John, Thank you for the link, it looks interesting but at 89 pages exactly as you described it: more than you want to know.
I will throw in what little I know on the chromium issue: - I also lurk in the IPC lead-free list, which also often discusses related RoHS issues, and there hasn't been a huge amount of discussion there about trivalent vs. hexavalent chromium either. - I recently went to a presentation given by Radisys in the Beaverton, Oregon (USA) area, the Radisys engineer said that the hexavalent chromium issue looked like it was going to be unexpectedly tricky, he had contacted the materials suppliers that Radisys uses (for their enclosures, I think??) and had run across a staggering number who not only did not have firm timelines for the move away from hexavalent chromium but were totally unaware of RoHS at all! He also said that he had been told that trivalent chromium was a problem for coatings on aluminum. Disclaimer: I am also an electrical engineer and, like Jim Knighten, my college curriculum was pretty light on materials science. I also would be glad to hear from any materials science experts on the list. -Camille Good Portland, Oregon --- John Woodgate <[email protected]> wrote: > In article > <[email protected]. > com>, Knighten, Jim L <[email protected]> writes > >My professor friend at University of Missouri-Rolla > says that in office > >environments (data center environments) the > oxidation is probably not a > >problem. > > > >"You're correct - an office environment would > probably not oxidize the > >Cr(III) to Cr(VI)." > > I don't think I could LIVE in an environment that > WOULD oxidize Cr^3 to > Cr^6. > > You can find more than you want to know about > chromium chemistry and > biochemistry at: > > http://64.233.183.104/search?q=cache:7WcVuGjRZIwJ:www.nature.nps.gov/haz > ardssafety/toxic/chromium.pdf+oxidized+Cr3%2B+to+Cr6%2B&hl=en > > But it is silent on the oxidation issue. IIRC, > oxidizing agents as > strong as Mn(VII)/permanganate, or stronger, are > required. > -- > Regards, John Woodgate, OOO - Own Opinions Only. > The good news is that nothing is compulsory. > The bad news is that everything is prohibited. > http://www.jmwa.demon.co.uk Also see > http://www.isce.org.uk > > > This message is from the IEEE Product Safety > Engineering Society > emc-pstc discussion list. Website: > http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to > [email protected] > > Instructions: > http://listserv.ieee.org/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Scott Douglas [email protected] > Mike Cantwell [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: > > http://www.ieeecommunities.org/emc-pstc > This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [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: http://www.ieeecommunities.org/emc-pstc
