Lucy Siegle: Two decades on and aerosol guilt is justifiably alive and well

Anyone who came of eco age in the 1980s will find it difficult to spray an aerosol with impunity.

There will always be that lingering feeling of guilt, a hangover from the time when scientists discovered that a seemingly innocuous CFC molecule responsible for propelling personal care products and keeping things cool in the fridge was rapidly increasing our chances of being fried alive by solar radiation, as chlorine in the stratosphere broke down the protective ozone layer.

Banners were waved, concerts held and we could hardly sleep for fear of the vanishing ozone layer. You may still have the 80s T-shirt.

Then, apparently overnight, a solution was found.

Was this thanks to the banner-waving and T-shirts? Probably not. It had more to do with the fact that the industry had already found an alternative in the form of hydrochlorofluorocarbons (HCFCs). Job done.

Well, not really.

Although much slower, HCFCs still depleted the ozone layer. The developed world moved on to the next miracle solution: hydrofluorocarbons (HFCs), without the chlorine.

The problem is that whereas these can be labelled "ozone friendly", their global warming potential is 10,000 times greater than carbon dioxide's.

A recent investigation by Britain's Environmental Investigations Agency estimated that the country's supermarkets produce the equivalent of 2 million tonnes of carbon dioxide every year - equal to flying from London to New York more than 2.5 million times - through their continued use of HFC refrigeration.

Their move to green refrigeration as practised in Germany appears to be proceeding at glacial speeds.

Arguably, then, you could be more culpable if you buy refrigerated goods than deodorants. In fact, most aerosol manufacturers claim they now use volatile hydrocarbons such as propane. What they don't always say is that these still have a global warming potential 10 times higher than that of carbon dioxide.

It is difficult to tell which propellants are in which aerosols. The trouble is that CFCs and HCFCs have migrated all over the world; one investigation even found an illegal smuggling trade in the latter.

Two decades on from the Montreal Protocol designed to phase out dangerous propellants, they are still in circulation in all types of products.

Sometimes they're unavoidable. If you're asthmatic, there's every chance your inhaler includes CFCs - an irony given ozone depletion's connection to respiratory illness - but until recently no other propellant could cut it. (CFC-free inhalers are now available.)

So should we spray or spritz? Well, nearly all ethically minded cosmetic companies prefer to put their product in a spritz format these days. Aside from the propellant issue, aerosol canisters are difficult to recycle, and reuse is impossible. So in short, kicking those aerosols to the kerb can only be a good thing.

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