>>We might be trying to make a mountain out of a molehill here. I agree that a mountain is being made of a molehill - however, I think the TC made the mountain, not those of us who have tried to interpret the mountain.
For my part, I have posted this exact question in the past and found the same spread of answers. So, I now use isopropyl alcohol as it is a harsher solvent than kerosene, and being an electronics manufacturer, we have boodles of it around here. If it stands up to the alcohol rub it will take the kerosene rub. Also, we manufacture some medical device products, and those standards call out alcohol for the rub test. (IEC601.1 clause 6.1(z)). Doug Massey LXE, Inc. -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Tuesday, January 02, 2001 4:29 PM To: [email protected] Cc: [email protected] Subject: RE: Seeking assistance from Chemical Experts We might be trying to make a mountain out of a molehill here. The basic intent of the various standards is to ensure that power rating information is not easily rubbed off. The international standards IEC/EN60950 (sec. 1.7.15) stipulate 15 second rub tests using water and "petroleum spirits". The makeup of these spirits is stipulated. However, if a label withstands the rub test with any of the usual "household" spirits, e.g. kerosene, isopropyl alcohol, rubbing alcohol, lamp oil, lighter fluid, gasoline etc., it will probably withstand the test same with any of the uniquely specified petroleum spirits. I assume each of us has at one time tried to remove printing or the complete label from a jar or bottle for other uses. My own experience is that if one "spirit" will work, so will the others. Some (gasoline) will work faster than others (lighter fluid). Conversely, if a randomly chosen spirit will not work, it is time to try a knife blade or blow torch (just kidding about the torch). George Alspaugh kmccormickinc%[email protected] on 01/02/2001 03:40:42 PM Please respond to kmccormickinc%[email protected] To: emc-pstc%[email protected] cc: (bcc: George Alspaugh/Lex/Lexmark) Subject: RE: Seeking assistance from Chemical Experts Thanks guys...BUT, I am not trying to convince UL that I am correct. This is all internal to the company I am working with. Just to give you an idea of how confusing this issue is, I have privately received responses stating that all the following are acceptable: Kerosene Isopropyl alcohol Rubbing Alcahol Lamp Oil Hexane Now I am not a chemical expert, but the chemical properties of these chemicals are not similar to one another (the simplest comparison is the boiling point, the above range from 60C - 300C). Calling UL and asking them what they use is easy...the hard part is proving that whatever the subject chemical is, it complies with the standard. Just wondering if anyone has had this experience before. >From: Gary McInturff <[email protected]> >To: "'[email protected]'" <[email protected]>, >[email protected] >CC: [email protected] >Subject: RE: Seeking assistance from Chemical Experts >Date: Tue, 2 Jan 2001 12:24:17 -0800 > >Not only cheap, but sometimes it is much easier just to do it their way >than >argue with them that you material should or should not be acceptable. Pick >your battles. Let them win this one. >Gary > >-----Original Message----- >From: [email protected] [mailto:[email protected]] >Sent: Tuesday, January 02, 2001 10:46 AM >To: [email protected] >Cc: [email protected] >Subject: Re: Seeking assistance from Chemical Experts > > >From the UL Test Data Sheets provided to me by my UL engineering office, >the >material listed in the text of the test data sheet is kerosene. >I don't know what the actual physical characteristics are, but if UL uses >this >for their test I would assume that it is acceptable for me to use. >Kerosene is an easy product to obtain and is not that expensive. > >I have included an excerpt of the UL 1950 test data sheet that I was given >by >UL. > >Oscar > >##### Excerpt from the UL 1950 Test Data Sheets ##### > >1.7.15 - PERMANENCE OF MARKING TEST: > >METHOD > > A sample of the marking label was subjected to this test. The >surface >of >each marking as noted below was rubbed by hand for a period of 15 seconds >with a >water soaked cloth, and again for a period of 15 seconds with a cloth >soaked >with the petroleum spirit noted below. > >RESULTS > >TEST CONDITIONS: > >Use of Marking _____________ ____________ > >Material _____________ ____________ > >Held by _____________ ____________ > >Applied Surface Material _____________ ____________ > > >OBSERVATIONS: > Water Kerosene > >Any Damage? _________ _________ > >Legible? _________ _________ > >Curled? _________ _________ > >Edge Lifted? _________ _________ > >Easily Removed Intact? _________ _________ > > >The marking was/was not durable and legible. > >Comments:___________________________________________ > >_____________________________________________________ > > Document: 060.Eng > > >##### End of Excerpt from UL 1950 ##### ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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