Sciencemadness Discussion Board

H2S

joe69cool - 30-7-2007 at 17:50

I'm preparing to generate some H2S for an experient. I'm concerned about its toxicity. Would preparing it outdoors with a gas-mask be enough or is it easily absorbed through the skin? I looked at some MSDS but I couldnt get a handle on this issue.

Oxydro - 30-7-2007 at 17:52

Um, I believe that it is toxic by inhalation only but doesn't it strike you that if you can't answer a question like that to your satisfaction you would be better off not making something that deadly? No second chances, and a false sense of security after a brief warning.

16MillionEyes - 30-7-2007 at 18:12

How much of this stuff are you making? If you need the H2S for its reducing properties then I'd suggest using thioacetamide. Just add a few drops to your solution and heat it up, the H2S will appear as aqueous and do its job. No stinky toxic gas evolved (just a negligible amount if you use just enough to react your solution). But if you really need it as a gas then if you do it outdoors you should be fine (unless you do something obviously stupid like stick the test tube inside a nostril or something). Just don't make too much of it or the smell no longer will help you keep away as the smell fades away even though concentration might not be getting smaller.

woelen - 31-7-2007 at 01:02

I myself sometimes experiment with toxic gasses, but when I make larger quantities, I do this on a windy day, with my back directed towards the wind. As long as you don't make more than gram quantities there hardly will be any risk if you do this outside on a windy day.

Another safety measure is to step back a few meters, every time you smell the gas. In this way you won't inhale so much that your sense of smell may become numbed. If the latter occurs, then things may become dangerous, because the warning effect is not present anymore.

If you want to make larger quantities (e.g. > 10 gram) then you really need a good fumehood, or you should wear a suitable gas mask.

chemrox - 31-7-2007 at 21:18

By all mean do this outside. Americans are way over cautious about these things. If you have a respirator, the kind with cartridges, and you have the cartridge that stops h2S, you could do it anywhere. A hood is nice but for one experiment? Go for it. If you have the respirator on and you smell H2S either it isn't fitted properly or the cartridge isn't right for the application. Butyl acetate is often used to check fit. The folks that sell the respirators sell little fit test cartridges. Having said all that, I had a chem set as a kid and one of the experiments was making an H2S gas genrator in a test tube. Maybe that explains some things ...anyway, a windy day works for me .. or a nearby exhaust fan...what's the experiment?