This question came to head when women with silicone breast implants made an association with leakage of the gel and subsequent development of cancer cells. This is where things really get black and white. The evidence for whites (silicone does not cause cancer) looks to be compelling. Until, that is, you come to the realization that the evidence is based on research carried out decades ago. The most quoted is the most problematic. It was conducted by Dow Chemical (maker of silicone) on one group of rats, just after the Second World War.
I also came across a reference to a review of 123 reports on cyclic polydimethlsiloxanes (D3, D4, D5, and D6). The review concluded: "These compounds are volatile and potentially of concern
in manufacturing; however, they also are used in consumer products,
such as hair sprays, and are found in breast implants, although in very
low amounts (see Chapter 3). They are practically nontoxic on
ingestion, dermal application, or inhalation, although they are mildly
irritating when placed directly on the skin or in the eyes. Subacute
gavage studies showed that these compounds had no untoward effect other
than a reversible increase in liver weight due to increases in both
cell number and cell size at doses ranging up to 2,000 mg/kg. Skin
application did not cause toxicity; however, some D5 penetrates the skin."
I was about to breath a sigh of relief until I discovered that the reports were all 40 years old.
And then I found this: according to research gathered by attorney Richard Alexander, of the Alexander
Law Firm in San Jose, California, Dow Chemical and Dow Corning have been aware of the toxic effects of silicone and silica since the 1950s, based on their own studies, but never published the data. They knew these substances were bioreactive, immunogenic, toxic, and inflammatory when introduced into the human body, states Alexander. (Update on Breast Implants,January 1998, website: http://consumerlawpage.com.)
"Silicone degrades into silica, usually at the surface of the gel implant, then fragments and subdivides into millions of microdroplets capable of migrating throughout the body" (according to PSC Records No. 1352, 7017. These are documents produced by Dow Corning in national litigation. Silica in the body is a toxic, carcinogenic substance, damaging the immune system, killing cells, and producing silicosis.
Silicone is toxic - true or false?
True, I'm afraid. The Journal of Toxicology reported that silicone injections led to multi-organ failure. Research collected by the Plaintiff's Steering Committee (PSC) for the National Breast Implant Litigation shows that silicone has marked effects on the adrenal glands and liver, induces chronic inflammation, and degrades into smaller molecules, including silica. Silicone fed to rabbits produced widespread toxic effects including kidney and spleen damage within four months. (Stanford Medical Bulletin, 10:1 , 23-26.) "That silicone is toxic in both animals and man is well proven", stated John S. Sergent, M.D., and colleagues in Textbook of Rheumatology (W.B. Saunders Company, 1993).