[Qiasfah]

"When the nanostructures are exposed to light, they receive an energy boost that creates "hot electrons". These "hot electrons" release a burst of energy that enables the nanostructures to degrade organic matter."

Organic matter, like our skin?

[alexbock]

The article doesn't go into much detail, but it may be safe for scale reasons, like the oligodynamic effect where metals like silver kill bacteria but can be safely worn on the skin. The research paper [0] indicates that they coated cotton with copper and silver.

[0] http://onlinelibrary.wiley.com/doi/10.1002/admi.201500632/ab...