 2970 urine samples by using online solid-phase extraction coupled with isotope dilution-high-performance liquid chromatography-tandem mass spectrometry. We used linear regression to examine associations between MEHHTP and MECTPP and several parameters including age, sex, race/ethnicity, and household income. We also compared the MEHHTP and MECPTP results to those of their corresponding DEHP metabolite analogs, namely mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) and mono-2-ethyl-5-carboxypentyl phthalate (MECPP). Results The weighted detection frequencies were 96% (MEHHTP) and 99.9% (MECPTP); urinary concentrations of the two metabolites correlated significantly (Pearson correlation coefficient = 0.89, p  Conclusions Exposure to DEHTP is widespread in the U.S. general population 3 years and older. These data represent the first U.S. population-based representative background exposure to DEHTP.