Occurrence, Homologue Profiles and Risk Assessment of Short- and Medium-Chain Chlorinated Paraffins in Edible Vegetable Oils

Dietary intake is the major route of human exposure to fat-soluble and persistent chlorinated paraffins (CPs), which tend to accumulate in lipid-rich foods such as edible vegetable oils. This study investigated the levels of short-chain (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in commercially available vegetable oils and assessed their potential health risks. The concentrations of SCCPs and MCCPs in 29 commercial edible vegetable oils were analyzed using comprehensive two-dimensional gas chromatography coupled with electron capture negative ionization mass spectrometry (GC × GC-ECNI-MS). Dietary exposure levels were estimated through probabilistic assessment integrating analytical results with dietary consumption data from the Chinese Total Diet Study (2017-2020). The margin of exposure (MOE) approach was employed for risk characterization. The average concentrations of SCCPs and MCCPs were 112 ng/g and 139 ng/g, respectively. The highest SCCP and MCCP concentration were found in sesame oil and peanut oil, respectively. Overall, MCCPs levels were generally higher than SCCPs. The estimated daily intakes (EDIs) of SCCPs and MCCPs were 56.06 and 73.63 ng/kg bw/d on average, with high consumers (P95) exposed to 180.91 and 230.49 ng/kg bw/d, respectively. Corresponding MOE at P95 were 1.27 × 10⁴ for SCCPs and 1.56 × 10⁵ for MCCPs. The current SCCPs and MCCPs dietary intake originated from edible vegetable oils did not pose a significant health risk. This study provides the first probabilistic exposure assessment of CPs in Chinese edible vegetable oils, offering current contamination profiles.