What is liquefied gas?
The main ingredient in liquefied gas is propane. Like methane, propane is a colourless and odourless gas that is extremely flammable and explosive. Propane is explosive if 2–11% of the space is filled with gas. An explosion can even be caused by a spark caused by static electricity. Propane is not directly toxic, but when it enters the air in large amounts, it can cause suffocation due to a reduction in oxygen content. When inhaled, it can cause drowsiness, nausea, feeling unwell, headaches, and weakness.
Propane is heavier than air, and therefore, when leaking, gas sinks into lower places – on the floor of the room, in cavities, cellars, drains, etc. Therefore, in the event of a leakage, mainly lower apartments and basements are at risk.
In order for a person to understand when gas is leaking, small amounts of fragrances are added to household gases. The fragrances make smelling the gas easy. If the gas leak occurs in the underground gas piping and the gas rises through the ground to the surface, the odorants are filtered and the characteristic odour is lost, which is why only a gas analyser can detect the gas content in the air.
A gas explosion is characterised by the fact that the fire that caused the explosion is dampened at the moment of the explosion. This means that, as a rule, there is no fire after a gas explosion. This is due to two things: first, the explosion takes place in a very short time; other objects in the room cannot yet catch fire, and the burned gas itself goes out immediately. Secondly, the explosion in the room causes such a high pressure that it suppresses the flames. The resulting pressure is high enough to break down the weakest structures, and the gases can escape.
In order to reduce the impact of explosions, doors, windows, and shutters are installed in gas installations in such a way that they open outwards and thus release explosive gases. In addition, intermediate ceilings are made of lightweight panels and glazed surfaces are increased. If the same conditions are met in other premises or in buildings where gas is used, the damage resulting from the explosion will be smaller. If there is a gas leak in the room, but there is no contact with the source of ignition, there will be a saturated mixture (too much gas and too little oxygen) at some point, which is no longer flammable.