5.0 Respirator Selection and Use

Proper selection and use of a respirator is critical to avoid impairment to an individual's health, including certain delayed lung diseases such as silicosis, pneumoconiosis, or asbestosis.

5.1 Respirator Selection

Select the proper type of respirator using the Respiratory Equipment Selection Guides in Appendices A and B.

5.2 Respirator Use

N95 respirators and air purifying respirators (the respirator type most commonly used at UNR) are not designed to be used in an atmosphere:


That is immediately dangerous to life or health (IDLH).


From which escape cannot occur without the aid of the respiratory equipment.


Containing less than 19.5% oxygen.


With unknown contaminants.

  • Under such conditions, air supplied respiratory protective equipment or self-contained breathing apparatus is required.

5.2.1 Do not wear a respirator if you have:


Not completed the Medical Questionnaire and obtained written medical clearance from the designated physician.


Not been trained by an Environmental Health & Safety Representative in the use of the respirator.


Not successfully completed initial fit testing.


Gone more than 12 months since your last fit test.


Facial hair that comes between the sealing surface of the facepiece and the face or that interferes with valve function.

5.2.2 DO NOT modify or alter your respirator in any manner, unless specified in the instruction manual.


Use only MSHA/NIOSH or NIOSH approved components and replacement parts for your specific respirator. Failure to use MSHA/NIOSH or NIOSH components and replacement parts VOIDS the MSHA/NIOSH or NIOSH approval of the entire respirator, invalidates all manufacturers' warranties, and may result in lung disease or exposure to other hazardous or life threatening conditions.

5.2.3 Inspect all components of your respirator system before use for signs of damage or wear that may reduce the protection provided.


Immediately replace any worn or damaged components with MSHA/NIOSH or NIOSH approved components or remove the respirator from service. See the MAINTENANCE section for proper directions for inspecting, cleaning, and storing your respirator.

5.3 Respirator User Seal Checks

For all tight-fitting respirators, the user shall perform user seal checks according to the following directions:

5.3.1 Negative Pressure User Seal Check

This test must be performed before each use and should be performed periodically during use.

This test is performed by closing off the inlets of the canister, cartridges or filters by covering with the palms of the hands, by placing seals over the canister or cartridge inlets, or by squeezing breathing tubes so that air cannot pass. Inhale gently so the face piece collapses slightly and hold breath for ten seconds. If the face piece remains slightly collapsed and inward leakage is not detected, the respirator is assumed tight and the exhalation valve and face piece are not leaking.

5.3.2 Positive Pressure User Seal Check

This test must be performed before each use and should be performed periodically during use.

This test is performed by closing off the exhalation valve and exhaling gently into the face piece. The fit is considered satisfactory if a slight positive pressure can be built up inside the face piece without any evidence of outward leakage. For some respirators, the exhalation valve cover must be removed. Carefully replace it after the test.

6.0 Respiratory Equipment