This document stipulates the product classification, basic parameters, environmental conditions, basic requirements, technical requirements, test methods, inspection rules, marking, packaging, storage, transportation and quality commitment of explosion-proof distribution boxes (hereinafter referred to as "distribution boxes"). This document is applicable to distribution boxes used in Class 1, 2, Class ⅡA, ⅡB, ⅡB+H2 or ⅡC Group T1~T6 explosive gas environments and/or Class 21, 22 Class ⅢA, ⅢB, ⅢC explosive dust environments .