10-22-97


To those more chemically minded than myself (i.e. everyone),

I've seen many notices that waste 2% osmium tetroxide can be

reduced to less hazardous form by mixing with twice volume of

corn oil. I'd like to implement this practice, but I also use a

lot of 0.5% ruthenium tetroxide. Can this also be reduced with

oil? The only thing I've heard of for RuO4 is sodium bisulfite,

which is quite toxic/harmful itself. It would be great to find a

single practice that works for both Os and Ru.



Also, does anyone know if buffer solutions (cacodylate or

phosphate) interfere with OsO4 reduction by corn oil?



Thanks for your help,

Karen



--

Karen Zaruba

kszaruba@mmm.com

3M Company, 3M Center Bldg. 270-1S-01

St. Paul, MN 55144


What makes you think that sodium bisulfate is toxic? The Merc

Index gives its LD50 (in rats) as 115 mg/Kg, and says that it is used

as a preservative and bleach in food.



best regards

mark



Mark W. Lund, PhD

Director >> Soft X-ray Web page http://www.moxtek.com<<

MOXTEK, Inc.

452 West 1260 North

Orem UT 84057 801-225-0930 FAX 801-221-1121

lundm@xray.byu.edu


My safety officer has told me that treating the osmium as noted may bring

charges of reprocessing hazardous waste, for which the University doesn't

have a license. They insist I give them the Osmium as is for disposal.

sbarlow@sunstroke.sdsu.edu



Thank you to those who responded so far to my question on reduction

of OsO4 and RuO4 to less hazardous states using corn oil.

So far no one has responded with experience with RuO4 and corn oil - any

others lurking out there want to add 2 cents? I did get a very

detailed reply from Wolfgang Muss on using ethanol to inactivate OsO4.

Also I have never heard of the "reprocessing hazardous waste" issue

that Steven Barlow brought up. Sounds like a wonderfully

forward-thinking, environmentally responsible policy to me. [Must have

been designed by the same folks that allow liability issues re:children

to make it too costly for our neighborhood to have a park.] Does this

reprocessing issue apply outside San Diego?





Answers to two questions:

The corn oil procedure for OsO4 appears in a "Technical Data Sheet"

from Electron Microscopy Sciences, with the following references given:

(I haven't read them, just the data sheet)



Cooper, K. Neutralization of Osmium Tetroxide in case of accidental

spillage and for disposal. Bulletin of The Microscopical Society of

Canada. 1988. 8:24-28. (Also I think I saw similar article in

Don Grimes' free publication, Microscopy Today).



Lunn, G.;Sansone, E.B. Osmium Tetroxide. Destruction of Hazardous

Chemicals in the Laboratory; Program Resources, Inc. Frederick, MD;

p211-213.





The other question was about the hazards of Sodium Bisulfite. I am

just going by an MSDS I have for CAS # 7631-90-5 from Sigma-Aldrich.

This states that sodium bisulfite is Toxic, Harmful by Inhalation and

Contact, causes Severe Irritation, and is a Possible Sensitizer. Taking

into account the fact that even bread pudding would probably show up

as harmful by inhalation on an MSDS, still the designations of Toxic,

Sensitizer and "Severe" Irritant are worth noting.



Still appreciate any further comments!

Karen



--

Karen Zaruba

kszaruba@mmm.com

3M Company, 3M Center Bldg. 270-1S-01

St. Paul, MN 55144


Just a guess, but since Ru is also a group VIII metal, and since

Ruthenium red is used to stain the lipid components of membranes, an un-

saturated oil should combine with Ru in much the same way as with Os.



William Tivol

tivol@wadsworth.org


Dear Karen,

for over ten years now I (use my OsO4-solutions) and dispose of my used up working

solutions in a way which is very safe, but uncommon. I ve had posters on that at

MSA-Meeting Boston 1992 (also included in the Proceedings, 50th Ann. Meeting, p.

754/755: MUSS W.H.: "Pro s for a multiple/repeated use and safe disposal with

recovery of OsO4 solution(s) in routine EM")

For about 1300-1600 specimen blocks to osmicate I need only 4-6 g OsO4/year.

I don t use the cornoil-disposal method, because I think Os a valuable metal which

shouldn t be wasted off the drain/ down the sink ("with a plenty flush of water" !! as has

been proposed by several people, which in my opinion would not fit ecological

considerations!) but be recovered and recycled.

I learned my lession at the 1992 Boston Meeting as well as within the last 5 years: I tried

people to convince that it is possible to reduce the amount of OsO4 used for

staining/postfixation of specimens AND recover all of the Os from solutions as used

(like buffers, like mixtures etc.) as this is possible in Switzerland, where a regular Os

recovery and recycling has been established for all EM-Labs aided by the

SGOEEM=Swiss Society for EM since 1972!!

It is not easy to convince people about that though the process is very easy, simple,

effective in my experience and more or less costs are low. I am doing it. I have,

unfortunately, no experience in "deactivating" RuO4, but I think, considering my scanty

knowledge from chemistry lessions and 17 years experience in disposal/recovery of

OsO2/Os (+/- pure), this should be no problem at all.

If you want to get informed about the reasons, why and how I do it: please don t hesitate

to contact me by e-mail.



Best wishes for a lucky day

to you and all of the community



Wolfgang MUSS

EM-Lab, Dept. Pathology, LKA

A-5020 SALZBURG, Austria/Europe.



W.Muss@lkasbg.gv.at


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