Many Australians have been studying the claims on the back of their sunscreen bottles following the release of a Choice report last week which alleged that 16 out of 20 popular Australian sunscreens “failed” to meet their own SPF claims. 

The report sparked commentary and speculation on social media, where consumers questioned how sunscreen is tested in Australia and why products with lower-than-advertised SPF ratings would be allowed to go to market.

Australian chemistry PhD, science communicator and cosmetic chemist Michelle Wong understands their concern but said testing sunscreen is much more complicated than most realise.

”I think [the report] looks shocking because a lot of people don’t realise how much variability there is in SPF testing,” she told 9news.com.au.

She also warned Australians not to fall prey to sunscreen misinformation that has emerged in response to the Choice report.

Some social media users have incorrectly pointed to the Choice report as “evidence” that sunscreen doesn’t work, despite the wealth of research proving that UV exposure causes cancer and sunscreen protects against UV rays.

“I’ve seen comments saying, ‘So sunscreen doesn’t work and it’s toxic, why are we rubbing it on our skin?'” Wong said.

She encouraged Australians to educate themselves on how sunscreen is tested and approved for sale in Australia rather than falling for online misinformation.

SPF stands for sun protection factor, a measurement of how well a product (in this case, sunscreen) protects the skin against ultraviolet radiation from the sun.

A product’s SPF rating is determined by testing the product on human skin and measuring how long it takes for the skin to start burning.

Products with a rating of SPF 10 or below are considered low protection, meaning the skin will start burning relatively quickly compared to products with higher ratings.

Sunscreens with SPF 15-25 offer moderate or medium protection and those with SPF 30-50 offer high protection.

SPF 50+ is considered very high protection and will protect the skin against sunburn for longer than its lower-rated counterparts – when applied correctly.

“Applying adequate sunscreen is more important than the actual SPF number,” Wong said.

“If you apply any sunscreen according to the directions, on any day where the UV is forecast to be three or over, then you’re going to be doing a lot for your skin.”

“That becomes one teaspoon for your head, face, neck, ears, one teaspoon for each limb, one teaspoon for the front of your body and one teaspoon for the back of your body,” Wong explained.

“Basically, if you’re not sure if you’ve applied enough sunscreen, you need to apply more.”

Some sunscreens are also broad spectrum, meaning they protect against both UVA and UVB rays.

About 95 per cent of the sun’s UV rays are classified as UVA while just five per cent are UVB, but it’s important to protect your skin against both.

How are sunscreens tested in Australia?

That responsibility falls to individual sunscreen brands, which are required to meet strict standards for sunscreen testing if they want to sell their products here.

Brands calculate the SPF rating of their products by testing them on people in accredited laboratories, many of which are overseas.

Sunscreen is applied to a person’s skin before they are exposed to a solar simulator that imitates sunlight.

Researchers then measure how long it takes for the skin to react where the sunscreen has been applied.

Measurements are also taken from an area of the skin where no sunscreen has been applied to compare the reactions.

The international standard for sunscreen testing mandates testing on at least 10 volunteers to calculate a product’s SPF.

Even then, results can vary between different labs because the human element of testing and recording results can lead to human error.

“SPF testing is one of those things that has a lot of variability,” Wong said.

Sunscreen sold in Australia must also be manufactured in a TGA-approved manufacturing facility, meet manufacturing quality standards, therapeutic good legislative requirements, and the testing and labelling requirements outlined in the Australian/New Zealand Sunscreen Standard (AS/NZS) 2604.

These rules apply to all sunscreens that are classified as therapeutic goods, which includes all primary sunscreens (products used primarily for UV protection) and some secondary sunscreens (products with a primary purpose other than sun protection, but which also contain sunscreening agents).

Once a sunscreen has been approved by the TGA for sale in Australia, it is entered in the Australian Register of Therapeutic Goods (ARTG).

The TGA may also conduct random or targeted reviews to ensure the sunscreens it has approved continue to meet strict safety and efficacy requirements.

What about the Choice sunscreen test?

According to the consumer advocacy organisation, it sent samples of the sunscreens to Eurofins Dermatest, an accredited and specialised Sydney-based lab which tested the samples in line with the AS/NZS and TGA requirements.

All 20 sunscreens underwent a five-person panel blind test, followed by a second five-person panel test for all but the two sunscreens which returned the highest SPF results.

One sunscreen, the Ultra Violette Lean Screen SPF 50+ Mattifying Zinc Skinscreen, was also sent to Normec Schrader Institute in Germany for additional testing (another five-person panel blind test) after reportedly returning an SPF of 4.

Choice called on the TGA to further investigate the SPF claims of the 16 sunscreens that “failed” its testing.

Wong agreed that all of the sunscreens which reportedly recorded lower SPF ratings than advertised should undergo additional testing by the brands that manufacture them.

Several sunscreen brands including Bondi Sands, ALDI, Coles/Baxter Labs and Ultra Violette have disputed the Choice findings.