TR TS 012/2011, On Safety of Equipment for Operation in Explosion-Prone Environments
Equipment ofGroup I intended for use in underground mine shafts and ground level mine structures that may contain mine gas and/or flammable dust.
Group II equipment intended for use in explosion-prone gaseous environments (except for underground mines and their ground level structures) (subgroups IIA, IIB, IIC).
Group III equipment intended for use in explosion-prone dust environments (subgroups IIIA, IIIB, IIIC).
Non-electrical equipment intended for use in explosion-prone environments.