UL 551

For UL 551, laboratory is Intertek Testing Services NA, Inc; standard title is Transformer-Type Arc-Welding Machines, verified against its source on 2026-08-10.

Laboratory: Intertek Testing Services NA, Inc. verified
Standard number: UL 551 verified
Standard title: Transformer-Type Arc-Welding Machines verified

Sourceosha.gov

Verified2026-08-10

Review by2026-12-08

DatasetWhich OSHA NRTL is recognized for which test standard: all 21 labs' scopes of recognition, cross-referenced

What the source says

UL 551 | Transformer-Type Arc-Welding Machines |

— osha.gov, retrieved 2026-08-10

Source

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

Last verified against source: 2026-08-10. Due for re-check by 2026-12-08. This page as Markdown · OKF bundle · full dataset as JSON.