What are the fire safety standards for sliding doors?

Answer 1

It depends upon whether the door is used for egress or simply fire separation. In general, a sliding door cannot be counted as part of a required exit unless it also has an emergency hinged mode to swing out when pushed.

Specific rules of the local building code or NFPA 101 Life Safety Code (and similar) would determine the actual criteria for allowing them, if at all. Similar rules apply to roll-up fire doors that deploy automatically.

Sliding fire doors that are not within any exit path could have as much as a 5-hour fire rating, be automatically closing, could weigh hundreds of pounds, could automatically latch into place, and would probably kill anyone who got in the way or became trapped without another exit from smoke or fire.