My optical supplier's chart says clear plastic (CR-39)
transmits 14% UVB. Plain glass transmits 92%.

See http://www.hidalgos.com/light_chart.html

Randy


"Richard J Kinch" wrote in message
. ..
Glass and plastic are *inherently* "black" to UV

Bunk.

You don't know anything firsthand, and you are talking to "authorities"
that don't either. None of you have actually measured this.

Common meniscus eyeglasses lenses have minimal UV absorption.

A $10 UV LED penlight from the auto parts store will prove this.

So will a sunny day and any of the thousands of common fluorescent objects
around the house.