Making sense of respirator ratings, certifications

by Brian Sodoma

If your company has been hired to deal with mold, work with solvents, or handle other situations where employees might be exposed to hazardous airborne contaminants, your crew will need respirators for protection. Like any safety product, understanding how the device performs and protects your team is imperative. Here, inPAINT turned to a PPE (personal protective equipment) specialist for guidance on how to pick the right one for the job.


Jason Lunn is an application development engineer at 3M with responsibilities for safety products, including respirators. He says, “The first thing to remember about respirators is that a ‘mask’ isn’t the same thing as a ‘respirator.’ Respirators are designed to help reduce the wearer’s respiratory exposure to airborne contaminants such as particles, gases or vapors. ‘Dust masks,’ sometimes referred to as ‘comfort masks,’ are not designed to filter out particles that can settle in the lung. As a result, workers should only wear a NIOSH (National Institute for Occupational Safety and Health)-approved respirator for respiratory protection.”


Broadly speaking, there are two different types of respirators, Lunn explained. The first general type is disposable filtering face-piece respirators, where the filter makes up the vast majority of the face piece. These products are relatively inexpensive and maintenance-free; they work well for sanding or scraping stained or painted surfaces, Lunn noted.

Reusable elastomeric respirators are the second respirator type. When used with the correct cartridges and/or filters, these respirators can provide protection against many different particles, gases and vapors. The initial cost is higher than disposable respirators, but the face piece can be cleaned and reused, and cartridges can be replaced as needed.

“A nice advantage of using reusable respirators is the wide range of cartridge combinations available to protect against a variety of airborne contaminants,” Lunn added.


Figuring out which disposable respirator or cartridge for reusable devices is right for the job can be tricky. NIOSH rates filters and cartridges using letters, numbers and/or colors. Ratings appear as follows:

NIOSH letters indicate the product’s resistance to an oily mist:

  • N-rated filters out solid and liquid aerosols that do not contain oils
  • R-rated filters out solid and liquid aerosols that are somewhat oil resistant
  • P-rated filters out solid and liquid aerosols that are strongly resistant to oils, or are oil proof

NIOSH numbers indicate the level of efficiency for filtering out particles:

  • A rating of 95 offers at least 95% filtration efficiency
  • A rating of 99 demonstrates at least 99% filtration efficiency
  • A 100 rating offers a minimum of 99.97% filtration efficiency

“For example, a disposable respirator that’s labeled ‘N95’ is NIOSH-approved to be at least 95% efficient at filtering out certain solid dusts and liquid mists that do not contain oil,” Lunn explained.

Colors are used to rate cartridges and indicate a certification for a specific contaminant type. Look for the colored band around the cartridge:

  • Black helps protect against certain organic vapors (OV)
  • White helps protect against specific acid gases (AG): chlorine, hydrogen chloride, sulfur dioxide
  • Yellow helps protect against certain organic vapors as well as acid gases (OV/AG)
  • Pink indicates that the cartridge is a high-efficiency particulate filter and has a P100 rating

“A cartridge that’s labeled ‘OV/AG/P100’ is NIOSH-approved to help protect against certain organic vapors, acid gases, and is at least 99.97% efficient at filtering out all particulates,” Lunn added.

Lunn also said proper fit is extremely important and majorly influences how well a respirator can perform. A user must make sure they get a good seal around their face before entering a contaminated area. He recommends reading the user instructions to learn more, including how to properly put on a respirator and perform a seal check.

Note that some manufacturers offer training, provide training materials, and also have a responsive call center. Ask questions. Manufacturers want you to understand the importance of proper fit and its benefits for your long- and short-term health.

To learn more about professional-grade PPE, visit

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