Customers often ask us whether certifications from Intertek, TÜV, or FM are accepted by UL. Unfortunately, we have to explain that this is not the case. We’ll explain why that is here.
Workplace Safety in the United States
To understand why TÜV, Intertek, and FM certifications are not accepted by Underwriters Laboratories (UL), we first need to take a brief look at how occupational safety is organized in the United States.
The Role of the Occupational Safety and Health Administration
The highest occupational safety and health authority in the United States is the Occupational Safety and Health Administration (OSHA), a federal agency that reports directly to the Department of Labor. To ensure the safety of workers and employees on U.S. soil, OSHA issues relevant occupational safety regulations.
These regulations, in turn, impose requirements on the equipment and machinery used in a company, for example, regarding noise protection or the covering of live parts. Verifying that new equipment and machinery comply with these standards is the responsibility of local authorities, which must approve them before they are put into operation. In the United States, these authorities are known as Authorities Having Jurisdiction (AHJ).
What is a Nationally Recognized Test Laboratory (NRTL)?
To facilitate approval by the competent authority and to assure buyers that they are purchasing a product that complies with occupational safety regulations, there are a number of certification marks. However, these are not awarded by OSHA itself, but rather by state-recognized testing laboratories, known as Nationally Recognized Test Laboratories (NRTLs).
A Nationally Recognized Test Laboratory (NRTL) is a private company that tests products on behalf of clients for a fee and, if the results are positive, issues a corresponding seal of approval. What sets NRTLs apart is that they are accredited by OSHA. This accreditation can only be granted if the testing laboratory conducts tests based on the relevant OSHA standards. In other words, a product tested by an NRTL meets the legal safety requirements.
That is why UL does not recognize component certifications issued by other testing laboratories
If all NRTLs are now required to comply with OSHA safety standards, why aren’t certifications from Intertek, FM, or TÜV recognized by UL? There are two reasons for this, both of which are closely related.
Every testing laboratory has its own testing guidelines
While OSHA safety standards specify the safety requirements for a product, it is up to the respective testing laboratory to determine exactly how compliance with these requirements is verified in practice. For this reason , each NRTL has its own internal standards and testing guidelines. These naturally vary from lab to lab. In Canada, CSA standards are generally the authoritative ones.
Regular inspections are required
However, the main reason why component approvals from different NRTLs cannot be mutually recognized lies in the nature of the testing. Of course, the laboratories cannot test every single product a manufacturer produces. That is why certification is based on representative samples. However, to ensure ongoing compliance with the standards, the NRTL conducts regular inspections following the initial acceptance.
Therefore, if Underwriters Laboratories were to recognize certification by Intertek, UL would have to regularly subject the product in question to an inspection in accordance with its internal standards.
Why We Trust UL
If the certifications and marks of approval issued by the individual NRTLs are not mutually recognized, every manufacturer naturally faces the question of which laboratory to use to have its products certified.
There are currently a total of 19 testing laboratories that hold the necessary OSHA accreditation to be designated as NRTLs. However, not all of them are accredited for the same areas. When it comes to testing control cabinets and other electrical and electronic equipment, UL, Intertek, FM, and TÜV Süd are particularly important. At KRAYER, we have chosen to partner with UL—and for good reason.
Highest Recognition
UL is the oldest and most widely recognized NRTLin the United States. Every inspector from a local authority is familiar with UL, and UL certification is highly regarded because the person in charge can be confident that the equipment complies with U.S. regulations. A UL-listed control cabinet therefore generally makes the acceptance testing of the relevant system much easier.
Wholesalers rely on the UL label
The high level of recognition and the strong trust that Americans place in the UL label are also the reasons why wholesalers in the U.S. often refuse to include products in their product lines that do not have UL certification. As a result, a large portion of the market may remain off-limits to exporters of non-certified products.
Insurance companies require UL certification
Last but not least, many commercial customers also use only UL-certified products—simply because they have to. Many insurance companies require their customers to use only devices and components with the UL label; otherwise, their insurance coverage will be void.
Zusammenfassung
The certification marks issued by the various OSHA-accredited Nationally Recognized Test Laboratories ( NRTLs ) cannot be mutually recognized due to the differing testing procedures—which each NRTL is permitted to establish on its own—and the mandatory follow-up inspections. That is why we rely exclusively on UL certification, which enjoys the widest recognition in the United States.
