Yes, there is no provision in the national fire door standard, but there are provisions in some special places, considering the evacuation of people. Mostly in some industry standards. For example, WH 0502-96 "Technical Standard for Fire Safety of Public Library Buildings" 5.2.3 The doors on the partition wall of fire protection zones of stacks and non-book databases should be Class A fire doors; The clear width of the fire door leading to the cashier in the basic stack room should not be less than 1.4m, and no threshold should be set; Steps or ramps should not be set within the range of 1.4m near the door.