We've recently done a great deal of research on this NRTL stuff and I can offer you the following comments based on research, conversations with, and letters to OSHA on some of the issues.
There are currently
27 States with their own OSHA body, however they're still required to enforce rules and regulations which are not less restrictive than the Fed's (29 CFR 1902.3(c)(1).
Only OSHA may define a NRTL and provides guidelines that they must follow (29 CFR 1910.7(b).
Product safety testing standards are defined in 29 CFR 1910.6. In some cases a standard does permit field certifications but that would be something written into the body of the standard.
Not all NRTL's are accredited with testing stuff. The
OSHA's NRTL Web Site provides a list of those bodies that are considered by OSHA to be a NRTL and what they accredited to test to.
The AHJ (Authority Having Jurisdiction) is not the local state electrical, building, or fire inspector, it is OSHA. OSHA will issue citations for offenses regardless of what the state electrical, building, or fire inspector approved.
In terms of fire protection equipment, there are 3 exceptions to the rules requiring the equipment to be listed:
- There is no NRTL that lists or tests such equipment (29 CFR 1910.155(3)(ii))
- The equipment has been tested and found to be acceptable by another Federal Agency (29 CFR 1910.155(3)(ii)).
- The equipment is fabricated and intended to be used by the manufacture, and has been tested with documentation made available to OSHA for inspection (29 CFR 1910.155(3)(iii)).
Our experience is based on working with three (3) State agencies, OSHA in Washington DC, and the USCG. All of the issues centered around fire protection, however I suspect the requirements for the other subparts of OSHA are very much similar.