and Appliances includes small scale tests that evaluate the flammability of polymeric
(plastic) materials, used for parts in devices and appliances, in response to a small,
open flame or radiant heat source under controlled laboratory conditions. The scope
of UL 94 clearly indicates that it does not cover polymeric materials used for building
construction, finishing or contents such as wall and floor coverings, furnishings or
decorative objects. The results of most UL 94 flammability tests are not applicable to
materials whose thickness exceeds 13.0 mm, or whose surface area exceeds 1m2.
The UL 94 Standard provides a method for rating the ignition characteristics of plastic
materials. Two UL 94 ratings that code officials commonly run across are HB and V (V-0,
V-1, or V-2). These ratings are established using small-scale tests in which approximately
5 by ½ inch samples are subject to a ¾ inch, 50W tirrel burner flame ignition source. To
achieve a HB rating, test samples, placed horizontally, burn slowly across the sample