Flame retardants are chemical substances used in furniture, plastics, building materials, several household products and consumer goods to reduce their flammability. Their widespread use has resulted in measurable concentrations of the compounds or their residues in the environment, biota and human biological samples. The previously used brominated flame retardants were found to be persistent and to have bioaccumulative and neurotoxic potential, which raised public awareness. The use of the emerging organophosphorus compounds have increased after phasing out some brominated flame retardants. The chemical properties and health impacts of the organophosphorus flame retardants have not been studied to the same extent. The effects on public health and the environment due to the exposure from their widespread occurrence are therefore unclear.

The aim of this study is to analyse exposure levels of the organophosphorus flame retardants TBP, TPP, TDCIPP and TBOEP in urine samples from a Swedish population of young men. The samples were collected through the enrolment for military service. Urine samples from year 2000, 2004, 2009 and 2013 were analysed for selected biomarkers of exposure with LC-MS/MS. The statistical analysis focused on temporal trends of the measured exposure levels.

The metabolites DBP, DPP and BDCIPP were found in concentrations above LOD (0.03 – 0.1 ng/ml) in the majority of the samples, and DPP in all samples. BBOEP were only found above LOD in some samples and in very low concentrations. There was a statistically significant decreasing trend for the concentrations of DBP over time