2 days ago
What to know about sunscreen, SPF and protecting yourself from the sun all year round
For many Australians, the first port of call for sun safety is sunscreen.
However, a new Choice report found 16 from a sample of 20 widely available sunscreen products failed to meet the SPF level on their label.
But experts say there's no need to panic.
Here's everything they say you need to know — from how sunscreen is tested, what to look out for when shopping and what else you can do to protect yourself from the sun.
SPF stands for Sun Protection Factor — how well something protects you against ultraviolet radiation (UV).
The higher the number, the less UV passes through to your skin.
SPF measures how much time it takes for an individual to burn while wearing a particular sunscreen.
If someone normally burns after 10 minutes in the sun, an SPF of 10 should allow them to spend 100 minutes in the sun before burning, says Melanoma Institute dermatologist Dr Linda Martin.
In percentages, that means the difference between an SPF50 and SPF30 might not be as much as you think.
If applied correctly, an SPF50 lets through just 2 per cent of UV rays, whereas an SPF30 allows 3.3 per cent through, Dr Martin says.
But Michelle Wong*, a cosmetic chemist and science communicator, says the gap in effectiveness grows, the less you apply.
"So instead of just 2 per cent or 3.3 per cent of UV getting in, you will be getting either 4 per cent or 6.7 per cent," she said.
Most of us only apply around a quarter of what is used in testing conditions, Dr Martin says.
An SPF rating is calculated through testing on humans in an accredited laboratory.
It can't be done in the sun because the conditions would be variable and dangerous. Instead, an instrument called a solar simulator that imitates sunlight is used.
Researchers measure the time it takes for the skin to redden in an area where sunscreen has been applied, versus an area that has no sunscreen on it.
Australia follows the international standard for sunscreen testing, which mandates testing on 10 volunteers.
Many sunscreen brands sold in Australia test in labs overseas.
In most cases, yes — sunscreens are very effective and the Choice results shouldn't make you lose faith, Dr Wong says.
Australia has some of the strictest sunscreen regulations in the world and all are regulated by the Therapeutic Goods Administration (TGA).
But the TGA says SPF results can vary between different laboratories because of the reliance on human testing.
For example, Dr Wong says the redness of skin can be interpreted differently by testing staff, and results can differ depending on ethnicity and where testing is done.
"Someone in Australia that's just come out of our summer is also going to have much more sun-tolerant skin than someone in, let's say, Europe," she says.
Dr Wong said the best one is the one you will apply generously and regularly, and fits in with your budget.
She says most of the time, an SPF30 is going to provide enough protection if you apply the right amount.
The higher the SPF, the better — but remember if you only apply a quarter of the right amount of SPF50, you're essentially wearing an SPF 12.5, Dr Wong says.
The TGA says SPFs in the range of 30 to 59 provide "high protection", while a SPF of 60 or higher provides "very high" protection.
While SPF filters what's called UVB rays, you also need to protect from UVA radiation.
UVB rays typically causes sunburn, while UVA penetrates deeper into the skin and can get through glass.
So, make sure your sunscreen says something like 'UVB and UVA protection' or 'broad spectrum'.
Also, if you're going to be spending a lot of time in the water (or just sweating heaps) then go for a water-resistant sunscreen.
Dr Wong said there's a lot of debate about chemical versus mineral sunscreens, but at the end of the day they offer similar protection.
You'll know you have a chemical sunscreen if the ingredients include things like octocrylene or aobenzone. You'll see zinc oxide or titanium oxide if it's a mineral sunscreen.
She says in general, chemical sunscreens are lighter but have a higher chance of stinging your eyes, while mineral ones will have a more matte texture but may leave more white residue.
Sunscreen can be applied underneath moisturisers and make-up, but Dr Wong says research shows they can be more effective when put over the top of skincare.
The general recommendation is that when the UV index is forecast to reach 3 or above you should apply sunscreen as part of your daily routine.
While UV radiation is generally higher in summer than winter, it's still there all year round.
You might even need to wear sunscreen indoors, depending on your circumstances.
For example, if you spend a lot of time driving, remember that untinted windows don't completely block UVA radiation.
However, the latest advice, which you can read here and is backed by the Australasian College of Dermatologists, reflects the fact that people with darker skin tones need different sun safety advice.
There's a lot we could cover here, but the most common mistakes are:
You remember slip, slop, slap, right?
Since that campaign was rolled out in 1981, two more have been added: seek shade and slide on sunglasses.
In full, the Melanoma Institute's five rules for greater sun protection are:
"Remember sunscreen is a filter. It's not a coat of armour and it's not the only step," Dr Martin says.
"Skin cancer is the most common, the most expensive and the most preventable cancer in Australia."
*Michelle Wong says in 2022 she did one-off sponsored posts with some of the brands tested by CHOICE.
