Why gases are so dangerous
Being safe around gases is a health and safety topic all of its own, but did you ever wonder why gases are considered so dangerous? Here are ten good reasons;
1. Gases don’t stay where you put them! The biggest difference between a gas and a liquid is that a liquid (pretty much) stays where you put it, whereas a gas moves. So even if you are in a safe place right now, the gas can come to you. Not only that…
2. Gases move very fast. A gas will move across a space very rapidly without any external help. This diffusion movement is simply the gas molecules bouncing off each other, other air molecules and the walls and heading in every direction. A typical gas molecule moves at about the same speed as a formula one racing car and has billions of collisions every second. So this means that…
3. Gases fill spaces: A gas which has leaked in a place will rapidly fill that space. Even if the gas is heavier than air the diffusion movement will make it mix and move until the space has been filled and a (relatively) uniform mix is achieved. The larger the gas leak, the faster this happens, and with a room full of gas a variety of dangers are present because…
4. Gases explode: Most people know that natural gas (methane) is explosive, but this also applies to many other gases. The way gases mix with oxygen in the air means they can readily create an explosive atmosphere. When the gas ignites it expands very quickly and the force can destroy buildings and kill people. That’s not all….
5. Gases corrode: Corrosive materials such as hydrofluoric acid also exist as gases, and if these come into contact with steel or glass or people, they literally dissolve them, in a most painful way. There’s still more…..
6. Gases poison: Carbon monoxide is a gas which attacks the haemoglobin in blood and poisons people. Hydrogen sulphide attacks the nervous system, paralysing people with a single breath at 1,000ppm. Chlorine, nitrogen dioxide, silane, arsine, sulphur dioxide, the list of poisonous gases is long and deadly, and they all poison in different ways, but they are all potentially deadly in quite low volumes. As if that wasn’t enough…..
7. Gases suffocate: Even “benign”, non poisonous gases such as nitrogen, or neon, helium or argon, will mix rapidly in air and reduce the level of breathable oxygen present, to the point where it is impossible to breath and people suffocate. Like drowning in air! Also…
8. You can’t see gases: Although gases will form “clouds” these are not like the fluffy white things in the sky, gases are often colourless or so lightly coloured they are hard to see, even in large concentrations. Still many gases are dangerous with concentrations so low, they are barely there at all, so even if they were strongly coloured they would be impossible to see, and...
9. You can’t smell gases: well, not always! natural gas (methane) has no smell, the pungent aroma associated with gas is added by the gas supplier. Likewise gases like carbon monoxide, arsine, carbon dioxide and nitrogen have no discernible odour. Often gases which do, like hydrogen sulphide, can only be smelled at safer concentrations (hydrogen sulphide attacks the nerves in your nose meaning when you really need to smell it, you can’t! Sneaky huh?) and of course…
10.You can’t hear gases; Despite the way they are often portrayed gases don’t hiss and whistle as they move around. Gas noise comes from gases being forced through small apertures or into odd spaces under pressure, but in normal everyday environments they make no noise at all. Take a moment to listen to the air around you. See!
All these things make gases very dangerous and unlike a Raptor riding a shark with a machine gun it can be difficult for us to recognise just how dangerous they are. Are they more dangerous than the Raptor? Well, possibly not, but certainly more likely!
Personally, I’d rather avoid both and just have a nice cup of tea!