Chemical additives in weathered microplastic in the marine environment: occurrence and risk

A Nordic project identified and measured residues of chemical additives in polyurethane (PUR) and polyvinyl chloride (PVC). Measurements were done in new plastic, and in plastic weathered for four months in Samnangerfjorden near Bergen. Targeted chemical analysis with GC-Orbitrap was performed for identification and GC-MS analysis for quantification. Four plasticizers were detected in PUR and three in PVC, before and after weathering: Dibutyl adipate, N-butylbenzenesulphonamide (only in PUR), dibutyl phthalate, and di-2-ethylhexyl phthalate (DEHP). Maximum concentrations were approx. 1000 ng/g plastic. Also triphenyl phosphite and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate were identified. Risk quotients for copepods, cod and fulmar showed low risk. Additionally, non-target screening with GC-Orbitrap identified sixteen chemicals, of which two had hazard classifications.