All foams will melt and burn. Stringent testing standards like the NFPA 285 Fire Test look at the entire assembly to fireguard the building. When foam insulations are part of an effective building assembly, they are tested to be complaint with the building fire code. (EPS Industry Alliance)
However, the low mass density (~ 0.7-1 lbs./ft3) that GPS is able to achieve, enables a lower flame spread and smoke develop than higher mass density foams (Neopor Commercial Brochure).
Neopor® and Neopor® BMB are fire and code approved by UL and ICC for ASTM E84, NFPA 286 and NFPA 285 for use in commercial cavity wall with a wide range of cladding approvals (i.e. multiple masonry veneer finishes over steel stud frame) (Neopor Commercial Brochure). BASF Neopor® has passed several NFPA 285 tests resulting in third party approval for a wide range of product thicknesses, densities, and other wall component choices (NFPA 285 Wall Assemblies). The systems are approved for Neopor® GPS over steel stud or concrete base walls with an array of exterior claddings including brick, concrete, CMU, stone veneer, terra cotta and stucco.