Short- and medium-chain chlorinated paraffins in honey from China: Distribution, source analysis, and risk assessment

Chlorinated paraffins (CPs) are industrial chemicals produced in large quantities. Short-chain CPs (SCCPs) were classified as persistent organic pollutants under the Stockholm Convention in 2017. Medium-chain CPs (MCCPs) became candidate persistent organic pollutants in 2021. CPs are now ubiquitously found in the environment. Honey bees can be exposed to CPs during foraging, and this exposure subsequently results in the contamination of honey and other bee products along with colony food production and storage. Here, SCCP and MCCP concentrations in honey collected from Chinese apiaries in 2015 and 2021 were determined. Total CP concentrations in honey from 2021 to 2015 were comparable, but the ratio of MCCPs/SCCPs was higher in 2021 than in 2015. SCCP and MCCP congener group profiles in all honey samples were similar and dominated by C₁₀-₁₁Cl_6-7 and C₁₄Cl_6-7, respectively. MCCP concentrations were also higher than SCCP concentrations in bees, pollen, and wax but not in bee bread, which were all collected in 2021. The order of average CP concentrations was determined as wax > bee > pollen > bee bread > honey. Poor relationships were found between SCCP concentrations in honey and other samples, but a relationship between MCCP concentrations in honey and other samples was observed. Migration tests of CPs in plastic bottles showed essentially no migration into honey during storage. The risks to humans from CPs in honey are low.