A number of gasket materials meet the FDA’s criteria for being Generally Regarded as Safe (GRAS) but the most versatile is silicone gasket material. FDA-compliant silicone rubber is a good choice for sealing and other applications in the food and beverage, medical and pharmaceutical industries. Here’s what you should know.
The Risks of Indirect Contact
Material used for gaskets and seals shouldn’t end up in food or other substances consumed by humans, but it can come into contact with them, either accidentally or by design. Solids and liquids may for example touch the seals and gaskets used in mixers, kettles and storage vessels.
If this happens, especially at elevated temperatures, there’s a risk of some of the chemicals in the seals being picked up by the foodstuff. In the best case, this might impart a taint or color but, depending on the details of the material, it could transfer potentially harmful chemicals that end up being ingested.
To avoid this, always use FDA-compliant materials wherever contact with foodstuffs is possible.
FDA Regulations
Among other activities, the Food and Drug Administration (FDA) regulates the materials used in food, beverage and pharmaceutical manufacturing. For elastomers like those used in gaskets and seals, the relevant regulation is 21 CFR 177.2600. This identifies what can and cannot come into contact with anything consumed by humans.
Some materials are considered GRAS, meaning their use is permitted. FDA-compliant silicone rubber is one such material.
Food-Grade Silicone Gasket Material
Silicone is an excellent material for gaskets. It’s soft but doesn’t take a compression set, and springs back to its original size when unloaded. It has a working temperature range of -67 to 450°F, and it resists mild acids and oils.
Food-grade silicone is almost always white, because it’s the colored additives that can result in contamination. Some buyers will ask for “white silicone” but this doesn’t guarantee it meets FDA standards. To be safe, when buying food grade silicone, always specify compliance with 21 CFR 177.2600.
We carry FDA-compliant silicone rubber in 48″ wide rolls and thicknesses from 1/32 to 1/4″. Cutting services are available.
