This draft stopping with spray foam is always interesting when you get a fire inspector arguing with an environmentally minded building inspector.
Take some out in the yard and light it with your lighter ... but be ready to drop it and get away. Hold your breath. The flame spread and toxic smoke problems far outweigh any small saving in energy you might achieve over rock wool or fiberglass IMHO. I have seen homes with a dozen empty cans laying around between the electricians, plumbers and window/door framers. That's a lot of extra nasty smoke in a fire.
