Environment, health and safety

What is the safety advantage of storing and supplying toxic gases such as arsine and phosphine adsorbed on a sorbent in containers below atmospheric pressure?

  1. AEven if the container leaks, the gas is unlikely to gush out
  2. BThe gas loses its toxicity
  3. CGas detectors become unnecessary
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Answer: A. Even if the container leaks, the gas is unlikely to gush out

With high-pressure cylinders, a broken valve or line can release a large amount of gas at once. In containers that store gas adsorbed on a sorbent below atmospheric pressure (sub-atmospheric delivery), a leak tends instead to draw air in, greatly reducing the risk of a massive release of toxic gas. Since the gas itself remains toxic, detection and exhaust measures are still required.

  • A. Correct. The low pressure reduces the risk of a massive release.
  • B. The toxicity of the gas itself does not change.
  • C. Measures such as detectors and exhaust are still required.
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