# UL 1638 — Which OSHA-recognized labs (NRTLs) can certify to a given test standard

For UL 1638, standard title is Visual Signaling Appliances; nrtl is ITS; laboratory is Intertek Testing Services NA, Inc; status is currently recognized, recorded from its source on 2026-08-10.

- **Test standard:** UL 1638 _(verified: appears in the quote below)_
- **Standard title:** Visual Signaling Appliances _(verified: appears in the quote below)_
- **NRTL:** ITS _(verified: appears in the quote below)_
- **Laboratory:** Intertek Testing Services NA, Inc. _(verified: appears in the quote below)_
- **Status:** currently recognized _(our reading, not quoted from the source)_

## What the source says

> UL 1638 | Visual Signaling Appliances |

## Source

- https://www.osha.gov/nationally-recognized-testing-laboratory-program/its

Last verified: 2026-08-10. Review by: 2026-11-08.
Part of [Which OSHA-recognized labs (NRTLs) can certify to a given test standard](https://referencesource.org/nrtl-recognized-test-standards/).