What's the difference between food grade and non-food grade O-rings ? (other than the "obvious" of course) ?
Just curious.
There are over a dozen materials that meet the requirements of the FDA for use in food applications. A few of the most commonly-requested include:
EPDM: Ethylene propylene diene monomer O-rings are designed to withstand a wide array of temperatures as well as resistance against phosphate esters and lipids. EPDM is perhaps the most widely-used food-grade O-ring material.
Nitrile Rubber: Nitrile rubber (butadiene acrylonitrile) is commonly used for food, medical, and cosmetic processing. It has excellent impact resistance and remains flexible throughout temperature cycles. Nitrile rubber is known for its durability even after repeated daily cycles.
Fluorocarbon: Fluorocarbons don’t absorb water and are known for their excellent high temperature resistance. They are ideal for use in applications in which steam or hot liquids are present and are in fact high-performing enough to be used in aerospace applications.
Neoprene: Highly resistant to oils, neoprene is also nearly impervious to ozone and the effects of ageing. An early alternative to natural rubber, neoprene is widely used for refrigeration and other food transport and storage applications.
Silicone: Silicone has quickly become one of the most popular food grade O-ring materials. It is highly stable and has one of the widest operating temperature ranges available today. It is an ideal material choice when the avoidance of cross-contamination is a priority.