Safe disposal of aerosol cans and the dangers of improper disposal

People use aerosol cans daily, either at home or the workplace, without a second thought, whether for antiseptics, shaving cream, paints, industrial solvents, antibiotics, automotive sprays, or insecticides. But what exactly are aerosol cans?

In short, an aerosol can is a self-contained dispensing system where a substance is stored inside a small metal canister and pushed out as a fine mist, a spray, or a foam.

600 million aerosols are used yearly in the UK, which equates to about 10 cans per person. 65% are made from tin-plated steel, the remainder from aluminium, both of which are recyclable.*

Aerosol cans are dangerous due to the mix of substances stored under pressure inside the metal canister. The gas within the cans turns the liquid inside into a finely dispersed mist. Even if the active ingredient is not a hazardous chemical (e.g., food products), it can still explode or turn into a dangerous projectile. The risk of these pressurised containers exploding and becoming flammable means they have the potential to release suffocating or toxic gases, and they can represent a real hazard to waste sector workers, recycling vehicles as well as plant and machinery, and the wider environment.

Types of aerosols 

Aerosols can be categorised into different areas. Below are some of the most common types and where you might find them.

Beauty and cosmetics comprise more than 50% of Europe’s aerosol production,* classified into three categories: hair, personal, and body care. Examples include hairsprays & styling sprays, dry shampoos, foams & gels, gel toothpaste, self-tanning and skin-whitening lotion and sun protection.

Household products equate to 20%, with several categories dedicated to home cleaning and maintenance air fresheners, polishing products, anti-static aerosol, aerosol starches, insecticides and herbicides.

12% of aerosols correlate to industrial & technical products. Classified into three categories and sold for mass-market and professional use: cleaning products, maintenance and paints. These aerosols include engine cleaners, tyre cleaners, de-icer, puncture repair & tyre inflators, aerosol adhesives and paint & finish.

Other aerosols not often considered include food products such as whipped cream, safety aerosols like horn aerosols designed to create loud noises, and 'novelty’ products such as silly string. 

Types of businesses using aerosols 

Nowadays, the use of aerosol products is very extensive, with businesses using them as part of their daily routines. A spray provides the volume to be dispensed optimally, enabling the contents to last longer. 

The unsung hero of garages, aerosols are nifty cylinders which provide a quick and easy application for everything from pigments to the accurate dispersal of lubrication. For Hairdressers, hairspray keeps their clients happy by keeping their new hairstyles in place. Silicone lubricant spray eases expansive movement for Plumbers, and maintenance spray displaces moisture, helping prevent metal parts from rusting and squeaking for Builders. To get surfaces in as good as new conditions, Painters and Decorators will often use spray paint or spray guns, to leave a smooth, even coat, unlike many traditional rolled and brushed paints. For your ice cream sundae or deluxe hot chocolate, restaurants and cafes will add squirty cream as it has a longer shelf life than plastic-contained cream. 

On a bigger scale, industrial premises and manufacturing sites use aerosols as they present a convenient and economical means of applying specialist aerosol cleaning fluids and lubricants for plants, machinery and other assets that are situated on site.

Disposing of household aerosol cans and your duty of care as a business 

Aerosol cans comprise approximately 60% tinplated steel and 40% aluminium, both recyclable metals.*

The cans contain liquid or gas pressurised with a propellant, so they must be disposed of correctly. Their contents can be dangerous under certain conditions, such as exposure to heat or in a compact garbage truck, which could run the risk of exploding. One of the biggest problems with aerosol cans in the workplace is their potential to ignite or explode other dangerous goods and hazardous substances.

Here are a few tips on how to dispose of household aerosols safely:

If empty, your aerosol may go into the regular recycling for cans/tins. Aerosol cans that are either partially or completely full must be separated from your other recyclables and general waste, as they are considered hazardous. Most councils collect aerosols via household collection; otherwise, they can be taken to your local recycling facility and put into the right banks.

Remove any detachable or loose parts of the aerosol, such as a plastic lid, and dispose of them separately within the appropriate recycling.

A business that produces waste has a duty of care to ensure that it’s handled and transported safely and in compliance with the law. All hazardous waste must be:

• Transported securely by a registered waste carrier in a vehicle, container or tank appropriate to the waste classification.
• Distributed evenly by weight across the vehicle or container.
• Accompanied by a consignment note.
• Taken to a facility with an appropriate pollution prevention and control permit, waste management licence or a specific, registered exemption.
• Suitably packaged and labelled, displaying required information on the vehicle or container and enabling people to take the correct precautions.
• Loaded and unloaded from vehicles and containers following proper procedures.

Hills Waste Solutions offer a wide range of containers suitable for hazardous waste and can provide safe and secure waste collection. See our skips, hooklift bins or waste compactors for more information.

How Hills recycles aerosol cans 

The waste management process seeks to recover the recyclable components within aerosol cans, whilst safely handling the potentially dangerous contents.

Empty aerosol cans can be recycled within the normal recycling waste, which will be segregated at the recycling facility. The householder should not puncture empty cans as this may be dangerous, and must take unused or partially full containers to household recycling centres, where the contents can be safely handled and the cans recycled. If the aerosols are either full or partly full, they must be treated as hazardous waste due to the nature of the gases, propellants and products they contain.  

Providing your can is empty, it can be recycled along with your tins in your dry mixed recycling bin at home, ready for kerbside collection. Detach the lid before placing it in the bin; however, labels can remain, as these are taken care of during recycling. Commercial customers should contact a waste management company directly to dispose of full or partially full containers.

Hills Waste Solutions provide hassle-free dry mixed recycling (DMR)  for businesses and can accept empty aerosols. When using our Red-top-recycler there is no need to separate your waste into different bins, as we’ll do this for you. Dry mixed recycling is collected and taken to a material recovery facility. Here, experienced operatives and technology combine to mechanically and hand sort the waste by material, segregating cardboard, paper, plastic bottles, aluminium cans and more for recycling. Each waste type is then baled and sent for re-processing, ready to be turned into new products. Any residual non-recyclable waste is diverted so that it can be processed to provide renewable energy.

At the appropriate facility, aerosol cans are recycled via the following process:

• A specialist machine pierces a small hole into the aerosol can, allowing any remaining liquid inside the can to drain – rendering the rest of the materials safe for disposal.
• The remaining components of the aerosol product are separated based on their material and then recycled through the usual channels.
• Once recycled, aerosols make a wide variety of products. E.g. recycled metals will be used to make parts for mobile phones, cars, aircraft, and electrical appliances.

The dangers of aerosol cans

Here are four ways aerosol cans present a dangerous hazard:

For example, adhesives, insecticides, automotive sprays, solvents, cleaners, paints, and varnishes are all hazardous substances and are capable of causing injury if a worker inhales or absorbs the chemicals. 

2. Cans are overheated.

Many home and workplace aerosol accidents occur when cans are left in the sun, in a car, or near a hot machine.  The pressure inside the can increases significantly in the heat and may cause it to explode. 

As the contents of aerosol cans are under high pressure, if you pierce, crush or flatten the can, it will spray uncontrollably. The can’s content may be toxic, and the propellant gas may also be flammable, presenting an explosion hazard. Do not pierce aerosols, even when empty, as some pressure and possibly some of the product are left.

4. Can is shaken, dropped or impacted.

Aerosol cans can be easily knocked over, dropped, or impacted by passing machinery and vehicles in the workplace, potentially leaving the contents (active ingredients, propellant, and solvent) volatile. In the most severe cases, aerosol cans may explode.

Due to the volatile nature of aerosol cans, as outlined above, it is crucial to ensure cans disposed of via kerbside recycling are empty to prevent accidents at the recycling place. Hills Waste Solutions and Wiltshire Council remind residents of the danger of placing unemptied aerosol cans into recycling bins following an explosion at a recycling sorting facility in Calne. 

Safety measures to ensure worker safety 

As partially full aerosol cans could cause explosions and potentially endanger recycling staff and property, it is vital to empty an aerosol can. Simply depress the nozzle until no more air or propellant is heard escaping. 

To keep staff safe and reduce costs from machine breakdowns, consult the Hills Waste Solution website on what you can and can’t recycle or throw away in your general waste bin.

Households disposing of aerosol cans that have yet to be emptied and any pressurised cylinders, such as camping gas cylinders and large NOx cylinders, can be taken to a household recycling centre; please speak to staff about the suitable location for these items. Businesses should contact Hills Waste Solutions for advice. 

What responsibilities do businesses and homeowners have with hazardous waste?

If you’re the owner or director of a business that produces hazardous waste, you’re legally obliged to dispose of your waste correctly and safely. You must assess the risk of any potentially harmful substance and take necessary steps to ensure employees, the public and the environment aren’t exposed to that risk.

To dispose of hazardous waste in line with legislation, you must:

• Separate it – mixing hazardous waste with anything else; even another hazardous waste is illegal.
• Store it considerately – in a suitable container in a secure location.
• Use a licensed waste carrier to transport it – Only authorised operators can carry out waste collection and movement using a licensed waste carrier to transport it.
• Make and keep records – consignment notes and paperwork for transported hazardous waste must be completed and held for three years. 
• Breaching the strict regulations in place is a serious matter and can lead to financial sanctions and even prosecution. Full details of businesses’ responsibilities regarding hazardous waste can be found here.

Aerosol cans are widely recycled in household collection schemes and at recycling points, but as a homeowner, following these top tips can help make the process safer and run more smoothly: 

• Ensure cans are empty before being put into banks or kerbside collections.
• Don’t pierce or attempt to flatten the cans before throwing them into the recycling.
• Loose or removable parts, like the lid, should be detached and disposed of separately in the appropriate recycling bin.
• Mix cans with other recycling, as this helps to dilute the proportion of aerosols within the overall collection.

The British Aerosol Manufacturers Association (BAMA) provides full guidance on the collection and processing of both empty and full cans.

For more information on the safe disposal of aerosol cans and hazardous waste, contact our Customer Support team on 0808 145 4533 or fill out the form here and let your experienced local waste management experts take care of it.

References*

^{https://www.hse.gov.uk/waste/metals.htm
https://www.aerosol.org/about-aerosols/uses-benefits/
https://www.walesrecycles.org.uk/recycle-an-item/aerosols}