Sunscreens can degrade car paint

[Guran]

Just wanted to alert people to some new research that has potential impact on the condition of the paint finish on your car.

It has been recently discovered that some components in some (about half!) sunscreens contain components that are photocatalytic. That means that in the presence of sunlight (ie UV radiation) and water, the sunscreen acts as a catalyst in the degradation process for paint finishes. What this means is that if you have sunscreen on your hands and then touch it on any paint surface, it leaves behind some of the sunscreen and those areas can subsequently experience accelerated weathering, resulting in patches of chalky discolouration. This effect has been observed for a wide range of paints, including car paint finishes. But not all sunscreens will cause this problem.

So the key message ... if you wear sunscreen, avoid contact with the paint on your car!

The active ingredients in the problem sunscreens are nanoparticles of metal oxides. This means that you need to look at the fine print on the sunscreen container and preferably avoid products that contain metal oxides such as titanium oxide (rutile and especially not anatase) or zinc oxide. Not all metal oxides cause problems with paint, it's only the nanoparticle ones ... so especially avoid sunscreens that mention "micro" or "nano" when describing the metal oxides. There is also some evidence to suggest that these nanoparticle metal oxides are not particularly good for human health. So there's another reason to consider avoiding them.

For more detailed background, see the following links:

http://community.safenano.org/blogs/...heir-mark.aspx

http://dx.doi.org/10.1016/j.porgcoat.2008.01.008

BTW, I work with the guy who did this research.

[Novator]

Thanks for the info, that was quite useful since I live in Hawaii and it can get awfuly hot and bright out

[ben14142001]

Oh, thanks. I usually block up during the summer and did not know about this!

-Ben

[EspressoBoy]

So in a nutshell, when you grease up, don't have sex on your car?

EspressoBoy
(Canada we have beaver)

PS
I know I am being too silly today, Thanks for the info, it's just that our winter is like a few days away...

[Guran]

Originally Posted by EspressoBoy

So in a nutshell, when you grease up, don't have sex on your car?

EspressoBoy
(Canada we have beaver)

PS
I know I am being too silly today, Thanks for the info, it's just that our winter is like a few days away...

No offence taken, mate. I guess the answer depends on whether or not you want a permanent reminder of the momentous event!

... and obviously in Australia we're about the enter summer and protection from the sun is a very serious issue down here, thanks to our clear blue skies and gaping hole in the ozone layer.

[EspressoBoy]

Wow, it's that bad eh? I can take the silly stuff out if ya think ppl will be offended.

EspressoBoy

[esscolab]

That's never going to be a problem for me in the UK, it's never sunny.

[123D-M]

frickin' Belgium