Occurrence and migration of phthalates in adhesive materials to fruits and vegetables

Labels or tapes are widely used on fresh fruits and vegetables, which may contain phthalates (PAEs). There are few studies on the contamination pathway of PAEs from labels or tapes to food stuff. In this study, the concentrations of eleven PAEs in adhesive labels, tapes, labeled fruits and vegetables on the market were investigated. The eleven PAEs were detected with the total concentration of 7.44-30.51 mg/m² in labels and tapes. Diethyl phthalate (DEP), di-n-butyl phthalate (DIBP), dimethyl phthalate (DMP), Bis (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) had the highest detection frequency in adhesive material samples. The concentrations of PAEs in labeled fruits were higher than that in unlabeled fruits, especially in the peel, indicating PAEs could transfer from labels or tapes to fruits and vegetables. Furthermore, the migration behaviors of PAEs from labels or tapes to apples, avocados and celery were investigated. It was found that the PAEs could penetrate to apple and avocado pulp through the peel, resulting in the residue of the PAEs in the whole fruit. Unlike apple peel, the thick avocado peel was more difficultly penetrated by the PAEs. Due to the high lipid content, the PAEs distributed more evenly in avocado pulp than in apple pulp. The migrations up to a maximum of 4.16 mg/kg were found for butyl benzyl phthalate (BBP) in avocado peel and up to a maximum of 0.188 mg/kg in avocado pulp. The average migration of the PAEs in celery ranged from 0.3 to 26.1 μg/kg in three days and the low migration might result from the rough surface and less contacting area. These findings suggest that the use of labels or tapes in direct contact may increase the risk of PAEs exposure to humans through fruits and vegetables.