All About N95 Respirator

All About N95 Respirator

All about N-95

An N95 mask or N95 respirator is a filter that has N95 NIOSH air filtration rating, its mean it filters almost 95% of airborne particles but it is not resistant to oil. It is common respirator and protect against small particulates but not gases or vapors. N95 respirators are same as FFP2 and FFP3 respirators which are used in European Union.

The N95 respirator is made of a fine mesh of synthetic polymer fiber also called nonwoven polypropylene fabric, which is produced through a highly specialized process called “melt blowing” that forms the inner layer which filters hazardous particles.



N95 respirators were designed by Dr. Lein-the Wu who was working in Chinese imperial court in 1910, which was the first that protected from bacteria in empirical testing. These respirators were reusable but bulky and uncomfortable, which was further evaluated in 1970 by Bureau of Mines and NIOSH, and developed single use respirator. The first N95 was developed by “3M” and approved in 1972 that used melt blowing technique.


It is required for health care worker who are expected to perform aerosol generating procedures with those patients who are suspected or infected with COVID-19.

            Fit testing is a critical component to a respirator protection program whenever workers use tight fitting respirators. It requires fit test to identify the right mode, style, and proper size of respirator for each individual. N95 respirator also requires a user seal check each time one is put on.

N95 respirator can be reused for a limited time after being removed, as long as they have not been used during aerosol-generating procedure and are not contaminated with patient’s bodily fluids. The manufacturing company may recommended maximum number of re-uses, if not mentioned than preliminary data suggest five uses per device to ensure safety margin.


People with COPD, cardiac disease, asthma or some other medical condition which causes difficulty in breathing should check before using N95 because these respirators can make it more difficult to breathe to wearer. Some N95 respirators have valve which can help to exhalation and make it easier to breathe but these respirators should not be used when sterile conditions are required.



If your respirator is damaged, soiled or causes increase in breathing difficulty then remove the respirator, discard it properly, wash your hands and replace with new respirator.

If respirator is not fitted you properly, then do not use it, it will not provide full protection.

People with facial hair and children may not use N95 respirator because a proper fit can’t be achieved and it will not provide full protection.

 Compare to surgical masks:-


A surgical mask is loose fitting, disposable device which create a barrier between mouth and nose with close environment. If worn in a proper way than a surgical mask will help block large particles, droplets, splashes, spray that may contain virus and bacteria. It also prevents spread of wearer’s saliva and respiratory secretion to others.

A surgical mask doesn’t protect you from very small particles which are secreted during cough, sneezes or certain medical procedures. Surgical mask also not protected from germs and contamination because of loose fitting. Surgical masks have efficacy of 10% to 90% depending on manufacturer.



During this corona crisis:-