Hi Like many things that were produced that were too stable, it doesn't break down until it gets someplace that it can cause problems. In its case, it would cause problems of ozone lay decay. For the purposes of putting out fires it worked well. It does produce some nasty hydrofluoric acid when heated enough. Early on, they tended to think that it was good to make things that didn't break down easily. Things like DDT and fluorocarbons were considered as the greatest thing. Now days, people talk about recycling and degradable. Dwight