ISO 6942 specifies two complementary methods (method A and method B) for determining the behaviour of materials for heat protective clothing subjected to heat radiation.

These tests are carried out on representative single or multi-layer textiles or other materials intended for clothing for protection against heat. They are also applicable to assemblies, which correspond to the overall build up of a heat protective clothing assembly with or without underclothing.

Method A serves for visual assessment of any changes in the material after the action of heat radiation. With method B, the protective effect of the materials is determined. The materials may be tested either by both methods or only by one of them.

The tests carried out according to these two methods serve to classify materials; however, to be able to make a statement or prediction as to the suitability of a material for protective clothing, it is necessary to take into account additional criteria.

Since the tests are carried out at room temperature, the results do not necessarily correspond to the behaviour of the materials at higher ambient temperatures and therefore are only to a limited extent suitable for predicting the performance of the protective clothing made from the materials under test.