Can I trust my sunscreen? Choice test results have created uncertainty over SPF claims and lab testing process

The Guardian

2 days ago

Sunscreen has been in the spotlight this winter, after testing by the consumer advocacy organisation Choice found 16 of 20 brands failed to provide the level of skin protection advertised on their bottles.
With Australia having one of the highest rates of skin cancer in the world, the Choice report left many worried and wondering: can I trust my sunscreen to protect me?
Even four Cancer Council branded sunscreens were flagged in the report: its Ultra Sunscreen SPF 50+ was found by Choice to have a sun protection factor of 24. The worst result, though, belonged to Ultra Violette's Lean Screen SPF 50+, which Choice's testing found had an SPF of just 4.
While some brands have fiercely disputed the findings, the investigation has prompted debate over the reliability of sunscreen testing, as well as questions over the way these products are regulated.
What's going on?
Australians love spending time in the sun and sun safety is instilled in people from a young age.
So the Choice investigation, with its results published in June, created a storm. Choice tested 20 popular SPF 50 or 50+ sunscreens from a range of retailers and prices in a specialised, accredited laboratory and found 16 of them did not meet their SPF claims.
No surprise, the Choice results have been contentious.
Choice has said it handed over its findings to the companies before they were released publicly. Some have produced test certificates showing that their product met the claimed SPF using the same testing method that Choice used.
When contacted by Guardian Australia, the brands stood firmly by their SPF claims and said they test their products in accordance with the regulations. The Cancer Council said it stood by its previous results but, out of an abundance of caution, has submitted their four products that Choice reviewed for additional testing.
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Ultra Violette, the sunscreen brand that had by far the worst-performing product according to Choice's testing, has fiercely disputed the findings. The Ultra Violette Lean Screen SPF 50 plus Mattifying Zinc Skin Screen, a higher-end product that retails for upwards of $50, returned a result of just 4 in Choice's test. A second test returned a result of 5, Choice said.
Ultra Violette has disputed Choice's findings very strongly and very publicly. It has taken the step of speaking directly to consumers via social media. One of the brand's co-founders, Ava Chandler-Matthews, posted a video on Instagram in which she strongly disputed Choice's methodology. In response, Choice has defended the rigour of its testing.
The SPF or sun protection factor rating of a sunscreen measures how well it protects the skin from sunburn by indicating how much ultraviolet radiation can still penetrate the skin through the product when applied properly. For example, SPF 30 is estimated to filter 96.7% of UVB radiation, whereas SPF 50 is estimated to filter 98%.
Dr DJ Kim, a senior lecturer at the University of New South Wales' school of chemistry, says the difference between SPF 30 and SPF 50 is actually 'very marginal'.
Kim says SPF ratings are given by timing how long it takes skin to burn with and without the sunscreen.
'Let's say that you took 300 seconds for your skin to burn with sunscreen, and then if … it took 10 seconds to burn without the sunscreen, then 300 divided by 10, that becomes SPF 30,' he says. 'So, it's not the most scientific method to measure the SPF factor, honestly.'
SPF claims in Australia are regulated by the Therapeutic Goods Administration (TGA).
Sunscreen brands must get approval from the TGA to sell their products to Australian consumers. To do this, they undertake SPF testing in accordance with the Australian/New Zealand standard in an approved laboratory.
The accepted method is to test sunscreen on human skin. The methodology involves putting the sunscreen on 10 volunteers who are exposed to artificial solar UV radiation. This is the method Choice says it used, working with an accredited laboratory that specialises in sunscreen testing.
Sunscreen brands submit their results to the TGA for approval to 'self-certify' that they have tested their SPF claims and that they stack up. The TGA does not usually do its own testing.
Dr Michelle Wong, a cosmetic chemist, says she doubts the TGA would have the resources to do all of the testing itself.
'And so, in terms of the regulations, most of the time, in this sort of situation where it's a public body, there is always going to be some level of an honour system,' she says.
There are potential inconsistencies in sunscreen testing. SPF effectiveness is measured by essentially getting people to put sunscreens in patches on their skin and measuring how 'red' they get over time.
A TGA spokesperson says it is a known issue that there is variability in SPF testing results across laboratories because testing on humans can be highly subjective and the response to a test can differ dramatically from one individual to another.
'While progress is being made internationally toward in-vitro sunscreen testing (for example, not on human subjects), which will improve consistency of results, these methods are not yet in place,' they said.
Wong, who is known for her work on social media and her blog Lab Muffin, says in-vitro testing would be easier for the TGA to run in-house, which would limit the variability of the results and stop the potential for fraud at labs seeking to make a profit.
She also suggests having a limited number of designated labs that are accepted by the TGA for sunscreen testing.
Wong says although sunscreen is complicated and there are 'technicalities' in the testing and regulation process, the most common problem is 'user error' in that people aren't applying enough product often enough.
'Sunscreens, in general, they work very well, and they are very effective at protecting your skin against sun exposure,' she says, noting that a sunscreen with an SPF of, say, 24 still offers very good protection.
Not long after Choice published its findings, sunscreen was back in the news for different reasons.
Last week, the TGA said it would begin consultation on additional controls for some sunscreen ingredients, including the controversial oxybenzone.
The medicines regulator says it has conducted a review of sunscreen ingredients used in Australia and is recommending additional safeguards for three chemical compounds.
The review proposes that some sunscreen products containing homosalate, oxybenzone and benzophenone be reformulated to ensure sunscreens meet what the TGA considers 'the highest standards of safety for prolonged and frequent use'.
Homosalate and oxybenzone are active ingredients in sunscreen, while benzophenone arises from another ingredient called octocrylene, either as an impurity during the manufacturing process or from degradation as the product ages.
The TGA has begun a consultation process to help determine the level in sunscreens at which these ingredients remain suitable for use.
A week before that, the Australian Competition and Consumer Commission launched legal action against the maker of two popular sunscreens over allegations it had misled consumers by falsely claiming its products are 'reef-friendly'.
The consumerregulator alleges Edgewell Personal Care engaged in greenwashing. While these sunscreens do not contain oxybenzone or octinoxate, another chemical linked to coral damage, the ACCC alleges that they contain other ingredients that risk causing harm to coral and marine life. Edgewell is contesting the proceedings.