Cleaning and Decontamination Procedures

When hazardous chemical, biological, or radioactive materials are used in the laboratory, it is important that all surfaces and equipment are regularly cleaned up and decontaminated. This will prevent cross contamination and accidental exposures. In addition to routine cleanup, equipment and surfaces must be decontaminated prior to:

• Remodeling or demolition
• Repair by either Facilities Management (FM) or outside contractor
• Vacating rooms or areas during the laboratory closeout process
• Disposal or recycling of unwanted equipment
• Relocation of equipment
• Returning faulty or damaged equipment for repair or replacement

Hazardous Chemical Decontamination

Surfaces and equipment must be thoroughly cleaned of chemical residue after use. If a large amount of chemical contamination is present, the decontamination should be treated as a spill cleanup. Please refer to the section on spill cleanup for more guidance.

It is necessary to fully understand the hazards associated with the chemicals you are working with. Review the SDS of the material you are working with to review necessary personal protective equipment (PPE) and to identify any incompatibilities. This ensures that your decontamination method is compatible with the material to be cleaned.

The most common method of chemical decontamination is to thoroughly wipe down surfaces and equipment with soap and water using disposable towels. The contaminated towels should be disposed of properly through the Hazardous Waste Program.

Special Hazard Considerations

Acids and bases: A surface contaminated with residual acid or base corrosives should be neutralized and/or diluted. Testing the pH of the surface after will help ensure that the decontamination method is sufficient.

Highly toxic chemicals: Extra care must be taken when decontaminating areas where personnel have been using highly toxic material. Surfaces, equipment, and glassware that contacted the material must be decontaminated after every use. Choose a solvent that the material is soluble in and compatible for decontamination. Avoid solvents that enhance absorption through the skin (such as dimethylsulfoxide). Also make sure gloves used for cleaning are compatible with the material and decontamination solvent. All material used during decontamination should be disposed of in the solid or liquid chemical waste. Once finished, practice good laboratory hygiene by washing your hands, arms, neck and face.

Stench chemicals: After work with stench chemicals, surfaces, equipment, labware, and glassware should be thoroughly decontaminated to prevent the release of noxious smells, even when that work is done in the fume hood. Reference the Stench Chemicals Fact Sheet for further guidance on cleaning up residual stench chemicals.

Grease and oil: Surfaces and equipment contaminated with greasy residue should be wiped with a surfactant capable of dissolving the grease such as soapy water. You can also choose an appropriate solvent or cleaner to clean the grease residue. Be sure to dispose of any greasy rags in the solid waste and solvent in the solvent waste.

Solid chemical residue: Traces of solid chemical residue can be cleaned by sweeping or by wetting with water or a solvent and wiping the surface with a disposable towel. Take special care not to aerosolize the dust particles while you are cleaning. Any contaminated towels should be disposed of properly through the Hazardous Waste Program.

Decontamination inside a glovebox: All surfaces, equipment, and glassware that came into contact with pyrophoric chemicals should be cleaned and quenched (deactivate all unreacted material to render it inert) inside the glovebox before removing the waste and exposing it to oxygen. Improper decontamination may result in fires. Be sure to decontaminate and quench with solvents that are compatible with the chemical you are cleaning up. For proper training and guidance in this area, staff and students must consult with their supervisor.

For surfaces contaminated with visible beads of mercury or surfaces suspected to contain mercury, DO NOT attempt to clean the area yourself. Contact HSRM for mercury abatement.

All chemical waste can be processed through the University's Hazardous Waste Program. For assistance or questions regarding the disposal of chemicals contact [email protected] or (612) 626-1604.

1. Spill procedures
2. Radiological Decontamination
   Any equipment that contains a radioactive source or that potentially came in contact with radioactive materials must be tested and cleared by the HSRM Radiation Safety Officer prior to handling for disposal. Please contact HSRM for assistance with radioactive decontamination procedures.
3. Decontamination of Biohazards and Infectious Agents
   For guidance on the decontamination of biohazards and infectious agents, please see the Biosafety's Decontamination of Biohazards and Infectious Agents webpage.