Getting kids to sit still and have sunscreen rubbed in has been a constant battle at the beach. They’re always wriggling and worming their way out of their parents’ clutches, so it’s no wonder the invention of the sunscreen spray was met with equal parts enthusiasm and relief when it came onto the market in the early 1990s.

It ushered in a new era of application. It was light on the skin and dried fast. It did away with grease, mess, drips and time wasting. Ease and convenience were a big part of the appeal and they were finally being prioritised, but not at the expense of effectiveness. Or so we thought…

In the decades since, we’ve slowly started to learn more about spray on sunscreen and how it can actually be quite dangerous to both people and the planet.

First in 2020 and then again in 2022, the Australia Cancer Council issued media release warnings and up-to-date research about the risks associated with aerosol sunscreens, from its inability to provide proper protection, to how easily it can be compromised by environmental factors like wind.

We’ve put together a list of the four most widely recognised reasons why you just shouldn’t settle for a sunscreen spray…

1. Inconsistent Coverage

Instructions such as “apply generously” and “apply liberally” are often used on sunscreen bottle labels, and the same goes for an aerosol version. The dangerous difference, however, is that because it sprays on clear with a mist consistency, it’s near impossible to tell just how well you’ve covered your skin and if you’ve missed a spot.

The sunscreen solution is also very diluted, as the cans need to have high amounts of propellant to dispense the pressurised and liquidised gases correctly. A lot of sunscreen to propellant ratios are 50:50, meaning only half of the entire spray bottle contains sun blocking ingredients. Therefore, to get adequate SPF coverage, you’d need to absolutely saturate your skin - essentially, defeating the purpose of an aerosol’s function in the first place.

As referenced in the first Cancer Council report, a study conducted by the Queensland University of Technology (QUT) looked at 9 of the country’s most popular and commercially available spray sunscreens. They determined that to be properly protected from the sun’s damaging UV rays, you’d need to spray each section of your body for at least 4 seconds, and for a maximum of 14 seconds to be sure - a lot longer than what the average person would be doing or willing to do.

And it’s worth noting that these conclusions were done in controlled, science lab conditions, so it would be even harder to get a good coating in normal locations where people would apply it, such as at home or outside in the elements. 

2. Accidental Inhalation 

Another issue linked to using sunscreen sprays is the gas itself. The most common chemical and organic compounds used are isobutane, butane, propane and hydrocarbon. Although they are usually odourless on their own, in combination and with other toxic sunscreen ingredients (such as benzene, oxybenzone, octinoxate, triclosan and parabens), they tend to have a faint, petrol station scent.

Scarily, by the time that smell hits your nose, the particles have already been absorbed into your bloodstream and have made their way into your lungs via inhalation. There, in some people, they can act as irritants and trigger allergies, cause respiratory problems (especially if you’re an asthmatic), and even become endocrine (aka hormone) disruptors with prolonged use.

Although mineral actives like titanium dioxide and zinc oxide are very effective and safe on the skin in cream-based sunscreens, both have the potential to be carcinogenic if used in aerosols and breathed in regularly. Even if you’re not using a spray yourself, just being in the vicinity of someone who is using one poses a risk. 

3. Hazardous When Hot

It’s ironic (but no less concerning) that a product designed to keep people safe in hot and sunny conditions, isn’t built to withstand the sun itself. 

The chemicals and alcohols that are inside a sunscreen spray are highly flammable and can react negatively to heat exposure - both when inside the can, and when outside the can and in the air or dry on the skin. This is problematic, considering the main places you’d keep a bottle of sunscreen when you’re out and about would be in your beach bag (where it’s warm) or in the car (again, where it gets warm).

Not only does this render this supposed sun saver as being prone to combustion - a chance you certainly wouldn’t want to take around anyone, let alone your children - another side effect of it overheating is that the effectiveness of the sunscreen itself is reduced.

4. Far From Eco-Friendly

Sunscreen sprays, by their very nature, are sadly not reef safe. Harmful nanoparticles (as previously discussed) are ejected from the nozzle in the form of a wispy yet potent cloud, which is too easily carried on even the lightest of winds and dispersed into the atmosphere. 

When enough people use spray on sunscreen and in high concentrations - as needed for full coverage - it becomes a biological and environmental threat. It can also leech from your skin and into the ocean when you go swimming, and enters the waterways when you wash it off at the end of the day in the shower.

Sunscreen pollution impacts the whole underwater ecosystem. This can include almost anything, from fish and other marine vertebrates like sharks, seabirds and turtles, to mammals like whales, dolphins, seals and otters, to reeds and deep-sea structures like corals. Some remnants have even been found inside sea turtle nests!

Not only does the contents of a sunscreen spray have the ability to disfigure or bleach coral reefs, it can also stunt the growth of green algae, which is an important source of food for ocean organisms. On dry land, the outlook isn’t much better, as the mist can settle on to the sand and soil around you, and temporarily burn turf and grass when it comes into direct contact.