1- What is UL certification?
UL certification is issued by an NRTL. The certification certifies a product's compliance with a specific standard and is valid in the United States. In Europe, it is commonly known as "UL" because it often refers to standards called "UL," but in reality, Underwriters Laboratories (UL) is just one of many NRTLs, and UL standards are not the only reference standards.
Certifications can be made not only with UL standards, but also with ASME, IEEE, ISA, NEMA, NFPA, etc.
After certifying a product, the NRTL authorizes the manufacturer to apply a registered mark. When a product bears a certification mark, it means that the NRTL has tested and certified the product and that it complies with the requirements of one or more standards.
2- What is an NRTL? Is the certification mark always the same?
In the United States, a Nationally Recognized Testing Laboratory (NRTL) is a private company or organization recognized by OSHA (Occupational Safety and Health Administration) and authorized to issue certifications and perform tests for certain types of products and according to certain standards.
Each NRTL applies its own registered mark, so the certification marks vary depending on the NRTL. A list of recognized NRTLs and the standards for which they are authorized to issue certifications is available on the OSHA website. UL is one of several NRTLs in the United States. Other examples of NRTLs include Intertek, TÜV SÜD America, TÜV Rheinland, MET Laboratories, Nemko, and CSA.
In Canada, certification bodies are accredited by the SCC (Standards Council of Canada).
3- What is OSHA?
The leading agency for workplace safety in the United States is OSHA. The Occupational Safety and Health Administration (OSHA) is an agency of the Department of Labor whose goal is to ensure workplace safety through the implementation of appropriate standards and regulations.
OSHA establishes federal regulations (CFR or Code of Federal Regulations) regarding workplace safety, determines which products require certification, and which are the Federally Recognized Notifying Bodies (NRTLs).
The general reference regulation for workplace safety is OSHA 29 CFR 1910 Occupational Safety and Health Standards; specifically, the main sections that concern machinery are 29 CFR 1910 Subpart O (for mechanical aspects) and 29 CFR 1910 Subpart S (for electrical aspects). The requirements established within the regulation have the force of law. The federal regulation is aimed at users and employers (similar to our Legislative Decree 81-08) and not directly at manufacturers. Manufacturers, however, must provide machinery and equipment that comply with the regulations so that their customers can use them.
To meet the requirements established in the regulations, standards written and/or recognized by ANSI can be used. ANSI also approves standards issued by third-party organizations (e.g., UL 508 A).
4- Is UL certification similar to the CE marking in Europe?
No, there are some fundamental differences between the “UL” certification and the CE marking:Europe USA
CE marking is mandatory and required by law in Europe. UL certification for machinery in the US is not mandatory, but voluntary.
The CE marking signifies that a given product complies with all the requirements of the applicable directives and regulations and does not refer to a specific standard. UL certification attests to compliance with a specific standard and not directly to legal requirements.
In Europe, the CE marking is issued by the manufacturer without the intervention of third-party bodies, through self-certification. In the USA, UL certification is issued by a third-party NRTL body.
Manufacturers can generally CE mark their machinery independently, compiling the documentation supporting the certification in the technical file. To issue the certification, NRTLs conduct product inspections and tests, as required by the standards.
In Europe, CE marking, according to Directive 2006/42/EC, applies to the entire machine as a product placed on the market and/or put into service. UL certification may only apply to certain aspects or equipment of the machine, depending on the applicable standard. For example, it is common to certify only the machine's electrical panel according to UL 508A.
5- Is the CE marking accepted in the USA?
The CE marking has no value in the U.S. and is not recognized by OSHA. A CE-marked machine can be sold and used in the U.S., but it does not guarantee compliance with U.S. regulatory requirements. From the OSHA website:
Does OSHA accept the “CE” mark or accept equipment certified by foreign testing organizations?
The CE mark is unrelated to the requirements for product safety in the United States. It is a generic mark used in the European Union (EU) to indicate that a manufacturer has declared that the product meets regulatory requirements in the EU that may or may not include product safety. In the United States, under OSHA's NRTL requirements, the product must have the specific mark of one of the NRTLs recognized to test and certify this type of product.
6- Is UL certification of machines mandatory?
No, certification of machinery and systems intended for sale and use in the USA is generally not required by law, but is voluntarily carried out by the manufacturer.
7- What are the obligations of the manufacturer of a machine destined for the USA?
Machines installed in the US must comply with federal laws as well as local laws, which can vary from state to state, county to county, or city to city. When it comes to electrical systems, local laws require compliance with the National Electrical Code (NEC), which corresponds to the NFPA 70 standard. The NEC is not a federal law but is adopted by each state in different editions; in some cases, local laws may also modify the NEC requirements. To determine which edition of the NEC applies where a machine is intended, it is necessary to check local laws, for example, using the NFPA Codefinder.
To ensure that the machine complies with the NEC and is accepted by the AHJ (Authority Having Jurisdiction)—which must issue an authorization for its use—machine manufacturers can independently apply various standards recognized and approved by ANSI. For example, compliance with the UL 508A standard for the electrical panel and the NFPA79 standard for on-board electrical equipment ensures that these comply with the NEC.
8- Why does a manufacturer UL certify the electrical equipment of its machine?
The main reasons why UL certification is carried out are:
to simplify and speed up the AHJ acceptance process;
because contractually required by the user;
for insurance reasons;
for legal reasons, to support the quality of one's work in the event of future accidents or disputes;
to avoid having to research local laws which can vary even from city to city.
9- Is there only one type of certification?
No, each NRTL develops different certification programs for each standard. For example, when talking about an electrical panel and UL 508A, there are certification programs for a single panel specifically produced for a machine, or for the certification of a mass-produced panel model, or even for issuing authorization to the manufacturer to build panels in accordance with UL 508A.
10- What is field evaluation?
If a machine and its electrical equipment are completed directly during installation at the customer's premises, or if modifications are made to the equipment during installation, making it impossible to certify before installation, a field evaluation is an option. A field evaluation is an assessment performed by the NRTL directly in the field. Field evaluation may be the best option in the cases described above and for non-series-produced machines and systems.
A field evaluation may be requested by the equipment manufacturer, but it can also be requested by the AHJ if they require an external opinion before approving the installation or have red-tagged a piece of equipment, meaning they have not approved it. For this reason, NRTLs often offer emergency field evaluation services, conducted within a few days to resolve any issues reported by the AHJ and allow the equipment to be started up.
However, if you choose to conduct a scheduled field evaluation of the machine rather than certifying it, it's a good idea to plan the process ahead of time with your chosen NRTL. Often, the evaluation can begin directly at the manufacturer's premises, before shipping, and be completed with a final check after installation. This provides immediate feedback on any changes that may need to be made before shipping the machine.
Following a successful field evaluation, the NRTL affixes a Field Evaluated Product mark.
11- Who is the AHJ?
AHJ stands for Authority Having Jurisdiction. The AHJ is a local authority responsible for verifying the installation of the machine. The AHJ conducts an inspection to verify that the installation has been carried out in compliance with the NEC and local regulations. Following the inspection, the AHJ accepts the installation and issues a start-up permit.
Inspection and authorization by the AHJ is mandatory and necessary for the user to use the machine.
Authorization issued by the AHJ is not equivalent to certification issued by an NRTL. The AHJ may issue authorization even if the machine is not certified. At its discretion, the AHJ may require a field evaluation.
If the AHJ reports problems and refuses to grant the permit, the identified issues must be addressed as quickly as possible. One solution is to request the intervention of an NRTL to conduct a field evaluation. In this case, the NRTL conducts an inspection, issues a report, and advises the manufacturer on how to resolve the problem.
The AHJ may be a firefighter, electrical inspector, or health department officer or manager, depending on local regulations.
12- Which standards should be used to design the machine for the USA?
When designing a machine intended for the USA, particular attention must be paid to the electrical equipment as there are very specific requirements that are different from those in Europe.
The two main rules to use are:
UL 508A Industrial Control Panels for the design of electrical panels
NFPA 79 Electrical standard for Industrial Machinery for the design of on-board equipment
Meeting the requirements of these two standards ensures the electrical equipment complies with the NEC. However, be careful: if portions of the electrical equipment are installed in parts of the building, the NEC must be used directly for these, not the standards listed above.
13- What standards should be used for the mechanical part of machines in the USA?
Unlike the electrical part, the safety of the mechanical part of the machine is very similar to that required in Europe, with the difference that there is no "machinery directive" establishing the fundamental requirements. In this case, it is possible to refer to various standards issued primarily by ANSI, which generally incorporate the same ISO standards adopted in Europe.
In this field the main reference standards are the ANSI B11 series standards.
The manufacturer must provide a machine that is also safe from a "mechanical" point of view so that its user customer complies with the CFR (Code of Federal Regulations) issued by OSHA, which are required by law.
14- What to do if you want to sell a car in the USA?
Check where the machine is being shipped (state, county, city) and, with the customer's help if necessary, check local regulations and which edition of the NEC is in effect.
Check for contractual or regulatory certification obligations.
Design the machine's electrical equipment using the NEC and reference standards (e.g. UL 508A and NFPA79).
Conduct a risk assessment, implement safety measures, and install protective devices using ANSI standards.
Produce the machine's accompanying documentation, including the manual and system diagrams, taking care to follow the manual writing rules and safety signs provided in the ANSI standards. Regarding electrical equipment, the relevant standards contain numerous requirements for drafting diagrams and manuals.
Choose whether to obtain certification from an NRTL or a field evaluation.
At Quadra Srl, we are familiar with many American standards and can recommend which ones to use. We can also assist in verifying machinery's compliance with regulatory requirements. We can also help prepare the appropriate documentation for NRTL certification procedures.
15- What to do if you want to obtain UL certification?
The company is free to choose any NRTL that is accredited by OSHA, but each NRTL is authorized to issue certifications only for certain types of products and according to specific standards.
A list of recognized NRTLs and the standards for which they are authorized to issue certifications is available on the OSHA website.
When choosing an NRTL, it's important to verify that it's authorized to issue certification for the standard you're interested in. Furthermore, if the machine is destined for both the US and Canada, it may be helpful to choose an NRTL that handles both US and Canadian (CSA) standards. A list of accredited certification bodies in Canada is available on the SCC website.
Finally, it's a good idea to check with the end customer to see if there are any specific contractual requirements regarding the brand to be applied.
To summarize, it is necessary to verify:
- NRTL authorization for the field of interest;
- acceptability of the NRTL by the end customer;
- type of certification;
- testing location (where checks and tests will be carried out);
- if you want to certify for both the US and Canadian markets, it is advisable to choose a body recognized by both countries;
- timing;
- costs.
16- UL Certification: What documents should I prepare?
It's important to check with your chosen NRTL to determine which documents are required. Generally, you'll need to compile a comprehensive set of technical documentation, which may include:
- list of safety-critical components and materials and, where applicable, their safety data sheets;
- mechanical layouts;
- photo of the car;
- component certification declarations and any test reports;
- electrical / pneumatic / hydraulic diagrams with component list;
- use and maintenance manuals.
17- What to do if you want to sell a car in Canada?
The leading body for workplace safety is the SCC. The Standards Council of Canada (SCC) is a state agency that promotes standardization; it is the equivalent of OSHA in the US. The SCC sets federal regulations, determines which products require certification, and which bodies are accredited for product certification.
The product certification process is entirely similar to that in the US. There are several certification bodies accredited in both Canada and the US, and certification marks valid for both countries.
The Canadian equivalent of the NEC is the CEC (Canadian Electrical Code), which corresponds to the CSA C22.1 standard. The main safety standards in Canada are issued by the CSA Group (Canadian Standards Association).
When selling a car in Canada, it's very important to check the destination province. Individual provinces may have local regulations that differ from federal regulations and standards and, in some cases, require specific certifications. One province to pay particular attention to is Ontario, as it adopts the Ontario Electrical Safety Code (OESC).
