NEMA Type 9 Enclosures Only for Class II Hazardous Locations?

Currently NEMA only defines Type 9 Enclosures for Class II Hazardous Locations. In contrast, Dusttight enclosures are referenced in NEMA 250 solely for Nonhazardous Locations.(Table 1) This conflicts with NFPA 70 Articles 500 & 502 in addition to the OSHA HazLoc regulation 1910.307 where dusttight enclosures are compliant in Class II Division 2 HazLoc.

Would clarification in future revisions of NEMA 250 assist stakeholders in providing consistency with NFPA 70 Articles 500 & 502 and the OSHA HazLoc regulation regarding dusttight enclosures in Class II Division 2 HazLoc?

Resource
NEMA Enclosures for Nonhazardous & Hazardous Locations