Decoding chemicals of emerging concern in personal hygiene products: Exposure implications for vulnerable populations

Personal hygiene products often contain various chemical additives to ensure their functionality and quality, but concerns persist regarding the potential harmful effects of their usage. In this work, a pilot study was conducted to characterize the chemical components in disposable sanitary pads and paper diapers by screening for a total of 92 chemicals, including synthetic antioxidants (AOs), organophosphate esters (OPEs), and phthalate esters (PAEs). Significantly higher concentrations of AOs (median for sanitary pads: 3.25 × 10⁵ ng/g, median for diapers: 2.25 × 10⁵ ng/g) were observed compared to OPEs (median for sanitary pads: 1.51 × 10³ ng/g, median for diapers: 803 ng/g) and PAEs (median for sanitary pads: 526 ng/g, median for diapers: 439 ng/g). This is the first investigation to highlight the high levels of AOs and OPEs in personal hygiene products, raising concerns about the human exposure risk. Based on median concentrations, the daily dermal intake of individual chemicals via personal hygiene products was preliminarily estimated to range from 0.01 to 2.18 × 10³ ng/kg bw/day. A preliminary hazard screening indicated that non-carcinogenic risks were low for sanitary pads but exceeded the threshold of risk concern (hazard index > 1) for some paper diaper samples, primarily driven by certain AOs [e.g., octyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO1135) and 2,4-di-tert-butyl-phenol (DBP)] rather than OPEs and PAEs. Notably, a primary exposure pathway for the previously detected DBP for menstruating women may be dermal contact with sanitary pads (potentially contributing up to 40.8% of total exposure). These findings reveal the high complexity of chemicals in personal hygiene products and expand our knowledge of their potential health risks.