What really is an SPF?

Photo: iStock

This story first appeared on Primped, and is republished here with permission.

We all know sunscreen is a must in summer – and a lot of us are already aware that we should be doing the “slop” part of slip, slop, slap all year round, especially if we spend a significant amount of time outdoors. But as much as us Aussies are well educated from birth on sun protection – thanks to ol’ burney sun down here in the southern hemisphere/also something about the ozone layer – there are still a lot of elements we’re pretty vague on. And sunscreen is probably the biggest grey area of them all. There’s so many types! What does ‘water resistant’ actually mean? And why did I slop it all over myself and then STILL wind up like a giant red faced loon after a day at the beach?

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I went to our good pals at the Cancer Council with all the important sunscreen questions, and let me tell you I learnt a thing or two.

Never really “got” what those numbers meant? ME EITHER. Basically, it’s how long you’re protected from sun damage for – but not in minutes, as I used to think. “Imagine that your skin normally begins to burn after 10 minutes in full sun without any protection,” Kimberly Mallett, research associate at Penn State Prevention Research centre, said recently in an article for the college. “A 30 SPF sunscreen would provide 30 times the protection of no sunscreen.” So a 50+ is going to give you 50 times the protection of no sunscreen, and so on. But, says the Cancer Council, don’t over-estimate the protection of SPF 50+. “SPF50+ offers only marginally better protection from ultraviolet B (UVB) radiation than SPF30+. When used correctly, SPF50+ filters out about 98% of UVB radiation compared to 96.7% filtered by SPF30+.” says Deahna Voulgaris, representative for the Cancer Council Australia.

Also important? The term “broad spectrum”. This can only be on a sunscreen if it offers both UVA and UVB protection – with UVA being the slippery suckers that cause premature ageing and tissue damage below the surface, while UVB are the bad boys that give you the burn – and the skin damage. “The Cancer Council recommends using any sunscreen that is purchased in Australia, labelled broad spectrum, water-resistant and SPF30 or above”.

If you lived your life thinking you could whip on the 2 hour water-resistant sunscreen, jump in the pool, and not bother reapplying until the specific amount of time it says on the bottle is up, you’ve been living a lie, friend. “Water resistant sunscreen does not wash off the skin easily when swimming or perspiring heavily. However, water-resistant sunscreen can be wiped off during physical activity or towelled off after swimming,” says Deahna. So even if the label on your sunscreen says it’s water resistant for four hours, chances are your vigorous game of “Marco Polo” has smudged a bunch of it off your skin. To be properly protected, you’ve gotta re-apply after swimming, exercising, sweating or towel drying. Annoying, I know. But them’s the breaks.

So you’re not splashing around in the water, and haven’t been running laps? You still have to re-apply your sunscreen every two hours to maintain the level of protection it promises. “Even blowing your nose or washing your hands means sunscreen being wiped and washed off. Reapplying regularly every 2 hours means you’re more likely to cover any parts of the skin you may have missed,” says Deahna.

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“Check the directions on the bottle – it’s likely you should be using more sunscreen than you are currently applying,” says Deahna. GREAT – what HAVE we been doing right? Anything?? “The average-sized adult should apply a teaspoon of sunscreen (about 3 ml) to each arm and the same for the face/neck (including ears), and one teaspoon (6 ml) to each leg, the front of the body and the back of the body,” she says. You also need to be putting it on at least 15-20 minutes before going out into the sun, so it “binds” to your skin.

Not planning on a lot of outdoors activities this summer? Sunscreen is still important. “If you are going to be indoors for most of the day, with only incidental sun exposure, a cosmetic with SPF30+ is adequate,” says Deahna. But if the UV levels are 3 or above (FYI, you can check daily UV levels on the SunSmart website, or the free SunSmart app, and lots of weather apps will also show you the UV level of the day), and you’re going to be outdoors for more extended periods of time, you need to go with a proper broad spectrum SPF 30+ sunscreen.

Application is key, too. “If you are going to wear sunscreen and moisturisers or cosmetics, it’s best to apply your sunscreen first – on dry, clean skin. This will allow the sunscreen to disperse effectively,” says Deahna. Also – you can’t add numbers together. Sunscreen doesn’t work like that! “Some people mistakenly believe an SPF20 moisturiser and an SPF10 foundation used together form a protection of SPF30. This is not true. You will only be protected to the level of the highest SPF product – in this case, SPF20.”

October 5, 20163:43pm

beauty | body+soul

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