Material

UL Gasket Materials

Engineered materials that meet widely recognized standards with stringent requirements from Underwriters Laboratories (UL)

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 recognized gasket materials.

Engineers Summary – What Engineers Need to Know

If a product will be submitted to UL for testing, using a UL recognized 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 recognized 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 recognized 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 recognized, 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 shown is this table:

UL 94 Classifications

Classifications Name	Description
UL 94V-0	Burning stops within 10 seconds, no flaming drips allowed.
UL 94V-1	Burning stops within 60 seconds, no flaming drips allowed.
UL 94V-2	Burning stops within 60 seconds, flaming drips are allowed.
UL 94HB	Lowest UL 94 rating. Slow horizontal burn (HB) tests are considered “self-extinguishing”.
UL 94HBF	Horizontal burn (HB) test 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
R10400, Medium Firmness Silicone Sponge	UL 94V-0
R10460, 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
R10404 – 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.

Liquid Silicone Compounds for Injection Molded Gaskets and Sheets

Material	UL Rating
Wacker ELASTOSIL® LR 3003	UL 94HB
Dow XIAMETER™ RBL-9591-50	UL 94V-0

Visit the Molding Compounds 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
R10460	JMST2, suitable for weather seal gaskets in lighting fixtures
R10470	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 recognized 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 48 – Gasketing for Electric Signage

UL 48 is the UL standard for electric signs; this specification addresses signage standards for a wide range of applications. View the Electric Signs UL 48 Gaskets page for more information, or request a touch brochure.

Request a Free Electric Signage UL 48 Gasket Material Touch Brochure

Includes small samples of these gasket materials to touch and feel.

Request Brochure

UL Terminology Notes for UL Recognized Gasket Materials

For many UL recognized 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.