Reference Source

UL 228

For UL 228, laboratory is UL LLC; standard title is Door Closers-Holders, and Integral Smoke Detectors, verified against its source on 2026-08-10.

Laboratory
UL LLC verified
Standard number
UL 228 verified
Standard title
Door Closers-Holders, and Integral Smoke Detectors verified
Sourceosha.gov
Verified
Review by
DatasetWhich OSHA NRTL is recognized for which test standard: all 21 labs' scopes of recognition, cross-referenced

What the source says

UL 228 | Door Closers-Holders, and Integral Smoke Detectors |

— osha.gov, retrieved 2026-08-10

Source

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