The big danger is static.
We were shown a video in high school where the demonstrator ran toluene through a horizontal glass tube, where the toluene ran out into a bucket he placed an earthed copper electrode near the stream.
Within a few minutes of the toluene flowing it went up as the charge jumped to the electrode.
As I said before, static is the danger.
A leaking fitting, at high pressure would get colder, it was static electricity that sparked.