The info on their site Maxi-frig is the same info that came with the refrigerant. Of course as with any company claim you have to be skeptical of the claims. In my experience it seems to do as claimed.

I am not concerned w/it being propane based either, I don't smoke, and the cab isn't air tight, so not likely to blow myself up or asphyxiate myself while driving.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed