4-3 Clear and Check the Mask


Seal the mask.

  • Cover the openings at the bottom
    of the outlet valve with the palm of
    your hand.
  • Blow out hard so that air escapes
    around the edges of the mask.
  • Cover the inlet port of the canister
    with the palm of your hand.
  • Breathe in.
  • Remove anything preventing a
    seal from forming between your
    face and the mask.