Flammability UL 94 HB

Horziontal Burning

The horizontal burning test is used to determine the HB flammability rating of a material.

The flammability rating is calculated for a test specimen as a function of the burning rate and taking account of the material thickness.

Pre-treatment:
48 hours / 23°C / relative humidity

Flame application 20 mm high Tirill burner flame
Flame application time 30 s
If the flame front reaches the first mark within 30 s, flame application is discontinued. 

 

Test criteria Burning rate in V Flammability rating
Test specimen thickness 3 - 13 mm ≤ 40 mm/min HB
Test specimen thickness ‹ 3 mm ≤ 75 mm/min HB
Flame is extinguished before first mark = 0 mm/min HB