OSHA Nationally Recognized Testing Laboratory (NRTL) Program — UL and other NRTL listing

NRTL listing (of which UL listing is the best-known example) is product-safety certification by a private laboratory that OSHA has recognised under 29 CFR 1910.7. It is not a general legal requirement for selling consumer goods at retail, but OSHA workplace standards require certain equipment — notably electrical equipment — to be approved by an NRTL, and buyers frequently expect the mark in practice.

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Applies to

Products used in US workplaces where OSHA standards require 'approved' equipment — for example, electrical conductors and equipment under 29 CFR 1910.303, where 'approved' is defined through 29 CFR 1910.399 as acceptable when certified, listed or labeled by an NRTL. For consumer goods sold at retail, NRTL listing is generally voluntary at the federal level.

Key obligations

01OSHA's electrical standard makes conductors and equipment acceptable only if 'approved' (29 CFR 1910.303(a)); under the definitions in 29 CFR 1910.399, an installation or equipment is 'acceptable' (and therefore approved) if it is accepted, certified, listed, labeled or otherwise determined to be safe by a nationally recognized testing laboratory recognised under 29 CFR 1910.7.source
02Listed or labeled equipment must be installed and used in accordance with any instructions included in the listing or labeling (29 CFR 1910.303(b)(2)).source
03Certification must come from an OSHA-recognised NRTL: an NRTL is an organisation recognised by OSHA that tests for safety and lists, labels or accepts equipment, has the capability to test to appropriate test standards, and is completely independent of the manufacturers, vendors and employers concerned (29 CFR 1910.7(b)).source
04NRTL listing involves ongoing surveillance, not just one-time testing: the NRTL must implement procedures for identifying listed equipment, inspect production runs at factories, and conduct field inspections to monitor proper use of its identifying mark or labels (29 CFR 1910.7(b)(2)).source
05Beyond OSHA's workplace rules, major retailers, insurers and local authorities having jurisdiction (AHJs, e.g. electrical inspectors) frequently demand NRTL certification as a commercial or local-approval condition even where no federal rule requires it for the product.sourceUnverified — check source

Conformity routes

NRTL certification (listing/labeling)When OSHA workplace standards require approved equipment (e.g. electrical equipment under 29 CFR 1910.303 via the 1910.399 definitions), or when retailers, insurers or AHJs require the mark. Any OSHA-recognised NRTL may certify within its recognised scope — UL is one of several.source
Alternative acceptance where no NRTL certifies the equipment typeUnder 29 CFR 1910.399, equipment of a kind that no NRTL accepts, certifies, lists or labels can be acceptable if inspected or tested by another federal agency or by a state/municipal/local authority responsible for enforcing the National Electrical Code and found NEC-compliant; custom-made equipment may be determined safe by its manufacturer on the basis of retained test data.source

Documentation

NRTL certification (listing) and authorisation to use the NRTL's markIssued by the NRTL, not by OSHA. The NRTL maintains control procedures for identifying listed and labeled equipment, inspects production at factories, and field-inspects use of its mark (29 CFR 1910.7(b)(2)).source
Listing/labeling instructionsEmployers must install and use listed or labeled equipment in accordance with instructions included in the listing or labeling, so those instructions form part of the compliance documentation (29 CFR 1910.303(b)(2)).source

Marking requirements

Certified products bear the certifying NRTL's registered certification mark. Per OSHA, the mark signifies that the NRTL tested and certified the product and that the product complies with the requirements of one or more appropriate product safety test standards.source
There is no US government-issued product safety mark under this programme (no FCC-ID-style government identifier): certification is performed by private-sector organisations recognised by OSHA, and each NRTL applies its own mark.source

Penalties

OSHA penalties fall on employers, not product sellers: an employer using equipment that is not approved as required can be cited, with civil penalties per violation (higher for willful or repeated violations) that OSHA adjusts periodically for inflation. There is no OSHA penalty for simply selling an unlisted consumer product at retail.sourceUnverified — check source

Further guidance

Frequently asked

Is UL listing required by law to sell my product?+

For most consumer goods sold at retail, no federal law requires UL or any NRTL listing. The legal requirement is OSHA's: certain equipment used in workplaces — notably electrical equipment — must be approved, which in practice means certified, listed or labeled by an OSHA-recognised NRTL. Separately, retailers, insurers and local electrical inspectors often insist on an NRTL mark as a commercial condition, so many products are certified even when the law does not demand it.

Is UL the only lab that can certify my product?+

No. UL LLC is one of the laboratories on OSHA's current list of recognised NRTLs, which includes many others (for example CSA Group, Intertek, TUV Rheinland of North America, TÜV SÜD America and SGS North America). Certification from any NRTL, within the scope of products and standards for which OSHA recognises it, satisfies the OSHA approval requirement.

Is the NRTL mark a government approval mark?+

No. OSHA recognises the laboratories, but the testing and certification are done by private-sector organisations, and the certification mark on the product belongs to the individual NRTL. Unlike FCC certification of radio equipment, there is no government-issued identifier for NRTL-certified products.

Is NRTL listing a one-time test?+

No. Under 29 CFR 1910.7 an NRTL must inspect production runs at factories to check continued conformance and conduct field inspections to monitor use of its mark, so a listing comes with ongoing factory surveillance and the certifier can withdraw the right to use its mark.

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