Is mylar toxic?

Our condo has a western exposure and we're on the second floor above neighbors who like to keep sauna-like conditions, apparently. So, our condo gets really warm. A couple of years ago, we decided to try putting mylar sheets (camping blankets, basically) over the windows. We cut them to the size of the glass and then taped all around the edges.

It's worked pretty well and has probably shaved a few dollars off our a/c bill in the summer. Today I noticed that the mylar on one of our sliding glass doors to our balcony was peeling off, and it had degraded and become sorta brittle and there were little silver flakes all over. And who was sitting in the pile of silver flakes, basking in the new-found sunlight? Albus.

So now he's got little silver flakes all over him and it's hard to get out of his fur- it just clings to him.

How worried should I be? I think the mylar's been breaking down for awhile and he's probably been sitting in it for a long time (we have heavy drapes and don't use our balcony very often, so I didn't know about it)...argh. He is not a cat I want to give a bath to.

If the mylar is similar to what mylar cat toys are made from - I'd say no. (unless a solid piece is eaten, then it's the typical problem from eating something that may not pass).

Ask the vet tomorrow (technically today)? I'd try using a flea comb on Albus first to help remove the mylar, if that didn't work I'd try a bath. And of course clean up what you can of and around the window.

Seems like it's a little thinner than the mylar balls, but maybe those just have more layers so they seem thicker. My comb seems to have disappeared (he has nice, sleek fur, so I've never had to brush him) and I cleaned up all the flakes.

So far, he seems okay, so I'll just keep an eye on him and make sure I clean up any more mylar. For some reason this only happened to one of the windows we put the mylar on.

I have mylar cat teasers that say:
CAUTION: Mylar is not digestible. Consumption can cause severe gastric distress in small animals.

YES, IT'S HIGHLY TOXIC IF EATEN. It's like shrapnel fire a cats stomach and then the toxicity of the chemicals used can cause your cat to go into kidney failure. I have $1800 in hospital bills to prove it. It uses the same ingredients as tinsel and balloons. The process used to make the plastic shiny and metallic was overlooked. These toys are deadly for cats.