Cleaning & Neutralizing Spills of Ammonia Solutions

This method was developed by Margaret-Ann Armour, Assistant Chair of the Chemistry Department of the University of Alberta.

Please note: Ammonia vapors can be very irritating. It may be necessary to use respiratory protection when cleaning up spills of ammonia solutions. Only individuals who have been trained and fit-tested by EHS in the past year and who have received approval from EHS and McCosh Health Center to use a respirator may use respiratory protection, such as self-contained breathing apparatus or air-purifying respirators. Contact James Boehlert at 258-7882 for more information.

Materials Needed

• Plenty of spill mix comprised of equal volumes of sodium bicarbonate, bentonite (clay cat litter) and dry sand.
• 5% aqueous hydrochloric acid (if neutralization is needed)

Procedure

1. Cover the spill with enough spill mix to absorb the liquid and to maintain dry layer of spill mix on top.
   
2. Scoop the mixture into a container and place it in a fume hood.
   
3. In the hood, slowly add the mixture to a plastic pail of cold water.
   
4. Check the pH and, if necessary, neutralize the liquid by stirring in 5% aqueous hydrochloric acid.
   
5. Decant the liquid into the drain. Dispose of the solid material in the regular lab trash or wash with warm water, dry and reuse as spill mix.

The addition of hydrochloric acid yields ammonium chloride, as indicated in the following reaction:

NH4OH + HCl ==> NH4Cl + H2O

If you have any questions about the procedure or where to get the appropriate supplies, please contact James Boehlert at 258-7882.