Chemical waste disposal
Guidance on how to package, label, store and dispose of chemical waste at the University of Toronto.
Overview
Chemical waste is not treated on campus. Instead, most of it is recycled through industrial processes:
- 100% of organic waste is recycled
- 50–75% of inorganic waste is also recycled
- Unrecyclable chemicals are handled by licensed contractors
What is chemical waste?
Chemical waste includes any solid, liquid or gas that contains or is contaminated with:
- Flammable solvents (for example: acetone, alcohols, acetonitrile)
- Leachate toxic materials (for example: heavy metals, pesticides)
- Corrosives (for example: hydrochloric acid, potassium hydroxide)
- Reactive chemicals (for example: sodium metal, cyanides, sulphides, explosives)
- Toxic materials (for example: chloroform, ethidium bromide, mutagens, carcinogens)
- PCBs (polychlorinated biphenyls > 50 ppm)
- Non-returnable gas cylinders
How to package chemical waste
Lab staff and researchers are responsible for providing waste containers to package the waste they generate.
In some situations, the Environmental Protection Services team can provide 20L plastic pails for solid and liquid chemical waste.
When packaging chemical waste, consider the following:
- Use containers that are chemically compatible with the waste generated
- Never mix incompatible chemicals in the same container
- Separate halogenated and non-halogenated solvents whenever possible
- Do not package chemical waste into biohazard bags as it misrepresents the hazards present
- Do not place chemical waste, dry chemical powders or closed chemical containers into drums designated for chemically contaminated glass and plastic
Labelling requirements for chemical waste
Attach a chemical waste label to each waste container generated.
Chemical waste labels are available for free from Environmental Protection Services.
Chemical waste labels must be filled out with specific information for disposal to occur.
Don’t use abbreviations, acronyms, trademark names or vague categories when listing the chemicals in your waste.
If your chemical waste is in original packaging, don’t affix the chemical waste label over top of the original product label.
Storage instructions for chemical waste
Chemical waste can be stored in your building’s central chemical waste facility.
Contact the Environmental Protection Services team if you’re unsure of your building’s chemical waste facility location.
If your building doesn’t have a central chemical waste facility, you must store your chemical waste in your lab space until pickup can occur.
Precautions and rules required when handling and storing of chemicals must also be followed for chemical wastes.
Segregate chemical waste by hazard class, not alphabetically.
Separate acids, bases, flammables, oxidizers and water-reactives from each other during storage and use appropriate secondary containment to contain spills.
Dispose of aging containers promptly as some chemicals degrade into more hazardous byproducts over time.
Chemical compatibility: Key rules
To avoid dangerous reactions and scenarios, never mix:
- Cyanides/sulphides with inorganic acids → liberates toxic gases
- Organic acids with inorganic acids → can lead to a fire
- Water-reactive chemicals with moisture → liberates toxic, flammable or corrosive gases
- Oxidizers with flammables or organic materials → can lead to a fire
Perchloric acid is a strong oxidizer and should not be stored or mixed with organic or flammable materials
If you’re unsure how to safely store or separate your chemical waste, contact the Environmental Protection Services team.
| Waste type | Disposal instructions |
|---|---|
| Ethidium bromide | Package all contaminated items in a leak-proof container and label clearly. |
| Expired paint cans | Treat as chemical waste. |
| Mercury thermometers | Collect broken thermometers and any free mercury in a leak-proof container. |
| Peroxidizable compounds | Order small quantities. Date containers when opened. Dispose within six months. |
Special cases
Asbestos
Asbestos-containing materials, such as Bunsen burner pads, gloves, etc., are disposed of by specially trained staff. Contact your building’s property manager.
Batteries
Household batteries should be placed into battery recycling bins that are located around campus. Look for the beige, dome-topped battery bin in your building or consult the U of T map for battery bin locations. Please apply tape to all lithium battery terminals before dropping them off. Contact the Environmental Protection Services team to dispose of any large, irregular or damaged batteries.
Empty drums
Some empty drums (20 to 205L capacity) can be recycled while others require regulated disposal. Contact the Environmental Protection Services team for more information.
Ethidium Bromide
All materials contaminated with ethidium bromide, including solids such as gloves, should be packaged in a secure container, labelled and treated as chemical waste. Gels contaminated with ethidium bromide should be packaged in leak-proof plastic containers (no garbage bags) and disposed of as chemical waste.
Explosives
Do not handle explosive materials. Examples of explosives include materials such as trinitrated compounds (TNT), dry picric acid (<20% by weight water content), fulminated mercury and heavy metal azides. These materials require special handling for disposal and must be checked frequently for signs of deterioration and aging. These signs include ‘sweating’ of a container, bulging, crystal formation around the cap, etc. Deteriorating explosive materials are potentially more dangerous to handle than new explosives. Inform the Environmental Protection Services team immediately.
Gas cylinders
Mercury thermometers
Mercury thermometers for disposal should be treated as chemical waste. Broken thermometers should be considered contaminated, and all free liquid mercury should be collected and packaged in a leak-proof container, together with all contaminated solids such as glassware, gloves used during the clean-up, etc.
Paint cans
Expired or spent paint cans are normally disposed of as chemical waste. Contact the Environmental Protection Services team for disposal options.
Peroxidizable compounds
These materials should be ordered in small quantities (less than six months’ supply) and dated when the container has been opened. Even if a commercial inhibitor has been added by the manufacturer, organic peroxide formation can begin within six months following exposure to air. Ordering smaller quantities and reducing the volume of these materials in storage encourages the quick turnover of inventory and reduces the likelihood of peroxide formation. Organic peroxides are explosive.
The following materials are potential organic peroxide formers:
- acetal
- decahydronapthalene
- dicyclopentadiene
- diethylene glycol
- dioxane
- diethyl ether
Contact the Environmental Protection Services team for disposal options.
Polychlorinated biphenyls (PCBs)
For any wastes that require special handling (explosives, organic peroxides, PCBs, etc.) contact the Environmental Protection Services team prior to disposal.
Chemical waste collection schedule
Waste collection is done on a first-come, first-served basis and as quickly as possible. Waste collection usually occurs within two weeks of a request.
To schedule a chemical waste pickup, contact the Environmental Protection Services team.
Get support
If you have questions, please contact the Environmental Protection Services team.
Please reference the Laboratory Hazardous Waste Manual (Chemical Waste Management) for more information about chemical waste procedures.
For more information about procedures for chemical labs, visit EHS’s Chemical and Lab Safety website.