ABOUT THE FIT TEST PROCESS:


Using Irritant Smoke (Stannic Chloride) Protocol. OSHA 29 CFR 1910.134

Northwest Response uses a qualitative Fit Test process.  The process uses a person’s response to an irritating “Dust” produced by a non-toxic stannic chloride ventilation smoke tube to detect leakage into the respirator.

The irritating “Dust” is non-toxic, however some persons may have a higher degree of sensitivity to the irritant than others. We have found that over 12,000 fit test 4 or 5 persons find the media very irritating during the sensitivity test (explained below)

A couple of notes to consider:

  1. We will only fit test an individual who has passed a Medical Evaluation and cleared to wear a respirator. If you do not pas the Medical Evaluation we will not fit test you.

Other Disqualifications from The Fit Test Process:

  1. Should the fit test subject (person being fit tested) have any of the following conditions, NWR will decline to fit test the individual using the “irritant” method.
    1.  Asthma will disqualify the individual from fit testing
    2. Allergic to Dust or Smoke will disqualify the individual from fit testing
    3. Any of the following will disqualify the individual from fit testing:
       Has any respiratory illness, such as CPOD, Emphysema, Chronic Bronchitis, Cystic Fibrosis/Bronchiectasis, Pneumonia, Pleural Effusion, recovering from COVID-19, seasonal congestion.
  2. Should the fit test subject present a “Hyper Sensitivity” to the irritant, the individual will be disqualified form proceeding with the fit test.

When Fit Testing we follow these OSHA “General Requirements and Precautions”

(1) The respirator to be tested shall be equipped with high efficiency particulate air (HEPA) or P100 series filter(s), or N95 filtering face-piece. 

(2) Only non-toxic stannic chloride smoke tubes shall be used for this protocol.

(3) No form of test enclosure or hood for the test subject shall be used.

(4) The smoke can be irritating to the eyes, lungs, and nasal passages. The test conductor shall take precautions to minimize the test subject’s exposure to irritant smoke (dust). Sensitivity varies, and certain individuals may respond to a greater degree to irritant smoke. 

Abnormal responses to the irritant are very short lived, and dissipate very quickly. However some hyper-sensitive individuals may experience the following:

  • Coughing that may last for several seconds.

The media “Stannic Chloride” while described as an irritant smoke by OSHA is in fact a non toxic particulate dust.

Northwest Response shall take great care when performing the sensitivity screening checks that determine whether the test subject can detect irritant smoke to use only the minimum amount of smoke necessary to elicit a response or a detection of the irritant from the test subject.

(5) The fit test shall be performed in an area with adequate ventilation to prevent exposure of the person conducting the fit test or the build-up of irritant smoke in the general atmosphere.

(b) Sensitivity Screening Check
The person to be tested must demonstrate his or her ability to detect a weak concentration of the irritant smoke.  A person that fails to detect a weak concentration of the irritant smoke, shall be disqualified from the fit test.

(1) The test operator shall break both ends of a ventilation smoke tube containing stannic chloride, and attach one end of the smoke tube to a low flow air pump set to deliver 200 milliliters per minute, or an aspirator squeeze bulb. The test operator shall cover the other end of the smoke tube with a short piece of tubing to prevent potential injury from the jagged end of the smoke tube.

(2) The test operator shall advise the test subject that the smoke can be irritating to the eyes, lungs, and nasal passages and instruct the subject to keep his/her eyes closed while the test is performed.

(3) The test subject shall be allowed to smell a weak concentration of the irritant smoke before the respirator is donned to become familiar with its irritating properties and to determine if he/she can detect the irritating properties of the smoke. The test operator shall carefully direct a small amount of the irritant smoke in the test subject’s direction to determine that he/she can detect it.

N95 fit testing(c) Irritant Smoke Fit Test Procedure

(1) The person being fit tested shall don the respirator without assistance, and perform the required user seal check(s).

(2) The test subject shall be instructed to keep his/her eyes closed.

(3) The test operator shall direct the stream of irritant smoke from the smoke tube toward the face-seal area of the test subject, using the low flow pump or the squeeze bulb. The test operator shall begin at least 12 inches from the facepiece and move the smoke stream around the whole perimeter of the mask. The operator shall gradually make two more passes around the perimeter of the mask, moving to within six inches of the respirator.

(4) If the person being tested has not had an involuntary response and/or detected the irritant smoke, proceed with the test exercises.

(5) The exercises identified in section I.A. 14. of this appendix shall be performed by the test subject while the respirator seal is being continually challenged by the smoke, directed around the perimeter of the respirator at a distance of six inches.

(6) If the person being fit tested reports detecting the irritant smoke at any time, the test is failed. The person being retested must repeat the entire sensitivity check and fit test procedure.

(7) Each test subject passing the irritant smoke test without evidence of a response (involuntary cough, irritation) shall be given a second sensitivity screening check, with the smoke from the same smoke tube used during the fit test, once the respirator has been removed, to determine whether he/she still reacts to the smoke. Failure to evoke a response shall void the fit test.

(8) If a response is produced during this second sensitivity check, then the fit test is passed.

Appendix A to §1910.134.  Test Exercises.

(a)….For the remaining fit testing methods, employers shall ensure that the test exercises are performed in the appropriate test environment in the following manner:

(1) Normal breathing. In a normal standing position, without talking, the subject shall breathe normally.

(2) Deep breathing. In a normal standing position, the subject shall breathe slowly and deeply, taking caution so as not to hyperventilate.

(3) Turning head side to side. Standing in place, the subject shall slowly turn his/her head from side to side between the extreme positions on each side. The head shall be held at each extreme momentarily so the subject can inhale at each side.

(4) Moving head up and down. Standing in place, the subject shall slowly move his/her head up and down. The subject shall be instructed to inhale in the up position (i.e., when looking toward the ceiling).

(5) Talking. The subject shall talk out loud slowly and loud enough so as to be heard clearly by the test conductor. The subject can read from a prepared text such as the Rainbow Passage, count backward from 100, or recite a memorized poem or song.

(6) Bending over. The test subject shall bend at the waist as if he/she were to touch his/her toes. Jogging in place shall be substituted for this exercise in those test environments such as shroud type QNFT or QLFT units that do not permit bending over at the waist.

(7) Normal breathing. Same as exercise (1).

(b) Each test exercise shall be performed for one minute. The test subject shall be questioned by the test conductor regarding the comfort of the respirator upon completion of the protocol. If it has become unacceptable, another model of respirator shall be tried. The respirator shall not be adjusted once the fit test exercises begin. Any adjustment voids the test, and the fit test must be repeated.

Consent to be fit tested:

  1. I understand the above OSHA guidance under 29 CFR 1910.134 and fit test methods used.
  2. I attest that I do not have any of the conditions that would disqualify me from fit testing as stated in the “Disqualification from The Fit Test Process”
  3. I have been truthful in answering the Medical Evaluation questionnaire.
  4. I hereby give consent to Northwest Response to proceed with the fit test process, fully aware that I may have an abnormal response to the irritant media used. 
  5. I understand that I will be disqualified from proceeding with the fit test should I have an abnormal response to the “irritant” during the sensitivity test.