Plasticizer contamination in edible vegetable oil in a U.S. retail market

With the wide application of plastics, the contamination of plasticizers migrating from plastic materials in the environment is becoming ubiquitous. The presence of phthalates, the major group of plasticizers, in edible items has gained increasingly more concern due to their endocrine disrupting property. In this study, 15 plasticizers in 21 edible vegetable oils purchased from a U.S. retail market were analyzed using gas chromatograph-mass spectrometry. Di(2-ethylhexyl) phthalate (DEHP) and diisobutyl phthalate (DiBP) were detected in all oil samples. Benzylbutyl phthalate (BzBP), dibutyl phthalate (DBP), and diethyl phthalate (DEP) were detected at a rate of 95.2, 90.5, and 90.5%, respectively. The detection rates for all other plasticizers ranged from 0 to 57.1%. The content of total plasticizers in oil samples was determined to be 210-7558 μg/kg, which was comparable to the content range in oil marketed in Italy. Although no significant difference (p = 0.05) in the total content of plasticizer was observed among oil species (soybean, canola, corn, and olive), the wider range and higher average of total content of plasticizers in olive oil than other oil species indicated the inconsistence of plasticizer contamination in olive oil and a possible priority for quality monitoring. No significant difference (p = 0.05) in the total content of plasticizers was found among glass-bottle (n = 4), plastic-bottle (n = 14), and metal-can (n = 3) packaging, implying that oil packaging is not the major cause of plasticizer contamination. The daily intake amount of plasticizers contained in edible oil on this U.S. retail market constituted only a minimum percentage of reference dose established by US EPA, thus no obvious toxicological effect might be caused. However, the fact that DEHP content in two olive oils exceeded relevant special migration limits (SMLs) of Europe and China might need attention.