1.1 ,This guide is intended to educate potential users of silicone elastomers, gels, and foams relative to their formulation and use. It does not provide information relative to silicone powders, fluids, or other silicones. The information provided is offered to guide users in the selection of appropriate materials, after consideration of the chemical, physical, and toxicological properties of individual ingredients or by-products. This guide offers general information about silicone materials typically used for medical applications. Detail on the crosslinking and fabrication of silicone materials is found in Part II of this guide.