Laboratory Glassware Care and Cleaning

Because your glassware is expensive and you are responsible for it, you will want to give it proper care and respect. If you read this chapter carefully and follow the procedures presented here, you may be able to avoid some unnecessary expense. You may also save time because cleaning problems and replacing broken glassware are time-consuming. 

For troublesome stains and residues that adhere to the glass despite your best efforts, use a mixture of sulfuric acid and nitric acid. Cautiously add about 20 drops of concentrated sulfuric acid and 5 drops of concentrated nitric acid to the flask or vial. 

You must wear safety glasses when you are using a cleaning solution made from sulfuric acid and nitric acid. Do not allow the solution to come into contact with your skin or clothing. It will cause severe burns on your skin and create holes in your clothing. The acids may also react with the residue in the container. 

Swirl the acid mixture in the container for a few minutes. If necessary, place the glassware in a warm-water bath and heat cautiously to accelerate the cleaning process. Continue heating until any sign of a reaction ceases. When the cleaning procedure is completed, decant the mixture into an appropriate waste container. 

Do not pour the acid solution into a waste container that is intended for organic wastes. 

---