[Brentward]

Benzene is not a PFC as it only contains carbon and hydrogen, not the fluorine that puts the F in PFC. According to Wikipedia [1], "fluoroalkanes are generally inert and non-toxic" and "do not bioaccumulate." That was surprising to me too, but apparently they have many established medical uses, including liquid breathing, which makes this application seem more reasonable.

[1] https://en.wikipedia.org/wiki/Fluorocarbon

[ghastmaster]

Thanks! I misread the chart in the wiki, not realizing benzene was there as a comparison to hexaflourobenzene.