UL 900

UL logoUnderwriters Laboratories, Inc. (UL) is an agency that lists products they have tested against criteria deemed appropriate for public safety. For Camfil Farr’s Industrial and Commercial filter product lines (excluding HEPA filters, tested under a different standard), the UL criteria are set forth in UL Standard 900.

UL 900 establishes smoke and flammability limits for clean air filters according to two classifications:

UL Class 1 – air filters which, when clean, do not contribute fuel when attacked by flame and emit only negligible amounts of smoke.

UL Class 2 – air filters which, when clean, burn moderately when attacked by flame, or emit moderate amounts of smoke, or both.

It is important to note that the toxicity of products of combustion, resulting from a filter’s exposure to flame, is outside the scope of UL 900, as is the filter’s filtration capability before or after flame exposure.

To obtain a UL listing on a product, application is made to Underwriters Laboratories, and several samples are then submitted for test. All of these samples must successfully pass the criteria established for Class 1 or Class 2. However, a listing is then granted only if the manufacturer further agrees to a follow-up service procedure.  In this procedure, a UL representative visits each point of manufacture and selects at random a sample of the listed product. This sample is returned to UL for retest to assure continued compliance with the appropriate test criteria.

Only products which have met the criteria for listing may use the UL label. Products manufactured by Camfil Farr, which specifically do not bear the UL label, are not required, by UL, to comply with UL 900 requirements, even though they may be similar in appearance to other listed products.

Listings and Classifications for a company’s products are published on the Underwriters Laboratories web site in their Online Certifications Directory at:


Kom i kontakt med oss


Abonner på nyhetsbrev fra Camfil