The U.S. Food & Drug Administration (FDA) "ensures that the food we eat is safe and wholesome, that the cosmetics we use won't harm us, and that medicines, medical devices, and radiation-emitting consumer products such as microwave ovens are safe and effective".
Although not strictly a medical grade standard, FDA Food Grade (21 CFR 177.2600) is often used when selecting a silicone rubber for a medical application.
This standard refers to "Rubber articles intended for repeated use with food".