For those interested, here is some information about the Classification of air filters covered by the UL Standard UL900.
"These requirements cover tests to determine combustibility and the amount of smoke generated for air filter units of both washable and throwaway types used for removal of dust and other airborne particles from air circulated mechanically in equipment and systems installed in accordance with the Standards for Installation of Air Conditioning and Ventilating Systems, NFPA 90A (Other Than Residence Type), and for Installation of Warm Air Heating and Air Conditioning Systems, NFPA 90B (Residence Type)." "Air filter units covered by this standard are classified as follows: a) Class 1 Units - Those that, when clean, do not contribute fuel when attacked by flame and emit only negligible amounts of smoke. b) Class 2 Units - Those that, when clean, burn moderately when attacked by flame or emit moderate amounts of smoke, or both." I hope you find this information useful. Randy Ivans Underwriters Laboratories Inc. Business Sector Coordinator Telecommunications Industry email: iva...@ul.com ------------- Original Text From: "John.E.Allen" <john.e.al...@btinternet.com>, on 5/6/98 9:54 PM: Hi Folks >From previous work I seem to remember that UL 900 on air filters and air filter units may be the standard which contains "Class 2 " filters. Can someone check this for me as I don't currently have a copy. Regards John Allen Product and System Safety Manager Racal Radio Ltd Bracknell UK ---------- From: Robert Tims[SMTP:rt...@emx.ericsson.se] Sent: 05 May 1998 18:27 To: nebs@world.std.com Cc: brian.mcauli...@tellabs.com Subject: Re: Flammability of air filters Brian, UL does not have a "Class 2" flame rating, per se. I do not have the -78 NEBS document with me today, so I am not sure in what context the "Class 2" rating you quoted came from. UL has classes for power and voltage... Hope this helps. If you need more help, perhaps spell out the exact wording of the standard to me in another e-mail. Regards, Bob Tims Compliance Engineer Ericsson Messaging Systems Inc. rt...@emx.ericsson.se
