# UL 1053 — Which OSHA NRTL is recognized for which test standard: all 21 labs' scopes of recognition, cross-referenced For UL 1053, laboratory is CSA Group Testing and Certification Inc; standard title is Ground-Fault Sensing and Relaying Equipment, verified against its source on 2026-08-10. - **Laboratory:** CSA Group Testing and Certification Inc. _(verified: appears in the quote below)_ - **Standard number:** UL 1053 _(verified: appears in the quote below)_ - **Standard title:** Ground-Fault Sensing and Relaying Equipment _(verified: appears in the quote below)_ ## What the source says > UL 1053 | Ground-Fault Sensing and Relaying Equipment | ## Source - https://www.osha.gov/nationally-recognized-testing-laboratory-program/csa Last verified: 2026-08-10. Review by: 2026-12-08. Part of [Which OSHA NRTL is recognized for which test standard: all 21 labs' scopes of recognition, cross-referenced](https://referencesource.org/nrtl-recognition-scopes/).