EN ISO 11612 Clothing giving protection against heat and flames
Protective clothing that is intended to provide protection against brief contact with flames and at least one type of heat. The heat can be convective, radiant or caused by large splashes of molten metal - or can occur in a combination of these effects. The requirements on limited flame spread must always be met.
Code A1-A2 = Protection against limited flame spread
Code B1-B3 = Protection against convective heat
Code C1-C4 = Protection against radiant heat
Code D1-D3 = Splashes of molten aluminium
Code E1-E3 = Splashes of molten iron
Code F1-F3 = Contact heat