UL/CSA certification: straight answers for European machine builders

No — and yes. The distinction is not a technicality, and getting it wrong costs money in both directions.

No, in the sense that matters legally to you: there is no U.S. federal requirement that a manufacturer certify a machine before selling it. OSHA says so itself, in writing:

“OSHA’s authority is limited to employers; therefore, OSHA does not require manufacturers or suppliers, as applicable, to have the products they manufacture or supply certified by an NRTL.”

OSHA, NRTL Program FAQ — Product Manufacturers and Suppliers

There is no American equivalent of the Machinery Directive: no conformity assessment before placing on the market, no mandatory safety mark applied by the manufacturer, no market surveillance authority that stops the machine at the border for lack of a UL mark.

Yes, in the sense that decides whether you get paid. OSHA regulates the employer — your customer. Electrical equipment in an American workplace is acceptable only if approved (29 CFR 1910.303(a)), and “approved” leads through a chain of definitions that ends at a testing laboratory OSHA recognises. OSHA has confirmed in writing that an industrial machine using electrical energy is utilization equipment covered by that rule — the whole machine, not just its components.

So your customer cannot lawfully put an unapproved machine into service. They know it, their EHS manager knows it, and their insurer knows it. The requirement reaches you through the purchase order rather than through the law — which is why it is negotiable in ways a legal obligation is not, and why it has to be settled before the contract, not after the crate is open.

• What the whole route looks like — U.S. market access for EU manufacturers
• Who can actually issue the certificate — NRTL listing and field evaluation

To the United States: yes, legally — and no, practically. To Canada: no, and in several provinces you are already in breach before the machine ships.

On the CE mark itself, OSHA leaves no room for interpretation:

“The CE mark is unrelated to the requirements for product safety in the United States.”

OSHA, NRTL Program FAQ

OSHA says the same about ATEX certification: for equipment in explosive atmospheres in the U.S. you need the mark of a laboratory recognised for the relevant American test standards, not an ATEX certificate.

This is not an oversight anyone is about to correct. The European Commission formally asked OSHA to accept a Supplier’s Declaration of Conformity — self-declaration, the CE mechanism — arguing the American system was a technical barrier to trade. OSHA analysed the proposal and in December 2010 declined to open a rulemaking, concluding that self-declaration “would not provide the high degree of protection required by the Occupational Safety and Health Act of 1970.” The question has been asked at the highest institutional level and answered.

Canada works the other way round, and this surprises everyone. There, the prohibition attaches to the act of selling. In Ontario, no person may “use, advertise, display, sell, offer for sale or other disposal” an electrical product unless it has been approved. Offering an unapproved machine for sale is the violation — the machine does not have to arrive first. In Quebec, selling, renting or installing unapproved electrical equipment is prohibited.

• The two countries, side by side — NRTL listing and field evaluation

Four things, and only one of them is the one everybody talks about.

1. Settle the electrical approval question before you quote. Not after. The route you choose — certification by a recognised laboratory, or the documented route for genuinely one-off equipment — changes your design, your bill of materials and your schedule. It is a design decision disguised as a paperwork decision. See Q5.

2. Design the electrical equipment to American practice, not European practice. A control panel built to EN 60204-1 and EN 61439-1 is not “nearly compliant” with NFPA 79 and UL 508A. Control voltage, conductor colours, conductor types, the disconnecting means and the short-circuit current rating on the nameplate are all different requirements, not different wording of the same requirement.

3. Check the federal obligations that do land on you. This is the part that gets missed while everyone worries about UL. Three examples that catch machine builders:

• Radio-frequency emissions. The FCC prohibits marketing a radio frequency device without authorisation, and “marketing” includes importation. Industrial machines are often exempt from the specific technical standards — but the exemption is conditional and falls away if even one device in the equipment does not qualify, so it is checked, not assumed. Note the irony: the FCC accepts a Supplier’s Declaration of Conformity, the very mechanism OSHA rejected.
• Lasers. If your machine contains a laser, a separate federal regime applies to you directly, with a report to the FDA before the product is introduced into commerce. See Q9.
• Electric motors. Efficiency certification obligations under the Department of Energy rules reach the manufacturer and importer.

4. Give your customer the file they are legally required to hold. Whatever route you take, the evidence has to sit in the American plant, in English, where an inspector can ask for it. Producing it is your job; keeping it is theirs. Say so in the contract.

• The full picture, in order — U.S. market access for EU manufacturers

A private laboratory that OSHA has recognised as competent to test and certify products against American safety standards. OSHA created the programme so that certain equipment would be tested and certified as safe for use in the workplace; the regulations date from 1988 and the first organisation was recognised in 1989.

To be recognised under 29 CFR 1910.7, an organisation must have:

• the capability to test and evaluate equipment against the appropriate test standards;
• adequate controls for identifying certified products, and follow-up inspection of actual production;
• complete independence from the employers subject to the requirements and from any manufacturer or vendor of the products it certifies;
• effective procedures for producing its findings and for handling complaints and disputes.

Three things about NRTLs that are worth more than the definition:

“UL” is a company, not a requirement. OSHA recognises around twenty laboratories, including CSA Group, TÜV Rheinland of North America, TÜV SÜD America, Intertek, DEKRA, Nemko, SGS, Eurofins and QPS. No OSHA electrical standard names any of them. You can put them in competition on price and lead time, and several have European operations.

Recognition is granted for specific test standards and specific sites. A certificate issued against a standard outside that laboratory’s scope, or from a site OSHA has not recognised, does not produce the legal effect you are paying for. Check both before you sign the order — it is two verifications, not one.

OSHA does not approve, test or endorse products. There is nothing to apply for and no agency to contact. If someone offers to sell you an “OSHA approval,” that tells you something about them.

• How to choose, and what it costs you in design time — NRTL listing and field evaluation

No. This is the single most expensive misunderstanding on this page, because the manufacturers who make it are the ones who did the most work.

The laboratory being recognised is not enough. The test standard must be an American one, within that laboratory’s scope of recognition. OSHA answered exactly this question for a control panel builder holding a CSA certificate issued to a Canadian standard: electrical equipment required to be NRTL approved and used in the United States “must conform to US recognized test standards.” CSA is a recognised NRTL — the certificate still did not do the job, because of the standard it was issued against. OSHA pointed to UL 508 as the applicable American standard.

International standards can be used, but only once an American standards body has harmonised them to U.S. requirements — which is why UL 61010, UL 60947 and similar documents exist. Your IEC file is not transferable as it stands, and it is not worthless either: it is the raw material for a gap analysis. Knowing which of your existing test reports and drawings survive that analysis is the difference between a project and a restart.

And certification creates obligations of its own. Once equipment is listed or labeled, it must be installed and used in accordance with the instructions in that listing. A certificate carrying restrictive conditions of use can generate violations at your customer’s site — and your customer will hold you responsible for them. Those conditions are negotiated with the laboratory, not accepted as they come.

• What actually transfers, clause by clause — NFPA 79 and EN 60204-1
• And for the panel — UL 508A control panels

There is a legal route built for exactly this case, and it is narrower than people hope.

The definition of “acceptable” in 29 CFR 1910.399 has three branches. The third covers custom-made equipment designed and fabricated for a particular customer, where it is “determined to be safe for its intended use by its manufacturer on the basis of test data which the employer keeps.”

Read the end of that sentence carefully, because it is the part that gets missed. The manufacturer makes the determination — but the employer keeps the data. Filing the technical file at your premises in Europe, the way you would for the Machinery Directive, does not satisfy this. The test evidence has to be in the American plant, available to an inspector, in English. That is a contractual deliverable, and it should be priced as one.

Two limits worth knowing before you build a strategy on this branch:

• “Custom-made” means one of a kind. OSHA has confirmed the term covers a one-of-a-kind piece of equipment fabricated for a specific customer. Equipment produced repeatedly to order for different customers does not qualify — which excludes a great deal of what manufacturers call “custom.”
• OSHA regards it as rare. Its own words: “Custom-made equipment, by its nature, is very rare.” And in the same 2007 preamble it notes that federal, state and local authorities generally look to recognised laboratories for equipment approval. The route is legally sound and practically unusual, so the file has to be impeccable — it will be read sceptically.

• The decision, with what each route costs you — NRTL listing and field evaluation

No, and the difference is not cosmetic. This answer will contradict something you have probably been told.

Field evaluation is sold across Europe as the standard solution for the machine that cannot be certified in the factory: an inspector visits the site, evaluates the equipment and applies a label. For the local electrical inspector — the authority having jurisdiction who signs off the installation under the state electrical code — it is often exactly the right answer.

For OSHA, it is a different question, and OSHA has answered it. Asked whether an independent body describing itself as a “Field Inspection Body” could make equipment acceptable where a recognised laboratory was willing to do the same work, OSHA replied:

“The Field Inspection Body is not a NRTL, so its approval would not make the equipment or installation ‘acceptable’ for purposes of Subpart S.”

OSHA letter of interpretation, 16 December 2013, answer 4

The reason is in the text. “Listed” and “labeled” both require a laboratory that makes periodic inspections of the production of the equipment — and a one-off has no production to inspect. The second branch of “acceptable” needs a public authority, and only for equipment of a kind no recognised laboratory will handle at all.

The practical consequence is a purchasing decision. If you go the field evaluation route in the United States, use a body that is itself an OSHA-recognised NRTL. Otherwise your customer can pay for the evaluation and still receive a citation. These are two separate legal tracks — the workplace one and the installation one — and a machine can satisfy one while failing the other.

• Both tracks, and who signs off each — NRTL listing and field evaluation

It is not federal law, there is no such thing as an NFPA 79 certification, and you should build to it anyway. All three statements are true at once.

NFPA 79 is not adopted into OSHA’s regulations: the list of standards incorporated by reference in 29 CFR 1910.6 contains a long run of NFPA documents and neither NFPA 79 nor the National Electrical Code is among them. Nor does NFPA 79 appear in OSHA’s list of test standards approved for use in the NRTL programme — which contains UL 508, UL 508A and UL 61010-1. So if you ask a laboratory to “certify the machine to NFPA 79,” you are asking for something that does not exist in that programme.

It still decides outcomes, through three doors:

• The National Electrical Code, adopted state by state and city by city rather than federally, points to NFPA 79 for industrial machinery — and the local inspector signs your customer’s installation permit.
• OSHA has stated that where no specific OSHA standard covers an electrical hazard, it may apply consensus standards, naming ANSI/NFPA 79 expressly.
• Your customer’s purchase order, which is usually where you meet it first.

So the honest formulation is: NFPA 79 is not the law, but it is the yardstick you will be measured against — by the inspector, by OSHA after an incident, and by your customer’s engineering department. Building to it is a commercial decision with a clear rationale, not a legal obligation someone can cite at you.

• The delta from EN 60204-1, clause by clause — NFPA 79

Yes — a completely separate federal regime, and this one does land on you directly.

Laser products in the United States are not regulated through workplace rules. They fall under the Food, Drug, and Cosmetic Act and 21 CFR, administered by the FDA’s Center for Devices and Radiological Health. There is no approval and no notified body: the manufacturer certifies the product against the federal performance standard, applies certification and identification labels in English, and files a report with the FDA before the product is introduced into commerce. The report receives an accession number, which is not an approval but is what customs expects to see.

Three points that decide whether this goes smoothly:

• A foreign manufacturer must designate a permanent resident U.S. agent, in writing, before offering the product for import. It is the American mirror image of the EU Authorized Representative — and it catches manufacturers who have never needed one.
• Integrating somebody else’s certified laser does not get you out of it. If you build the machine around the laser, you are a manufacturer under these rules in your own right.
• Your IEC 60825-1 work is partly reusable, through a route that changed recently. The FDA allows conformance to the IEC standard in place of parts of the federal standard — but under Laser Notice 56. Laser Notice 50, which the industry quoted for two decades and which is still cited in supplier documentation today, was withdrawn on 31 December 2024. If a checklist or a component supplier still refers to Laser Notice 50, it is working from a superseded document.

• The whole route, including the U.S. agent — FDA laser product registration

A voluntary industry guideline that behaves like a mandatory requirement, because it arrives in the purchase order rather than in the law.

SEMI is an industry association, not a regulator. Its S-series are safety guidelines, and SEMI S2 is the environmental, health and safety guideline for semiconductor manufacturing equipment. It is not law in the United States or in Canada, and OSHA lists these standards while stating plainly that they are not OSHA regulations.

What makes it binding is the contract. Fab purchasing specifications routinely require a third-party SEMI S2 evaluation report before delivery, with the right to refuse the equipment or cancel the order if it is missing.

Three things nobody tells you until you are in the middle of it:

• There is no “SEMI S2 certification.” SEMI does not accredit or certify anyone and keeps no register of evaluators. What you get is an evaluation report, valid for the model and serial number evaluated — not a certificate, and not transferable to the next machine.
• It is not pass/fail. The guideline defines several outcomes, including one that lets you meet the performance goal without meeting the letter of a criterion — but only where the residual risk is low. High-severity items, and code items that would affect field labeling, are marked as non-conforming regardless.
• It does not replace electrical approval. No SEMI standard appears in OSHA’s list of test standards for the NRTL programme. An S2 report is not and cannot become a listing. The two run in parallel and you need both.

• What an S2 evaluation involves — SEMI S2/S8 equipment safety