What is an N95 mask?
Sep 13, 2022
Source: Cainiu Health
Dr. Guo Xiheng
Introduction
N95 respirators are a certification category for respirators in the United States, accredited by the National Institute for Occupational Safety and Health (NIOSH). Under standardized conditions of specific temperature and humidity, these masks can filter out more than 95% of non-oil-based particles, such as aerosols, at a specified airflow rate of 85 liters per minute, hence the name "N95."
N95 respirators are a certification category for respiratory protection in the United States, accredited by the National Institute for Occupational Safety and Health (NIOSH). Under standard conditions of specific temperature and humidity, these masks can filter more than 95% of non-oil-based particles—such as aerosols—at a specified airflow rate of 85 liters per minute, hence the name "N95".
What is an N95 mask?
An N95 mask can filter over 95% of extremely fine non-oil-based particles with a diameter of 0.3 micrometers. Masks capable of filtering over 99% of such aerosol particles do exist but are less commonly used and rarer; these are known as N99 masks and offer relatively higher protection.
The protective performance of N95 masks is excellent, effectively filtering nearly all respiratory droplets, making them suitable for routine preventive use. There is generally no need to use masks with protection levels higher than N95. Medical surgical masks can also be used for protection, offering similar filtration efficiency to N95 masks under certain conditions. However, medical surgical masks should be discarded after about four hours of use and do not protect against haze or smog. N95 masks can typically be worn for 1–2 days, but if used in medical settings, they are considered disposable and should be discarded promptly after use.
N95 masks are used for occupational respiratory protection, including against certain microbial particles such as viruses, bacteria, mold, anthrax bacilli, and tuberculosis bacilli. A key feature of N95 masks is their ability to prevent droplet infections caused by splashes of patient bodily fluids or blood. The U.S. Occupational Safety and Health Administration (OSHA) requires healthcare workers who may be exposed to tuberculosis bacteria to wear masks meeting the N95 standard or higher.
