Hazardous Waste Program fact sheet
Division of Environmental Quality Director: Leanne Tippett Mosby

Waste aerosol cans are a challenge for businesses to manage. A business may generate one or two cans on an infrequent basis or many as processes demand. All contents of the can (product, inert ingredients, propellants and gases) may or may not be identified on the label or Material Safety Data Sheet. Cans become waste when they are empty and product can no longer be expelled, or when the product has exceeded the useful shelf life. Sometimes cans become waste when the nozzle or valve fails or the contents begin to solidify. To minimize waste disposal problems, the Missouri Department of Natural Resources encourages businesses to:

Aerosol cans and other wastes generated by households are exempt from hazardous waste regulation. A decision tree for managing waste aerosol cans is found on the last page of this fact sheet. Use the decision tree to identify the management strategy that applies to your situation then refer to the Waste Management Options section for details regarding the management option. References: 40 CFR 261.7 and 10 CSR 25-5.262(l) incorporating 40 CFR 262.11.

Waste Management Options

Small and infrequent (de minimus) quantities
If your business is a conditionally exempt small quantity generator of hazardous waste and it generates one or two cans on an infrequent basis (or if you are a household or farmer), you may dispose of these in a Missouri sanitary landfill. Missouri’s Hazardous Waste Law does not allow anything other than very small amounts of hazardous waste to be disposed in Missouri sanitary landfills.┬áIf your business is a small quantity generator or large quantity generator of hazardous waste, you may not dispose of any hazardous wastes, including hazardous waste aerosol cans, in a Missouri sanitary landfill.

Empty aerosol cans that are recycled as scrap metal are exempt from most hazardous waste regulations [40 CFR 261.6(a)(3)(iii)]. Non-empty aerosol cans should only be sent to a recycler or punctured in a unit at a facility that is capable of managing pressurized containers and able to properly capture and manage all vented liquids, gases and propellants.

Improper depressurization of aerosol cans is extremely dangerous, and the release of hazardous material may violate the Missouri Hazardous Waste Management Law or the Clean Air Act. If aerosol cans are destined for scrap metal recycling, the process of emptying the cans is considered part of the recycling process and a hazardous waste treatment permit is not required for this activity. However, any liquids or gases removed from the cans are solid wastes if they cannot be used for their intended purpose. If unusable, the collected residues must be evaluated to determine if they are hazardous waste (40 CFR 262.11). If the contents are hazardous waste, they are subject to all applicable hazardous waste regulations regarding on-site management, transportation, treatment and disposal. Even if the can and the contents are nonhazardous,

Department of Transportation regulations may apply to the transportation of some cans as hazardous material. If the contents of some cans are hazardous and the contents of others are not, the bulking and commingling of the contents is not considered illegal dilution. However, bulked contents must be evaluated for use, recycling or disposal as described above.

Satellite Accumulation
Spent aerosol cans may be kept in satellite accumulation for up one year. This allows a facility to accumulate up to a 55 gallon drum of spent aerosol cans prior to final management. If waste streams are different (such as aerosol cans with flammable paint wastes and aerosol cans with toxic insect sprays) up to 55 gallons of each waste stream may be accumulated. Facilities may consider this option when it does not generate a large number of aerosol cans in its operations and wishes to maximize time spent on emptying cans prior to recycling or disposal.

For all aerosol cans, use as much of the can’s contents as possible for the intended purpose. For the can to be empty, the pressure of the propellant gas should be unable to propel any more material from the can. (Note: If the nozzle or valve malfunctions, and some of the contents remain, the can is not empty.)

If the can is empty of all liquids, gases and propellants, it may be recycled or disposed in a sanitary landfill. Recycling as scrap metal is strongly encouraged. If the can is not empty, a generator must perform a hazardous waste determination on both the can and any residuals remaining in the can (liquids, gases or propellants). If the can or the contents are hazardous waste, it must be managed under all applicable regulations including transport, treatment and disposal as a hazardous waste.

Since aerosol cans containing acutely toxic materials including those that are P-listed or U-listed (such as certain types of pesticides) cannot be triple rinsed, disposal may be the only option. Although the venting of an aerosol can is not considered treatment, the captured liquids, gases or propellants may be subject to hazardous waste regulations if they cannot be used or reused without any additional processing or treatment. As previously noted, the characteristics of any unusable residues must be identified and, if hazardous, transported, treated, and disposed of according to all applicable regulations.

For more information
Missouri Department of Natural Resources
Hazardous Waste Program
P.O. Box 176, Jefferson City, MO 65102-0176
800-361-4827 or 573-751-3176 office
573-751-7869 fax