Technology

Under pressure

Light, versatile and airtight, the aerosol is a popular (and highly recyclable) package capable of storing and dispersing foam, paste, dry or wet spray, gel, cream or powder. Leonie Butler looks at what is being done to keep them in the recycling the loop

On first thought, I don’t consider myself to be part of a household of aerosol users. But then, there is that hairspray I use, and the deodorant, and the shaving foam in the bathroom, and yes, I did once buy a can of ‘spray tan’, and we do have a bottle of furniture polish that is gathering dust. Then there’s the can of spray paint we used to touch up a scratch on the car, the WD40, the... you get the gist. The thing is, they’re often products that are not used on a day-to-day basis, and so are not items that are regularly thrown out. As such, unlike, say, a newspaper, it hasn’t become an automatic response to put them aside for recycling.

Under Pressure - aerosolAerosols are nothing new, though. Ever since 1928, when Norwegian Erik Rotheim wanted a simple way of putting wax on his skis, aerosols have been in production. It took a few years until they became mainstream, but in the 1950s the market began to take off (and accelerated when CFCs were phased out in the late 1980s). In 1999, the most commonly found aerosols in the household waste stream included: antiperspirants/deodorants (32.5 per cent), hair spray (13 per cent) and air fresheners (11.2 per cent). Current estimates suggest that each year, the UK uses around 600 million aerosols domestically – that’s 10 cans per person, or 27 cans per household on average – which account for four per cent of the metals packaging stream.

As far as packaging goes, being composed of either tinplated steel or aluminium, plus some plastic and rubber components, aerosols are one of the more easily recyclable forms. For the householder, the rules for recycling are simple: ensure the aerosol is completely empty and do not pierce, crush or flatten, and detach any loose or easily removable part. Plastic caps and nozzles are, technically, recyclable as part of a mixed plastic reprocessing system, but most local authorities (and certainly those that don’t collect mixed plastics) advise their residents to detach and dispose of the extraneous bits, so in practice they usually end up in landfill. The metal bits, however, can be recycled using the same process used for beverage cans.

It is estimated that there are about 25,000 tonnes of tinplated steel and 4,500 tonnes of aluminium available from recycling aerosols in the UK. Unfortunately, though, there are no separate figures for how many of the aerosols consumed in the UK are recycled, as they are collected and recycled along with other metal packaging.

This highlights, however, the potential for aerosols to be added to a local authority’s collection without taking up significant capacity and at no extra cost. Indeed, empty aerosols are now accepted for kerbside collection by 307 local authorities. When banks and magnetic extraction are included, around 90 per cent of local authorities are said to accept them. “Once it is understood that empty aerosols can be easily and safely handled and the value of the material, [local authorities] rarely hesitate. Most of the hesitation we have seen has been on the part of waste management companies and this is diminishing rapidly too”, explains Sue Rogers, Director of BAMA (the British Aerosol Manufacturers’ Association).

One reason for unwillingness is the perception of a risk of explosion. However, investigations into the potential of recycling aerosols in 1999 by PPS Recovery Systems concluded that ‘although flammable or harmful residual contents are potential hazards, taking some basic precaution to control risks to an acceptable level means that empty aerosols may be included in the household waste recycling stream’.

What’s more, Rogers says that half-used aerosols are not a significant concern. “Waste characterisation studies in the UK, Germany, Netherlands and USA all show low residues in cans sent for recycling, with an average well below three per cent contents. In practice, if an occasional part-full aerosol is added by mistake this should not cause a problem as it is unlikely to cause a flammable atmosphere. That is why the advice in the UK as elsewhere in the world is that empty aerosols sent for recycling should be kept in their normal concentration in the metals stream and not segregated.”  

She adds: “All our studies show that most consumers do actually use up the contents before disposing of the aerosols. BAMA recommends that aerosols are labelled ‘please recycle when empty’ to highlight the need to empty them.” (I’m still at a loss as to how to empty that spray tan can, though.)
Once the household aerosols have been collected and sorted, the metals are sent to various reprocessors where detinning recovers tin and high-grade steel, while the aluminium used to make aerosols is 99.7 per cent pure and so is of high value.

There are a number of specialist companies in the UK that can handle full or part-full aerosols from industrial sources and several waste management companies take aerosols from industrial sources as well. Once the cans are emptied, they can be sent for recycling just like household aerosol containers.

Despite the ease of recycling, it is suspected that there are still a number of aerosols that slip through into landfill. A survey carried out in August 2009 on behalf of Alupro (the Aluminium Packaging Recycling Organisation) found that around 85 per cent of people who were not able to recycle aerosols and foil would recycle both if facilities were available. With this in mind, the Aerofoil campaign was launched earlier this year to increase awareness of the situation. Alupro Executive Director Rick Hindley comments: “Because they are made of endlessly recyclable aluminium and steel, aerosols and foil trays are a useful source of material to the reprocessing industry.”
With more education, it is hoped that recycling aerosols could become second nature.