Toxicology data

A wealth of data exists to assess the toxicity of cyclosiloxanes. Commonly, the method for assessing toxicity is through studies in the laboratory (sometimes with rats). If a risk is identified, these studies are then analysed for their relevance to human health.  

Health fate and exposure data

Years of studies have confirmed the safety of cyclosiloxanes for human health. Some earlier studies indicated potential health effects from octamethylcyclotetrasiloxane (D4), but a series of new assessments in Toxicology Letters, and recent weight-of-evidence studies, add further compelling evidence that D4 does not present a risk to human health.

These recent assessments are consistent with a large body of peer reviewed publications supporting the safety of D4 and independent government assessments in Australia and Canada concluding that the use of D4 does not pose a danger to human health.

Relevance for human health

To understand if studies performed in labs (with rats) are relevant for human health, it is necessary to look at two things: their “mode of action”, that is, the trigger which may cause an effect, as well as the potential risks to humans.

The two sections below provide an overview of the potential modes of action and risks. Overwhelmingly, the studies conclude that the minimal effects observed in some high-dose rat studies are not relevant to humans. There are therefore no risks from the use of cyclosiloxanes in consumer products (or otherwise).