Silicone substances, or siloxanes, are used in personal care products and cosmetics because of their desired properties such as emollient effects. Siloxanes are divided into cyclic siloxanes (ring structure) and acyclic siloxanes (linear structure).
The cyclic siloxanes are problematic as they can be toxic to human reproduction and are very slowly degradable in the environment. In many products the long chain, linear siloxane substance dimethicone is used as a substitute, but it may contain background contamination from the cyclic siloxanes.
Consumer risk assessment
The potential consumer risk from the found siloxane concentrations was evaluated in relation to dermal exposure and inhalation exposure (spray products) and specifically for small children in relation to oral exposure from sucking of their fingers.
It was difficult to assess the risk of several of the analysed siloxanes, as the available toxicological data were either very old or lacking. As a result, there is no documentation for the safe use of these siloxanes in cosmetics. Four of the analysed products used in rather large quantities (sunscreens, body lotions) were found to constitute a potential risk to the consumers based on their content of cyclic siloxanes. Especially children were found to be at risk.
Environmental assessment
All siloxanes are poorly degradable in the environment, especially in soil.
As mentioned, there is an ongoing process of substituting cyclic siloxanes, for instance with dimethicone in cosmetic products. As a rule, the high molecular dimethicone is not as toxic and bioaccumulative as the other smaller siloxanes, but as the substance will ultimately degrade into smaller molecules, these will show similar toxicity and potential for bioaccumulation.
Get more details in the report Survey and risk assessment of siloxanes in cosmetic products
DHI prepared the toxicological risk assessment and the Danish Technological Institute carried out the chemical analyses.
If you have questions regarding the report or about siloxanes, please contact:
Poul Bo Larsen
pbl@dhigroup.com
Tel +45 4516 9478
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