Choosing the right respirator to protect workers from airborne contaminants can be a confusing process – and the consequences of selecting the incorrect respirator can negatively impact a worker’s safety and health!

You’ll often find multiple respiratory hazards in a single workplace, and some exposures are unknown. Additionally, the person responsible for selecting respirators or administering a respiratory program might not be a certified industrial hygienist or safety professional, and may have limited experience or expertise in this area.
A woman wears nursing scrubs and a blue half face piece.Here’s where we can help.

Hazard Assessment

  • Identify the contaminants in the workplace. Good sources of information may include [Material] Safety Data Sheets (MSDS/SDS), process and plant engineers, and maintenance personnel.
  • Check for published Threshold Limit Value (TLVs), Permissible Exposure Limit (PELs), any other available exposure limits, and Immediately Dangerous to Life and Health (IDLH) information. References for this information include Occupational Safety and Health Administration health standards (29 CFR 1910.1000 and others), TLVs and Biological Exposure Indices published by the American Conference of Governmental Industrial Hygienists (ACGIH), Workplace Environmental Exposure Level (WEEL) Guides series published by the American Industrial Hygiene Association (AIHA), National Institute for Occupational Safety and Health (NIOSH) recommended exposure limits, and supplier recommendations on MSDS.
  • Check if work environment is oxygen-deficient. Monitoring the environment for oxygen content may be necessary.
  • Check the physical state of the contaminant: Is it dust, mist, fume, gas, vapor or combination? Check the vapor pressure of an aerosol against the temperature extremes of the workplace.
  • Determine the concentration of contaminants — measure the time-weighted averages and peak exposures.
  • Check other routes of entry besides respiratory such as skin absorption; and other health effects such as sensitization, irritation, and corrosion to skin or eyes.
  • For gas and vapor contaminants, determine if there are odor, taste, or irritation warnings. A gas or vapor with good warning properties will allow detection of contaminants at concentrations below recommended exposure limits.


  • In cases of unknown contaminants or concentrations, IDLH concentrations or oxygen deficiency, a self-contained breathing apparatus (SCBA) or combination airline respirator is required.
  • When the contaminant concentration can be measured or estimated, a hazard ratio for each contaminant is calculated by dividing the measured concentration by the exposure limit or guideline to determine if respiratory protection is required.
  • A respirator with an assigned protection factor (APF) greater than the calculated hazard ratio should be selected. In addition, the cartridge chosen must be appropriate for the contaminant (for example, an organic vapor cartridge for xylene or an acid gas cartridge for hydrochloric acid). When a gas or vapor contaminant is present, the employer may use an air-purifying respirator with a chemical cartridge change out schedule or an airline respirator. For environments where both gas, vapor and particulate exposures are anticipated, such as paint spraying or pesticide applications, a chemical cartridge along with a particulate filter may be necessary.

Still have questions? Need help selecting your respirator? Get in touch with us today.

Michael Douglas

National Manager, Marketing Segments

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