Migration of plasticizer from poly(vinyl chloride) milk tubing

Milk samples were collected from a dairy in Norway at various stages of the milking process in order to assess the extent of migration of di(2-ethyl hexyl)phthalate (DEHP) from plasticized tubing used in commercial milking equipment. In control milk samples obtained by hand milking, DEHP contamination was below 5 micrograms/kg, whilst for machine milking, concentrations in the milking chamber for each individual cow averaged 30 micrograms/kg and rose to 50 micrograms/kg in the central collecting tank. Retail pasteurized skimmed milk samples from Norway were found to contain 20 micrograms/kg DEHP, and two retail cream samples contained 1200 and 1400 micrograms/kg of DEHP, reflecting the association of plasticizer with the fat phase. Retail whole milks from the UK contained 35 micrograms/kg of DEHP. This contamination is believed to originate from environmental sources as DEHP plasticizer was not used in the milking equipment.