I'd be interested in this actually. My labor is free.
Straight from the OSHA web site, found in CFR1910.106. I cut the applicable language from the standard; here it is for your review.
(Note the bold passage, the subject has never come up in my job so I would have to research further to explain what qualifies in terms of an approved grade of plywood, I don't think I would subject my newly constructed wooden cabinet to the fire test! See the last words highlighted, I cannot explain that at all. If I have time a bit later I might have to see if we have an ANSI standard addressing this, or perhaps check out approved plywood with NFPA. If I get something I will let you know.)
1910.106(d)(3)(ii)(a)
Metal cabinets constructed in the following manner shall be deemed to be in compliance. The bottom, top, door, and sides of cabinet shall be at least No. 18 gage sheet iron and double walled with 1 1/2 - inch air space. Joints shall be riveted, welded or made tight by some equally effective means. The door shall be provided with a three-point lock, and the door sill shall be raised at least 2 inches above the bottom of the cabinet.
1910.106(d)(3)(ii)(b)
Wooden cabinets constructed in the following manner shall be deemed in compliance. The bottom, sides, and top shall be constructed of an
approved grade of plywood at least 1 inch in thickness, which shall not break down or delaminate under fire conditions. All joints shall be rabbetted and shall be fastened in two directions with flathead woodscrews. When more than one door is used, there shall be a rabbetted overlap of not less than 1 inch. Hinges shall be mounted in such a manner as not to lose their holding capacity due to loosening or burning out of the screws when subjected to the
fire test.