Phthalates in cow's milk: possible contamination pathways at farm level

Phthalates are organic lipophilic compounds which are mainly used as plasticiser. Human exposure occurs mainly via food intake and can cause negative health effects. Phthalates are not only present in food because of environmental contamination, but also as a result of migration from contact materials. This study investigates phthalates in cow’s milk in order to determine their contamination pathways at farm level.The levels of eight phthalates were determined in raw milk samples collected during summer and winter at five farms located in ‘The Kempen’ (Belgium). Both manually and mechanically obtained milk samples were collected. Analysis was performed by GC-MS.The analysis of the mechanically milked samples revealed a difference in average total phthalate level between summer and winter (572 versus 379 μg/kg fat). While total phthalate levels of the different farms during winter were nearly of similar magnitude (291-587 μg/kg fat), a wide range could be observed during summer (95-1550 μg/kg fat). Comparing milk samples within a farm, lower total phthalate levels were found in manually than in mechanically obtained milk (100 versus 179 μg/kg fat). Di(2-ethylhexyl) phthalate, which is the most commonly used plasticiser worldwide, was the most dominating one (79 % of the total concentration in milk from the cooling tank).The results indicate that contamination pathways for phthalates in cow’s milk vary across seasons. An explanation therefore is that the feed composition is different during summer and winter. Comparing manually with mechanically obtained milk samples reveals that the milking equipment is another important contamination pathway.Phthalates are organic lipophilic compounds which are mainly used as plasticiser. Human exposure occurs mainly via food intake and can cause negative health effects. Phthalates are not only present in food because of environmental contamination, but also as a result of migration from contact materials. This study investigates phthalates in cow’s milk in order to determine their contamination pathways at farm level.The levels of eight phthalates were determined in raw milk samples collected during summer and winter at five farms located in ‘The Kempen’ (Belgium). Both manually and mechanically obtained milk samples were collected. Analysis was performed by GC-MS.The analysis of the mechanically milked samples revealed a difference in average total phthalate level between summer and winter (572 versus 379 μg/kg fat). While total phthalate levels of the different farms during winter were nearly of similar magnitude (291-587 μg/kg fat), a wide range could be observed during summer (95-1550 μg/kg fat). Comparing milk samples within a farm, lower total phthalate levels were found in manually than in mechanically obtained milk (100 versus 179 μg/kg fat). Di(2-ethylhexyl) phthalate, which is the most commonly used plasticiser worldwide, was the most dominating one (79 % of the total concentration in milk from the cooling tank).The results indicate that contamination pathways for phthalates in cow’s milk vary across seasons. An explanation therefore is that the feed composition is different during summer and winter. Comparing manually with mechanically obtained milk samples reveals that the milking equipment is another important contamination pathway.C