Nanoparticles and sunscreen

Skin cancer, including melanoma and non-melanoma, is Australia’s most common cancer. Regular sunscreen use has been proven to prevent basal cell carcinomas and melanomas.

Nanotechnology has been used in sunscreens for many years. To date, our assessment, drawing on the best available evidence, is that nanoparticles 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 formulas and their components are regulated through the Therapeutic Goods Administration (TGA). The TGA has conducted a review of the scientific literature in relation to the use of nanoparticle zinc oxide and titanium dioxide in sunscreens.

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's report concerning the safety of sunscreens can be found here.

Cancer Council looks closely at TGA’s advice, as well as our own evidence-based reviews.

Sunscreens also use ‘microfine’ or ‘micronised’ particles, which are larger than nanoparticles:

Nanoparticles are smaller than 100 nanometres and invisible to the human eye – a nanometre is 0.000001 millimetre.
Microfine particles are smaller than those used in conventional white zinc sunscreens, however are larger than nanoparticles – usually in the range of 100 to 2500 nanometres.

In the manufacturing process used to produce microfine particles, some particles can inadvertently be ground smaller, ending up being classified as nano-sized. Manufacturers advise this is a small percentage of the total, generally less than one per cent and does not classify the sunscreen as nano-based.

Irrespective, there is no credible evidence that sunscreens containing nanoparticles pose a health risk. There is plenty of evidence however, proving that sunscreen can help reduce the risk of skin cancer, in particular non-melanoma skin cancer.

In 2011, skin cancer claimed more than 2000 lives and we urge Australians to protect themselves using a combination of measures:

Slip on some sun-protective clothing – that covers as much skin as possible
Slop on broad spectrum, water resistant SPF30+ sunscreen. 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.
Slap on a hat – that protects your face, head, neck and ears
Seek shade
Slide on some sunglasses – make sure they meet Australian Standards

Labelling of sunscreens:

While there is no credible evidence that nanoparticles in sunscreens have any adverse health impact, Cancer Council respects the consumer’s right to know what is in their sunscreen.

As a result we would have no objection to accurate and reliable labelling.

So as to ensure the labelling provides accurate and reliable information it is essential to establish internationally accepted definitions of what constitutes nanomaterials (often bigger than nano clumps of nanoparticles), nanoparticles, nanotechnology and simply ‘nano’. There also needs to be agreed and consistently applied standard reference methods for the measurement of particle size across all sunscreens.

Ultimately, the labelling of sunscreen is a decision for the Therapeutics Goods Administration.

For more information

This page was last updated on: Tuesday, April 2, 2013