How dangerous are Zinc Oxide nano-particles to the skin?

[Solid Snake]

How dangerous are Zinc Oxide nano-particles to the skin?

I'm sorry ahead of time if this is the wrong place to put this. I'm just curious if anyone here knows if nano-particles of zinc oxide sunscreen actually harms the skin? Would it speed up photoaging (considering that it is effective in blocking UVA rays, which cause photoaging)??

I've seen conflicting reports, so I wanted to know what people here thought. Thank you so much.

 

[Evo]

I'm sorry ahead of time if this is the wrong place to put this. I'm just curious if anyone here knows if nano-particles of zinc oxide sunscreen actually harms the skin? Would it speed up photoaging (considering that it is effective in blocking UVA rays, which cause photoaging)??

I've seen conflicting reports, so I wanted to know what people here thought. Thank you so much.

Please post the peer reviewed sources you read so that we can be on the same page as you. Otherwise, we have no idea what you are referring to.

Thank you!

 

[Ryan_m_b]

Zinc oxide nano particles have been introduced to sun cream in recent years as they block UV light and due to their small size are transparent to visible light. Thus more preferable to consumers rather than applying white cream. There have been concerns about their safety for a while but the data at the moment seems to be inconclusive. Some in vivo studies show that ZnO NPs damage epidermal cells:

DNA damaging potential of zinc oxide nanoparticles in human epidermal cells
http://www.sciencedirect.com/science/article/pii/S037842740900023X

But animal studies mostly show that ZnO NPs don't get absorbed any more than regular ZnO (which has been used in products for ages I gather) and don't elicit any biological response:

Dermal absorption and short-term biological impact in hairless mice from sunscreens containing zinc oxide nano- or larger particles.
http://www.ncbi.nlm.nih.gov/pubmed/24266363

It seems from a cursory reading that the consensus is that ZnO NPs are safe to use in cosmetics but continual research is needed.

 

[Borek]

regular ZnO (which has been used in products for ages I gather)

It is a common ingredient in many creams and gels - and I don't mean cosmetics, but drugs.