Development of a novel method for estimating dermal contact with hand-applied cleaning solutions

Area of Science:

• Occupational health and safety
• Dermal toxicology
• Exposure science

Background:

• Quantitative dermal exposure assessment for hand-applied cleaning solutions is challenging due to scenario-specific variables.
• Estimating dermal exposure requires accurate measurement of the hand surface area contacted by cleaning agents.
• Current literature lacks established methods for quantifying hand-skin contact area during cleaning tasks.

Purpose of the Study:

• To evaluate a novel simulation approach for measuring skin contact area during hand cleaning with liquid products.
• To refine dermal exposure and risk estimates for users of hand-applied cleaning solutions.
• To address the lack of data on hand surface area contacted by cleaning solutions.

Main Methods:

• A simulation approach using cotton rags wetted with pigmented cleaning solutions.
• Volunteers wore white cotton gloves while performing simulated cleaning tasks.
• Digital imaging analyzed glove stains to quantify the pigmented solution-contacted hand surface area.

Main Results:

• The novel method successfully estimated both palmar and dorsal hand surface areas contacted across three cleaning solutions (denatured alcohol, aqueous solution, lacquer thinner).
• The volume of cleaning solution applied to the rag and rag thickness consistently predicted contacted surface area.
• Cleaning time was also correlated with contacted surface area for denatured alcohol simulations.

Conclusions:

• The developed simulation approach is a feasible and effective tool for quantifying hand surface area contacted by cleaning solutions.
• This method can significantly reduce uncertainty in dermal exposure assessments for hand-applied cleaning products.
• The findings support the use of this simulation for improved risk assessment in occupational and consumer settings.