UL 94 Flame Rated Gasket Materials

Flame resistance and fire safety are often top priorities for companies producing consumer, residential, and commercial products. Many products require UL or Intertek testing for flame resistance and flame propagation. The prevailing flammability test for rubber materials is UL 94. There are several tests under UL 94 including horizontal burn tests and vertical burn testing, vertical being more stringent than horizontal. There are special categories for foams (HBF and HF-1) and thin materials (VTM-0, VTM-1, VTM-2).

Best UL 94 Gasket Materials and UL 94 Pad Materials

Flame Retardant Materials
Materials Flame Rating Standard thickness Firmness Sealing Cushioning
Flame Rated Silicone Foam
UL 94V-0 .031″-0.5″
(6-14psi to compress 25%)
(UL 50E, NEMA 3, NEMA 4, IP64, IP65, IP66)
Good – moderate dampening, very good rebound
R10400 M
Flame Rated Silicone Sponge
UL 94V-0 .062″-0.5″
(9-14psi to compress 25%)
(NEMA 3, NEMA 4, IP64, IP65, IP66)
Good – moderate dampening, very good rebound
Fire Block Material
UL 94V-0 .062″, 0.125″, 0.25″
(1.59mm, 3.18mm, 6.35mm)
Firm N/A Good
Flame Rated Solid Silicone
UL 94V-0 .020″-0.125″
65 durometer Shore “A” Good
(NEMA 4, NEMA 6, IP67)
Flame Rated EMI Gasket
UL 94V-1
.062″ & 0.125″
(1.59mm & 12.7mm)
30 durometer Shore “A” Good
(NEMA 4, NEMA 6, IP67)
Conductive silicone
Flame Rated LSR
UL 94V-0 .031″-0.5″
50 durometer Shore “A” Good
(NEMA 4, NEMA 6, IP67)


Other Good UL 94 Flame Rated Materials:


Common Industries Gasket that Require Flame Rated Materials

  • Residential and commercial lighting gaskets (UL 496, UL 8750)
  • Commercial signage (UL 48)
  • Commercial cooking equipment and ventilation gaskets (NFPA 96)
  • Enclosure gaskets (UL 60950)
  • Industrial controls gasket (UL 508, UL 60947)
  • Handheld electronics cushioning pad and gasket (UL 94)
  • Rugged cushion pads and water seals (UL 94)
  • Flame rated EMI gaskets (UL 94)
  • Telecommunications base stations (UL 94)


FAR 25.853

FAR 25.853 is an FAA flame test for materials used in aircraft interiors. There are several tests including a Vertical Burn Test, 45 Degree Burn and Horizontal Burn test. FAR 25.853(a) relates to interior compartments occupied by crew or passengers. Materials must be self-extinguishing under the vertical burn test.

Flame Tested Components include:

  • Interior ceiling panels
  • Interior wall panels and partitions
  • Galley structure
  • Large cabinet walls
  • Structural flooring
  • Materials used in the construction of stowage compartments
Requirements for Vertical Burn:
Flame Time: Drip Flame Time: Burn Length:
Average not to exceed 15 seconds (60 second test or 12 second test) Average not to exceed 3 seconds for 12 second test Average not to exceed 6″ for 60 second test
Average not to exceed 5 seconds for 60 second test Average not to exceed 8″ for 12 second test

For details related to FAR 25.853, reference Federal Regulations,14 CFR Part 25.


UL 94V-0 Flame Retardant Silicone Sponge Burn Test Video

UL 94V-0 rated R10400 silicone sponge is exposed to a flame from a torch in this video. This is not an official UL test. Silicone foam and silicone sponge have a wide temperature range but without special chemistry they will burn. R10400 silicone sponge is formulated to meet an aggressive UL 94V-0 flame rating.


Contact Stockwell Elastomerics for Flame Retardant Gaskets and Flame Rated Gasket Materials

Contact Us for further assistance with custom UL 94 gaskets using flame rated gasket materials, including UL 94V-0, UL 94V-1, UL 94HBF, UL 94HF-1, FAR 25.853.