Concentrations of perfluorooctanesulfonamides in Canadian total diet study composite food samples collected between 1992 and 2004.

Canadian Total Diet Study composite samples collected from 1992 to 2004 (n = 151) were analyzed for a series of perfluorooctanesulfonamides that are likely breakdown products or manufacturing residuals associated with perfluorooctylsulfonyl phosphate esters. These esters have been incorporated into coatings for paper and paperboard used in food packaging. N-Ethylperfluorooctanesulfonamide (N-EtPFOSA), perfluorooctanesulfonamide, N,N-diethylperfluorooctanesulfonamide, N-methylperfluorooctanesulfonamide, and N,N-dimethylperfluorooctanesulfonamide were extracted using solvent extraction and quantified by gas chromatography-mass spectrometry. Perfluorooctanesulfonamides were detected in the picograms per gram to low nanograms per gram of wet weight range in all food groups tested-baked goods and candy, dairy, eggs, fast food, fish, meat, and foods to be prepared in packaging. The highest concentrations of total perfluorooctanesulfonamides were observed in fast food composites (from less than the method detection limit to 27300 pg/g of wet weight). Concentrations of N-EtPFOSA appeared to decrease over the sampling period (1992-2004) in French fries and other fast food composites; no such trend was apparent in freshwater fish, marine fish, and shellfish composites. A basic estimate of dietary exposure to perfluorooctanesulfonamides suggests that Canadians (>12 years old) are exposed to approximately 73 ng/person/day from these foods.