Consumer aerosol products, such as deodorants, now release more volatile organic compound pollution than all cars in the UK, according to new research by the National Centre for Atmospheric Science and University of York.

The harmful chemical pollutants, called volatile organic compounds or VOCs, are a precursor to toxic smog. They are used in nearly all compressed aerosol dispensers.

Researchers found that aerosol products now account for 6.1% of all VOC emissions in the UK, which equates to more emissions than the entire car fleet.

In enclosed indoor spaces, where we spend most of our time, high concentrations of VOCs can cause symptoms ranging from headaches and lung irritation, to nervous system damage and some types of cancer. 

If they are released outside, they can react with secondary pollutants to create small particulate matter and photochemical smog, which can cause irreversible damage to our hearts and lungs, and devastate wildlife and agriculture.

Aerosols have grown rapidly in popularity over the last sixty years. Globally, nearly forty billion cans of disposable aerosol are used each year and demand is rising in lower and middle income countries.

Researchers found that in high-income countries people use around 10 aerosol cans per year. The largest contributor is personal care products, but other contributors include cleaning products and air fresheners.

In part, the increasing proportion of VOC emissions from domestic products in the UK has been fuelled by the decline in emissions from vehicles. Throughout the 1990s and 2000s, cars were by far the largest source of VOC pollution in the UK, but these emissions have been driven down by measures including catalytic converters and fuel vapour recovery at filling stations.

The emphasis is now on international policymakers to find equally successful ways to clean up compressed aerosols, either by reducing the use of VOCs, or encouraging less damaging propellants such as nitrogen. At present VOCs are used in around 93% of aerosol cans.

Co-author Professor Alastair Lewis, University of York and National Centre for Atmospheric Science, said: 

“Virtually all aerosol based consumer products can be delivered in non-aerosol form, for example as dry or roll-on deodorants, bars of polish not spray.  Making just small changes in what we buy could have a major impact on both outdoor and indoor air quality, and have relatively little impact on our lives.

“The widespread switching of aerosol propellant with non-VOC alternatives would lead to potentially meaningful reductions in surface ozone and dangerous smog. 

Aerosol propellants have a history of legislative restrictions. They were previously produced using halocarbons, often called CFCs, before the Montreal Protocol in 1987 ushered in less damaging replacements to protect against the depletion of the ozone layer.

Although VOCs are less damaging than the CFCs they replaced, they now present a new challenge for policymakers. No-one foresaw the rapid rise in global consumption of aerosols, which has led to nearly 1.3 million tonnes of VOC being released per year globally from aerosol cans.