Safety & Compliance · SOP
Annual Respirator Fit Testing Protocol
A comprehensive standardized procedure for conducting annual qualitative fit testing of tight-fitting respirators to ensure proper facepiece sealing and worker protection against airborne contaminants in industrial environments.
Estimated Time
45 min
Difficulty
Intermediate
Regulation
CSA Z94.4
Version
2.1
Purpose
To establish a standardized, repeatable procedure for conducting annual qualitative fit testing of tight-fitting half-face and full-face respirators. This protocol ensures that each respirator wearer achieves an adequate facepiece seal, minimizing the risk of occupational exposure to airborne particulates, vapours, and gases. Compliance with CSA Z94.4 and the employer's respiratory protection program is mandatory.
Scope
This SOP applies to all employees, contractors, and visitors required to wear tight-fitting half-face or full-face respirators as part of their job duties at industrial facilities, manufacturing plants, chemical processing sites, and construction sites. It covers qualitative fit testing methods (saccharin, Bitrex, and irritant smoke) only. Quantitative fit testing using a PortaCount or similar instrument is governed by a separate SOP. This procedure does not apply to loose-fitting PAPRs or supplied-air respirators.
Safety Precautions
- Verify all respirator cleaning stations and compressed air lines are de-energized and isolated per site-specific lockout/tagout procedures before performing maintenance or cleaning tasks.
- During fit testing, the test subject must wear the respirator being tested, chemical splash goggles (if using liquid challenge agents), nitrile gloves, and any other PPE required by the site hazard assessment. The test administrator must wear gloves and eye protection when handling fit test solutions.
- Handle fit test solutions (saccharin, Bitrex, or irritant smoke) in accordance with the manufacturer's Safety Data Sheet (SDS). Keep solutions in labelled, sealed containers away from food and drink. Irritant smoke generators must only be used in well-ventilated areas with local exhaust ventilation.
- Ensure all respirator components are thoroughly cleaned and sanitized between test subjects using manufacturer-approved disinfectant wipes. Allow components to air dry completely before reuse. Never share respirators without cleaning.
Required Tools & Materials
- Respirator fit test kit — qualitative (saccharin, Bitrex, or irritant smoke method per CSA Z94.4 Annex B)
- Respirator cleaning supplies — approved sanitizing wipes (e.g., Sani-Cloth or equivalent)
- Nebulizer for saccharin/Bitrex solution delivery — calibrated within 30 days
- Fit test hood or enclosure — transparent, with neck cuff and exhalation port
- Digital timer or stopwatch — accurate to ±0.5 s
- Manufacturer-approved respirator components — facepiece, cartridges, filters, and valve assemblies
- Penetration test solution (if using saccharin method — 10% saccharin in distilled water)
- Calibration certificate for nebulizer or fit test instrument
- Fit test record forms (paper or digital) per regulatory retention requirements
Procedure: Step-by-Step
1
Pre-Test Preparation. Select a clean, undamaged respirator facepiece and assemble it with manufacturer-approved cartridges and filters. Inspect all straps, buckles, valve seats, and sealing surfaces for cuts, tears, or deformation. If any defect is found, replace the component before proceeding. Verify that the respirator is the correct size and model for the test subject based on prior fit test history.
2
User Seal Check. Instruct the test subject to don the respirator and perform both a positive-pressure seal check (exhale gently while blocking exhalation valve) and a negative-pressure seal check (inhale sharply while blocking cartridge inlets). Both checks must hold for at least 5 seconds without detectable leakage. If the seal check fails, adjust strap tension and repeat. Document seal check results on the fit test record.
3
Test Solution Preparation. Prepare the fit test solution according to manufacturer specifications. For the saccharin method: dissolve 10 g of sodium saccharin in 100 mL of distilled water. For the Bitrex method: dilute Bitrex solution (denatonium benzoate) to 0.05% (500 ppm) using deionized water. Label each container with preparation date, concentration, and expiry date (use within 24 hours). Discard any solution that appears cloudy or contains visible particles.
4
Nebulizer Calibration. Fill the nebulizer with fresh test solution (saccharin or Bitrex). Attach the nebulizer to the fit test hood and connect to compressed air supply set to 50 psi (345 kPa). Calibrate the nebulizer output flow to 0.05–0.10 mL per minute using a graduated cylinder. Record the actual flow rate and nebulizer serial number on the test form. If output deviates by more than ±10%, replace the nebulizer nozzle and recalibrate.
5
Test Protocol Execution. Have the test subject don the respirator and enter the test enclosure. Sequence of exercises (each timed at 60 seconds unless noted): (a) normal breathing — stand still, breathe normally; (b) deep breathing — breathe deeply and slowly; (c) turning head side to side — rotate head slowly between left and right extremes; (d) moving head up and down — tilt chin up then down; (e) talking — recite a standard passage aloud (e.g., rainbow passage); (f) grimacing — hold a grimace for 15 seconds; (g) bending over — touch toes then return upright; (h) normal breathing — stand still, breathe normally.
6
Pass/Fail Determination. If the test subject detects the bitter taste of Bitrex or the sweet taste of saccharin during ANY exercise, the test is FAILED. Record the specific exercise during which leakage was first detected, the respirator model and size, and any observations about fit. A failed test requires remasking with a different size or model respirator and retesting after a 15-minute rest period. Two consecutive failures require referral to the respiratory protection program administrator.
7
Documentation. Complete the fit test record form within 1 hour of test completion. Include: subject full name and employee ID, date and time of test, respirator manufacturer, model and size, test method (saccharin/Bitrex/irritant smoke), nebulizer serial number, test outcome (pass/fail), tester name and signature. File the signed record in the subject's employee health file. Retain records for the duration of employment plus 5 years per WorkSafeBC requirements.
8
Post-Test Cleaning. Disassemble the respirator facepiece and remove cartridges and filters. Discard used test cartridges. Hand-wash facepiece in warm water (43 °C max) with mild detergent, then rinse thoroughly. Apply manufacturer-approved disinfectant wipes to all surfaces. Allow to air dry on a clean, non-absorbent surface. Wipe down the fit test enclosure interior and nebulizer exterior with disinfectant wipes. Store components in a clean, sealable container away from direct sunlight.