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Are they playing with a straight bat or is SPF50+ all spin?

Tuesday 29 January, 2013 by Terry Slevin

But now it seems there is a new kid on the sunscreen block.

Sunscreen makers are starting to increase claims about how sun protective their lotions, creams and gels are. New rules mean a claim of SPF50+ is now legal in Australia.

That is a boost on the old reliable SPF30+, but so what? Just how much better is it and should we be throwing out our SPF30+?

It is worth noting on a few fronts. Firstly, it is catching up with what overseas travellers have already noticed. Sunscreens with SPF numbers of 50-75 and even 100 are not uncommon outside Australia. But panic not - we are not falling behind.

SPF stands for Sun Protection Factor and the number reflects how protective a sunscreen is against UVB radiation, which causes sunburn and increases skin cancer risk. An SPF 15 for example, filters about 94% of UVB radiation, leaving about 1/15th of the radiation getting through. But it also means skin that would normally burn in about 10 minutes in the midday summer sun would take about 150 minutes before the burn would occur. So the lotion "screens" but does not "block" the sun.

For SPF 30+ it's the same story; about 1/30th gets through so 96.7% of the UVB rays are filtered out. And with SPF50+ - you guessed it - 1/50th gets through, or about 98% is filtered out.

So while there might sound like a world of difference between the numbers 30 and 50, we're talking just 1.3% improvement in UVB protection.

And while 98% protection might sound like a suit of armour against the sun, it's not. To achieve the protection claimed on the label you need to apply enough of it - most people only use about half the amount needed - and reapply it every two hours.

I worry that with SPF50+ people might think they can use even less, or stay in the sun longer, if they see a bigger number on the bottle.

The other important thing about the change in sunscreen rules is that sunscreens will need to be 30% better in the UVA protection they provide if they wish to be labelled ‘broad spectrum'. UVA does not burn the skin, but it definitely contributes to premature aging and also contributes to skin cancer risk. So good UVA protection is vital for all of us under the Australian sun.

Here are a few simple tips:

  • Sunscreen shouldn't be used as the first and last defense against the sun. Don't forget the other "S"s - Slip on a Shirt, Slap on a Hat, Seek some shade and Slide on your sunnies. Think of construction workers - they don't go on site just wearing safety boots without the helmet and high visibility gear. A combination of strategies is required.
  • Don't throw out the old SPF30+ sunscreen. Cancer Council recommends using any water resistant, broad-spectrum sunscreen with an SPF of at least 30 so use up what you have.
  • Whether it's current SPF30+ or the new SPF50+ in the beach or tennis bag or the pump pack near the shed door - put plenty on. About a teaspoon for each limb and a teaspoon for the front of the body and one for the back. At 5ml per teaspoon it's about 35ml per average adult.
  • Reapply every two hours - regardless of the SPF, all sunscreens can be washed off, towelled off or wiped away when we rub that last wave out of our eyes.
This blog was originally posted on Cancer Council Australia .

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