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Home > Materials > UL Listed Gasket Materials

UL Listed Gasket Material, UL Gaskets

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Underwriters Laboratories (UL) is the leader in product safety testing, from testing and qualifying final products down to the component level. Among the basic components are gasketing and rubber materials. These materials are tested for industry application as well as flammability. Stockwell Elastomerics inventories many UL listed gasket materials.

Engineers Summary - What Engineers Need to Know

If a product will be submitted to UL for testing, using a UL listed gasket material can save time and money since the material itself has already been qualified. Common UL listings for rubber and gasket materials include:

UL 94 for Flammability, Applies to Many Industries

  • Caution point - material thickness must be considered, thinner grades of a listed material may not meet the requirements
  • Caution point - some material manufacturers have a caveat that the material "is capable" of passing UL 94. This often means it is not a UL listed material but is expected to pass an in situ testing.

UL 50 and UL 50E for Ingress Protection for Electrical Enclosures (typically dust and water)

  • Caution point - while materials may be UL 50 listed, not all will perform well in the field and/or over time. Enclosure design plays a significant role in passing pressure jet wash down. Also, long term compression set and stress relaxation are common failure modes that do not show up in short term testing.

UL 1570 (fluorescent), UL 1571 (Incandescent), UL 1572 (HID), UL 8750 (LED), UL 1598C (LED retrofit) Applies to the Lighting Industry.

  • Caution point - often RTI (Relative Temperature Index) must be considered; UL does not recognize temperature ratings on manufacturers' datasheets.
  • Caution point - often UL 94 requirements are required to be met as well

UL 508 Applies to Industrial Control Equipment

  • Caution point - UL 508 is being phased out and replaced by UL 60947

UL 157 Applies to General Gasket Materials (JMLU2 and JMST2)




UL 94 Flammability Test and UL 94 Flame-Rated Materials

UL tests rubber materials (under the UL "Plastics" category) for their ability to resist flame spread and to self-extinguish. UL 94 has 12 classifications; for rubber materials, the most common are:

  • UL 94V-0 - vertical burn test, excellent flame rating for rubber and foam materials
  • UL 94HB - horizontal burn test, good flame rating for rubber materials
  • UL 94HBF - horizontal burn test, good flame rating for low density foam (such as PORON)

Products Commonly Stocked by Stockwell Elastomerics with UL 94 Listings

Stockell Elastomerics has in inventory the following products with UL 94 listings as described on UL's website:

Open Cell Foam
Material UL Rating
F-12, Extra Soft Silicone Foam UL 94V-0
BF-2000, Ultra Soft Silicone Foam UL 94V-0
BF-1000, Extra Soft Silicone Foam UL 94V-0
HT-870, Soft Silicone Foam UL 94V-0
PORON Microcellular Urethane Foam (various firmness) UL 94HBF

Visit the Silicone Sponge and Silicone Foam Sheet Material Data Sheets page or the PORON Data Sheets page for detailed technical information on the above materials.


Closed Cell Foam
Material UL Rating
HT-800, Medium Firmness Silicone Foam UL 94V-0
HT-820, Firm Silicone Foam UL 94V-0
HT-840, Extra Firm Silicone Foam UL 94V-0

Visit the Silicone Sponge and Silicone Foam Sheet Material Data Sheets page for detailed technical information on the above materials.


Closed Cell Sponge
Material UL Rating
R-10400, Medium Firmness Silicone Sponge UL 94V-0
R-10460, Medium Firmness Silicone Sponge UL 94HBF
4119-N, Neoprene Sponge UL 94HF-1

Visit the Silicone Sponge and Silicone Foam Sheet Material Data Sheets page or the Closed Cell Rubber / Neoprene Data Sheets page for detailed technical information on the above materials.


Thermal Interface (Gap Filler / Gap Pads)
Material UL Rating
Ultra Soft V0 – Thermal Gap Pad UL 94V-0
TC2006 – Thermal Gap Pad UL 94V-0
TC3006 – Thermal Gap Pad UL 94V-0
TC-3008 – Thermal Gap Pad UL 94V-0
R-10404 – Thermally Conductive Silicone Sponge UL 94V-0
TF-400 Series – Thermally Conductive Silicone Coated Fabric UL 94V-0

Visit the Thermally Conductive Materials Data Sheets page for detailed technical information on the above materials.



UL 50 and UL50E Ingress Protection for Electrical Enclosures

UL 50 and UL 50E are very similar with regards to NEMA and the IEC Ingress Protection (IP) Rating, which is to define levels of protection against foreign objects entering into an electrical enclosure. This includes people, dirt, dust, water and fluids under various conditions. One significant difference is that UL 50 qualifies gasket materials whereas NEMA does not. A significant condition on the UL 50 materials is periodic recompression. A gasket material that meets the periodic recompression qualification may be used on a door gasket and/or can be serviced without replacing the gasket.

Products Commonly Stocked by Stockwell Elastomerics with UL 50 Listings and Other UL Gasketing Ratings

Stockell Elastomerics has in inventory the following products with UL 50 listings and other UL ratings for gaskets as described on UL's website:

UL 50 and other UL Gasket Materials
Material UL Rating
HT-800 UL 50, UL 50E, UL 508, UL 1570, UL 1571, UL 1572, UL 157, periodic recompression
HT-820 UL 50, UL 50E, UL 508, UL 1570, UL 1571, UL 1572, UL 157, periodic recompression, previously passed UL 197
HT-870 UL 50, UL 50E, UL 508, UL 1570, UL 1571, UL 1572, UL 157, periodic recompression, previously passed UL 197
R-10460 JMST2, suitable for weather seal gaskets in lighting fixtures
R-10470 JMST2, suitable for weather seal gaskets in lighting fixtures
F-12 JMST2, suitable for weather seal gaskets in lighting fixtures
SNS100S JMST2, suitable for weather seal gaskets in lighting fixtures
PORON 4701-30 UL 50, UL 50E, periodic recompression
PORON 4701-40 UL 50, UL 50E, periodic recompression
PORON 4701-50 UL 50, UL 50E, periodic recompression
PORON 4790-92 UL 50, UL 50E, periodic recompression
PORON 4701-41 UL 50, UL 50E, UL 157, UL 508, periodic recompression
4219 UL 48, UL 50, UL 50E, UL 465, UL 508, UL 465, UL 984, continuous compression

Visit the Silicone Sponge and Silicone Foam Sheet Material Data Sheets page, the PORON Data Sheets page or the Closed Cell Rubber / Neoprene Data Sheets page for detailed technical information on the above materials.



UL 508 - Gasketing for Industrial Control Equipment

Several materials are currently listed for UL 508. It is important to note that UL will be phasing out UL 508 to harmonize with the Industrial Control Equipment standard (IEC 60947). UL 508 will be completely phased out in 2017 and new products will be tested to UL 60947 starting in 2012. UL 60947 will replace the existing UL 508 standard.


UL Terminology Notes for UL Listed Gasket Materials

For many UL listed materials, there is some confusion on how the UL listing should be written, particularly concerning spaces and dashes ("-"). For example, UL 94V-0 is also seen written as: UL 94 V0, UL 94 V-0, UL 94V0, UL94 V0, UL94 V-0, UL94V0, and UL94V-0. UL 50 is also seen as UL50, while UL 50E might be shown at UL50E or UL 50 E.


Contact Stockwell Elastomerics for UL Listed Gasket Material

Contact Us for further assistance with UL listed gasket materials and UL gaskets.


UL® and the UL logo are registered trademarks of Underwriters Laboratories.


Related Information:


Silicone Materials Selection Guide

    All Material Data Sheets