Impact of household cooking on release of fluorinated compounds PFOA and PFOS from Tefal coated cookware to foods

Abstract

Perfluorinated compounds (PFCs) have taken worldwide attention in recent years. Several PFCs are being used in manufacturing food contact materials, including non-stick coatings (polytetrafluoroethylene (PTFE) or Teflon) for cookware and also their use in paper coatings for oil-and moisture-resistant. PFCs are suggested as a new class of Persistent organic pollutant (POP), where they are chemical stability and do not degrade well naturally hence may accumulate in the body and poses problems for human safety. Thus, it is necessary to assess the migration of PFCs from food contact articles to food under typical cooking conditions. The main objective of this investigation was to study the effect of cooking at prolonged use (repeating for ten times) in household Tefal utensils on leaching PFOA and PFOS compounds from the Teflon layer which coats the inner surface of utensils to food-contact such as tomatoes fruit as the acidic food and white dry beans as the non-acidic food without and with adding of table salt. Also, measurement the surface morphology of Tefal layer before and after cooking by using small shapes as a pattern of Tefal cookware which analyzed by X-ray Diffraction (XRD) and X-ray Microanalysis (EDX), as well Environmental Scanning Electron Microscopy (ESEM). The obtained results indicated that, when the repeat of cooking increased from 1 up to 10 times, the amounts of Perfluorinated compounds (PFOS and PFOA, especially PFOS) were progressively increased in the food contact (tomatoes paste or white dry beans) from the Tefal cookware. On the other side, the addition of table salt to the tested samples at all repeats of cooking (1, 5 and 10 times) caused a highly leaching of perfluorinated compounds from the Teflon layer to food-contact more than the same tested samples at the same conditions without salt. Therefore, the acidic food such as tomatoes paste was more effect on the amounts of both PFOS and PFOA in the food-contact than the non-acidic food. Before that, the ESEM images of coating surface of Tefal layer after repeat of cooking exhibited some damage.