Sunscreens unplugged – all you need to know this summer

Friday 1 October, 2010

Recently there has been significant discussion about sunscreens in the media.

Here SunSmart sets the record straight by telling everyone the facts so that you can stay safe in the sun this summer.

What is SPF?

The sun protection factor (SPF) number on sunscreens indicates the degree of protection it offers against UV radiation.

Sunscreens with SPF of 4 and above are listed on the Australian Register of the Therapeutic Goods Administration (TGA) and, therefore, must comply with the Australian/New Zealand Standard for sunscreen products.

The highest SPF for sunscreen available in Australian is SPF30+ however its anticipated from late 2011, sunscreen with a sun protection factor of 50+ will be set to go on sale.

In laboratory conditions SPF 30+ sunscreen filters 96.7% of UV radiation while SPF 50+ filters 98% so interestingly SPF 50+ doesn't offer much extra sun protection than SPF 30.

What does ‘broad spectrum' mean?

UVA radiation penetrates deep into the skin, affecting the living skin cells that lie under the skins surface. UVA causes long-term damage like wrinkles, blotchiness, sagging and roughening and also contributes to skin cancer.

UVB radiation penetrates the top layer of skin and is the main cause of skin damage and skin cancer. Broad spectrum sunscreen filters both UVA and UVB radiation.

What's in sunscreen and how does it work?

Sunscreens contain ingredients that absorb UV radiation, such as octyl methoxycinnamate (OMC), a prime UVB filter. Some ingredients absorb and reflect UV radiation, such as zinc oxide and titanium dioxide.

Historically, when used in sunscreens, zinc oxide and titanium dioxide are visible, giving the skin a white colour. This effect can be reduced when these chemicals are used in nanoparticle form, where they cannot be seen on the skin but still retain the sun-screening properties of the coarser material.

Is sunscreen safe?

Recently, there have been questions raised about the safety of sunscreens that contain nanoparticles. Concerns relate to the theoretical possibility that if nanoparticles were to be absorbed into skin cells, they could possibly interact with sunlight to increase the risk of damage to these cells.

Nanotechnology has been used in sunscreens for many years. To date, the Cancer Council's assessment, drawing on the best available evidence, is that nanoparticulates used in sunscreens do not pose a risk. However, we continue to monitor research and welcome any new research that sheds more light on this topic.

Sunscreen has been proven to reduce the risk of skin cancer, in particular non-melanoma skin cancer. Skin cancer claims more than 1,700 lives each year in Australia and we urge Australians to continue to protect themselves with all five sun protection measures when ultraviolet (UV) radiation is at damaging levels.

Which sunscreen should I use?

Sunscreen can be brought as a cream, lotion, milk or gel. All sunscreens labelled SPF30+ broad spectrum work well. Prices is not always an indication of quality so make sure you choose one that best suits your skin type and activity.

If your skin has a reaction to one sunscreen, talk to your doctor or chemist about choosing another one with different ingredients.

Applying sunscreen

Apply sunscreen 20 minutes before you go outside when the UV Index is at 3 and above. The average-sized adult should apply more than half a teaspoon of sunscreen (about 3 ml) to each arm and the face/neck (including ears) and just over one teaspoon (about 6 ml) to each leg, front of body and back of body.

If outdoors, reapply sunscreen every two hours as sunscreen is easily wiped or sweated off. Putting sunscreen on every two hours helps keep you protected. Remember that sunscreen should not be used to extend the time you spend in the sun.

Key sun protection steps

Sunscreen alone is not sufficient sun protection in summer. When the UV Index is 3 or above, use a combination of the following five sun protection measures:

  1. Slip on sun-protective clothing - that covers as much skin as possible
  2. Slop on SPF30+ sunscreen - make sure it is broad spectrum and water-resistant. Put it on 20 minutes before you go outdoors and every two hours afterwards. Sunscreen should never be used to extend the time you spend in the sun
  3. Slap on a hat - that protects your face, head, neck and ears
  4. Seek shade
  5. Slide on some sunglasses - make sure they meet Australian Standards.

Particular care should be taken between 10am and 3pm when UV Index levels reach their peak.

To find out the UV Index levels look out for the UV alert on SunSmart's website, in the weather section of daily newspapers, on the Bureau of Meteorology website. Live UV levels for Melbourne are at www.arpansa.gov.au/uvindex.

To find out more about sunscreen or to download the Sunscreen information sheet go to www.sunsmart.com.au/sun_protection/slop/  

Updated: 01 Oct, 2010