Abstract
Dodecamethylcyclohexasiloxane (D6) is a siloxane substance mainly used in cosmetics and personal care products. While octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) were once commonly used in personal care products, their usage has been restricted due to the classification as persistent, bioaccumulative, and toxic (PBT)/very persistent and very bio-accumulative (vPvB) substances. While D6 has emerged as a substitute for D4 and D5, the risk assessment for D6 remains limited compared to the evaluations for D4 and D5. To address this gap, we conducted a comprehensive risk assessment of D6. In this study, we reviewed the toxicity information on D6 and calculated the exposure level to D6, considering the content of D6 in cosmetic products. No observed adverse effect level (NOAEL) of 1500 mg/kg bw/day was established in a repeated dose toxicity study after oral administration to rats. Negative results were found in tests on the ocular and skin irritation, skin sensitization, and genotoxicity of D6. According to the product content of up to 48% of D6 reported in 2012, the Systemic Exposure Dose (SED) was 5.4E-06 to 7.04 mg/kg bw/day for a 60 kg adult using the exposure factors from Korean cosmetic usage. The Margin of Safety was estimated to be between 35.5 and 4.63E+07, posing a potential health risk of D6 according to the maximum concentration and the product type. Further consideration of the potential of D6 as PBT or vPvB is also required.
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Acknowledgements
This study was cosmetic safety evaluation project conducted by the Korea Cosmetic Industry Institute (KCII) and funded by the Ministry of Health and Welfare
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This study was cosmetic safety evaluation project conducted by the Korea Cosmetic Industry Institute (KCII) and funded by the Ministry of Health and Welfare.
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Yeonju Ko: Conceptualization, Data curation, Formal analysis, Investigation, Writing—original draft, Writing—review & editing. Hyunjoon Choi, Seongwon Choi, Donghyun Lim, Shinai Choi, Jiyeon Hong, Young A Yoon, Hyun Chung: Data curation, Investigation. Kyung-Min Lim: Funding acquisition, Project administration, Writing – review & editing. Kyu-Bong Kim, Joo Young Lee, Seung Jun Kwack: Writing—review & editing. Ok-Nam Bae: Conceptualization, Funding acquisition, Investigation, Project administration, Supervision, Writing—original draft, Writing—review & editing.
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Ko, Y., Lim, D., Choi, H. et al. Risk assessment of cyclohexasiloxane D6 in cosmetic products. Toxicol Res. (2024). https://doi.org/10.1007/s43188-024-00235-2
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DOI: https://doi.org/10.1007/s43188-024-00235-2