Volatile methylsiloxanes in beauty and personal care products sold in India and human exposure assessment

This study investigated the presence of cyclic and linear volatile methylsiloxanes in 174 beauty and personal care products (PCPs) sold in India. Siloxanes were detected in all the samples with a detection frequency of 20 to 99 %. The cyclic siloxanes viz. decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) were predominant in all the samples, and the total concentration of cyclic siloxanes was as high as 773,000 μg g^-1. About 40 % of the samples exceeded the European Union guideline value (0.1 %) for wash-off and leave-on products. The estimated per-capita run-off emissions of total siloxanes from beauty and PCPs were between 158,000 and 2,680,000 μg day^-1 (average: 988,000 μg day^-1). Hair serum, makeup remover, body wash, face wash, and shaving foam showed higher average per-capita run-off emissions for total siloxanes (range: 2950 to 505,000 μg day^-1). The estimated per-capita air emissions of siloxanes were between 42,600 to 1,950,000 μg day^-1 (average: 551,000 μg day^-1). Hair serums, moisturizers, deodorants, foundation, primers, lip colour, makeup removers, and aftershaves were the major contributors to air emissions (0.44 to 56.3 %). The average dermal and inhalation exposure to siloxanes from using beauty and PCPs was 4020 and 642 μg kg-bw^-1 day^-1, respectively. The average daily dermal and inhalation doses for ∑octamethylmethycyclotertrasiloxane (D4) + D5 were 16.9 and 172 μg kg-bw^-1 day^-1, respectively, which is higher than the chronic reference dose for inhalation exposure. Among the studied siloxanes, cyclic siloxanes predominantly contributed to consumer exposure from applying beauty and PCPs.