Methane, for the win.
Of course, throw in some other factors, actual concentration of the methane. One bowel's worth of methane in a small compartment mixed with a couple of cubic feet of air, of which only ~20% is O2, compared to a steady supply of potentially evaporating kerosene out in the open...
Uh, inflammability of methane vs. [basically] kerosene?
Methane, for the win.
Of course, throw in some other factors, actual concentration of the methane. One bowel’s worth of methane in a small compartment mixed with a couple of cubic feet of air, of which only ~20% is O2, compared to a steady supply of potentially evaporating kerosene out in the open...
Are we talking about explosion and fire risk or just flammability?
First the auto-ignition temperature for methane is 580°C while Jet fuel has an auto-ignition temperature of just 210 °C. Also the risk with fueling is a spill in which vapors can be trapped in an enclosed area along with a spark. With methane the risk of explosion in a bathroom is almost none and that infinitesimal risk is present whether airborne or refueling. The 911 terrorist crashed into the world trade center because the planes were full of jet fuel. With your reasoning the 911 terrorist should have instead crashed in LA with empty fuel tanks and full methane holding tanks.
Yes you can ignite methane with a match in the bathroom but it is such a small amount it’s fire or explosion risk is zero.
Kerosene is Classified as a Class I, Group D flammable vapor under article 500 in the NEC. Methane isn’t even covered by the the NEC.