Silicone as a base material is physiologically neutral, thanks to its macromolecular structure and the intramolecular bond between silicon and oxygen. The molecules are too large to permeate cellular membranes, and the human metabolism is not capable of cleaving these molecules. Most of the properties (temperature resistance, elasticity, etc.) are based on the chemical structure of the silicone and not achieved by additives (plasticizers, ageing inhibitors, etc.).

The only filler in the silicone is silica for improvement of the mechanical properties. As it is generally known, silica is administered orally, as an additive in tablets, and is unobjectionable. The silicones I use are medical grade silicones. With regard to the raw materials and manufacture, they are subject to strict regulations, and each batch is controlled for compliance with these regulations.