Analysis of phthalate plasticizers in commercial cow milk and matched packaging materials: Occurrence and exposure risk assessment

Phthalate esters are ubiquitous plasticizers that may migrate into dairy products from food-contact materials along the production and packaging chain. Seven PAEs (DMP, DEP, DPrP, DIBP, DBP, BBP and DEHP) were quantified in 24 commercial cow-milk products marketed in Kazakhstan and in 24 matched retail packages. Milk and packaging extracts were analyzed by optimized QuEChERS–GC–MS (recoveries 84.0–114.5%). PAEs were detected in all milk samples, dominated by DBP, BBP and DEHP. Milk concentrations ranged from <LOQ–55.4 (DMP), <LOQ–64.3 (DEP), <LOQ–422 (DPrP) and <LOQ–22.3 (DIBP) µg L⁻¹, while higher-molecular-weight congeners were elevated: DBP 130.9–1362.4, BBP 108.3–641.6 and DEHP 100.5–368.6 µg L⁻¹. Concentrations in packaging were significantly higher than in paired milk (Wilcoxon, p < 0.05) for most analytes, excluding DPrP; LDPE pouches and aseptic cartons showed the strongest signals. Dietary exposure to DIBP, DBP, BBP and DEHP was estimated for five age groups. Individual hazard ratios were <1, but the cumulative hazard index approached 0.8–0.9 in children (2–11 years) for milk in LDPE and Tetra Pak. These results support preventive control of phthalate migration across the dairy contact chain, prioritizing packaging formats widely consumed by children.