We can use an n95 mask many times. For eight hours of sporadic or nonstop use, the respirators will work optimally. Regular substitution is required.
In most cases, when it comes to its shelf life, you will use it for no more than 5 years from the date of production (check the date printed on your mask package).
In addition to that as storage conditions affect their longevity, you should ensure that you store them correctly in their original packaging.
OSHA directs you to reuse the N95 mask if its functional and organizational integrity is maintained. On top of that, it should not soil or physically harm its filter content.
In any of the following cases, you need to discard your N95 mask:
After close contact with an atmosphere or a patient's region that is co-infected or infected with the disease, discard yours. If it is tainted with nasal secretions, respiratory secretions, blood or some other bodily fluid, dispose of your mask. After using it in an aerosol-generating process, get rid of your mask.
Can You Reuse an N95 Mask?
N95 is the first-grade requirement for the degree of occupational safety in the United States for the filtration effect. That is, for these non-oily particles, like dust and microorganisms, the over-rate effect is at least 95 percent under the test conditions defined in the standard. The N95 mask can be reused if the frequency of use of the mask is not high, and there is no cough, runny nose, sneezing of these symptoms.
The inner part of the mask, that is, the side near the face, should not be contaminated during storage if it is intended to be reused. If there is a cough, runny nose, sneeze with these symptoms, it should be replaced in time as long as the mask gets dirty. It should be replaced in time if the respiratory resistance is obviously increased.
Few research has shown that it can be reused 3-5 times, but it is important to pay attention to the fact that the mask can be infected with the virus in the repeated use phase, so it is necessary to disinfect the outside.
After leaving dense traffic area, you should change mask (can’t reuse):
You must replace it regularly at this time. Also, remove your hands from both sides, do not touch the front. Take the mask off and don't throw it away at all. Since the mask is covered by a virus, it must be destroyed immediately after it has been removed.
The virus density to which ordinary people are exposed is however very small, so being so vigilant is unnecessary. It is possible to reuse this useful mask. Without heading to the hospital or dense traffic, the N95 mask can be used around five times
After usage, the N95 mask must be held in a dry and ventilated position if continuous use is necessary. For packaging, do not fold up.
CDC about reuse of N95 masks:
Reuse means the practice of multiple encounters with patients using the same N95 respirator but removing it after each encounter ('doffing'). Prior to the next encounter with a patient, the respirator is stored between encounters to be put on again ('donned'). Even when reuse of N95 respirator is practiced or recommended, there are restrictions in place that limit the number of times the reuse of the same FFR.
During previous respiratory pathogen outbreaks and pandemics, restricted reuse has been suggested and commonly used as an alternative for conserving respirators.
However, the CDC states that extended use is favored over reuse because less touching of the respirator and therefore less risk of contact transmission is expected to involve it.
How to extend the lifespan of my N95 mask to reuse it?
Hydrogen Peroxide Vaporization:
In pilot studies, decontamination of hydrogen peroxide vapor (HPV) has been shown to enable multiple cycles of N95 processing with appropriate function preservation. During the COVID-19 pandemic, it is now approved by the FDA as an emergency method for N95 decontamination for healthcare personnel.
This decontamination method can only be used on N95 models that do not contain cellulose, such as a pandemic. It is used by Stirred (up to 2 cycles) or Steris devices (up to 10 cycles) in industrial facilities such as Battelle (up to 20 cycles) as well as in individual hospitals.
In order to ensure proper inactivation of viral particles with minimal mask degradation, proper UV treatment of N95 masks requires clear dosing protocols and complete surface area illumination. Home UV light usage is not recommended due to the accuracy required. Some hospital systems in the United States have enforced this form of decontamination.
As a method of decontamination that can adequately destroy the virus and maintain the philter integrity for reuse, dry heating of the mask at 70 ° C for 30 minutes was suggested. Recent experiments at the NIH using SARS-CoV-2 clearly indicated that this method can be used for two cycles to kill the virus without compromising fit.
Moist heat has been shown to be efficient for flu viruses (heating at 60-70 ° C and 80-85 percent relative humidity), but there is minimal evidence on the temperature, humidity, and time needed to fully inactivate SARS-COV-2 viral particles. In addition, the parameters needed for killing the virus on N95 can adversely affect the mask's filtration efficacy. This approach is not currently recommended for N95 due to the lack of clear data on a protocol to achieve both aims.