From:
Alyssa Brand <abrand**At_Symbol_Here**LBL.GOV>
Subject:
Re: [DCHAS-L] [External] [DCHAS-L] Nitric Acid Disposal
Date:
Jul 16, 2021 19:14 UTC
Reply-To:
ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
In-Reply-To:
Re: [DCHAS-L] [External] [DCHAS-L] Nitric Acid Disposal
After an incident at LBNL with an overpressurized waste container with nitric acid in it, we adopted a policy that all nitric acid greater than 5% must be neutralized prior to disposal as waste, unless it's essentially the original material and hasn't been used for anything. This is a simple benchtop treatment procedure. I have done it myself multiple times, and I much prefer using magnesium hydroxide over a bicarbonate because the magnesium hydroxide does not release carbon dioxide. That keeps the reaction from becoming too vigorous. It's still important to monitor the temperature and cool as necessary and to add the base slowly, but at least you can't end up with a huge foaming mess spilling all over the place. It also self-limits the final pH to 9 because after that point the magnesium hydroxide is no longer soluble.
Alyssa Brand
Laboratory Safety Specialist, Cryogenic Liquids SME, Deputy CHSO
EHS Research Support Team
Lawrence Berkeley National Laboratory
(510) 486-7246
Pronouns: She/her/hers
Hi All,
Chris made an excellent point here!
I believe the nitro compound is completely soluble in dichloromethane.
Nitration is a common reaction in the organic lab. If we carefully separate the organic layer during the separatory funnel extraction, there should not be any organic product
and solvent in the aqueous layer. Only the formation of the emulsion during the extraction can create issues in layer separation. The extraction process is an important step for any organic synthesis, and the organic chemist is very familiar with the process.
Regards,
Tilak Chandra, Ph.D.
608-622-9761
