Case study: Is bisphenol S safer than bisphenol A in thermal papers?

Area of Science:

• Environmental Science
• Toxicology
• Occupational Health

Background:

• European Chemical Agency identified risks with dermal exposure to Bisphenol A (BPA) in thermal paper.
• BPA is being replaced by Bisphenol S (BPS) in thermal paper, necessitating a risk assessment for BPS.
• Previous assessments indicated BPA exposure via thermal paper might exceed safe levels (DNEL).

Purpose of the Study:

• To assess the dermal exposure risks of Bisphenol S (BPS) from thermal paper for the general and occupational populations.
• To compare BPS exposure risks with those previously identified for BPA.
• To evaluate the adequacy of current risk management measures for BPS in thermal paper.

Main Methods:

• Developed two exposure scenarios for BPS dermal exposure: one based on urinary excretion and another on skin transfer from thermal paper.
• Calculated exposure levels for the general population and workers under both scenarios.
• Compared estimated exposures with systemic Derived No Effect Levels (DNELs) to determine Risk Characterisation Ratios (RCRs).

Main Results:

• General population exposure estimates were similar across both scenarios (0.016-0.013 µg/kg bw/day).
• Worker exposure in the skin transfer scenario (0.96 µg/kg bw/day) was 17-fold higher than in the excretion scenario.
• The most reliable scenario (urinary excretion) indicated controlled risk, while the skin transfer scenario suggested inadequate risk control for both populations.

Conclusions:

• Dermal exposure to BPS via thermal paper may pose risks, particularly for workers, under certain exposure scenarios.
• The current data suggests a potential inadequacy in risk control for BPS, similar to concerns raised for BPA.
• There is a critical need for more toxicodynamic and toxicokinetic data, especially regarding dermal exposure routes, to accurately assess BPS risks.