- Types of protective masks
- Masks with filters - the filtration class has meaning
- Filter masks - application
- Filtered masks versus SARS-CoV-2
- What to do to make the masks effective?
- Filter masks as anti-smog barriers
Masks with a filter protect against harmful particles, smog, dust and are responsible for the filtration of impurities. Currently, they are also used to reduce the risk of coronavirus infection. The filtering mechanism used in the masks can be very different. For this reason, you should carefully read its intended use, as incorrect use of filter masks may have negative he alth consequences. Find out what types of filter masks are there. Which of them are recommended for protection against coronavirus?
Masks with a filterare primarily intended to protect against harmful factors that may enter the body through the respiratory tract. A real threat to our he alth is currently posed by aerosols, dusts and carcinogenic substances present in the air. Depending on the lifestyle we lead or the place where we work, we may be more or less exposed to them on a daily basis. Such substances getting into the upper respiratory tract can harm our body. The risk of serious respiratory diseases can be reduced thanks to a properly selected and properly used protective mask. In the current situation, masks are also used as one of the security measures to prevent the spread of SARS CoV-2 virus.
Types of protective masks
There are different types of masks on the market. Their individual types differ in shape, purpose or filtering properties.
This means thata mask designed to protect against harmful smog particles may not work in an epidemic threat as an anti-virus mask . Moreover, wearing the mask improperly can cause us serious he alth problems.
There are the following types of protective masks:
- surgical masks,
- filter masks,
- anti-smog masks,
- cloth masks.
Surgical masksare intended for medical use, the main purpose of which is to protect against the spread of viruses and bacteria. They are made of a specially compressed, hypoallergenic and dust-free 3-layer non-woven fabric with a high level of propertiesfilters.
These masks have special grips with rubber bands that give them the right position on the face. The masks are disposable and should be disposed of immediately after use.
Half-filtering masksmay have a breathing valve, thanks to which the exhaled air is discharged outside, which prevents the mask from getting wet quickly. Additionally, thanks to the valve, the feeling of stuffiness is reduced.
According to the CDC (Centers for Disease Control and Prevention), masks that are equipped with a valve pose a greater risk that the air we exhale will leak into the environment without any filtering. This is especially dangerous in the medical community.
In this type of masks, the effectiveness in protection against contamination depends on the filter they are equipped with. Some filtering masks are designed for single use, but some can be used multiple times - provided that the filter is changed regularly.
Filtering half masks , compared to surgical masks, are more rigid, tight and provide a better fit to the face. Filtering half masks protect against harmful viruses, bacteria and dust. What distinguishes the different types of masks - is the total internal leakage - related to the leak caused by the fact that the mask does not fully adhere to the face.
Masks with filterare equipped with an active carbon filter. The most commonly used material is HEPA-like, ie compressed polypropylene fibers. The main task of these fibers is to trap mainly mechanical impurities, not gaseous ones.
Anti-smog masksare often equipped with polypropylene fibers with pressed grains of activated carbon.
Masks with filters - the filtration class has meaning
There are masks with the following filtration classes, subject to the European standard EN 149: 2001
- FFP1 grade- low filtration efficiency - they retain about 80% of particles with a diameter smaller than 2 micrometers,
- FFP2 masks- retain about 94% of particles smaller than 0.5 microns in diameter,
- FFP3 masks- retain approximately 99.95% of particles smaller than 0.5 microns in diameter.
Filter masks depending on the specific filter class
| Filter class | Effectiveness | % of contaminants retained (from 300 nm) | Limit of maximum internal leakage |
| FFP1 | ≥ 1 μm | 80% | 25% |
| FFP2 | <1 μm i ≥ 0,5 µm | 94% | 11% |
| FFP3 | <0,5 μm | 98% | 5% |
Filter masks - application
Personal respiratory protection masks("filtering face piece" -FFP2, FFP3 ), equipped with a filtering system to protect the user against the risk of infection. These masks are intended for medical use, primarily for those who perform invasive respiratory procedures on intubated patients.
Personal respiratory protection masks, also known as FFP2 and FFP3 filter masks, are designed to fit snugly around the face. All the inhaled air in these masks passes through the filter only. Masks of this type can only be worn until they are wet.
FFP1 masksare often used during renovation and construction works as anti-dust masks.
FFP2 masksare used in industrial plants where the permissible concentration of substances such as smoke, toxic dust or aerosols in the exhaled air is exceeded.
Filtered masks versus SARS-CoV-2
Masks with a filter are used by medics because of their high effectiveness in protecting against virus infection.
According to European standards, the medical worker caring for the patient is required to wear an anti-viral mask with the filtration class FFP2 or FFP3.
FFP3 half masks are characterized by the most efficient filtration of harmful microparticles . They provide high protection against very small particles of pollution - for example asbestos.
In the event of medical procedures that generate aerosols, use FFP2 and FFP3 filtering masks .
Scientists have shown that infected SARS-CoV-2 virus can persist in the air for at least 3 hours in the event of an aerosol.
Therefore, in rooms without negative pressure ventilation, a filtering mask of FFP2 or FFP3 class should also be worn by people who are not directly performing the medical procedure in which the aerosol has been generated.
What to do to make the masks effective?
The US Centers for Disease Control and Prevention (CDC) have issued guidelines for three key factors that must be met for the mask to work effectively:
- The mask must be properly put on and worn during the exposure.
- Maskit must fit snugly against the wearer's face so that there are no gaps between the wearer's skin and the mask gasket.
- The filtering layer of the mask must capture more than 95% of the particles from the flowing air.
Filter masks as anti-smog barriers
We can also includeanti-smog masks(anti-dust) -N95, N99 . They are worn to minimize contact with contaminated air, to prevent harmful dust from entering our respiratory tract.
Thanks to the activated carbon filter, pollutants in the air you breathe are trapped before they reach your lungs.
The mask will fulfill its purpose if we use it correctly - i.e. follow the manufacturer's recommendations regarding regular filter replacement.
The recommendation to replace the filter applies only to reusable anti-smog masks . For the disposable ones, the filters cannot be reused and should be thrown away.