When you think about aerosol spray and pollution, you might immediately picture a big, vintage hairstyle held together with loads of high-pollution hair spray. Sepia-toned images of blissfully unaware ‘60s housewives spraying their aerosol with abandon might pop into your head, underscoring how long ago that all seems. Aerosol can pollution feels like an ancient relic for many people, gone along with those now-deflated hairstyles. We’re so much more aware of what substances can harm the planet today, aren’t we? Still, the question lingers at the back of your mind. Since there have been so many regulations placed on aerosol can pollution since the 1970s, is it still really a problem? 

We could sum up this answer in one word: Yes. Aerosol can pollution is definitely still an issue plaguing our planet. But instead of leaving it at that and sending you on your way, let’s break it down. To get at why aerosol spray is still causing pollution, we’ll have to get through some history first.

Aerosol Spray Origins

Aerosol can pollution goes back way farther than you might think. The pressurized technology that would lay the foundations for the first aerosol spray cans was invented in the 1920s. The first patent for an aerosol spray can was handed out in Norway to chemical engineer Erik Rotheim. He was looking for a way to apply wax to his skis more effectively, and he found that pressurized aerosol was the best way to do it.

Scientists at the U.S. Department of Agriculture built on this advancement, and a couple decades later, they created what is often considered the first spray can. It was originally used for insect spray, and the canisters were much bigger and bulkier than the aerosol cans we know today. It took several decades before these cans were a popular way to package products, though. The U.S. military used this new-fangled aerosol spray technology to combat Malaria in the South Pacific during World War II, but it would be a while before aerosol cans were used widely for consumer products.

The first mass-produced aerosol valve was patented in 1953. After that, the aerosol spray technology could really take off. It was used in all kinds of products — hairspray, antiperspirant, and spray paint were (and still are) all common uses.

Aerosol Can Pollution Controversy

Aerosol spray was all the rage in the decades after companies started mass producing the cans. Rock-solid hair styles were definitely in vogue since they had the hairspray to hold them in place, and all the other types of aerosol sprays were taken advantage of, too. Consumers weren’t aware of any problems with their aerosols, and they simply took advantage of the convenient new technology without any concern for the environment. However, that didn’t last. Concerns about aerosol can pollution arose in the 1970s. To get into what those concerns were and how they’ve since been addressed, we need to know a little more about aerosol spray technology.

Aerosol Spray Primer: First Coat of Knowledge

First of all, “aerosol” might not mean what you think. When scientists refer to aerosols, they essentially mean little particles in the air. For example, they’d be correct in calling fog or smoke aerosols. An aerosol spray dispenses the product as a mist or foam by mixing a propellant with the product (unless it uses bag on valve technology, which separates the propellant from the product). Those propellants are where most of the problems lie.

The propellant is a pressurized gas that usually takes the form of a liquid within the container. Once the nozzle is pressed, the pressure is released, and the propellant turns back to a gas. It tries to escape the now-open can and pushes the liquid out with it. The nozzle has a very small hole that breaks the liquid (or foam or gel, depending on the product and type of nozzle) into tiny droplets, making it an aerosol.

Chlorofluorocarbons

That’s not a tongue twister — that’s the name of the type of aerosol propellants that have been (mostly) banned in the United States since the late 1970s. They were one of the main culprits behind aerosol can pollution.

To explain why, we have to give a little background on the ozone layer. You’ve probably heard of the hole in it. That phrasing is a little misleading, though — there’s not actually a hole, it’s just an area where the layer is thinning, and that changes size seasonally. The ozone layer is 10 to 30 miles above the planet’s surface in an atmospheric layer called the stratosphere, and it helps protect Earth from solar radiation. It’s very effective at absorbing the kind of high energy ultraviolet radiation that’s harmful to living beings. Protecting the ozone layer has been linked to reducing conditions like skin cancer.

The thing about chlorofluorocarbons (CFCs) is that they break up ozone molecules, contributing to that thinning of the ozone layer. This happens when UV radiation breaks chlorine atoms off of CFCs, and then the chlorine goes on to break up ozone molecules. Getting any more specific than that is a little too technical for our purposes here, but suffice it to say that the CFCs in aerosol sprays definitely contributed to the thinning of the ozone layer.

The problem was bigger than just aerosol can pollution, though. CFCs were also used in air conditioners, Styrofoam, and industrial cleaning products. In order to combat the growing hole in the ozone layer, some serious changes would need to be implemented.

Preventing Aerosol Can Pollution

Concern over the environmental impact of CFCs began in the 1970s, but it wouldn’t be until 1985 that this link between ozone depletion and CFCs would be scientifically proven. In the United States, CFC use in aerosol sprays became a major political issue as the public became aware of the likely link between aerosol can pollution and the hole in the ozone layer. That public pressure helped cause the U.S. to ban the use of CFCs as propellants in 1978. 

That was a big initial win for environmental activists concerned about CFCs, but there were still other regulations they wanted to see enacted. Aerosol cans are not the only source of CFCs. They were (and still are in some countries) used in other products like air conditioners and spray foam insulation. Aerosol can pollution was just one part of the CFC problem, so there was still a long way to go in eliminating them from the environment and protecting our atmosphere.

To decrease the damaging effects of CFCs and protect the ozone layer, governments around the world pledged to decrease CFC production in all products over time. In 1987, 191 countries signed the Montreal Protocol. This agreement slowly phased out CFCs and continues to be an effective method of suppressing their manufacture and release into our atmosphere.

Today’s Propellants

Since CFCs have been banned for consumer products, aerosol spray manufacturers have had to come up with other propellants. Most often, they use gases like propane and butane. These gases don’t damage the ozone layer like CFCs do, but they have their own sets of concerns. They are highly flammable. That makes aerosol sprays utilizing these gases as propellants dangerous to have near flames, and that makes some people nervous to have them around the house, especially if small children are involved. Another drawback is that propane and butane are dangerous to inhale, potentially harming you. 

Plus, many of today’s propellants contain hydrocarbons or other compressed gasses that still contribute to global warming. A few-seconds-long burst of deodorant might feel harmless, and it mostly is, but aerosol can pollution still contributes to your carbon footprint, and it adds up over time. 

That’s not even the end of modern aerosol can pollution. There’s another harmful three-letter acronym that they release into the atmosphere: VOCs.

Volatile Organic Compounds

Just because CFCs are a thing of the past doesn’t mean the new propellants are completely pollution-free, either. They contain substances called Volatile Organic Compounds (VOCs) that can also be harmful to the environment. When they come into contact with sunlight, VOCs can react with nitrogen oxides to create ozone pollution. 

Now, you might be thinking, “Wait, didn’t CFCs destroy ozone and that was a bad thing? So creating it must be a good thing, right?” Wrong. Ozone is helpful high above the Earth in the stratosphere because it blocks those powerful UV rays, but down here in the troposphere, ozone has a more infamous name: Smog. 

Breathing ozone can have serious health effects, especially if you’re over 65 or have a lung disease. There are immediate breathing effects, like shortness of breath, coughing, and asthma attacks, but there are also long-term exposure risks. Those with long-term exposure to smog might have an increased risk of dying early. 

So, this is serious stuff. Before you go throwing out all your aerosol sprays, though, it is important to note that aerosol can pollution is not the only source of VOCs in our atmosphere. Not even close. VOCs can also be emitted from vehicles, chemical plants, and refineries, among other sources. That means aerosol can pollution is far from the main culprit behind smoggy cities, but it is a contributing factor.

Modern Alternatives

The world has come a long way since 1987, and so has aerosol technology. Traditional aerosol sprays just don’t cut it for many consumers anymore. One newer alternative is bag on valve technology. 

In a bag on valve aerosol can, the bag separates the product from the propellant. The propellant stays in the can outside the bag, and the product stays nice and cozy in the bag. When the button is pressed, the propellant squeezes the bag, sending the product out into the world. 

One of the most appealing aspects of bag on valve technology is that the propellants are most often compressed air or nitrogen. Therefore, you don’t have to worry about the flammability like you would with most traditional aerosols. On the aerosol can pollution front, these are also a better option. They obviously don’t contain any CFCs, like all modern aerosol sprays, but they also reduce the amount of VOCs released, compared to traditional aerosols. That means less pollution and easier breathing. 

If you want to cut aerosol cans out of your life entirely, though, there are home remedies for many of the things we use aerosol sprays for, too. You can always implement quick fixes like switching to cream sunscreens instead of the spray on variety, or you can take more involved steps like crafting your own air freshener in a spray bottle. Taking these steps will definitely decrease the amount of VOCs you’re releasing, but do note that aerosol can pollution is far from the biggest offender in that department. There are probably other areas of your life that you could make a bigger difference in.

So, yes, aerosol can pollution is still a problem.

This all brings us back to where we started. We got pretty deep into the weeds on the ozone layer, CFCs, and aerosol spray’s long history of environmental problems. We also covered more modern issues with the technology and the substances used in propellants today. By using flammable gases like butane, CFCs aren’t an issue any longer. However, there are still concerns about aerosol spray propellants. In addition, we covered all the forms of aerosol can pollution that didn’t end when CFCs fell out of favor, like VOC pollution. If you weren’t aware before, now you know all about the more sustainable options for aerosol sprays out on the market. Bag on valve technology can be a great substitute for traditional aerosol sprays. They release fewer VOCs and use safer propellants.

Aerosol can pollution is by no means as big of a problem as it once was — the banning of CFCs greatly reduced the environmental harm of aerosol propellants. But it’s definitely still around. With all this knowledge in mind, you can be a more informed consumer and pick the products that most closely align with your values.