Respirator Types and Ratings Explained

Picking the right respirator can seem like a daunting challenge. This guide has been developed to help explain the four most common types of air purifying respirators and the ratings in which they are certified.

Types of Air-Purifying Respirators:

• Particulate Respirators (Dust Masks)
• Combination Respirators
• Gas & Vapor Respirators

Particulate Respirators

Disposable dust masks and particulate respirators are not designed to be washed or cleaned. Because of their cloth-like construction disposable respirator masks should be disposed of if they become wet and/or damaged.

In 1995 The National Institute for Occupational Safety and Health (NIOSH) released a testing certification for particulate respirators with the intention of creating a standard in which respirator users could understand and follow in practice. The 42 CRF Part 84 has created the following particulate certifications:

N-Series (N95, N99 and N100)

N-Series particulate respirators are NOT resistant to oil and provide protection against solids and liquid aerosol particulates that do NOT contain oil. The difference between an N95, N99 and N100 respirators is simply the filter’s efficiency level. The higher the efficiency the more particulates the respirator will filter out.

N95 respirators are the most commonly used N-Series particulate respirators and are commonly used to protect wearers from particles or “dust” such as those from grinding, sanding, sweeping, sawing, bagging or processing minerals such as coal, iron ore, flour, metal, wood and pollen. N95 respirators may also be used to filter against liquid or non-oil based particles from sprays that do NOT also admit oil aerosols or vapors. N-Series respirators have a non-specific service life and can be used as long the mask is not damaged or breathing resistances is not detected.

R-Series (R95)

R-Series particulate respirators are resistant to oil and provide protection against both solid and liquid aerosol particulates that may contain oil. R95 respirators are commonly used to protect wearers from particles or “dust” such as those from processing minerals such as coal, iron ore, flour, metal, wood and pollen. R-series respirators are only certified for use for up to 8 hour of service life. R-Series particulate respirators are the least common type of particulate respirator due to the respirators specific service life.

P-Series (P100, P99, P95)

P-Series particulate respirators are similar to the R-series and provide protection against both solid and liquid aerosol particulates that may contain oil. However, P-Series respirators have a non-specific service life and can be used as long the mask is not damaged or breathing resistances is not detected.

P100 respirator masks are commonly referred to as HEPA filters or HEPA face masks.

Gas & Vapor Respirators

Gas & Vapor respirators are designed specifically to protect wearers against harmful gases and vapor and require the user to wear either a half-mask or full-mask respirator along with respirator cartridges. Gas and Vapor respirators do not protect wearers from particulates. For environments that contain both harmful particulates and gas and vapors, wearers must use combination respirators. Selection of the appropriate respirator cartridge will depend on the gas or vapor that is present. The most common respirator cartridge is typically an organic vapor cartridge. For more information on selecting the proper respirator cartridge for your application please see our respirator selection guide.

Combination Respirators

Combination respirator cartridges are design to provide users with both vapor and particulate protection in single cartridge. Combination respirators require the use of either a half-mask respirator or full-face respirator mask. Most respirator manufacturers including 3M respirators, North respirators and MSA respirators all offer combination cartridges. When heavy particulate filtration is required, users may consider using a standard gas or vapor respirator cartridge along with a respirator pre-filter rather then a combination cartridge. This configuration will allow the wearer to replace the particulate filter as frequently as needed without having to also replace the gas and vapor cartridge. This configuration is commonly used in applications involving spray paint or pesticides.