Determination of chlorinated paraffins and olefins in plastic consumer products of the Swiss market

Abstract

Chlorinated paraffins (CPs) are plastic additives, which are targeted by international regulatory entities due to their persistence, bioaccumulation, potential for long-range environmental transport and adverse effects. In this work, CPs were analyzed in plastic consumer products of the Swiss market collected in 2021. Up to 144 plastic samples were pre-screened with a GC-ECD method. Plastic samples containing CPs (32, 22%) were further analyzed at homologue level by an LC-APCI-Orbitrap-HRMS method. Respective mass spectrometric data were extracted and evaluated with the CP-Hunter program at the rate of seconds per sample. Qualitative analysis of the LC-HRMS method revealed distinctive CCl-homologue distributions of both chlorinated paraffins and olefins (COs), highlighting the diversity of CP-mixtures present in the Swiss market. The presence of C- to C-homologues in plastic consumer products is reported herein for the first time. Based on the specific fingerprints and the parameters deduced, these samples were grouped with a principal component analysis (PCA). Three industrial strategies were identified in the manufacturing of CP-containing plastics to either comply with or circumvent regulations. These strategies included the avoidance of the SCCP-fraction (type-A), the indiscriminate use of complex technical CP-mixtures (type-B) and the combination of technical CP-mixtures of different carbon-chain lengths and chlorination degrees (type-C). Results showed that the most used strategy was type-B and a partial substitution of SCCPs by MCCPs and LCCPs. Quantitative analysis exhibited that the SCCP content of 20 (14%) out of 144 plastic samples exceeded the Swiss legal limit of 1.5 mg SCCPs per g of plastic. The CCl-homologue distribution of these plastic samples were type-B and type-C. Therefore, regular monitoring should be conducted to ensure that the composition of plastic products adheres to current regulations.