An industry specific guideline (SEMI S2, developed for the semiconductor manufacturing industry) that I spend a lot of time with has cautions against "hazardous power", defined as 240VA or greater regardless of the potential.
In the same industry, fire risk is a very muddy topic to sort out. In a chip fab, even the smallest amount of smoke can cause thousands of dollars damage in an ultra-clean-room. It's often difficult to get people to sort out a fire that can destroy a building from one that can credibly cause significant harm to personnel. Although fire can cause immense amounts of damage, *generally speaking*, people rather successfully avoid it unless thier egress is impeded. It seems that to truely define the potential risk of most fires, one must understand a general model of the enviroment in which they will occur. It is very difficult to frame such a general model (with consensus acceptance) with a product sitting on a test bench. There are certainly some fires that are particularly threatening to personnel, such as colorless hydrogen fires. Most fires, however, are self-revealing. Of course one must appropriately consider explosions that may precede or follow a fire. -Lauren Crane -----Original Message----- From: Allen, John To: [email protected] Sent: 11/6/2001 4:10 AM Subject: RE: "Safety Critical" etc - the future Hi Folks I agree with John W - and a single fire can (and does!) kill and injure FAR more people than a single electric shock. Additionally, a large number of products are SELV and/or battery operated where there is no shock hazard but is often a fire hazard - think of the power available from modern batteries, and especially vehicle batteries. John Allen Thales Defence Communications Division Bracknell, UK -----Original Message----- From: John Woodgate [mailto:[email protected]] Sent: 05 November 2001 22:36 To: [email protected] Subject: Re: "Safety Critical" etc - the future I read in !emc-pstc that CE-test - Ing. Gert Gremmen - ce-marking and more... <[email protected]> wrote (in <ABEJKCKDFONELAIPOFHNMEFCEKAA.cetes [email protected]>) about '"Safety Critical" etc - the future', on Mon, 5 Nov 2001: >Those components that encapsulate into one single component the 2 safety >layers >that are normally used to isolate the operator (and others) from a hazard. >In electrical safety land that's mostly an electrical hazard A safety-critical component may be related to a fire hazard, not a shock hazard. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Eat mink and be dreary! ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: [email protected] Dave Heald [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
