What characteristic defines “P” respirators in terms of oil resistance?

The characteristic that defines "P" respirators in terms of oil resistance is that they are oil-resistant. Specifically, the designation "P" denotes that the respirator can be used in environments where oil aerosols are present, distinguishing it from other classes that may not be suitable for such conditions.

"P" class filters are designed to effectively filter out particulate matter, including those found in oil contaminants, making them suitable for use in various applications where oil exposure is likely. This categorization is critical for ensuring the safety and effectiveness of respiratory protection when working with oily substances, as exposure to oil can compromise the integrity and performance of the filter.

The distinction between "P" class and other types underscores the importance of selecting appropriate respiratory protection based on workplace hazards, particularly when oil mist or aerosols are a concern. Understanding this classification helps in maintaining compliance with health and safety regulations and ensuring the protection of workers in relevant environments.