[Squee]

I left a Herman Miller mesh chair exposed to sunlight, through a window, for about four days. My blind is by my desk and I forgot to shut the damn thing before leaving for a trip. Admittedly, it wasn’t extremely sunny the whole time but perhaps two of the four days were very sunny and upon arriving home, the sun was beating down onto the delicate mesh seat. The material is a kind of plastic/rubber, specifically this:
https://www.hermanmiller.com/en_lac/resources/materials/textiles/aireweave-2/graphite/1a703/

I know that plastics don’t go well when paired with UV radiation. The sun has been unevenly distributed on the seat, as some of it was out of the ray trajectory (uneven damage would be worse for my posture than if the whole seat was compromised). I guess I’m paranoid I’ve ruined the integrity of the seat. Perhaps I’m overestimating the damage done? I mean, I would usually open my blinds once a week during cleaning and have about an hour or so of sun reaching the chair anyway. But I’m wondering if many hours straight of sun would multiply the effect of UV damage, when compared to just an hour or so.

Thanks for reading!

[Borek]

Glass blocks most of the UV, only the least energetic UV-A passes. After just four days I wouldn't care too much.

[Squee]

Good to know. And specifically this kind of plastic? What’s your opinion on its UV-A resistance? I had a poke around on the internet but I couldn’t find too much information on this type of plastic.
Thanks.

[Borek]

And I doubt you will find anything really specific - while there are some general tendencies, there are plenty of minute details in the composition/production methods which have a serious impact on the properties of the final material. The only sure way is to make an extended test. My bet is producer did such test and classified the material as "good enough" according to some industry (or internal) standard, but that's definitely out of my area of expertise.

As I wrote: after just four days I wouldn't care. Several months could leave a trace.

[Squee]

I understand! It was also not in the centre of the room, so it avoided being blasted for half the day. Thanks for your input, Borek.