My advice is 'Don't touch them', I have friends who have been blown up by LP instalations. One of them 3 times! And he was a pro. That stuff is highly dangerous because it is heavier than air and stays in a cloud rather than dissipate like natural gas. LP likes to go to a corner and just lie there until it is ignited. Then the camper trailer is flattened, the service man is blown across the floor, cars blow apart on the highway; I mean, it is some bad stuff.
Call a pro and leave home until he is through!