Archived posting to the Leica Users Group, 2000/03/26
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Check this site: http://www.sirius.com/~bry_lab/index.htm They also have a link to MSDSs for all their listed chemicals! EDTA, by the way, was the preservative material found on O.J. Simpson's sock- the defense swore up and down that it was there because the police used blood from a collection tube, where EDTA is used as a preservative! However- No one mentioned that it is used in laundry detergent, food packaging, and about 3 squillion other things as well as photo developer! Almost ubiquitous! Pyrogallol is formed from heating Gallol and driving off a -COOH radical (I think an acetyl group.... I'll have to check the chem handbook) to form what could be called 1,2,3 trihydroxybenzene. As a chemical, it is toxic to the liver and kidneys, can cross the brain blood barrier, and if lab tests with rats and dogs are any indication, a level teaspoon ingested by a normal human is a fatal dose- LUGgers would probably require more. However- in the dilute form used in the PMK fornulary, it appears to be no more toxic than any of the other developer agents with the cyclical benzene or phenol compounds. If you observe standard lab procedures, and stick with the pre-mixed- it is supposed to be safe. Dan (I don't call my children 'Mutant Offspring' for nuttin') Post - ----- Original Message ----- From: Timothy R. Kuntz <covbldrs@usit.net> To: <leica-users@mejac.palo-alto.ca.us> Sent: Sunday, March 26, 2000 2:21 PM Subject: Re: [Leica] PYRO > Richard - thanks for the list. In thinking this just a little further, the first question I'm going to be asked and which we'll start looking for are the MSDS's (Material Safety Data Sheets). These are available from the manufacturer on request. Therefore, (in addition to what the heck is EDTA?) I'll start a data base of the chemical names, manufacturers/suppliers, and get a copy of the MSDS's, and list a recommended PPE (personal protective equipment). I can easily get vendor's names & so forth from our HSE department. > > build the list: > > Following are the chemicals involved: > Metol > Sodium Bisulfite > Pyrogallol > EDTA > Sodium Metaborate > > Thanks, > > Tim K > >