Determine whether UL 10B or UL 10C applies when specifying fire testing for a rolling steel fire shutter.

Steps

1. Check UL 10C's own stated scope: its test methods apply solely to swinging door assemblies (including frames with lights and panels) and explicitly do not cover sliding, rolling/coiling, or elevator-entrance assemblies.
2. Check UL 10B's scope: it applies broadly to door assemblies 'of various materials and types of construction' for use in wall openings, which is the standard applicable to rolling/coiling steel fire doors and shutters.
3. For a rolling steel fire shutter, specify testing/listing under UL 10B (and confirm whether the product's listing also references NFPA 252, the related fire-test-methods standard for door assemblies), not UL 10C.
4. If the opening also requires positive-pressure fire performance and involves a swinging door component elsewhere in the assembly, evaluate that separate component against UL 10C on its own terms.
5. Confirm the specific product's UL listing documentation states which standard(s) it was actually tested and certified under, rather than assuming based on door type alone.