Share 'stove hood vents'

we had a serious fire and it likely started in the vent hose leading away from the vent hood above the stove. The hose was made of plastic. Is this code? Is it illegal? Has anyone heard of plastic being used? I would think the exposing temperatures would prohibit its use, especially during a stove fire. Am looking for any info or similar experience with plastic vent hose in stove hoods. If anyone…