With the help of students from Trinity College, Colac, Friends of the Earth has completed a Citizen Science Experiment investigating the effect that a number of popular Australian sunscreens have on the coating of Colorbond steel and on varnished timber. The experiment replicated a 2008 study which found that nanoparticles of anatase titanium dioxide in sunscreen were reacting with sunlight and aggressively producing free radicals which broke down the coating on Colorbond steel 100 times faster than would normally occur. Our experiment found that several popular sunscreens caused serious damage to wood varnish.

Louise Sales, Nanotechnology Project Coordinator with Friends of the Earth, said “when nanoparticles in sunscreen are able to completely strip wood varnish in a matter of weeks this raises serious questions about what these ingredients could be doing to our skin.”

Scientists have warned that anatase titanium dioxide is “capable of destroying virtually any organic matter” and questioned its use in sunscreens. The Citizen Science Experiment repeated the exterior exposure testing of the 2008 study by industrial chemists Phil Barker and Amos Branch from Blue Scope Steel. This measured the extent of gloss reduction in pre-painted steel products that were exposed to different sunscreen formulations over a 12-week period. Our experiment also investigated the extent of gloss reduction in wood panels coated with a popular weatherproof timber varnish.

“We understand several Australian sunscreens have reformulated to avoid using anatase titanium dioxide, following the alarming Blue Scope Steel findings. However, despite these actions from industry and clear concerns from scientists, our sunscreen regulator – the Therapeutic Goods Administration – has taken no action to remove this potentially dangerous ingredient from our sunscreens” said Ms Sales.

The results from our Colorbond exposure experiment were inconclusive. However, clear trends emerged from the timber panel exposure experiment. It was found that almost all sunscreens affected the polyurethane timber varnish. However, the highest levels of gloss reduction were found in a product known to contain nanoparticles of anatase titanium dioxide.

“It’s incredible that these ingredients are allowed in children’s sunscreen products. We are calling on the Government to urgently ban the use of anatase titanium dioxide in sunscreen. They also need to ensure that any other nano-ingredients in sunscreen are labelled and undergo stringent safety testing,” concluded Ms Sales.

Watch FoE’s short video about the study

Read more about the experiment