EN 50525-3-21 applies to flexible cables, insulated and sheathed with halogen-free crosslinked compound and having low emission of smoke and corrosive gases when exposed to fire. NOTE 1 Low emission of smoke is checked in accordance with EN 61034-2. Low emission of corrosive gases is checked as part of the check for absence of halogens (see Annex B of EN 50525-1). The cables are of rated voltage U0/U 450/750 V. The cables are intended for the connection of equipment and machinery to the fixed supply. The maximum conductor operating temperature for each of the cables in this standard is 90 °C. NOTE 2 HD 516 contains extensive guidance on the safe use of cables in this standard. This EN 50525-3-21 should be read in conjunction with EN 50525-1, which specifies general requirements.