Pandemic Influenza Respirator - Fit Testing

Qualitative Fit Test Procedure For Disposable Air Purifying Respirators Providing Airborne Pandemic Influenza Virus Protection


This qualitative fit test procedure is used with disposable-negative pressure air purifying respirators and typically is used with saccharin mist (sodium saccharin) or bitrex mist (denatonium benzoate) as the challenge agent.
Employees must pass an initial medical evaluation overseen by a physician or other licensed health care professional to verify that wearing a respirator will not aggravate an existing medical condition (asthma, emphysema). After the initial medical evaluation, medical evaluations can be suspended until a pandemic influenza virus occurrence becomes likely. At that time a medical evaluation must be done before respirator use begins. The evaluation requires completion of a medical questionnaire presented in person for review by medical staff. Medical examination may be optional if medical staff’s review of the questionnaire determines an exam is not required. Check with your department management about how to schedule a medical evaluation. Check with your department management about how to schedule a medical evaluation if one is needed.


  1. a. "Qualitative fit testing" (QLFT) is a pass-fail method of testing adequacy of respirator-face seal. This is a subjective test where the test agent is presented and subject is asked while performing exercises whether he/she can sense the test agent.
    If subject passes test a "standard" protection factor is assigned.
  2. b. "Challenge agent" means aerosol used, in this case saccharin (sodium saccharin) or bitrex (denatonium benzoate), so that "quality" of respirator fit may be checked.
  3. c. "Test subject" means person wearing the respirator for qualitative fit test.
  4. d. "Fit factor" means ratio of challenge agent concentration outside versus inside the respirator face piece.


  1. a. Qualitative fit testing of disposable air purifying respirators using saccharin or bitrex solutions is typically done with a fit test kit. The kit contains the basic items needed to perform fit qualitative tests.
  2. a. The fit test apparatus is a simple hood worn by the subject to be fit tested. The hood creates a small chamber over the subject’s head and has a small opening in the front plastic window to allow the fit test solutions to be sprayed in.
  3. b. The fit test solutions come packaged in small bottles or in boxes containing the solutions in tubes. There are two strengths of the fit test solutions provided: a weak sensitivity solution and a much stronger fit test solution.
  4. c. Two nebulizers are provided for creating and spraying the fit test mists into the hood. One nebulizer is for the sensitivity solution and the other is for the fit test solution.


  1. a. Open the nebulizer to be used with the sensitivity solution and pour a small amount (approximately one teaspoonful) of the Sensitivity Test Solution into the nebulizer. Put top back on and store in upright position.
  2. b. Open the second nebulizer and pour a small amount of the Fit Test Solution into this nebulizer. Put the top back on.

Sensitivity Test

Test is done to assure person being fit tested can taste the test solution at very low levels. The Sensitivity Test Solution is a very dilute version of the Fit Test Solution.
  1. a. Test subject must not smoke, eat, drink, or chew gum for 15 minutes before test.
  2. b. Test subject puts on hood without a respirator.
  3. c. Position hood forward with six inches between test subject's face and hood window.
  4. d. Test subject breathes through his/her open mouth with tongue extended.
  5. e. Unplug both sensitivity nebulizer openings and check that the nebulizer is creating aerosol spray (away from test area).
  6. f. Using nebulizer with Sensitivity Test Solution, spray aerosol into hood through hood window. Start by squeezing nebulizer bulb ten times. Aim spray to side, not directly at the mouth.
  7. g. After ten squeezes, if test subject can detect the test solution (sweet taste of saccharin or bitter taste of bitrex) note the number of squeezes and proceed to fit test.
  8. h. If not tasted, inject additional ten squeezes of aerosol into hood and check for detection. If not detected, repeat with ten more squeezes. Note number of squeezes required to produce a taste response.
  9. i. If 30 squeezes are inadequate, end test and retest using a different fit test solution.
  10. j. Remove test hood, and give subject a few minutes to clear taste from his/her mouth.

Fit Test

  1. a. Test subject must not smoke, eat, drink, or chew gum for 15 minutes before test.
  2. b. Test subject must choose a respirator type that provides adequate face fit.
  3. c. Test subject should put on respirator to be tested and perform a successful fit check.
  4. d. After face piece is adjusted, test subject wears face piece for approximately five minutes before conducting qualitative fit test.
  5. e. Have test subject put on and position test hood as before, and breathe through his/her mouth with tongue extended.
  6. f. Unplug both fit test nebulizer openings and check that the nebulizer is creating aerosol spray (away from test area). Monitor the nebulizer spray during the fit testing to assure aerosol continues to be released when bulb is squeezed. If amount of aerosol release is suspect, clean out nebulizer jet with tool provided or with warm water.
  7. g. Using the nebulizer with the Fit Test Solution, inject fit test aerosol into hood using same number of squeezes required to produce a taste response from test subject in Sensitivity Test.
  8. h. To maintain an adequate concentration of aerosol during this test, one-half the number of squeezes used to produce a taste response in the Sensitivity
    1. a. Test is injected into hood every 30 seconds.
  9. i. After initial aerosol is injected, ask test subject to perform following test exercises for 60 seconds each:
  1. i. Normal breathing.
  2. ii. Deep breathing - Breaths should be deep and regular, but do not hyperventilate.
  3. iii. Turning head side to side - Movement should be complete with at least one turn every few seconds. Do not dislodge respirator seal by bumping respirator on chest or shoulder.
  4. iv. Nodding head up-and-down - Movement should be complete with at least one nod made every few seconds. Do not dislodge respirator seal by bumping respirator on chest or shoulder.
  5. v. Talking - Ask subject to slowly read aloud the special paragraph titled the "Rainbow Passage" to simulate talking while wearing the respirator.
  6. vi. Normal breathing.


"When the sunlight strikes raindrops in the air, they act like a prism and form a rainbow. The rainbow is a division of white light into many beautiful colors. These take the shape of a long round arch, with its path high above, and its two ends apparently beyond reach. There is, according to legend, a boiling pot of gold and one end. People look, but no one ever finds it. When a man looks for something beyond his reach, his friends say he is looking for the pot of gold at the end of the “rainbow".
  1. j. Test is terminated any time test aerosol is detected by test subject, because this indicates an inadequate fit. (Wait 15 minutes before retesting and perform sensitivity test again.)
  2. k. If entire test is completed without subject detecting taste of aerosol, test is successful, respirator fit is deemed adequate, and a protection factor of 10 is assigned.

Other requirements

  1. a. Test subject has not passed qualitative fit test if taste of aerosol is detected. If hair growth or apparel interferes with a satisfactory fit, they shall be altered or removed to eliminate interference and allow a satisfactory fit. If a satisfactory fit is still not attained, test subject must fit test on and use an alternate type of respirator.
  2. b. Test shall not be conducted if there is any hair growth between skin and face piece sealing surface.
  3. c. Test subject shall be given opportunity to wear assigned respirator. If respirator does not provide satisfactory fit during actual use, test subject may request another fit test, or of necessary, a different type of respirator.

Repetition of test

Because sealing of respirator may be affected, qualitative fit testing shall be repeated immediately when test subject has a:
  1. a. Weight change of twenty pounds or more.
  2. b. New facial scarring in area of face piece seal.
  3. c. Significant dental changes; i.e. multiple extractions with prosthesis, or dentures.
  4. d. Re constructive or cosmetic surgery.
  5. e. Any other condition that may interfere with face piece sealing.


After fit testing is done, dispose of solutions left over in nebulizers. Rinse nebulizers with warm water to prevent clogging. Wipe out inside of hood with a damp cloth or paper towel.

Record keeping

A summary of all test results shall be maintained for duration of employment plus thirty years. The summary shall include as a minimum:
  1. a. Name of test subject.
  2. b. Date of testing.
  3. c. Name of the test conductor.
  4. d. Pass or fail obtained from every respirator tested (indicate manufacturer, model, size, and approval number)