Fire rated frames and doors labels are used to prevent the passage of fire and smoke between two compartments. Fire rated frames and doors labels are used as a passive means of protecting people and property from fires. Model codes in the United States generally reference NFPA 80 : Standard for Fire doors and Others Openings Protectives when it comes to installation and maintenance of fire doors.
The International Building Code and International Residential Code require that fire rated frames and doors be given a fire-resistance rating after extensive testing by an approved agency. There are a number of testing agencies in the United States, but some well-known agencies that test and certify fire doors include Underwriters Laboratory (UL), Intertek Testing Services (Intertek ETL), and QAI Laboratory, LTD (QAI). Doors are tested following standards, including UL10B, UL10C, ASTM E2074, and NFPA 252.
After it has been tested, the door and frame receive a label that describes the amount of time the component is expected to provide protection when exposed to fire. When combined, all of the components of the door form an assembly that protects the opening. For this reason, all components of the door must include a rating label, including the door panel, the door frame, lock sets, gaskets, hinges, and door protection plates. In other cases, the entire assembly (including all hardware) has a single rating.
A permanent label is attached to the door panel and the door frame, usually on the hinge side of both. Most other components have a testing agency symbol formed or stamped into the material to identify that the testing agency confirms the components meet the testing requirements.
S-Label or Smoke Rating
Many codes require an S-Label for certain doors in some occupancies. For instance, corridor doors often require smoke protection to prevent smoke from leaking from or into an occupied space.
S-label is not exactly a smoke rating. But, the S-label indicates the door meets the leakage tests that are part of UL 1784: Standard for Air Leakage Tests of Door Assemblies and Other Opening Protectives. However, smoke cannot pass through if air cannot leak through the door assembly. An S-label is usually achieved by installing UL approved gasketing.
Annual Fire Rated Door Inspection
National Fire Protection Association, NFPA 80-2019 (5.2.4) requires that fire rated doors be inspected each year to confirm that the door is in good condition and that all of the required components work as required. The building owner is responsible for having the inspections done by a qualified person and for maintaining proper records of the inspections.