Gasoline, propane, alcohol, natural gas and diesel fuel are all combustible and their fumes are all explosive in high concentrations if unable to escape an enclosed space. There is no better protection than knowing the characteristics and dangers of each fuel. We know gasoline expands and contracts with changes in temperature, we know the usual gas cans can only hold a limited amount of pressure before leaking fumes out into the open. We have kept gasoline for years in cockpit lockers; we keep nothing larger than 3 1/2 gallon containers and choose those with tight fitting lids. We may carry 5 gallon cans attached to a board at the stanchions but prefer the smaller cans. We keep them at stable temperatures as well as possible and if it gets too hot will vent them in the open deck before returning them to a locker. The newer no vent tanks are a poor compromise btween regulations and manufacturing so we use old ones we have tested and trust. We are vigilant about removing any possible source of sparks from the locker. The nose makes for an excellent sniffer, gasoline fumes have a strong odor. No cooking or open flames near the locker. Quit smoking many years ago so don't have to worry about that other than occasional invitee. We used to run a copper line from a propane tank on deck to a stove inside the cabin and we are still here we knew the dangers and used to perform all the functions that today's fancy switches and sensors perform in a propane system. Always keep the tank valve closed when the stove is not in use, always stand in front of the stove to watch for flare ups or flame outs. Keep a clear path to the tank valve and periodically use your nose to sniff for gas leaks. We did have a pressure gauge so that we could test for leaks. Is good to have all the new technology but it is better when combined with the knowledge of each fuel. I grew up at a time when we did not get many second chances from mistakes so we paid attention to those that came before us and fervently applied the teachings.