NaCl + AgNO3 --> AgCl (ppt) + (Na+) + (NO3) + Cl .

The Silver Chloride that comes out of solution should be a milky white colour.

As you can see, the Nitrate is still there , just in a "different form".

If you dispose of this down the drain, and at a  later date dispose of either
alkali metal solutions or ammonia solutions down the drain ,impact sensitive
compounds can be formed. It is not a wise idea to dump Silver Chloride down the
drain.
( Realistically, labs across North America do dump some, but we do not
recommend
it. )

It also depends on the amounts , if it is 5ml every month , that is one thing
but if you are talking about 20 liter's a day that is another. and the
concentration of all materials must also be taken into consideration.

Gordon Fenn
BDH Inc
Toronto, Canada.





HistoScientific <histosci@shentel.net> on 11/01/99 08:47:37 AM

To:   histonet@pathology.swmed.edu
cc:    (bcc: Gordon Fenn/BDH/EMI/Merck)
Subject:  Neutralizing Silver Nitrate



Dear Netters,

I recently visited a large histology research laboratory where they mix
deionized salt (yes, Morton's table salt) with their Silver Nitrate
waste and dump it down the drain.  They swear that it neutralizes the
Silver Nitrate waste.  Is this true?  Does anyone else use this
"protocol".  I look forward to your responses.

Sincerely,

Tom Galati
Histo-Scientific Research Labs.
107 Killmon Road
P.O. Box 30
Basye, VA  22810
(540)856-2222
fax: (540)856-2227
histosci@shentel.net