The flame retardant that is put in EPS & XPS foam called HBCD, will be phased out in a year or two. It looks like the only alternative they will have is a chemical called Polymeric Flame Retardant (Polymeric FR) made by DOW.

I wonder if the the new Polymeric FR will be on-par with HBCD? They will have to retest this new chemical and see what it does to ICF and SIPs when put to the fire test.