Obviously, some topics are more topical than others. Nano-ingredients are but an example. As a proof, several studies have been recently released, all detailing the potential toxicity of zinc oxide and titanium dioxide nanoparticles, used mainly in sunscreens. All the conclusions are in line with a call to prudence and with the considering of the effects of these ingredients on our health and our environment.
The first team of scientists investigating the toxicity of the sunscreen ingredient nano zinc oxide on skin have concluded that the substance can significantly decrease levels of the protein collagen when applied to rats.
Researchers from the International Institute of Biotechnology and Toxicology (IIBAT) in India carried out a repeated dose toxicity study by applying the substance to the skin and tails of rats for 28 days. They found that the collagen content was significantly decreased following nano zinc oxide treatment compared to control animals. The authors highlighted the need for regulators to address the toxicity of such materials, in light of their increased use in consumer products.
The results from a second study investigating if zinc from such materials can penetrate human skin have also been published this week. Researchers based in Australia carried out a pilot study on three subjects by applying a formulation containing nanoparticles to their skin twice daily for five days, with minimal UV exposure. The authors concluded that there was evidence of a small amount of absorption, which they stated was consistent with previous results from a larger outdoor trial involving greater exposure to UV rays.
A thirdgroup of researchers, based in the …
