(978)686-6332 sales@nedc.com
flame retardant gaskets

HT-800 Silicone Foam, R10460 Silicone Sponge

We manufacture all types of gaskets at NEDC. One of the more common requests is for flame retardant gaskets. Customers look for UL94 listed materials because their product is also UL listed. This makes it easier to meet their requirements. 

UL 94 discusses flame retardancy of materials. To be more specific it discusses how long the material will support a flame in different orientations and for different types of materials. At NEDC, we have a number of different materials to choose from when we discuss flame retardancy. There are organic options for flame retardant materials – however, most times we are selling silicone-based products to meet flame retardant requirements. This blog post deals with gasketing materials only, however many thermal pads and RF absorbers also are UL94 listed.

Levels of Flame Retardancy

UL94 is widely accepted as a small scale flammability test. It measures the flammability of plastics/rubber materials. It has a number of different ratings/tests for different type materials and their applications. 


-Thin Material Vertical Burning Test(VTM-0, VTM-1, VTM-2)

-Radiant Panel Flame Spread Test

-Horizontal Burning Foamed Material Test(HBF, HF-1, HF-2)

-Vertical Burning Test(5VA, 5VB)

-Vertical Burning Test(V0, V1, V2)

-Horizontal Burning Test(HB)

In this blog post, we are strictly looking at the UL94V, and UL Horizontal Burn Foamed test that can have the following outcomes:

UL94 V0(most stringent), UL94V1(good), UL94V2(least stringent of the test). 

HF-1(most stringent), HF-2(good), HBF(least string of the test)

Other specifications that are used to test flame retardancy/flame-spread include ASTM E162 ASTM E84, FMVSS NO. 302. We have not included more detail in these specifications as they are not used by all the products below. However, we have noted them appropriately. 

Silicone Foam Selections

Product Manufacturer UL94 Rating Firmness Other Ratings
F12 Saint Gobain V0 Very soft ASTM E162 <35
HT-800 Rogers Corporation V0, HF-1 Medium ASTM E162 <25, FMVSS 302(pass)
HT-840 Rogers Corporation V0, HF-1 Extra-Firm ASTM E162 <25, FMVSS 302(pass)
HT-870 Rogers Corporation V0, HF-1 Very soft ASTM E162 <25, FMVSS 302(pass)
HT-820 Rogers Corporation V0, HF-1 Firm ASTM E162 <25, FMVSS 302(pass)

Silicone Sponge Selections

Product Manufacturer UL94 Rating Density Other Fire Ratings
Norseal R10460 Silicone Sponge  Saint Gobain HBF Medium
Norseal R10400M Silicone Sponge Saint Gobain V0 Medium ASTM E162 Class B(26-75)

Silicone Rubber Selections

Product Manufacturer UL94 Rating Durometer Other Fire Ratings
HT-6360 Rogers Corporation V0(>.020’’) 65A ASTM E162 <10

For more information on flame retardant gasketing materials, or you believe you your application could use flame retardant gaskets please contact sales@nedc.com

Share this Article: