Nanoparticle sunscreens are safe and don't penetrate the skin
6 June 2016
Nanoparticle sunscreens are both effective and safe to use, according to the latest evidence.
The work dispels the commonly held belief that these products are a risk to human health.
Public concern followed a 2008 report that found nanoparticles could bleach the painted surfaces of coated steel. Researchers from RMIT University have now countered that claim with evidence that human exposure to zinc oxide nanoparticles is “completely different” and they do not penetrate the skin as previously feared.
“Here they are formulated to remain on the skin’s surface, which is constantly shedding its outer dead cells,” writes Associate Professor Paul Wright in the MJA.
Additional fears are that nanoparticles might increase free radical levels in human skin, but, according to Dr Wright, the evidence points to the opposite being the case.
“We have seen that zinc oxide and rutile titanium dioxide nanoparticles directly reduce the quantity of damaging free radicals in human immune cells in vitro when they are co-exposed to the more penetrating UV-A wavelengths of sunlight,” he writes.
The important message to convey is that the benefits outweigh the risks, he says.