Health : how to make a HEPA filter mask at home?
So can you make your own DIY face protection mask? The question whether DIY protective masks are effective against viruses is a very controversial question. Scientists and doctors agree: self-made cloth masks offer little protection and are not very effective at filtering out small particles. Recently, however, an idea has prevailed: could the HEPA filter help protect against coronavirus?
According to an article in the New York Times, scientists have started testing different materials to make face masks. Scientists around the world have worked to identify everyday materials that can best filter out microscopic particles. According to recent tests, the HEPA filters used for the ovens have ranked well, as have the vacuum cleaner bags, several layers of pillowcases and fabrics similar to flannel pajamas. The threaded coffee filters have an average result. Scarves and bandana fabrics have the lowest result, but can still capture a small percentage of the particles. In addition, the article reports that a fabric mask sewn from two layers of high quality quilted fabric is quite effective. And that may be all that regular people who socialize and go out only need when it is needed.
The face protection mask is very easy to make
Doctors caring for people with coronavirus can wear two types of masks. The first type is the face protection mask called N95. This type of mask can filter up to 95 percent of aerosols in the air and can then stop 99 percent of pathogens. However, these masks are only reserved for doctors and hospital staff and you should know that this type of mask is only effective if it is applied correctly to completely cover the mouth and nose. These masks are commonly used by doctors during epidemics such as the swine flu epidemic of a few years ago.
The second type of respiratory protective masks are what are called “surgical masks”. These masks are worn by surgeons during operations to avoid possible infections from smears and droplets and also to protect the patient from viruses and bacteria that doctors can carry. If the surgical mask is correctly put on the face, it can also retain the majority of pathogens.
To make your mask, you will need a HEPA filter
The two types of face protection masks are generally intended only for doctors and hospital staff. Authorities recommend not buying these two types of masks for personal use and keeping them for doctors. But since there are no specific recommendations about wearing a mask or the material it is made of, then anyone can make a face mask themselves at home. And even if the homemade mask is not 100 percent effective and cannot guarantee protection against the coronavirus, it is especially effective in protecting others if you are sick without knowing it.
If you want to sew your mask yourself, you can do it using fabric from an old t-shirt, for example, or a pillowcase. However in comparison with N95 masks and surgical masks, homemade face protection masks do not offer such protection, if at all. This is the reason why the vast majority of people seek to integrate a filter into their masks to guarantee more protection. If you also want to use a filter for your mask, it is recommended to use wet wipes or absorbent paper. But does absorbent paper or wet wipes really protect against the virus? No study can confirm this yet.
Cut the ends of the filter to be able to insert it into the fabric mask
Regarding the HEPA filter, is it able to protect erasure against COVID-19? Let’s first see what is a HEPA filter. HEPA is actually the abbreviation for ‘High Efficiency Particulate Air’ and it is a designation used to describe filters that are capable of catching 99.97 percent of particles that are 0.3 microns. Even though the HEPA standard was not established until 1983, the development of HEPA filters dates back to the Second World War. The particles which are 0.3 microns in size are the most penetrating particles. Scientists have found that particles of this size escape air filters more often than larger or smaller particles.
What are HEPA filters made of and how do they work? The majority of HEPA filters consist of integrated glass fibers which are twisted and rotated in a myriad of directions to create a fibrous labyrinth. When the particles pass through this labyrinth, they come out of circulation in the following ways:
Direct impaction : Large contaminants like dust, mold, pollen travel in a straight line, collide with a fiber and stick to it.
Be very careful not to damage the filter
Screening: The air stream carries a particle between two fibers, but the particle is wider than the hole, so it is slaved.
Interception: The air flow is agile enough to reroute around the fibers, but, thanks to the inertia, the particles continue on their way and adhere to the sides of the fibers.
Diffusion : Small and ultra-fine particles move more erratically than larger ones, so small particles are more likely to hit and stick to the fibers.
HEPA filters were divided into several classes according to European standard 1822-1 according to their ability to filter air in 1982. Meanwhile, the EU standard was modified in 2009. All filters that can filter the at 99.98% capacity is called HEPA. All filters that filter air up to 99.97% of the air are called EPA. If you ever order such filters from the United States, you must ensure that they comply with the Mil Std.292 standard.
There are several classes of filters which comply with the European standard of 1982, DIN 24183 and the American standard Mil. Here is an overview:
-EU 10 or H 10 filters are filters that are able to filter up to 85 percent of fine particles. These filters are not sold in the United States.
-EU 11 and H 11 filters are filters that filter more than 95 percent of fine particles in the air. In the United States these filters are simply called ’95 percent ’.
-EU 12 or H 12 filters also comply with the standard and can filter up to 99.7 percent of fine particles in the air.
-EU / H 13 and EU 14 / H 14 filters are HEPQ filters which are capable of filtering more than 99.99 percent of fine particles, air and dirt in the air. These filters are generally recommended for people with allergies.
In theory, HEPA filters could remove even the smallest particles of coronavirus from the air, although there are currently no scientific studies to prove this. It is therefore not very clear whether a face protection mask with a HEPA filter could indeed effectively purify the air and protect against the coronavirus. But at least this type of mask will filter the air better than the fabric mask. It is also generally unclear whether breathing through a mask with a HEPA filter will be safe for health. However, since there are such masks with HEPA filters and these masks are recommended for allergy sufferers, it can be assumed that these masks can improve air quality and that they do not harm health.
If you ever want to make yourself a face protection mask with a HEPA filter, it is recommended to seek advice from the local health authorities or your doctor. It is also important to know that babies and children should never wear face masks with HEPA filters as there is a risk of suffocation.
So how can you make a protective mask with a HEPA filter? In reality, making such a mask is like child’s play even if you have never done it before. You must first have a HEPA EU 13 or 14 filter. You must then cut off its ends and remove the fabric from the filter. There are three traces of hot glue, used to hold the different sheets of HEPA fabric together.
Remove the sheets carefully, being careful not to tear or damage the filter fabric. Cut into a rectangle 15 cm x 20 cm. Then make four folds uniformly distributed in the same direction with a width of 1 cm and sew them. The filter is ready and you can now insert it into the fabric mask.