References for safety concerns

Looking for some references for safety concerns with HVAC rooms (gas furnaces) with missing ceiling areas in a small commercial structure. Several missing ceiling tiles in one unit and missing drywall in another. Would like to reference specific codes or standards/narratives. Thanks for the help!

You’re going to need to be more forthcoming and specific about the details of the structure and why you even feel it is a concern?

Concerned with lack of fire break, area opens directly into attic space above ceilings.

One unit is a rehab facility and had a recent fire marshal request replacement/repairs during an inspection. Occupant (not buyer) did not know what code the marshal was citing, but the buyer wants info to negotiate repairs prior to purchase. I do not have access to the fire marshal and he left no paperwork. I’ve not found the code/requirement available online.

So this is an apartment, office space, retail? We can’t help if you don’t supply ALL relevant information.

I assume you have been here in your research?..

3 separated office spaces in a 5000 sq/ft structure, 3 separate natural gas fired HVAC units located in mechanical rooms. (2 units are 90+ power vented units and one 80 mid efficiency natural draft unit)

No, very good resource link. Thank you.