Silicone (a compound of silicon, oxygen and hydrocarbons) is used to enlarge breasts, erase wrinkles, flesh out thin lips and buttocks, and even to enlarge the penis. One concern with the safety of silicone gel is that it seeps out, even if the envelopes remain intact. The seepage is spread elsewhere in the body by white blood cells. The immune system may be injured, making some women more susceptible to connective tissue disorders, such as systematic lupus erythematosus and scleroderma. It is not known whether the presence of implants can have any effect on a foetus, or increase the chances of breast cancer. However, with the implants in place, screening of breasts using X-rays is less likely to detect a cancer when it is still small and potentially most curable.
The US Food and Drug Administration (FDA) banned silicone-gel implants for most women in 1992 because of concerns they might leak or rupture, causing diseases of the immune system. The FDA restricts their use to post-mastectomy reconstruction. Reports first surfaced in the mid- to late 1980s alleging that silicone breast implants caused autoimmune diseases.