In addition to dermatologists and sunscreen consumers, governing bodies are also concerned about these reviewed experiments. The European Union and Australian cosmetic regulatory bodies have reviewed the toxicity of titanium and zinc nanoingredients in sunscreens. In 2006 the Australian Therapeutic Goods Administration conducted a review of scientific literature in relation to the use of titanium and zinc nanosized particles. They concluded that ‘‘there is evidence from isolated cell experiments that zinc oxide and titanium dioxide can induce free radical formation in the presence of light and that this may damage these cells. However, this would only be of concern in people using sunscreens if the zinc and titanium penetrated into viable skin cells. The weight of current evidence is that they remain on the skin surface and in the outer dead layer.