Aerosol Cans

Quite a number of cleaners, paints, and adhesives used in auto repair are packaged in aerosol spray cans. These cans are thin-walled steel pressure vessels pressurized with one of several hydrocarbon propellants, such as butane. When empty, the propellant and product are gone and the cans are not considered hazardous wastes. However, partially empty spray cans may be regulated as hazardous wastes because they contain ignitable, or chlorinated solvents.

Aerosol cans are expensive and have greater environmental consequences.  Ounce for ounce, spray-on product sold in aerosol cans is roughly twice the cost of bulk product.  You pay for propellants in every aerosol can you purchase.  Most aerosol cans contain 10-15% propellant by weight. 

Problems

Environmental Impact

Carbon dioxide, propane, and butane are commonly used aerosol propellants.  These are “greenhouse gases” that contribute to global warming and smog formation.  Every year, individual auto repair and fleet maintenance facilities discard hundreds, and sometimes thousands, of aerosol cans used to dispense brake cleaners, carburetor cleaners, lubricants and penetrants, engine degreasers, and numerous other products as trash, taking up valuable landfill space.

Pressurized cans present additional environmental concerns. If punctured, contents may be released so forcefully that injuries could result. Extreme temperatures may cause cans to rupture, and moisture may cause them to rust, resulting in a release of the contents with potential to harm the air, water or land. Pressurized cans sent to a landfill present safety concerns during compacting, and fire hazard becomes more acute if container contents are vacated using an aerosol-puncturing device for the purpose of disposal.

Worker Safety

Some aerosol products  such as paints, solvents, pesticides are hazardous. Most aerosol cans pose a fire hazard because they contain highly flammable propellants such as propane and butane. Aerosol products must be used with adequate ventilation and/ or personal protective equipment to prevent inhalation, employee exposure and potentially harmful health effects. (Always check the Material Safety Data Sheet (MSDS) for proper usage and follow the directions!)

Regulations

US EPA and many states may consider used aerosol cans that are not empty hazardous waste

Required Paperwork

·         Purchasing  - Request a Material Safety Data Sheet (MSDS) for all aerosol products. Occupational Safety and Health Administration (OSHA) regulations require products. (Hazard information should also be provided in foreign languages for employees who may not understand English.)

·         Storage  - Inspect all hazardous waste storage areas and document inspection results.

·         Shipping  - Keep shipping papers/ manifests for a minimum of three years to show waste has been shipped properly.

·         Disposal  - Know where waste is going. Request proof that the waste has been received and disposed of or recycled properly. Keep records for a minimum of three years.

Solutions

Waste Reduction

First, determine whether or not a material is even needed. Could the entire process using the aerosol be eliminated? If required, choose a non-hazardous product or the least hazardous product that will do the job (a Material Safety Data Sheet — MSDS— is one resource that may be helpful). Use only as much as is needed. Store aerosol products in a dry area not subject to extreme temperatures. Follow label directions to clean the nozzle after use to prevent clogging. Use up products before buying others. To apply paints, use a brush instead of an aerosol, or consider electrostatic painting, when possible.

Refillable Spray Bottles

Shops and facilities that switch to refillable spray bottles are saving money by avoiding the high cost of aerosol cans and are helping to protect the environment by eliminating the solid and potentially hazardous waste stream they produce. 

There are two basic types of refillable spray bottles:

1. Metal bottles that spray product using compressed air
2. Plastic bottles that use a hand pump to spray product. 

Refillable metal bottles more closely resemble aerosol cans in terms of their design and performance.  These bottles are filled with product (for example, brake cleaner) from a bulk container and are pressurized with air at 80 to 200 pounds per square inch using a compressed-air hose.  Plastic bottles are also filled from bulk containers but do not require compressed air.  Instead, pumping a trigger to create a mist or stream of product operates them.

What to consider when selecting refillable spray bottles:

Capacity.  The capacity of air-pressurized, refillable spray bottles varies from 7 fluid ounces to 1 quart. Smaller bottles are useful for spraying hard-to-reach areas. Larger bottles are more convenient because they require less frequent filling and therefore less technician time.

Construction material.  Refillable spray bottles are available in different materials and with different finishes (aluminum, stainless-steel, brass, and steel) for use with different types of bulk product.  Ask the spray bottle manufacturer whether the bottle is compatible with the product you intend to use.

Nozzle type.  1-quart, refillable spray bottles come with standard spray and stream nozzles.  A nozzle that can be adjusted from stream to spray is also available. Smaller bottles (16- and 8-fluid ounce) are available that closely resemble the size and shape of aerosol cans and have a spray pattern similar to an aerosol can spray.

Nozzle extensions.  Nozzle extensions up to 12 inches long are available for spraying areas that are otherwise difficult or impossible to reach.

Cost.  Air-pressurized, refillable spray bottles cost from $25 to $60 each, depending on the construction material.  Chemically resistant plastic bottles and hand pumps cost from $1 to $6 each.  Be sure to check with the product vendor about plastics that are compatible with their chemical product.

Economy.  Ounce for ounce, bulk product is cheaper than aerosol cans. Most common spray-on products are available in containers ranging in size from 1 to 55 gallons. You may be able to obtain free refillable spray bottles from your vendor when you purchase their product.

Maximizing benefits.  Refillable spray bottles do work and can reduce costs-if they are used correctly.  Therefore, be sure to:

·         Avoid product losses due to spills during refilling. Use funnels and pumps to minimize spills.

·         Keep replacement parts on hand. Small, inexpensive parts such as nozzle seals, filler caps, valves, and nozzles may deteriorate with repeated use and pressurization.

·         Refillable spray bottles will be used if they are as convenient for workers as aerosol cans; therefore, provide every technician with a refillable spray bottle for each type of frequently used aerosol product.

·         Water in the shop air lines may cause corrosion in some steel refillable spray bottles.  Ensure that your shop air supply has a water removal device.

Recycling

Under the federal Resource Conservation and Recovery Act (RCRA), aerosol cans may be recycled if they have been emptied through normal use or punctured and drained to remove significant liquids.  Some states such as California have more stringent regulations than RCRA. Be sure to investigate state regulations before recycling aerosol cans.  Shops are responsible for properly managing any captured wastes recovered from puncturing and draining.

Although spray cans may be discarded in the trash, they are recyclable due to the fact that the majority of the can is steel; in fact, the typical spray can contains at least 25% recycled steel. A number of recyclers that collect drained oil filters for recycling will also accept empty spray cans along with the filters. The oil filters and spray cans are shredded and melted down to make new steel.

Waste Management

Managing Empty Aerosol Containers

Empty means the can contains no product and no pressure. Empty containers are exempt from hazardous waste rules. They have no special storage, labeling or disposal requirements. Recycle them, if possible, or send them to an incinerator that will recover the metal. If you have a small number of empty aerosol containers, they may be able to be mixed with your solid waste. Check with your solid waste handler first.

Managing Non-Empty Aerosol Containers

First, try to return or exchange malfunctioning aerosols. Malfunctioning aerosols returned to the supplier or manufacturer are considered “product” -  not “waste.” Hazardous waste rules do not apply. You must follow applicable Department of Transportation (DOT) requirements for transport. Non-empty aerosols that cannot be returned or exchanged must usually be managed as a hazardous waste. Regardless of the contents, most aerosols are hazardous because they are ignitable (D001) due to the type of propellants used.

Storage and Labeling of Waste Aerosols

Waste aerosols whose contents (including propellants) are non-hazardous have no hazardous waste storage requirements. Follow fire protection requirements for product storage. Store hazardous waste aerosols in a closed container marked with:

• The words Hazardous Waste,
• A clear description of the waste, and  
• The accumulation start-date (the date you first placed waste in the container).

If you have only a few aerosol cans, you may mark them individually as outlined above, and place them in a fire-safe storage cabinet. You may designate a special cabinet for waste, or reserve and mark a special section of your product cabinet for waste. If storing incompatible materials, store them in separate containers (such as plastic dishpans) within the waste storage area. Perform and document weekly inspections of the waste.

Disposal / Recycling Options

Non-empty aerosol cans, even though they have been determined to be non-hazardous, have few disposal options. They generally cannot be sent to a landfill or a solid waste incinerator. They will probably need to be managed by a company specializing in hazardous and problem waste disposal.

Aerosol cans containing hazardous product or propellant should be shipped to a hazardous waste facility for proper disposal. Conditionally Exempt Small Quantity Generators (CESQGs) have the additional option of taking waste aerosol cans to a CESQG collection site.

Companies that regularly have significant numbers of similar waste aerosols may be interested in using an aerosol-puncturing device. (Use of a puncturing device does not require a waste-treatment permit at this time.) If you choose to use one, here are some precautions to keep in mind:

DO

• Follow the manufacturer’s instructions for operating, cleaning and maintaining the puncturing device.
• Staff operating the device should be thoroughly trained and should wear appropriate personal protective equipment — tyvek body suit, nitrile gloves, full-face respirator (or half-face respirator with safety goggles and face shield) containing the appropriate cartridges. WARNING: The major propellants of aerosol cans (propane and butane) are extremely flammable. A filter unit does not capture them — they vaporize quickly into the surrounding air, producing a flammable hazard. Smoking should not be allowed in or near the puncturing area. To prevent static sparks, ground steel containers before you begin to fill them.

• Sort cans by size and puncture similar sizes at the same time. You may wish to puncture cans containing solvents, degreasers and/or lubricants last to help clean the puncturing unit.
• Operate only in an open, well-ventilated area. Avoid confined spaces.
• Collect liquids in an appropriate, marked and labeled hazardous waste container — such as a rust-free drum with a bung opening that can be fitted with a pressure-release valve.

• Use up the contents of an entire spray can before starting another. Make sure that the can is completely empty before discarding it. Devices are available to puncture aerosol cans and capture any remaining contents.
• Return to the seller any spray cans that malfunction (for example, the tip breaks off).

• Use refillable mechanical spray cans when possible. Consider phasing out the use of spray cans in your shop. You may realize a large savings by switching to non-aerosol products.

• Establish a distribution control system to limit aerosol cleaner use.
• Consider phasing out the use of spray cans in your shop.
• Store your empty spray cans along with your drained and crushed oil filters for pickup and recycling.

DO NOT

• Spray in or around other solvents. Hazardous contamination may result.
• Empty the contents of spray cans by releasing into the environment
• Discard partially empty spray cans into the trash dumpster.

• Do not puncture aerosol cans containing any of these ingredients: ethyl ether (often found in starting fluids), chlorinated compounds, pesticides, freons and foamers, oven cleaners, unknowns. These types of aerosols should be lab-packed and managed as hazardous waste.