If its pure EPS, then its going to have a flammability issue. They claim its pure polystyrene with no additives, which means no resistance to fire whatsoever.

If its pure EPS, then its going to have a flammability issue. They claim its pure polystyrene with no additives, which means no resistance to fire whatsoever. It could be mitigated if its encased in plaster properly (I have EPS external wall insulation, but its encased in cement and silicone render.)