Short-, medium-, and long-chain chlorinated paraffins in South African indoor dust and cat hair

Abstract

Polychlorinated n-alkanes or chlorinated paraffins (CPs) contain a magnitude of structural isomers and are categorized as short-chain (SCCPs), medium-chain (MCCPs), and long-chain (LCCPs) CPs, according to the carbon chain lengths. In this study the ƩSCCPs, ƩMCCPs, and ƩLCCP concentrations are reported for South African indoor dust and pet cat hair. The median concentrations of the ƩCPs (C₉-C₃₇) ranged from 33 to 663 μg/g for freshly collected dust (FD), 36-488 μg/g for dust collected from household vacuum cleaner bags (VD), and 1.2-15 μg/g for cat hair (CH) samples. MCCPs were the dominant CP group, followed by SCCPs and LCCPs. The ƩMCCP concentration ranged from 13 to 498 μg/g in dust and 0.6-6.5 μg/g in cat hair. SCCPs with shorter carbon chains and lower chlorine substitution were observed in cat hair. LCCPs with carbon chains > C₂₀ were detected in dust and hair samples, possibly indicating the use of wax grade LCCP formulations. Non-traditional Kendrick mass defect plots were used to obtain information on the magnitude of CPs and provide evidence of possible interfering compounds. This is the first report on the occurrence of SCCPs, MCCPs, and LCCPs in the South African indoor environment.

Keywords: Indoor dust; Indoor environment; Long-chain chlorinated paraffins; Medium-chain chlorinated paraffins; Pet cat hair; Short-chain chlorinated paraffins.