N95 is the buzzword these days in the medical community and everywhere else, too. But if you don’t use the N95 (or any other type of respirator) properly, it may not be all that much more effective than a garden-variety surgical mask.
Let’s dive into why the N95 mask is recommended for serious communicable diseases such as tuberculosis, SARS, and influenza, and talk about the best way to wear these specialized pieces of equipment as protection against COVID-19.
N95 mask breakdown
The name of the mask and all the related vocabulary can be a little cryptic if you aren’t familiar with NIOSH lingo. Here’s the breakdown of what it all means:
N stands for non-oil
It means that it is not resistant to oil. It is a letter class for rating respirators. Other ratings could be R (oil resistant for eight hours) and P (oil-proof).
95 represents the efficacy
95 means that the mask can block 95% of the minute (up to 0.3 microns) particles. Masks ending in 100 will mean that they are 99.97% efficient; this is high efficiency comparable to HEPA quality filters.
An N95 respirator face mask can filter out a minimum particle size of 0.3 microns (comparable to dust and fume respirators). Large droplets are unable to pass through them.
The filtration material of the N95 mask is a hydrophobic propylene fiber that is electrostatic and nonwoven.
Some disposable N95 masks have an exhalation valve, which makes it easier to breathe (exhale), but can allow infected wearers to spread droplets to those around them.
Who are N95 respirators for?
Most N95 respirator face masks are designed for construction and other industrial workers who are frequently exposed to dust and small particles. These manufactured masks are regulated by the National Institute for Occupational Safety and Health (NIOSH), which is part of the Centers for Disease Control and Prevention (CDC).
Some N95 masks are manufactured for their use in healthcare settings. These are mostly disposable and are worn by health care personnel during medical procedures to prevent the spread of particulate materials and microorganisms through body fluids.
Guidelines on reuse, extended use, and reprocessing of N95 masks
Reuse, extended use, and reprocessing of N95 masks all affect the filtration capacity of the masks.
Extended use refers to the use of the same N95 respirator during contact with several patients without removing the respirator in between encounters. The CDC recommends that extended N95 mask use can be safe for up to eight hours.
It can be implemented if many patients are infected with the same respiratory disease and they are placed in the same dedicated wards/rooms. Extended use is recommended to prevent the shortage of respirators during a pandemic or an outbreak. Current guidelines suggest wearing a face mask or shield over N95 masks to decrease the chances of its soiling.
Extended use of the N95 mask is generally a better option than reuse as it has fewer chances of contact transmission due to less touching of the respirator.
- Discard N95 respirators that become contaminated with blood or body fluids from patients or following aerosol-generating procedures.
- Discard the respirator when leaving a designated area for the specific infection.
- Consider wearing a protective face shield or cover over the N95 respirator.
- After touching the respirator, wash your hands with soap or an alcohol-based hand sanitizer.
- If the respirator is damaged or it is hard to breathe through, remove and discard it.
Reusing of N95 masks refers to the use of the same respirator multiple times but is removed, stored, and then reused after each encounter with the patient. However, only limited reuse of the N95 mask has been recommended by the CDC (up to five times).
Limited reuse is also practiced for coronavirus infection as the virus loses its viability after 72 hours. This reuse strategy is adopted to conserve respirators during respiratory pathogen outbreaks or pandemics.
To be reused, the N95 mask should be dried enough to disinfect the virus (for more than 72 hours). The mask can be hung in storage for drying or kept in clean, breathable containers. Make sure masks do not touch each other and are not shared between people. Before reusing, a user seal test must be performed according to the manufacturer’s instructions.
Reprocessing and decontamination
Different reprocessing strategies have been established by the CDC and mask manufacturing companies. While reprocessing, the filtration capacity and the electrostatic charge of the manufacturing material (polypyrene) should be conserved as much as possible. The mask should fit securely and inactivate any viruses or infectious agents present on the mask.
Hydrogen peroxide vaporization, moist heat, dry heat, and UV treatment may be used to decontaminate masks. However, the best method may vary depending on the specific N95 mask you are using.
- Hydrogen Peroxide Vaporization – An FDA-approved method for N95 respirator emergency decontamination. It is recommended for N95 masks that do not contain cellulose fiber (1860 model). This method is used in industrial settings as well as in hospitals by using specific sterilization equipment like Battelle CCDS™, STERIS, etc.
- UV Treatment – This method is used in some hospitals. Masks are treated with ultraviolet radiation by following a set protocol of disinfection but this method requires a lot of precision.
- Moist Heat – Heating masks at 60-70°C in the presence of 80-85% humidity is an effective way to disinfect N95 masks. This method is effective for the flu virus, but there have been limited studies performed on this type of treatment, and it may affect the filtration efficiency of masks.
- Dry Heat – Disinfecting the mask by using dry heat (70°C for 30 minutes) can be done, but research on finding optimal parameters for this method is in its early stages, so it is not yet recommended by the CDC.
Other common decontamination methods like bleaching, boiling, sanitizing, or washing with soap are not recommended for N95 masks.
The N95 has become popular because of its availability and efficiency, however, there are other options medical professionals could consider as well:
- Surgical N95 – A NIOSH-approved N95 respirator, which has been approved by the Food and Drug Administration (FDA) as a surgical mask.
- N99 – Non-oil resistant. It filters 99% of airborne particles.
- N100 – Non-oil resistant. It filters 99.97% of airborne particles.
- R95 – It is partially resistant to oil and filters at least 95% of airborne particles.
- P95 – It is oil proof and filters 95% of airborne particles.
- P99 – It is oil proof and filters at least 99% of airborne particles.
- P100 – It is oil proof and filters at least 99.97% of airborne particles.
Individual certified N95 masks should have the following labels:
- NIOSH-approved name or business trademark
- NIOSH logo or NIOSH written in block letters
- NIOSH certification and the approval number
- NIOSH filter name according to the efficiency level
- Model number or part number
N95 masks are manufactured by multinational conglomerate corporations like 3M, Honeywell, Kimberly-Clark corporation.
Although healthcare regulatory authorities across the globe have recommended the use of an N95 face mask for healthcare workers, many individuals from the general public are buying them to mitigate the chances of getting COVID-19. According to Technaivo’s N95 respirator market research report, the latest coronavirus pandemic is expected to boost the sales of N95 respirator face masks.
The general public should reserve N95 respirators for the medical community unless they believe they may be infected or may be around someone else who is. Instead, look for cloth mask substitutes to provide protection in public, and combine with social distancing and frequent hand washing.