UL Marks



Technical Tips & FAQs

Deciphering UL and CSA certification markings

Question: What are the differences between the different certification marks on industrial products? What is the difference between UL and CSA and UR markings?

Answer: Deciphering the differences between the many UL and CSA marks can be a bit confusing at times. While both apply to standards of equipment in the United States and Canada, they are not the same or interchangeable. More detailed information can be found at the UL and CSA websites. Both entities have a searchable database to learn more information about specific testing done on a product or what standards the product meets. Here is a short guide on how to tell the differences in their uses and meanings as they apply to products from Sprecher + Schuh.

Underwriters Laboratories

UL Listed The UL Mark on a product means that UL has tested and evaluated representative samples of that product and determined that they meet UL's requirements. Testing is based primarily on UL’s Standards of Safety. The mark is followed by identifying information or a control number which can be used to look up the product in their database.
cUL Listed This mark indicates the product was tested by UL and meets Canadian standards by a special agreement between UL and CSA. Canadian standards may be slightly different from US standards.
UL Listed This mark indicates the product was tested by UL and meets both US and Canadian standards.

Canadian Standards Association

UL Listed The CSA mark means a product has been tested by CSA, and meets applicable standards for safety and/or performance in Canada. Additionally, CSA tests and certifies to standards published by ANSI, UL, NSF and other leading standards publishers. The CSA mark is usually accompanied by a Class and/or File number which can be looked up in their database for more information on the tested product.
UL Listed The CSA mark with the US indicates the product was tested by CSA per an agreement with UL, and is certified for use in the US according to applicable US standards.
UL Listed The CSA mark with the C and US indicates the product was tested by CSA per an agreement with UL, and is certified for use in both Canada and the US according to applicable Canadian and US standards.

Component Marks

UL also has a component mark known as the UL Recognized mark. Though the mark is available, UL does not require UL Recognized components to be marked. Because components are intended for use in a larger panel or system they are not tested as part of the entire system and may be subject to certain restrictions. Just because the components of a product have the UR mark does not indicate the entire product or system is UL approved.

UL Listed These are UL component marks for the US and Canada, respectively.
UL Listed This mark is the UL component mark certifying the component is approved by US and Canadian standards.

UR marks are sometimes accompanied by a Control Category Number (CCN), which can be used to look up the specific restrictions that apply to the component. For example, a CCN of NKCR8.E33916 indicates the category "Auxiliary Devices Certified for Canada - Component".  By looking up this number in the Online Certifications Directory (OCD) on, information regarding the specific product category, restrictions and associated catalog numbers and other similar components can be found.  This number is also associated with UL508A Supplement SA, Table SA1.1. If the component can be used without further testing in a UL508A panel, its prefix can be looked up in the SA1.1 table.  If "notes" are not present, the component has no restrictions. If "notes" are present in the table, restrictions will be listed and should be followed. Common prefixes include the following:

CSA does not have an equivalent component mark.  For a component to be CSA approved the CSA panel standards state that a recognized component must be listed in a table of "Non-Certified Components" that would be part of the CSA panel file. This requires contacting CSA and having them look at the component, and if accepted, adding it to the "Non-Certified Components" table in the CSA panel file. However, since 2003, agreements have been in progress between the two entities for UL to accept CSA component certifications.

In summary, a UL Listed product can be used in both a UL508A and a CSA panel without further question, but not the other way around. For official logos from UL and CSA, please visit their respective websites.

March 2015

Jason McCoy

Jason McCoy, Product Manager

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