# UL 307B — Which OSHA-recognized labs (NRTLs) can certify to a given test standard For UL 307B, standard title is Gas Burning Heating Appliances for Manufactured Homes and Recreational Vehicles; nrtl is UL; laboratory is UL LLC; status is currently recognized, recorded from its source on 2026-08-10. - **Test standard:** UL 307B _(verified: appears in the quote below)_ - **Standard title:** Gas Burning Heating Appliances for Manufactured Homes and Recreational Vehicles _(verified: appears in the quote below)_ - **NRTL:** UL _(verified: appears in the quote below)_ - **Laboratory:** UL LLC _(verified: appears in the quote below)_ - **Status:** currently recognized _(our reading, not quoted from the source)_ ## What the source says > UL 307B | Gas Burning Heating Appliances for Manufactured Homes and Recreational Vehicles | ## Source - https://www.osha.gov/nationally-recognized-testing-laboratory-program/ul 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/).