Attaching and Removing the filters:

  1. In one hand, palm a filter using just your first knuckles to hold its outer edge. Think throwing a discus, NOT a Frisbee.
  2. With the other hand, hold the respirator by just the back of the airlock , NOT by the whole respirator.
  3. Press the filter onto the air lock using your palm to compress the foam gasket.
  4. While compressing, twist the filter clockwise approximately a quarter turn to attach. To remove, twist counterclockwise.


Basic instructions:

  1. Practice breathing in and out your mouth. Focus on completely closing off the nasal cavity.  For some this is intuitive for others it takes some practice. If needed use nose plugs.
  2. Repeat but with the respirator in place.
  3. Think you’ve mastered it? Take the smoke test, e.g. wear it in a confined space, light something on fire, breath deeply, and occasionally and carefully, exhale through your nose. With a City Gill and P100 filters, you should not smell any smoke. If needed use nose plugs until you get the hang of it.
  4. Before removing, take a quick slurp. Anything put in the mouth triggers a salivation response, this diminishes with time.  Trimming off excess silicon parts can help.
  5. To talk, take a deep breath, remove the respirator, pontificate, and reinsert.
  6. When needed, remove the filters and wash in hot soapy water, dry, and if stuck, use a blunt object to gently free the air lock flappers.


Advanced Instructions for maximal aerobic use – Cheetah Mode:

  1. Blow your nose. If outside, launch a couple of snot rockets!
  2. Breath in through your mouth and out through your nose.  This eliminates re-breathing any spent air.
  3. For a fast respiration rate, try inhaling at a moderate rate followed by a fast exhalation. Experiment.
  4. Try 3M’s 2017 N95 filters.  These offer less protection but do have a bit lower breathing resistance.

Note, Cheetah mode takes practice to minimize air leakage through the nose.  It is worth the effort!