A quick story. The boss came to my job site and picked me up for a quick torch cut. he was moving a culvert in a gas station. I asked what does it do? He said it collects the gas that's spilled in the soil. I asked how do I not get blown/burned up? He said we drop this dry ice in the pipe the co2 displaces the oxygen. I asked what about the gas in the soil and outside the pipe? He said that guy over there says he does it all the time. I replied good, have him do it. I explained when we blow up a gas station maybe live and are in court and say that guy said it would be OK, what about that will he remember?
Then I said no. And piss off. He went for a walk, came back and asked me what I wanted to do. We called the fire dept. They came out sprayed some chemical to kill the gas, we did the dry ice too, they blocked the drive shut off the pumps and charged a hose with 3 guys ready to wash me down. I made the cut and went home alive and as intact as ever. Cleaning this gas tank today went well too.