Take a little bottle, say one ounce of whatever you are testing and put it in the freezer overnight, pull it out, thaw it and see what is left.

YD

 

so i was cleaning up the garage a little more today and found yet another
fresh bottle of 8oz Speedshine.

this time i let it defrost all the way... and took a sniff. the smell is
back to the regular speedshine smell. so by smell, it seems to be
fine. i think im going to toss this bottle in my trunk to use as BCE.