An N95 mask sometimes referred to as an N95 respirator, is a type of air-filtering protective device meant to filter out contaminants, bacteria, and airborne particles from the immediate environment. The N95 mask has a filtering efficiency of 95% and it can filter particles larger than 0.3 microns. The N95 mask is regulated and approved by both the FDA and NIOSH.
The N95 mask or N95 respirator is the most in-demand protective piece in the US nowadays because it is needed by the healthcare workers in dealing with patients with COVID-19 infections.
How does the N95 mask work?
Originally designed for industrial use, the N95 mask works by filtering out particles through the nonwoven material. The particles are trapped as they are forced to make twists and turns in the material's fibers. The mask becomes more efficient as the particles build up. As the build-up of the particles inside, the mask becomes difficult to breathe through, which makes the N95 mask not recommended for reuse.
What are the materials used in making N95 masks?
Depending on the brand, model, design, and application, the N95 mask is consistent with different materials. However, an N95 mask is usually made from the following:
- N95 mask Filter - Polypropylene
- N95 mask Strap - Polyisoprene
- N95 mask Nose foam - Polyurethane
- N95 mask Nose clip - Aluminum
- N95 mask Staples - Steel
So, how are N95 masks made?
Generally, N95 masks consist of several layers of nonwoven fabric, usually made from polypropylene. Usually, the layers consist of two outward protective layers, the pre-filtration layer, and the filtration layer.
The two protective layers covering the inside and outside of the N95 mask are made from fabric. These layers are created using a spun bonding, a process that uses nozzles blowing melted threads of polypropylene to layer threads between 15-35 micrometers. The fibers are then thermally bonded. The protective layers have a 20 and 50 g/m2 in density and act as a barrier to all elements in the wearer's exhalations.
In between the spun-bond layers is a pre-filtration later with a 250 g/m2 density. It is made from nonwoven material and processed through a hot calendering process. In this process, the materials go through high pressure heated rolls. This makes the layer thicker and stiffer.
The last layer is the filtration layer, which is made through a melt blowing process, a process very similar to spun bonding. The fiber on this layer is much smaller. It is also more durable.
Before leaving the factory, the N95 mask is sterilized.
N95 mask testing methods
There are several testing methods for N95 masks that are done by the CDC, these include the following:
- Test for particle penetration using charge neutralized sodium chloride aerosol spray that has a median of 0.3 microns.
- Test for a moderately high-work rate by having an airflow rate of 85L per minute.
- Test for breathing resistance at 35mm and exhalation resistance at 25mm.
- Test for the level of exposure by loading 200mg of aerosol, clogging the mask up for high-level exposure.
The FDA also tested the N95 mask for flammability, fluid-resistance, biocompatibility, and particulate and bacterial filtration. The N95 mask tested before leaving the manufacturer's factory.
The importance of buying high-quality N95 masks
Quality is very important when buying an N95 mask. Some of the reasons are the following:
- Wearing a high-quality N95 mask prevents irritation.
- High-quality N95 masks are high -protective.
- N95 masks with impressive quality are generally breathable, comfortable, and lightweight.
Since there are plenty of counterfeit N95 masks being sold online, make sure to do at least the flame test and water test for your N95 mask. These tests are simple ways to determine if the N95 mask is genuine and of good quality.
For the flame test, get lighter and wear the N95 mask. Position the lighter 6 inches away from the mouth. Once the lighter is activated, try to put out the fire. If you successfully put out the fire, then the mask is of low-quality.
For the water test, you'll need the N95 mask and water. Hold the N95 mask by the ear straps and fill it in with water. If there is no leakage, it means that the mask is of great quality.
Guidelines on N95 mask usage
Since the start of the coronavirus pandemic, there has been an increasing demand for N95 masks. Because of the fact that the virus affected millions of people in the United States alone, healthcare workers are facing a scarcity of N95 masks, thus, the CDC has issued updated guidelines on how healthcare workers can stretch the supply of N95 masks.
- Using N95 mask past the expiration date of the shelf life for outside the operating room applications. If used in operating rooms, it is important to check the seal.
- Using respirators approved and regulated outside US jurisdiction, including European EN 149-2001 standards and China’s GB 2626-2006 and GB 2626-2019 standards.
- Allowing workers to put cloth masks over the N95 mask to help preserve it.
- Prioritize the use of N95 masks in high-risk activities including aerosol-generating medical processes.
KN95 masks vs N95 masks
The N95 mask is very similar to the KN95 mask. Both face masks or respirators have the same filtering efficiency, which is 95%. They differ in their design and material composition, but both are meant to provide the wearer a high level of protection against tiny airborne particles, contaminants, and bodily fluid.