JOABOA TECH Fire Resistance comparison Testing for XPS, EPS, Graphite plate & Rigid PU foam 

Thanks Amy for the vital info.

Testing is unfair The first took 20 seconds The last seven seconds only

Last one is which type of foam?

Hey guess what... you barely touched the PUR with as much time flaming as the others, and you have a backer board on the PUR. That's a phony test. You want a real winner? Pick PIR.