NRTL listing, field evaluation, and the one-off machine
There are two authorities to satisfy in the United States and they ask different questions. Most projects that go wrong went wrong by answering only one of them.
The first is OSHA, and its question is about the workplace: may your customer’s employees work on this machine? The second is the authority having jurisdiction — the electrical inspector who signs off the installation under the code your customer’s state has adopted. The same machine can satisfy one and fail the other.
Knowing which route serves which authority is not a formality. It decides whether the machine gets energised on schedule, and it has to be decided at quotation stage, because each route asks something different of the design.
| OSHA | authority having jurisdiction | |
|---|---|---|
| Route 1: certification | OSHAauthority having jurisdictionfederal, state and local authorities generally look to recognised laboratories for equipment approval | |
| Route 2: documented | OSHAon the basis of test data which the employer keeps | authority having jurisdictionthe file will be read sceptically |
| Route 3: field evaluation | OSHAWe are deliberately not telling you that an NRTL field label satisfies OSHA. | authority having jurisdictionit is often exactly right |
Route 1: certification by a recognised laboratory
The main road. A Nationally Recognized Testing Laboratory tests the equipment against an American test standard and authorises its mark.
Three things about this that are routinely got wrong, and each costs money:
“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. Several have European operations, and you can put them in competition on price and lead time.
Recognition is granted for specific test standards and specific sites. A certificate issued against a standard outside that laboratory’s scope of recognition — or from a site OSHA has not recognised — does not produce the legal effect you are paying for. That is two checks before you sign the order, not one.
Fact — check it yourself
The standard has to be an American one.
This is the trap that catches the manufacturers who did the most work. OSHA answered exactly this for a control panel builder holding a CSA certificate issued to a Canadian standard: equipment required to be NRTL approved and used in the United States “must conform to US recognized test standards.”
CSA is a recognised laboratory — the certificate still did not do the job, because of the standard behind it.
OSHA letter of interpretation, 11 May 2004 (Penmar Automation)
International standards can be used once an American standards body has harmonised them, which is why UL 61010 and UL 60947 exist.
There is no NFPA 79 certification. NFPA 79 does not appear in OSHA’s list of test standards approved for the NRTL programme, which contains UL 508, UL 508A and UL 61010-1. If someone quotes you for “NFPA 79 certification,” they are quoting for something that does not exist in that programme. NFPA 79 still matters enormously — as the design basis, and as the yardstick you will be measured against — but you cannot buy a certificate for it.
Fact — check it yourself
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 can generate violations at your customer’s site, and your customer will hold you responsible. Those conditions are negotiated with the laboratory, not accepted as issued.
29 CFR 1910.303(b)(2)
Route 2: the documented route for genuinely one-off equipment
Fact — check it yourself
The definition of acceptable in OSHA’s rules has a third branch, written for exactly this case:
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 again. You make the determination; your customer holds the evidence.
29 CFR 1910.399
Filing the technical file at your premises in Europe — the reflex you have built up under the Machinery Directive — does not satisfy this. The test evidence has to be in the American plant, in English, available when an inspector asks. That is a contractual deliverable, and it should be scoped and priced as one.
Two limits 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 most of what the industry calls “custom.”
- OSHA considers it rare. Its own words: “Custom-made equipment, by its nature, is very rare.” And in the same document 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 will be read sceptically. It has to be built to be read that way.
Route 3: field evaluation, and what it is actually worth
This is the section that will contradict something you have been told, so it comes with the citation.
Field evaluation is sold across Europe as the standard answer for the machine that cannot be certified in the factory: an inspector comes to site, evaluates the equipment, applies a label. For the local electrical inspector it is often exactly right — the authority having jurisdiction has discretion to approve, and a field label is how that discretion is usually exercised.
For OSHA it is a different question, and OSHA has answered it in writing. 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 definitions. 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 requires a public authority, and only for equipment of a kind no recognised laboratory will handle at all. OSHA’s own NRTL programme directive defines the scope of recognition as test standards and sites, and defines field inspection as surveillance of products the laboratory has already certified — not the evaluation of uncertified equipment.
The purchasing decision that follows is worth stating plainly. If you take 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 — and the argument that the laboratory’s involvement made the equipment acceptable rests on a reading of the text that OSHA has never confirmed for a field label as such.
What this is not
We are deliberately not telling you that an NRTL field label satisfies OSHA.
Nobody can tell you that with a citation in hand, because OSHA has not said it. What we can tell you is which reading is defensible, what it rests on, and how to structure the evidence so that the question is as strong as it can be made.
Canada: a different system, not the other half of this one
“UL/CSA” is spoken as one thing. It is two, and the Canadian one works closer to the European logic you already know — with one reversal that changes your project plan.
The prohibition attaches to selling, not to using. In Ontario, no person may use, advertise, display, sell, offer for sale an unapproved electrical product. Offering the machine is already the violation; the machine does not have to arrive first.
In Quebec, selling, renting or installing unapproved electrical equipment is prohibited. There is no equivalent of the American custom-made branch.
The province decides, not the federal government. Ontario, British Columbia and Quebec each adopt the Canadian Electrical Code with their own amendments and their own timing. Federal rules reach only federally regulated workplaces. There is no single “Canadian body” to approach — a question we are asked constantly, and the honest answer is that it does not exist.
Approved components do not make an approved assembly. Ontario’s regulation says so in the text: the product as assembled must itself be approved. This is the argument European builders reach for first, and in Canada it is answered before it is made.
Three points that save real money:
- Quebec evaluates at your plant. For specialised or limited-quantity equipment, the special evaluation is carried out at the manufacturer’s premises — in Europe, before shipping. You never discover the problem on a Canadian site.
- Ontario allows a sample. Where a field evaluation agency examines one sample, the finding can extend to units of identical design and construction. For a small series of identical machines, that is one evaluation instead of several.
- British Columbia ties the label to the installation, not to the model. If your customer later moves the machine to another plant, the question reopens. Worth knowing before you write the warranty.
A machine designed to NFPA 79 is not thereby ready for Canada. The Canadian counterparts are different documents: CSA C22.2 No. 301 for industrial electrical machinery, and CSA C22.2 No. 286 for industrial control panels. The certification bodies and the field evaluation bodies are two distinct categories of accredited organisation, and a province recognises them separately.
Fact — check it yourself
One more Ontario surprise, and it lands on your customer.
A new machine with light curtains, safety devices that command a stop, or interlocked guards triggers a Pre-Start Health and Safety Review by a professional engineer, at the owner’s or employer’s expense, before the equipment may be operated. There is an exemption where the equipment and its protective devices were manufactured to the applicable current standards and installed to the manufacturer’s instructions — and the documents establishing the exemption are kept at the workplace.
That exemption is something you can hand your customer. It is one of the clearest examples of documentation being worth money.
O. Reg. 851 (Industrial Establishments), s. 7, Table item 2
What we do
- Route selection, before the quotation. Which authority you have to satisfy, in which state or province, and what each available route requires of the design. This is an hour that changes the bill of materials.
- Gap analysis against the applicable American or Canadian test standard, starting from your existing IEC file — so the certification project starts from what you have, not from zero.
- Preparation and management of the certification project with a recognised laboratory, including negotiating the conditions written into the certificate.
- The custom-made evidence file, built to be read by an inspector: in English, structured, and delivered to your customer with the contractual language that puts it where the rule requires it.
- Canadian special inspection, including the Quebec route carried out at your own plant, and the Ontario Pre-Start exemption documentation.