What does the "N" in N series respirators indicate?

The "N" in N series respirators signifies that the respirator is not resistant to oil. This labeling system is part of a classification scheme established by the National Institute for Occupational Safety and Health (NIOSH) for various types of particulate respirators. N series respirators, including those marked N95, are designed to filter out at least 95% of airborne particles, but they do not provide any protection against oil-based aerosols.

Understanding the implications of this classification is crucial for selecting the appropriate respirator in different work environments. In settings where oil mist is present, using an N series respirator would not be suitable since it may not perform effectively or maintain its filtering capabilities when exposed to oil. Therefore, knowing this characteristic helps ensure the safety and health of individuals working in environments that may contain oil or oil-based contaminants.