UL 641
For UL 641, standard title is Type L Low-Temperature Venting Systems; nrtl is UL; laboratory is UL LLC; status is currently recognized, recorded from its source on 2026-08-10.
- Test standard
- UL 641 verified
- Standard title
- Type L Low-Temperature Venting Systems verified
- NRTL
- UL verified
- Laboratory
- UL LLC verified
- Status
- currently recognized our reading
Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.
What the source says
UL 641 | Type L Low-Temperature Venting Systems |
— osha.gov, retrieved 2026-08-10
Source
- osha.govhttps://www.osha.gov/nationally-recognized-testing-laboratory-program/ul