Alternatives to Chromic Acid Cleaners in Laboratories
Chromic acid is widely used in many laboratories for cleaning glassware.
Because of the hazards for health and environment some alternatives have been developed as commercial products, but also as laboratory-made substitutes.
Potassium hydroxide ethanol is a mixture of the alkali in denaturated alcohol that may contain toluene (Repr.2) and hydrazine ( Carc.1B, aquatic toxicity 1 for both acute and chronic effects).
Strong alkali or acid solutions are corrosive.
The Division of Research Safety-Chemical Safety Section of the University of Illinois at Urbana Champaign (UIUC) in USA published a Fact Sheet on alternatives to chromic acid used to clean laboratory glassware. Previously, an internal study made by UIUC in 1992 showed that 26 of its laboratories were using chromic acid as cleaner and concluded that this was due to unawareness of available alternatives at that time. Another possible cause identified back then was that people did not realised the hazards of the chemical and the fact that they were passed on to waste.
After using several alternative cleaners commercially available on the market, researchers found that they provide ‘’ sufficient cleaning capabilities for their needs’’. Laboratory made solutions (acidic or basic) that can be neutralized and sewered after use, also achieve desired cleaning levels.
The alternatives included commercialised cleaners ( see Further information) and other chemicals often available in laboratories: hydrochloric acid, potassium hydroxide ethanol, oxidizing agents without chromium or other metals.
The substitution eliminates the use of hexavalent chromium in oxides and chromates known to be hazardous for the workers and environment.
Corosive alternatives need proper handling and the use of personal protective equipment.
Corosive wastes need to be neutralised before disposal.
1. MSDS ALCONOX Lab cleaning powder
Type of information supplier
Division of the Research safety, of the University of Illinois at Urbana Champaign, http://www.drs.illinois.edu/
Division of the Research safety, of the University of Illinois at Urbana ChampaignType of publication and availability
Fact sheet, freely available on internet
Publication or last update: