UL 555 — Fire Dampers
Reference: UL 555 · Scheme: OSHA NRTL product safety. The 3 laboratories below appear in the Current list of Nationally Recognized Testing Laboratories for this standard. Retrieved July 2026; ranking criteria on the methodology page.
| # | Laboratory | Location | Cert / ID | Approved | Registry accreditations |
|---|---|---|---|---|---|
| 1 | Intertek Testing Services NA, Inc. | Lake Forest, California, United States | — | — | 9 |
| 2 | UL LLC | Northbrook, Illinois, United States | — | — | 6 |
| 3 | Southwest Research Institute | San Antonio, Texas, United States | — | — | 1 |
Facts reproduced from the linked registry as retrieved July 2026. No ratings, no reviews — see methodology.