[alwayslikethis]

Correction: Ammonia is not flammable since the flash point is significantly above room temperature. It would only be explosive if you consider the pressure vessel exploding, but we also have natural gas powered cars which also have pressurized cylinders. The main real issue is the toxicity.

[lazide]

Nope. Anhydrous ammonia between 18-25% is literally ‘explodes like gas vapor’ type explosive/flammable.

[https://www.worksafebc.com/en/resources/health-safety/risk-a....] [https://www.osha.gov/laws-regs/standardinterpretations/1994-....]

It does have a higher ignition point than gas. But one a spark can definitely reach. It’s been a common problem in industry where ammonia gets used a lot (refrigeration in particular).

BLEVE’s are also a problem too of course. And the toxic nature of breathing it in! Haha.

[totetsu]

Wasn’t that what happened on the docks in Beirut? Or were their fireworks stored next to it that time

[lazide]

Different (but related) chemical. That was ammonium nitrate (fertilizer + blasting agent). Which ammonia is used to make at large scale.

[ForgedEngine]

The flash point is well above any ambient temperature it would be stored at.

[lazide]

Your point is?

Gasoline fumes don’t typically auto-ignite either. And that is all flash point is about.

[ForgedEngine]

No, autoignition and flash point are two completely different things.

[lazide]

Ah, thanks for the correction.

Anhydrous ammonia’s ‘flash point’ (producing flammable/explosive vapors) is well below room temperature at STP? It boils at -28F. That’s why it is so commonly used for refrigeration.

It does have a specific LEL and UEL that makes it less dangerous than gasoline. It also has a much higher auto ignition temp.

Yeah, anhydrous ammonia is less dangerous than gasoline (1 instead of 4) on the fire diamond due to it being less easy to ignite.

But flash point doesn’t help you here?

electrical sparks or open flame can still definitely do it. And have, multiple times.

Some pretty amazing clips in industrial accident videos from it, actually. My favorite part is when the chunk of roof almost makes it to the highway.

[https://youtu.be/QWCiqoLb-VU?si=ZEsBDFVTQkHSpkRS]

[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.

[bluGill]

Who cares of it explodes, just breathing the stuff is deadly.