Sanitary Gaskets: Ensuring Safety and Compliance in the Food and Beverage Industry

Posted on by Marco Rubber Staff

Sanitary Gaskets: Ensuring Safety and Compliance in the Food and Beverage Industry

Did you know gaskets can influence the color and taste of different food products? Or that they can negatively harm the end users of pharmaceuticals or medical devices?

Odds are, yes, you know this. 

But how exactly can sanitary gaskets solve these problems? Are they available in enough compounds to stand up to your application?

We think the answer is yes. Let’s talk about it.

What Are Sanitary Gaskets?

Gaskets are flat pieces of rubber or plastic used between two other flat surfaces to create an air—or liquid-tight seal, depending on the application. In the food and beverage, pharmaceutical, and other highly regulated spaces, it is critical that sanitary gaskets follow pertinent regulations. A few of the most prominent are FDA 21 CFR 177.2600, USDA 3-A, and USP Class VI. 

FDA 21 CFR 177.2600

The materials used in gaskets can be considered indirect food additives. This means that they come into contact with food but should not be mixed into it. In other words: these materials must not make the food unsafe for human consumption.

Title 21 of the Code of Federal Regulations Section 177.2600 best addresses seals as an indirect food additive. 

If a material is considered safe to touch the food, it is classified as Generally Recognized as Safe (GRAS) for use in manufacturing and packaging. 21 CFR 177.2600 identifies acceptable materials for use in o-rings and gaskets, including usage percentages that will minimize the impact on food and water. 

USDA 3-A

USDA 3-A regulations are incredibly important in the dairy industry as well as other specific food and beverage applications.

Milk and plant-based hydrocarbons, like edible oils, are known to pull carbon among other ingredients from plastic and rubber components, like o-rings and gaskets. This extraction can quickly discolor fatty foods and oils as well as milk. 

Thus, gaskets and o-rings require “white list” elastomers that meet the stringent requirements found in USDA 3-A. These formulations include different proportions of certain ingredients to prevent contamination.

To consider a material 3-A compliant, a sanitary gasket manufacturer must receive a Third Party Verification inspection.

USP Class VI

USP Class VI is  a testing method to determine biocompatibility of materials used in the production of pharmaceutical and medical products. This testing determines if there are no harmful reactions or long-term effects from chemicals found in plastic materials. 

The United States Pharmacopeia and National Formulary (USP-NF) carries out three USP Class VI testing methods: system injection test, intracutaneous test, and implantation test. These tests are carried out on specimens using chemicals found in plastic materials.

The test conclusions inform plastic and rubber manufacturers what should or should not be used in products that facilitate the medical and pharmaceutical industry.

Manufacturing Standards for Sanitary Gaskets

Sanitation and safety are critical components of manufacturing gaskets for use with food and beverages. The best (and really only) way to manufacture a truly sanitary gasket is in a cleanroom.

To demonstrate compliance, manufacturers must keep careful production records following ALCOA+ best practices. ALCOA+ stands for:

Attributable

Legible

Contemporaneous

Original

Accurate

Complete

Consistent

Enduring

Available

Tracking and recording information according to ALCOA+ is required by the FDA as a Current Good Manufacturing Practice (CGMP) in the production of pharmaceuticals. This is a proven method for improving data integrity by improving traceability, expediting certifications, and providing evidence of high-quality management systems.

As we enter into Industry 4.0, the production, storage, and management of data is more critical than ever before. By properly managing data to demonstrate appropriate manufacturing processes, end users can rest assured that their sanitary gaskets are truly that: sanitary. Manufactured, cleaned, and packaged in a cleanroom, these sanitary gaskets should not present any harmful effects.

Common Materials for Sanitary Gaskets

Depending on your application, several materials might work best for you. 

Silicone

Silicone is an inorganic, common synthetic polymer known for its versatility and excellent resistance to various obstacles. It is used in a wide range of applications that do not require high tensile strength or tear resistance.

  • Pros:

    • Resistance to extreme temperatures (-75° to 450°F), ozone, UV, weather, chemical, oil, water steam, and corona discharge.
    • Available in compounds for almost any need:
      • Flame retardant grades
      • Electrically conductive materials
      • Extreme high and low temperature grades
      • Platinum cured formulations

  • Cons

    • Not right for applications that require:
      • high tensile strength
      • high tear resistance
      • high dynamic resistance
      • high abrasion resistance
      • use with fuels or petroleum-based oils
      • high impermeability

Perfluoroelastomers (FFKM)

Perfluoroelastomer (also known as FFKM) is a fluorinated, carbon-based synthetic rubber known for its chemical and heat resistance and high-performance capabilities. It is best suited for high-temperature applications where other materials often fail. 

  • Pros:

    • Features high temperature ratings, up to about 635°F (335°C), and lower temperatures, going down to -49°F (-45°C)
    • Nearly universal chemical compatibility
    • Excellent gas and liquid permeation resistance
    • Excellent weather ability and ozone resistance
    • Self-extinguishing and non-flammable in air
    • Low outgassing properties (low extractables)
    • Good mechanical properties, improving sealing performance
    • Suitable for explosive decompression, CIP (Clean in Place), SIP (Steam in Place), USP Class VI, and FDA

  • Cons

    • FFKM should not be used with molten or gaseous alkali metals
    • Premium cost

Polytetrafluoroethylene (PTFE)

Polytetrafluoroethylene, also known as PTFE or Teflon, is a hard plastic that is inelastic and very rigid, whereas FFKM is extremely flexible. PTFE is best suited for applications that need excellent chemical and temperature resistance but do not need a high compression set.

  • Pros: 

    • Unaffected by all known acids, alkalis, and solvents allowing for maximum chemical resistance
    • Low coefficient of friction, making it an excellent nonstick option
    • Very wide temperature range, from -329°F (-200°C) to 482°F (250°C)
    • Chemically inert
    • Self-cleaning
    • Durable
    • Non-flammable
    • Good corrosion resistance
    • High electrical resistance

  • Cons:

    • Very hard; therefore, it exhibits poor compression set
    • PTFE cannot be stretched to install in equipment
    • It cannot be cemented
    • It is unweldable

Ethylene Propylene (EPDM)

Ethylene Propylene (EPDM) is an extremely durable copolymer with some of the best cold-temperature resistance. Because it can withstand extreme elements, EPDM is best suited for weatherproofing.

  • Pros:

    • Excellent resistance to ozone, sunlight, and weathering
    • Can withstand extremely cold temperatures, with an operating temperature as low as -58°F (-50°C) (with highs of 302°F (150°C))
    • Compresses well
    • Highly resistant to tears, abrasion, and steam
    • Adheres to metal very well
    • Works well with adhesives

  • Cons

    • Does not fare well with fuels, oils, and non-polar solvents

Nitrile Butadiene Rubber (NBR)

Nitrile Butadiene Rubber (NBR) is one of the most popular elastomers. It is very common in several applications due to its low cost and comprehensive benefits. NBR is a potential solution for harsh environments, such as extremely abrasive applications. 

  • Pros:

    • Excellent abrasion resistance
    • Good compression set
    • Good tear resistance
    • Good non-polar solvent resistance
    • Good water resistance
    • Good oil resistance
    • Cheaper than fluoroelastomers
    • Good low temp resistance to -65°F (-54°C)
    • Good oil and fuel resistance
    • Low cost

  • Cons:

    • Poor ozone, sunlight, and weather resistance
    • Limited high-temperature resistance
    • Poor flame resistance

Common Sizes and Customization

Sanitary gaskets are available in a variety of custom and standard sizes. Here at Marco Rubber, our sanitary gaskets fall under our On-Time In-Full (OTIF) promise: all stocked commodities will ship in full within 24 hours of your order.

At Marco Rubber, we know the importance of your sanitary gasket in your production, and we do not take it lightly. That is why we offer many sanitary gaskets to meet your needs. We have formulations that are FDA, USDA, and USP Class VI compliant – as well as many customization options with a deep bench of knowledge.

We take pride in knowing we get solutions to you fast. For example, we offer USP Class VI formulations with only a 6-8 week lead time. Standard sizes and materials can be at your facility in days.

When you work with Marco, you are working with experts dedicated to being your sealing partner. We find the solution that works best for you. 

Talk to a team member today.