Sun protection using sunscreens

There is well established evidence that exposure to ultraviolet radiation (UVR) from the sun can lead to skin cancer. Sunscreens are an effective method of sun protection when used with a combination of other protective measures.

PDF iconSun protection using sunscreens

Health effects from solar UVR

ARPANSA and other national and international health authorities, including the World Health Organization have assessed that overexposure to ultraviolet radiation (UVR) causes eye damage, sunburn, tanning and other skin damage that can ultimately result in skin cancer.

This damage can be prevented by using good sun protection, including sunscreen that is at least SPF30 or higher, broad-spectrum and water-resistant.

The Australian Standard for sunscreens allows a sun protection factor (SPF) rating of 50+, which filters 98% of UV radiation in comparison to SPF30, which filters 96.7%. Both SPF30 and SPF50 sunscreens will provide excellent protection as long as they are applied properly.

Sunscreen effectiveness

There is more to sun protection than just sunscreen. No sunscreen provides complete protection against UVR.

During the daily sun protection times (when the UV level is 3 and above) use a combination of the five sun protection measures.

Sunscreen also needs to be carefully applied and reapplied:

  • Apply sunscreen 20 minutes before you go outside and again every two hours.
  • Use a generous amount of sunscreen – the average adult needs 35ml for one full body application, which is the equivalent of more than half a teaspoon to each arm and the face, and just over one teaspoon to each leg, the front of the body and the back.
  • Check sunscreen is within its use-by-date and store below 30°C.

SPF rating

sample sunscreen dispenser - white plastic container with pump A sunscreen’s SPF rating indicates the level of protection provided against UVR. It’s the ratio of the UVR dose someone would receive without sunscreen to that received with a carefully applied sunscreen eg if an SPF30 sunscreen is applied properly to skin, that covered skin will receive a UVR dose 30 time smaller than skin without any sunscreen.

Sunscreens sold in Australia must be labelled with an SPF of at least 4 to the highest rating of 50+. SunSmart recommends choosing a sunscreen labelled SPF30 or higher that is also broad-spectrum (will filter out both types of UV radiation) and water-resistant.

Sunscreen protection of SPF30 for a fair skinned person provides 30 times more protection to the exposed skin; if the skin reddens without protection in 10 minutes, then applying SPF30 sunscreen provides protection for up to 300 minutes if applied correctly.

The purpose of using sunscreens is to reduce UVR exposure, not to extend the time spent outside in the sun. Sunscreen should be reapplied every two hours, whether the label says to or not. This is because sunscreen can be easily wiped off, lost through perspiration and is often applied unevenly in the first place. Always reapply after swimming or water sports.

The following table shows that a broad spectrum sunscreen with SPF30 blocks 96.7% UVR and a SPF50 blocks 98%. This is only a marginal increase in the UVR blocked by the sunscreen.

SPF % UVR Blocked
4 75
8 87.5
15 93.3
30 96.7
50 98


Sunscreens are available as either a primary or secondary sunscreen.

  • Primary sunscreens are a product primarily to be used to protect the skin from UVR.
  • Secondary sunscreens have a function other than sun protection whilst still providing some protection of the skin from UVR i.e. moisturisers, make-up, lip balm, anti-ageing, anti-wrinkle creams.

The composition of sunscreens

Chemical sunscreens absorb UVR while physical sunscreens reflect and scatter UVR to protect the skin. Sunscreen can be purchased as a cream, lotion, spray or gel. Choose one that best suits your skin type and activity, and that you find easy to apply. If you have sensitive skin or have a reaction to a product, try a fragrance-free or sensitive formula. If you don’t want sunscreen residue to remain on your hands, a gel may work best for you.There has been concern regarding nanoparticles being absorbed by the skin and harming living tissue. A Therapeutic Goods Administration (TGA) review concluded that ‘the current weight of evidence suggests that nanoparticles do not reach viable skin cells and remain on the surface of the skin and the outer layer of the skin that is composed of non-viable cells’.

In Australia, sunscreens can only be sold if they are listed on the TGA Australian Register of Therapeutic Goods (ARTG) and are compliant with the Australian Standard for sunscreens. Sunscreen active ingredients and maximum concentrations must be approved by the TGA as being both safe and effective.

The Australian sunscreen standard

The Australian Standard for sunscreens limits the maximum protection claimed on the labelling of sunscreen products to SPF50+.

Sunscreen manufacturers are unable to claim the terms ‘sunblock’, ‘waterproof’ and ‘sweat proof’ as these terms are considered to be potentially misleading. The maximum water resistance claimable is four hours for SPF30 and above.

Protection messages

The Cancer Council Australia provides further protective advice through national, state and territory Sunsmart programs and activities.

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