I think that most everyone will agree that propane on a boat is intrinsically dangerous because said gas is heavier than air—any that escapes can pool in the bilge waiting for a spark to blow us into the latter part of next week.
And there are safer alternative fuels, mostly liquids (diesel and paraffin/kerosene, as well as compressed natural gas CNG), but none offer the combination of easy availability and instant on-demand easily-adjustable heat that propane delivers.
So, for the food obsessed, like Phyllis and me, propane is really the only practical solution—it’s not for nothing that professional chefs tend to cook on gas.
(It’s an interesting aside that, in my experience, a mariner’s willingness to cook on liquid fuels, like kerosene, is inversely proportional to their interest in cooking and food. I'm not expressing any criticism here, just an observation, and I'm sure there are exceptions.)
Having said all that, there are a bunch of things on boats that are at least as dangerous as propane—the boom comes to mind. And so a lot of staying safe is recognizing risks and managing them, rather than eliminating every risk, whether we are talking booms or kabooms…sorry, it was too good to resist.
To that end, here is a list of ways to reduce the risk of propane explosion that I have learnt in some 35 years of going to sea with the fuel, that are in addition to the standard safety precautions, such as a vapour-tight locker for the bottles, required by the authorities.