Nanoparticles & sunscreen

Friday 12 March, 2010

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 formulas and their components are regulated through the Therapeutic Goods Administration (TGA). In early 2009, the TGA conducted an updated review of the scientific literature in relation to the use of nanoparticulate 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 at: www.tga.health.gov.au/alerts/sunscreens.htm  

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.
  • Cancer Council sunscreens contain microfine particles, but do not contain nanoparticles.

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 5 sun protection measures when ultraviolet (UV) radiation is at damaging levels. In Victoria, this is generally from September to April each year.

When the UV Index is at 3 and above:

  • 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
Updated: 12 Mar, 2010