Food Grade Gaskets

To avoid contamination, food and beverage handling and processing equipment is generally fabricated from materials like stainless steel. Gaskets can’t be avoided though, and some will come into contact with the products being manufactured. When this is the case it’s essential they are made from gasket material considered food grade.

The FDA publishes a long list of substances that can safely be included in elastomeric (rubber-like) gaskets: it’s in 21 CFR 177.2600. However, relating that to common gasket materials is no easy task. Asking a gasket material supplier for their expert advice and recommendations is a better approach. Here’s what you should know.

Food-Grade Material Choices

Commonly used gasket materials are also available in grades considered food-safe. That means material choice is dictated by what the application needs. Only once temperature, environment, media and pressure, (summarized by the acronym TEMP,) are known do you need to add the “food grade” requirement.

Silicone is often the first choice when food grade is required. It’s an excellent gasket material with a wide temperature range, low compression set, good strength and elasticity and resistance to many chemicals. In some applications though it may be overkill. Nitrile, neoprene, EPDM, Gylon®, Viton® and PTFE are alternatives that may perform better while possibly saving money.

Not Necessarily White

An absence of color-adding substances mean food-grade gasket materials are usually white. However, there are alternatives. Food-grade EPDM for example is available in black, and food-grade silicone may be translucent or other colors.

The bottom line is, don’t assume your food-grade gasket material must be white. If you need something else, ask us.

Contact is the Important Point

Consider food-grade material mandatory for gaskets coming into contact with food. Elsewhere in a food or beverage facility though, you can use other materials. To avoid confusion, a plant may decide to use only food-grade material everywhere, or implement appropriate controls to prevent misuse.

Seek Specialist Advice

If you’re responsible for food handling and processing equipment you need to know about food grade gasket materials. You could spend a lot of time on research, or you could come to us instead.

An FDA investigation of a food contamination incident found a gasket at the root of the problem. Cleaning agents weren’t penetrating small cracks and E. Coli was able to gain a foothold. In their findings, the FDA suggested inspectors should:

• Look at how frequently a food manufacturer inspects and replaces gaskets
• Challenge the effectiveness of Clean-in-Place (CIP) procedures
• Verify that gasket material is FDA approved for use

Responsible food manufacturers conduct rigorous cleaning and inspection regimens. Whenever any doubt exists as to the fitness of a gasket it gets replaced, but that presents those performing the refurbishment with the question of what material to use.

The FDA maintains listings of approved FDA gasket materials. PTFE and many elastomers such as NBR, SBR and EPDM are included, but two points are sometimes overlooked by those shopping for FDA gaskets. First, any markings, such as part numbers or other information used for traceability must also be FDA compliant. Second, any adhesives used to hold the gasket in place must also comply with FDA requirements.

Where should FDA gaskets be used?

Any surface coming into direct contact with food must be manufactured from materials known to be safe. (“Safe” in this context means either materials already listed by the FDA or those it considers “Generally Recognized As Safe” (GRAS).) This includes gaskets used in food preparation equipment such as kettles and mixing vessels, as well as those used in sanitary couplings; the kind of fittings used for moving dairy or brewery products.

How to select appropriate materials?

One approach would be to trawl through the various applicable FDA documents, noting which would work in your application. A less time-consuming approach is to ask your gasket vendor for advice. Describe your application in detail, particularly the temperatures and pressures involved and the cleaning regimens employed, and they’ll know which materials are suitable. You’ll receive FDA gaskets that work in your application and contamination risks will be reduced.

Food grade non-metallic gaskets are made from materials approved by the FDA for repeated and demanding contact with edible products. They must withstand high pressures, have a wide temperature tolerance and be extremely resistant oils, acids and chemicals without degrading or becoming susceptible to bacteria formation—for the obvious reason that food-grade gaskets and seals must not impact food quality or safety whatsoever. FDA-approved food-grade non-metallic gaskets are also used in pharmaceutical and cosmetics manufacturing for the same reason.

There are several materials that we can use to fulfill food grade non-metallic gasket orders:  

White Nitrile (Buna-N)—Commonly used in food processing because it remains durable and flexible when cycling between temperatures of -31°F to +230°F. It is highly resistant to petroleum, mineral and vegetable oils, acids and a wide range of aromatic hydrocarbons.

White Neoprene—Works well in food-processing and packaging environments, as well as pharmaceutical, commercial kitchens, cosmetics plants and grocery store applications with a temperature tolerance of -20°F to +180°F.

Red or White FDA Silicone—Have a temperature tolerance between -94°F to +392°F and are often used in everything from food processing to laboratory and surgical applications because of its low volatility and durability. Resists oils and acids well.

EPDM—Food-grade EPDM has a temperature tolerance of  -20°F to +230°F. It’s smooth, resists abrasion, is color-stable, non-marking and odor-free; for these reasons, it has earned the additional approval of the USDA for poultry and meat processing.

PTFE—As one of the most chemically-resistant plastics available, FDA-compliant PTFE is extremely common in food and beverage processing, cosmetics and pharmaceutical manufacturing. It also has an outstanding temperature tolerance of -328°F to +500°F.

Gylon®—This is a specific brand of PTFE with a 450°F to +500°F . It is extremely chemical and temperature resistant with reduced creep relaxation qualities.

While all of these materials (and a few others not listed here) are FDA-compliant, not all of them are suitable to all food, cosmetics or pharmaceutical production processes. Please contact Hennig Gasket and Seals, Inc. at 1-800-747-7661 and we can discuss which food-grade, non-metallic gasket material would be best for your needs.