Insulation, Radiant and Vapor Barriers - Drywall and Gypsum Board?

I am using a specific type of rigid foam insulation to insulate the concrete floor and walls of a sub-level basement (it's a Polyisocyanurate rigid foam with aluminum facers on each side). I have checked a few resources on the Internet to research this material. In each instance, it states this insulation requires an interior finish of a minimum of a half-inch of gypsum board or equivalent 15 minute fire barrier. Does drywall meet that standard, I have no idea if drywall if considered equivalent to gypsum board or if it is even a fire barrier? I planned to cover the insulation that will go in the walls with drywall. The same insulation will be used on the floor but covered only by 3/4 inch plywood that will be padded and carpeted. Thanks in advance.

Jim

to my understanding 5/8" drywall, will give you a 1 hour fire rating with the exception of cutouts..electrical outs and such... not sure what kind of gases that product may give off though..that is something you should consider prior to installing... foam boards can give off gases prior to the drywall burning through I believe..

Good Luck

Jim