I have foam looking particles, that keeps blowing in from my window sills, that turns to dust if touched?

Question

its an older home, with long tall windows that only open 4-6" . every time I open them, I get showered with this foam substance and real fine dust thats irritating to breath

Answer 1

Not sure what it is , ,just make sure its not asbestos.

Answer 2

If the windows are the older sash and weight styles (either a rope or chain at the top of the bottom window) , can you see a pulley or opening at the top of the window if there's no rope or chain? Chances are that the window is binding or sticking in the track vertically as it opens at a slight angel. A quick way to verify this is to open the window and measure at each end with a tape measure. If you know the sash rope/chain is broken or missing see the link below.

As for the foam it sounds like old deteriorating sprayed on insulation or foam. A quick inspection of the sash pockets during the repair will verify this.