<font color="blue"> I don't think our volunteer's get much training </font>
It's a problem everywhere, no matter how sophisticated the department. My son-in-law is a professional fireman/medic in a rural department (Okeechobee, FL) and while they get excellent training, he knows more about the LP Gas hazard than other members in his department, because he also held an LP Gas license under my company, and got his training from the same safety expert from whom I got mine.
Florida has a Division of LP Gas, which employs several inspectors around the state. They are propane safety experts. Their primary job is to inspect all propane facilities, public and private, for safety concerns. They are also called every time there is a leak or an incident concerning LP Gas. They are the "Go To" guys for the fire departments. Often, when they show up at an emergency, the fire department is taking the wrong action or giving the wrong advice. There is so much misinformation about propane that it's tough to overcome everyone's fears.
Here's a question for anyone: Consider the scenario mentioned by Pineridge, that someone shoots a hole in a propane tank. What would happen? Hint: think about the fact that when you light up a propane plumber's torch, like a Bernzomatic, that you are holding the tank in your hand. Are you worried about the tank blowing up because there's a flame shooting out of it?
Short answer: The propane will leak out. How long it takes depends on whether the hole(s) are in the vapor area or liquid area, and how big the holes are (a big hole in the vapor area will take longer to leak out, because the liquid will not vaporize fast enough to keep up with the leak). The gas or liquid coming out close to the tank will have not enough air to be combustible. In other words, even if there is a source of ignition, there should be no flame really close to the tank. When the gas does mix enough with the air to light, it will only do so if there is a flame or spark. If not, it will simply dissipate in the air to the point where there is not enough propane in the mix to ignite. If it does ignite, it will be like a flamethrower, or a giant Bernzomatic torch. It will not blow up.
If the air is still, and enough combustible gas gathers around the leak, and it is ignited, it will "floomph" until all the fuel is exhausted, which will be right away, and it may create enough of an air-pressure surge to knock you over if you are close enough. Then, if it is still leaking, it will setttle into the torch mode.
The greatest frequency of leaks is caused by a valve or pressure release that fails. Usually, the safest thing is to ignite the leak and let it burn until the tank is empty. This is mentally the hardest thing for the fire departments to do. That's why the LP Gas safety inspectors are called in at every leak.
I got really close to our local inspector while I was in business, and he lives not very far from my Okeechobee property, so we have maintained the friendship since I retired. He is not only an LP Gas expert, he is also a trained and experienced fireman, so he can see both sides. His stories are great.
