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Activity 001: Respirator Fit Check and Seal Verification

Activity ID: U10M3-ACT-001 Duration: 30 minutes Objective: Practice proper donning, seal checking, and evaluation of half-face elastomeric respirators.

Overview

Students practice the complete respirator donning sequence, perform positive and negative pressure user seal checks, and evaluate respirator fit on their own faces. This builds the muscle memory and habits needed for reliable respiratory protection in all blasting operations.

Materials & Equipment Needed

  • Half-face elastomeric respirators (multiple sizes: S, M, L) — 3M 6000 series or equivalent
  • P100 particulate filter cartridges (2 per respirator)
  • Mirror (wall-mounted or handheld)
  • Respirator inspection checklist (provided)
  • Fit test solution (Bitrex or saccharin) — for qualitative demonstration only
  • Fit test hood (optional, for qualitative fit test demonstration)
  • Cleaning wipes (respirator-safe, alcohol-free)
  • Resealable bags for respirator storage

Instructions & Procedure

Phase 1: Respirator Inspection (10 minutes)

  1. Select a respirator — try medium size first
  2. Inspect all components using the checklist:
  3. Facepiece: check for cracks, tears, distortion, hardening
  4. Head straps: check for loss of elasticity, fraying, broken buckles
  5. Inhalation valves: check for tears, distortion, proper seating
  6. Exhalation valve: check for tears, distortion, debris
  7. Filter cartridge gaskets: check for proper seal surface condition
  8. Install P100 filter cartridges — twist until locked (quarter-turn)
  9. Document inspection findings on checklist
  10. If any defect found: set aside and select a replacement

Phase 2: Donning and Seal Check (10 minutes)

  1. Hold respirator in one hand, cradle chin in chin cup
  2. Pull lower head strap over head, position at base of skull
  3. Pull upper head strap over head, position at crown
  4. Adjust lower straps: snug against jaw line. Not so tight it causes discomfort.
  5. Adjust upper straps: pull facepiece firmly against nose bridge
  6. Press nose clip (if equipped) to conform to nose shape

Positive Pressure Check: 1. Place palm over exhalation valve cover 2. Exhale gently — do not force air 3. Facepiece should pressurize slightly (puff outward) 4. Hold for 10 seconds. No air should escape at edges. 5. If air escapes: readjust straps and repeat

Negative Pressure Check: 1. Place palms over both filter cartridge surfaces 2. Inhale gently — do not suck hard 3. Facepiece should collapse slightly inward 4. Hold for 10 seconds. Facepiece should remain collapsed. 5. If facepiece springs back: seal is compromised — readjust or try different size

  1. Practice removing and re-donning 3 times until procedure is smooth

Phase 3: Fit Evaluation and Comfort Assessment (10 minutes)

  1. With respirator properly donned, perform these movement checks:
  2. Turn head side to side — seal should maintain
  3. Nod head up and down — seal should maintain
  4. Talk aloud (read a paragraph) — seal should maintain
  5. Bend at the waist — seal should maintain
  6. Evaluate comfort: rate 1–5 for pressure on nose, jaw, cheeks, and breathing resistance
  7. If seal fails during movement, try the next size up or down
  8. Clean respirator with wipes when finished
  9. Store in resealable bag with your name and date
  10. Complete the fit evaluation form

Discussion Points

  • What happened to the seal when you turned your head or talked?
  • How does strap tension affect comfort versus seal quality?
  • Why might someone need to try multiple respirator brands, not just sizes?
  • What would you do if you could not achieve a seal with any available size?

Expected Outcomes

  • Students correctly inspect, don, and seal-check a half-face respirator
  • Students can identify seal failures and correct them through adjustment or size change
  • Students understand that fit is personal — no single model fits everyone
  • Students demonstrate the habit of systematic seal checking before each use

Assessment Rubric

Criterion Excellent (4) Proficient (3) Developing (2) Beginning (1)
Inspection thoroughness All components checked and documented Most components checked Several items missed Incomplete inspection
Donning procedure Correct sequence, both straps positioned properly Minor sequence error Incorrect strap positioning Unable to don without help
Seal check execution Both checks performed correctly, seal achieved Checks performed, minor issue One check performed Checks not performed
Comfort evaluation Thorough assessment, appropriate size selected Adequate evaluation Basic evaluation No evaluation

Safety Considerations

  • Do not share respirators between students without thorough cleaning and new filters
  • If a student has a medical condition that may be affected by breathing resistance, consult with facility health coordinator before participation
  • Students with facial hair that contacts the seal surface cannot achieve a reliable fit — discuss alternative protection (PAPR with loose-fitting hood)
  • Latex allergy: verify respirator material — most modern respirators use silicone or thermoplastic

Last Updated: 2026-03-19