Practice question

A 4-gas meter reads 19.0% oxygen. How should an Operations responder interpret this reading?

  1. Normal — atmosphere is safe to enter
  2. Oxygen-deficient — atmosphere is below 19.5% and unsafe without SCBA
  3. Oxygen-enriched — risk of fire is increased
  4. Reading is invalid; recalibrate the meter

Answer: B — Oxygen-deficient — atmosphere is below 19.5% and unsafe without SCBA

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