Rub It In Sunscreen facts.

Know what’s in your sunscreen and be sure to place as much importance on quantity as quality, writes

Choosing a sunscreen is not always straightforward. Should you opt for a chemical sunscreen (one with chemical ingredients that absorb UV radiation) or a physical one (with ingredients that work by reflecting UV rays)? Then there’s the SPF (sun protection factor) to consider. SPF50 may sound more potent than SPF30, but it’s not a licence to stay out in the sun for longer, stresses Heather Walker, chair of Cancer Council Australia’s National Skin Cancer Committee.

“There’s only a small difference in the level of protection,” she says. “SPF30+ sunscreens filter about 96.7 per cent of UV radiation, while SPF50+ sunscreens provide 98 per cent protection. But the amount of sunscreen used is likely to be more important than the difference between SPF30 and 50. Most of us don’t apply enough.”

Whether you use a physical or chemical sunscreen, it should have an SPF of 30 or higher, be broadspectrum and also water-resistant to allow for sweating, not just swimming, Walker advises.

Walker says that while health concerns about some ingredients found in sunscreens have been raised, its role in preventing skin cancers is proven.

Some of the physical sunscreens contain tiny nanoparticles because the ingredients that protect skin from sunlight – zinc oxide and titanium dioxide – can leave a white film on the skin. Processing them into fine particles can prevent this. A review by Australia’s Therapeutic Goods Administration concluded that sunscreens with them are safe, says Walker, because the particles don’t penetrate skin. If you favour a physical sunscreen minus the nanoparticles, choosing onethat’s thicker and more opaque is your best bet.

Last year, Danish researchers found in lab tests that some ingredients in sunscreen could interfere with the function of sperm cells. The effects of those chemicals aren’t fully understood. What is known is that 2000 people die of skin cancer in Australia each year. Sunscreen reduces that risk.

“Australian research estimated that, in 2010, more than 1700 cases of melanoma and 14,190 cases of squamous cell carcinoma – a nonmelanoma but sometimes fatal skin cancer – were prevented by long-term sunscreen use,” says Walker. “While we don’t have any evidence that sunscreen is bad for you, we know it prevents skin cancer and helps save lives.”

‘Reapply sunscreen every two hours, but don’t make it your only defence. Combine with other sun-protection measures, including shade, protective clothing, a hat and sunglasses.’ Heather Walker, National Skin Cancer Committee