[ForgedEngine]

Flash point and boiling points are different. The flashpoint of ammonia is 270F. Below this temperature at 1 atm, ammonia will not catch fire no matter what.

That video took place in an engine room, so any combination of heat, flame, or spark is possible.

[lazide]

“Flash point is the temperature a liquid (usually a petroleum product) will form a vapour in the air near its surface that will “flash,” or briefly ignite, on exposure to an open flame”

If ammonia is boiling (and producing a fog) of concentrated vapor which then burns/explodes in exposure to an open flame, which it will definitely do at even OF, that is an entirely academic point no?

It still has the same effect.