Polydimethylsiloxane (PDMS) is a fluid mixture of fully methylated linear siloxane polymers ended with trimethylsiloxy units, and is widely used in food additives, cosmetics and biomedical devices. Toxicological studies showed that PDMS is not absorbed to any appreciable extent through human skin or gastrointestinal tract, and is rapidly excreted without change into faeces. No acute toxicity and a minimal dermal irritation, but ocular lesions resulting in a slight conjunctivitis and iriditis have been observed. No carcinogenicity, teratogenicity and genetic toxicity have been identified. It seems reasonable to deduce that PDMS might have no adverse health effects under proper usage.