ABSTRACT
Wear nitrile rubber gloves, laboratory coat, and eye protection. Cover spill with a 1:1:1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. Scoop mixture into a container of water. In the fume hood, carefully acidify this solution with 3 M sulfuric acid (prepared by cautiously adding 9 mL of concentrated acid to 46 mL of cold water) until a pH of 1 (pHydrion paper) is obtained. Slowly and while stirring, add solid sodium thiosulfate until the solution becomes cloudy and blue colored. Neutralize the solution by adding sodium carbonate. After a few minutes, a bluegray flocculent precipitate is formed. Let the mixture stand for a week or filter immediately through Celite. After standing, much of the supernatant can be decanted. Allow the remaining liquid to evaporate or filter the solid. The liquid in both methods can be washed into the drain. The solid residue should be washed with hot water, dried, packaged, labeled, and sent to a secure landfill site. The spillage site and contaminated clothing should be washed thoroughly with soap and water to remove the oxidant.1,2
Waste Disposal
Small Quantities. Wear nitrile rubber gloves, laboratory coat, and eye protection. In the fume hood, slowly and carefully add the cleaning solution (100 mL) to a container of water (about 1:1 dilution). Adjust pH to 1 by the addition of 3 M sulfuric acid or sodium carbonate. While stirring, slowly add solid sodium thiosulfate (about 13.5 g) until the solution becomes cloudy and blue colored. Neutralize the solution with sodium
water to remove sodium sulfate, and then dried, packaged, labeled, and sent to a secure landfill site.1
