Difference between UL10D and UL10B

December 15, 2021
Casandra Murphy

UL 10D evaluates Fire Protective Curtain Assemblies that provide supplemental, passive fire protection as part of an engineered fire protection system. These methods are intended to assess the ability of fire-protective curtain assemblies to remain in a horizontal or vertical opening during a predetermined test exposure.

Fire-protective curtain assemblies provide nonstructural separation only and are not intended to be substituted for structural hourly rated partitions or opening protectives that have been tested for fire endurance and hose stream performance.

UL 10B is the UL Standard for Safety Fire Tests of Door Assemblies. These fire tests apply to door assemblies of various materials and types of construction for use in wall openings to retard the passage of fire and evaluate the ability of a door assembly to remain in an opening during a predetermined test exposure. The tests expose a specimen to a standard fire exposure controlled to achieve specified temperatures throughout a specified time period, followed by the application of a specified standard fire hose stream.

Both tests are not representative of all fire conditions, which vary with changes in the amount, nature, and distribution of fire loading, ventilation, compartment size, and configuration. All of this can affect the performance of the assembly in a real-life situation.

UL 10B does not address smoke, nor UL 10D . The smoke test standard is UL 1784 – The purpose of the test is to determine only the resistance of a door assembly, in the closed position, to air leakage resulting from a specified air pressure difference applied across the surface of the entire door assembly. These requirements cover the investigation of air leakage through door assemblies installed in wall openings where air leakage is intended to be controlled.