Snowberry founder Soraya Hendesi adds often people assume an SPF 50 will give twice as much protection as an SPF25. In fact, an SPF 50 only provides minimal extra protection, and only if applied at the same rate. For this reason, in Australia, sunscreens with an SPF higher than 30 are banned because they mislead consumers.
"Dermatologists recommend any sunscreen product should be replenished within two hours of first application, which makes claims of 'eight hour protection' look a little suspect," says Hendesi.
Frazer says from talking to her patients, she feels people least understand the difference between UVA and UVB rays. "Both cause skin cancer. I think of UVA as the sneaky rays as so many sunscreens protect mainly against UVB and only a small amount of UVA."
UVA can penetrate glass and if people don't feel they're burning they have a false sense of security, stay out longer, and get UVA damage like premature skin ageing.
Some ingredients have also raised concerns. Nanoparticles, proven to be effective in screening UV rays, are easily absorbed into the skin. But the risks are yet to be established, says Westlake adding that potential carcinogens are also hotly disputed.
"Many scientists question these claims and suggest they're not only unreliable but pose greater risk if they lead to consumers choosing to go unprotected. What's undisputed is the danger of melanoma and this should be at the top of our minds."
Outside our own skin, it's important to choose a natural sunscreen that's good for the environment, recommends Hendesi.
To find the right sunscreen for you, the experts say it's important to consider your lifestyle.
"If you will be exposed to water, or will be sweating, you will need a water resistant formulation," says Frazer, "whereas if you need an everyday sunscreen to go under makeup, it's important to find one that offers the best broad spectrum protection, but is comfortable to wear under your foundation."
Beyond this, Westlake says scientists have made some interesting discoveries in terms of our skin's own sun defence mechanisms. They're much more sophisticated than previously thought, and the skin reacts to UV radiation much faster than was thought.
"The skin 'knows' it's exposed to UV radiation the moment you step into the sun. This discovery is highly likely to influence sunscreen formulations in the future."
What to look for:
Only a certified 'broad spectrum' sunscreen protects against UV-A and UV-B. Moisturising SPF products are generally not certified broad spectrum.
Any sunscreen should be replenished within two hours, especially when outdoors and after swimming or exercise.
Sunscreens have limited lives. Check the use-by date.
Win:
Element magazine has three premium sunscreen products to give away to readers; Antipodes Immortal Performance Plus Daily Moisturiser with natural SPF 15 50ml;
An Evolu Manuka Honey UVA/UVB Defence protective balm Lip Treatment with SPF 15 15ml; and packs of Snowberry Everyday Broad Spectrum Medium Sun Protection 50ml.
Rebecca Blithe