What does the "P" in P series respirators stand for?

The "P" in P series respirators stands for "oil proof." This designation indicates that respirators classified under this series are designed to provide a higher level of protection against airborne contaminants, including those that are oily. P series respirators can filter out both solid particulates and liquid aerosols, making them an excellent choice in environments where exposure to oil aerosols is a possibility.

Different series of respirators are categorized based on their resistance to particular types of particles and gases. For example, the N series (not resistant to oil) is not suitable for oily environments, while the R series (restricted resistance to oil) offers some degree of protection but is not as robust as the P series in terms of oil exposure. Therefore, the P designation is specifically indicative of the respirator's ability to withstand the presence of oil, making it crucial for workers who may encounter oil mist and similar hazardous substances.