I too believed the white plastic vent line was a fire hazard so I
replaced it.

Curious as to how well it would burn I got my garden hose out and ran
a experiment.

tried lighting a small piece of the plastic with my grill lighter,
white plastic turned brown.

got out the big guns expecting a blaze tried lighting the 10 foot long
piece with my mapp gas torch. all it did was smoulder and turn brown.

saw some plastic type at a large hardware store, if its fireproof, i
will go back to it.

it no longer appears to be flammable, another urban legend debunked