Thats not Freeze 12 you are thinking of, Freeze 12 is made up of 85% 134a w/ a heavier gas to push the mineral oil in the system. But that is true, there was a big scare back in the mid 90's, jack leg refrigerant mfrs were using propane and a type of butane? (I think) It cools well but when you get in a wreck or have a leak in the engine compt <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/scared.gif" alt="" /> <img src="/forums/images/graemlins/zombie.gif" alt="" />