TL;DR
A UL listing is certification by Underwriters Laboratories that a product sample was tested to the applicable safety standard and that the factory submits to ongoing follow-up inspections, evidenced by the UL mark on the label. Electrical codes generally require listed equipment, listed by UL or an equivalent recognized laboratory such as ETL or CSA, and inspectors fail installations built with unlisted gear.
What it means
A UL listing is certification by Underwriters Laboratories that a product sample was tested to the applicable safety standard and that the factory submits to ongoing follow-up inspections, evidenced by the UL mark on the label. Electrical codes generally require listed equipment, listed by UL or an equivalent recognized laboratory such as ETL or CSA, and inspectors fail installations built with unlisted gear. The mark certifies the product as manufactured, not the installation, and counterfeit marks on imported electrical goods are common enough that the hologram label and file number are worth checking.
Where it sits in the glossary
UL listing is part of the Certifications group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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