This part of IEC 62821 specifies test methods which are particular for cables with insulation, and sheath based on halogen-free, thermoplastic compound, and having low emission of smoke and corrosive gases when exposed to fire, of rated voltages  U₀/U up to and including 450/750 V a.c.

General requirements are specified in IEC 62821‑1 and particular types of flexible cables are specified in IEC 62821‑3.