Do not fall victim to sun-damaged skin or, worse yet, skin cancer. Here’s a timely reminder of why sun protection is essential.
Despite having the highest rates of melanoma in the world, Australia has been slow to adopt the heightened protection offered by SPF 50+ sunscreen. Having already been successfully introduced to Europe, North America and even to our neighbours in New Zealand, 2013 saw the super-strength sun protection introduced Down Under. Here we revisit what SPF 50 actually means, and how it differs from other SPFs.
SPF 50+
Since 1998, Australia has abided by the Australian/New Zealand Sunscreen Standard ruling, allowing products to be labelled with a maximum SPF claim of 30+. In 2013, however, a revised Standard was published, upping the limit to 50+.
According to the Department of Health and Ageing, approximately two in three Australians will be diagnosed with skin cancer before the age of 70 and are four times more likely to develop a skin cancer than any other form of cancer. So why has it taken so long to introduce these higher levels of protection to our shores?
The concern has always been that people will think that, by using a sunscreen labelled SPF 50, they can either use less of it or won’t have to apply it as often. And while an increase from 30 to 50 sounds like a lot, in reality the extra protection offered by SPF 50 isn’t nearly as significant. Add to this the fact the average person puts on between 25 and 50 percent less sunscreen than the recommended amount, and you can see why the authorities may have urged caution over introducing what merely appears to be a significantly more effective level of protection.
Diminishing returns
No sunscreen affords 100 percent protection from the harmful rays of the sun. According to Ric Williams, research and development manager at NexGen Pharmaceuticals, a sunscreen with SPF 15 blocks 93.3 percent of UVB rays, whilst a sunscreen with SPF 50 blocks as much as 98 percent.
‘Arguably, an SPF 15 sunscreen provides full UVB protection for healthy individuals,’ he says.
‘The difference of 4.7 percent between a SPF 15 and SPF 50, would not seem significant to most individuals.’
However, Williams also notes that, whilst the UVA protection given by any sunscreen is minimal, the higher the SPF, the better protected you are from UVA, and especially UVA II radiation.
Although UVB radiation is the primary cause of sunburn and skin cancer, UVA radiation is what causes photoageing – ageing from the sun that can result in wrinkles, sun spots and uneven pigmentation. In high doses, UVA radiation can also cause skin cancer.
The proper way to use sunscreens
‘The use of sunscreen is an important preventative measure to help reduce the risk of developing skin cancer and premature skin ageing,’ says Williams. ‘Skin is susceptible to attack by the sun, resulting in the destruction of collagen and elastin structure, and more seriously the damage to cells’ DNA leading to possible cancer formation.’
No matter what level of protection you choose, therefore, the best advice is to apply your sunscreen properly.
‘Sunscreen should be applied liberally enough to all sun-exposed areas that it forms a film when initially applied. If you’re not using this much — about half a 100g tube (every time you put sunscreen on your whole body); you’re probably not getting enough protection from UV,’ says Williams.
According to Williams, scientists use a simple formula to determine how much sunscreen should be used. ‘As an example, for a person about 175cm tall and weighing about 82.5kg they will require approximately 40g – almost half a typical 100g tube, of sunscreen to cover their body to the same level as is specified in the Australian Standard test procedure,’ he says.
Using this amount means you are using the effective level as stated on the label. Using less means you are not getting the SPF stated on the label.
‘The prudent course is to reapply the sunscreen at regular intervals to ensure an adequate film is maintained,’ says Williams, who also stresses that using sunscreen is a filter only.
‘What that means is that the sunscreen continuously allows the passage of a low level of ultraviolet radiation – even if it is SPF 30. Reapplication of the sunscreen does not remove the damage that has already been caused by the transmitted radiation,’ he explains. ‘When you reapply the sunscreen, unlike a cure, you do not “start the clock again.” So the purpose of reapplying the sunscreen is to ensure that it is still covering the skin properly. Even if an SPF 30 sunscreen is reapplied regularly, if the intensity of the UV radiation is high enough and if the skin is exposed for long enough, invisible damage, or even physical damage in the form of sunburn, could occur.’
Williams says that another misapprehension is that the sunscreen starts to work immediately it is applied. ‘All sunscreens in Australia come with the warning that the sunscreen should be applied 15-30 minutes before going into the sun and it should read 15-30 minutes before entering the water,’ he says. ‘This time allows the water in the product to evaporate and the waterproof sunscreen film to properly form on the skin surface.’
Nature’s protection
The mineral zinc oxide has long been known to provide complete protection from UVB and UVA radiation, and is the only FDA-approved sunscreen for children under 6 months of age. However, zinc oxide can leave an undesirable white residue on the skin.
Modern advances in nanotechnology have meant that scientists have been able to reduce the particle size of the zinc oxide to just 80 to 120nm. At this size, the zinc oxide can sit on the surface of the skin, still working effectively as a sunscreen, without causing a white appearance.
Nanotechnology, however, has sparked scientific debate with some fearing the escape of particles into the blood stream. ‘In early 2009, the Therapeutic Goods Administration (TGA) conducted an updated review of the scientific literature in relation to the use of nanoparticulate zinc oxide and titanium dioxide in sunscreens,’ says Williams.
‘The TGA review concluded that the potential for titanium dioxide and zinc oxide nanoparticles in sunscreens to cause adverse effects depends primarily upon the ability of the nanoparticles to reach viable skin cells; and to date, the current weight of evidence suggests that titanium dioxide and zinc oxide nanoparticles do not reach viable skin cells; rather, they remain on the surface of the skin and in the outer layer of the skin that is composed of non-viable cells.’
The TGA is continuing to monitor the emerging scientific literature to ensure appropriate action is taken should any tangible safety concerns be identified. Currently, however, no specific warnings about nanoparticles need to be placed on labels of sunscreens.
In Australia, all active ingredients, such as zinc oxide and titanium dioxide, must be declared on sunscreen labels, to help consumers make informed choices. However, it is not a requirement for sunscreen labels to declare the particle size of the active ingredients.
What is SPF?
SPF refers to the Sun Protection Factor offered by various sunscreens. The level of SPF given to each sunscreen is measured using a complex mathematical equation, and refers to the amount of ultraviolet raditation required to cause sunburn with the sunscreen on, as a multiple of the amount required without the sunscreen.
Traditionally the SPF is rated for sun damage by UVB rays only. However, the new legislation requires the industry to change these standards and include information about the potential to protect from UVA radiation, too.
The protection given to individuals by a certain level of sunscreen will vary depending on:
• the amount applied
• the frequency of application
• the skin type of the user
• immersion in water through swimming
• amount of sunscreen absorbed by the skin.
