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Hydrogen Balloon Explosion and Fuse Wires

Discussion in 'Science' started by sdm79, Mar 22, 2019.

  1. sdm79

    sdm79 New commenter

    Hi. Not allowed to explode H balloons in class according to my technician and Head of Science unless I have official risk assessment from an official source and it is not in the SoW. Anyone know where or how I can get this?

    Have done this many times and seen other teachers do it lots in previous schools so a bit perplexed that my current school has never done it and are making such a fuss.

    Same when I wanted practical for finding fuse ratings of various fuse wires by melting them. Can't do that apparently either.

    Any thoughts appreciated?
  2. Hellfyre

    Hellfyre New commenter

    Cleapss have a risk assessments for hydrogen experiments.
  3. bonxie

    bonxie Lead commenter

  4. yodaami2

    yodaami2 Lead commenter

    You can damage ears with the volume of a ballooon. OR you can get kids pretending to have damaged ears which is more likely and the one reason I would not do this! #stillgoingstronafter30yearscostheycanthanganysh@tonme
  5. averagedan

    averagedan Occasional commenter

    Many, many years ago lots of people were injured by hydrogen balloons due to not knowing how to handle hydrogen/prepare it - I'm guessing that your line manager is from this era?

    CLEAPSS publish a guide called "safer chemicals, safer reactions" and the combustion of hydrogen is covered here.

    The danger comes from two sources. Firstly people using hydrogen generators in school as the hydrogen source, the hydrogen generator often uses a transition metal and generates impure hydrogen due to air being in the delivery tube/collection vessel, in bright sunlight or a hot room this can explode. This can be worked around by buying in a non-reusable canister of pure hydrogen from a chemical supplier (don't get the re-usable ones).

    The second danger is that of oxygen & chlorine. Some people have been known to mix pure oxygen and chlorine with the hydrogen, it was even on the syllabus many years ago, an explosive mixture is formed that is highly unstable and will explode without warning. Hence it no longer being on the syllabus......

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