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Ohio State University Extension


Respirator Protection and Fit

Agricultural Tailgate Safety Training for Operators and Supervisors
Agriculture and Natural Resources
Agricultural Safety and Health Program

Objective: To wear the correct respirator for the job and make sure it fits properly.

Trainer’s Note

There are many daily jobs that require the use of respirators to protect your lungs. It is important to use the respirators correctly to receive their full benefit. Have respirators on hand to try on for fit and to show the different types. Review the true or false quiz.


A dust/mist respirator will always have two straps and should not be confused with single strap masks. Single strap respirators are not approved and do not protect against small particles. It protects your lungs from most dusts, mists, pollen, and certain low toxicity pesticides, as specified on the label, by removing small particles from the air you breathe.     

Respirators protect against those hazards. Three types of respirators are used during normal work activities:

Particulate respirators use a filter to trap solid particles like dust or mold. They also filter out liquid particles like paint or pesticide mist. They are sometimes called N95 respirators.

Gas/vapor respirators use a cartridge to absorb gases and vapors. They are also called single cartridge respirators. A fit test is required before use.

Combination respirators have a filter for particles and a cartridge for gases and vapors. They are also called dual cartridge respirators. A fit test is required before use.

Dual cartridge respirators are available to handle a long list of contaminates. The three types mostly used by farmers and ranchers are those effective for pesticide application, those for ammonia, and those for spraying toxic paints and using solvents. However, they are not designed for use against gases that are extremely toxic even in small concentrations such as manure or silo gases from a recently filled silo. They should not be used for contaminants for which they were not designed to handle or in oxygen deficient places. An air-supplied respirator should be worn in oxygen-limited environments.

A respirator should not be used if: 

  • You have a beard, mustache, long sideburns, a deep facial scar or deformity.
  • You have lung disease, heart trouble, or breathing problems. A doctor’s advice may be needed before using a respirator in these situations.
  • It has not been approved for the specific hazard you are protecting yourself against.
  • It does not accommodate for glasses.

Fit Tests For Respirators

Dust Respirator fit testDrawing of a person with a hand on their nose and mouth, over respirator

  1. Check for proper fit each time you put on a dust respirator.
  2. Cup both hands in front of the mask. Be careful not to push on the mask or move it.
  3. Inhale deeply. Check to see if the facepiece collapses toward your face.
  4. Smile, then frown.
  5. If the mask is drawn in and no air is leaking in around the edges, you have a proper fit.
  6. If you don’t have a proper fit, try readjusting the straps or repositioning the respirator on your face.
  7. Repeat the test until you have a proper fit.
  8. Check the written material that comes with the respirator for other specific fitting instructions.

Dual Cartridge Respirator Fit TestDrawing of a person with both hands over cartridge openings to test for negative pressure

  1. For a positive pressure test, put on your respirator and block off the exhalation valve with the palm of your hand, as shown in the picture to the right.
  2. Gently exhale, then hold it for about 10 seconds.
  3. Place your hand on the facepiece to see if it is bulging slightly.
  4. Smile, then open your mouth. If you notice a slight bulge and you don’t detect any air leaks, you have a proper fit.
  5. For the negative pressure test, place the palms of your hands over the cartridge openings (as shown in the picture to the right), and gently inhale, holding your breath for 10 seconds.
  6. You will notice that the facepiece is collapsing slightly.
  7. Smile, then open your mouth. If the facepiece is collapsing slightly and you don't detect any air leaks, you have a proper fit.

**Both fit tests should be done to ensure a proper fit**  

General Tips and Recommendations

  • If the hazard appears to be immediately dangerous to life and health, leave the area immediately or do not enter.
  • Use a full-face respirator to avoid skin or eye irritation.
  • Change filters or mask according to the manufacturer’s instructions or when it becomes hard to breathe.
  • Change cartridges according to the manufacturer’s instructions or if a substance taste or smell is noticed, or if eyes, nose, throat, or lungs become irritated.
  • Stored respirators in a sealed plastic bag or a container after use.

For more information, visit the Occupational Safety and Health Administration (OSHA) website to watch a video on respirator fit:

Review the Following Points

  • Respirators will help protect your lungs.
  • Choose the proper respirator for the hazards you are working around.
  • Use the correct cartridge depending on what it will protect you from when breathing in the presence of pesticides, anhydrous ammonia, grain dust, paint sprays, or other contaminants.
  • Read the instructions that come with the respirators and also the labels of pesticides and other contaminates.
  • Be sure there’s a tight seal between your face and the facepiece. Perform the fit tests!

About These Modules

The Ag Tailgate Training Series was developed by members of the Agricultural Safety and Health Program in the Department of Food, Agricultural and Biological Engineering. Revised by Dee Jepsen, State Agricultural Safety Leader, with editing assistance by Lisa Pfeifer and Cody McClain.

True or False Answer Key

  1. T
  2. T
  3. F
  4. T
  5. F

Quiz: Respirator Protection and Fit



True or False?    

1. It is important to perform respirator fit tests to check for a tight seal between the facepiece and your face. T F
2. You should not wear a respirator if you have a mustache or beard. T F
3. After inhaling deeply, while performing the dust respirator fit test, the respirator should have bulged outward. T F
4. When using a dual cartridge respirator, you should perform a positive and negative pressure test. T F
5. Dual cartridge respirators can be used for any type of toxic gas. T F






Originally posted Aug 12, 2019.