How to block UV light (transparent material)?
I contacted the manufacturers of curing stations directly and got some interesting feedback. Not all of them were keen on sharing their information, but two responded:

Elegoo is using Polypropylene
Creality is using polycarbonate

I am sure they are using some additional UV blocking on the plastics with a coating, but thats all I could find out.
Thanks to @Greenonline for pointing me in the right direction!