A number of potentially toxic chemicals were found in common cold-pressed seed oils. Seed oils tested included poppy seed oil, rapeseed oil, sesame seed oil, pumpkin seed oil, and others. Chemicals detected included Polycyclic Aromatic Hydrocarbons (PAH), PCBs, flame retardants and pesticides. While concentrations of most chemicals were low, high levels of the organophosphate pesticide chlorpyrifos were detected. The reason for this is many pesticides are fat soluble, and therefore, accumulate in fatty-tissues inside the plant. Other pesticides detected include - Pirimiphos methyl - DDVP and DDT.
The aim of this study was to investigate levels of polychlorinated biphenyls (marker and dioxin-like congeners), polycyclic aromatic hydrocarbons (EPA 15 + 1), polybrominated diphenyl ethers (14 predominant congeners) and pesticides (74 compounds) in various cold-pressed vegetable oils. Poppy seed oil, rapeseed oil, sesame seed oil, pumpkinseed oil, hempseed oil, linaire oil, borage oil and evening star oil were investigated. Results of this study revealed that concentrations of PCBs, PBDEs and PAHs were low in majority of the investigated samples. However, high concentrations of organophosphorus insecticides were found. Chlorpyrifos methyl and pirimiphos methyl were the pesticide residues most commonly found in the studied oils. Concentration of 15 + 1 EPA PAHs was within the 17.85 - 37.16 ug kg-1 range, concentration of (marker) PCBs varied from 127 to 24,882 pg g-1, dioxin-like TEQ values were below 0.1 pg TEQ g-1. Concentration of PBDEs was below LOQ in most cases.