In hazardous locations, the employer must make sure every wiring component and item of utilization equipment is maintained in the explosion-proof, dust-ignition-proof or dust-tight state that suits it. That means no screws, gaskets, seals or threaded connections loose or missing, and no other defects that would compromise a tight condition. The duty is continuing: equipment that was approved for the classified location on installation must be kept in that condition throughout its use on the job, so enclosures opened for servicing are to be put back with every fastener, gasket and seal in place.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.