Development of an in vitro model to simulate migration of organic contaminants from pad products to human sweat and enhance dermal exposure risk assessment

Dermal sorption is an important route for human exposure to organic chemicals embedded in consumer products, but the related chemical migration from consumer products to sweats was often overlooked in assessing skin exposure risk. To address this issue, the present study selected polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), and benzothiazoles (BTs) as the target compounds and developed an in vitro simulation model with two artificial sweats (i.e., acidic and alkaline), a sorbent, and a PVC standard material. An appropriate biological inhibitor (ampicillin) and incubation time of 20 d for assessing the maximum migration efficiency of chemicals were selected. The mass balance of the target compounds during the in vitro incubation was verified. The established in vitro simulation model was used to determine the migration ratios of PAEs and BTs in three types of mouse pads. The maximum migration ratios of DBP, DIBP, DEHP, and BT from leather pad to both sweats were less than those for silicone and rubber pads. Key controlling parameters in migration ratios should be examined in subsequent investigations. Risk assessment showed that the daily exposure doses of PAEs and BTs in mouse pads were higher than the literature data. The hazard index of PAEs in leather pad exceed 1, indicating that PAEs could induce non-carcinogenic effects to human health through hand contact. Overall, the established in vitro simulation model provides a feasible alternative for assessing the potential risk for dermal exposure to consumer products. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Dermal sorption is an important exposure route for organic chemicals in consumer products, but migration of these chemicals to sweat has been overlooked. This study used an in vitro simulation model to assess migration of PAHs, PAEs, and BTs from consumer products to sweats, finding differences in migration ratios among different mouse pad materials and identifying key parameters for further investigation. The study also found that daily exposure doses of PAEs and BTs exceeded literature data, with potential non-carcinogenic effects from PAEs in leather mouse pads. Overall, the established in vitro simulation model provides a feasible alternative for assessing dermal exposure risk from consumer products.