About Respiratory Filters

What are the different respirator filters?

The N stands for not resistant to oil and the 95 is the evaluation requirement for an N95 face mask. It means it has a high filtration efficiency of about 95%.  It can filter out pollutants in this high percentage.

It’s highly recommended especially for serious communicable diseases such as the likes of tuberculosis, SARS, and influenza. The requirements needed for an N95 mask are stricter and higher than an ordinary face mask or surgical mask for that matter.

All respirator filters are rated either as N, R, or P for their level of protection against oil aerosols. This rating is very important in any usage or industry because some industrial oils can remove the electrostatic charges from the filter media, therefore reducing the filter efficiency and performance.

  • N if they are not resistant to oil
  • R if somewhat resistant to oil
  • P if strongly resistant to oil-proof

There are nine types of particulate respirator filters:

  • N95, N-99, and N-100
  • R-95, R-99, and R-100
  • P-95, P-99, and P-100


The National Institute for Occupational Safety and Health (NIOSH) and the Centers for Disease Control and Prevention (CDC) recommend the use of a NIOSH-certified N95 for the protection of healthcare workers and people who come in direct contact with patients or people with communicable diseases or those exposed in areas with flu and cough outbreaks.

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