What do we need to know about protective masks?
A good surgical mask has three layers made of polypropylene non-woven fabric. The middle layer should be made of a non-woven fabric providing an adequate degree of filtration between BFE 95%-99%.
Its outer layer should be hydrophobic, i.e. it should repel water, blood and other body fluids to which a surgeon, for example, may be exposed during a surgery. The inner layer must be hydrophilic, i.e. it must absorb the sweat and saliva of the person wearing it. The middle layer acts as an antibacterial and antiviral filter.
The outer side of the mask may be of a different colour, e.g. blue or green, for better recognition. The mask on the reverse side would not perform well.
It is highly recommended to follow certain rules before putiting the mask on:
- Wash hands with soap and water.- Hold the mask with a stiff, bendable strap upwards, coloured side outwards.
- Mask with elastic bands - hold the mask by its elastic bands and place each band behind the ears.
It has been now mandatory in several European countries to cover up one's mouth and nose in public places. It is not required to be done with a specialized mask. However, it is worth knowing about different types of protective masks. Not all masks have the same purpose, not all are used in the same manner. Which one provides the most effective protection against pollution and microorganisms suspended in the cloud of exhaled air? How do they protect against the coronavirus? We explain all of this.
Disposable hygienic and surgical masks
Surgical disposable masks are most often used. Their task is not to filter air, but to create a physical barrier between mucous membranes and potential contamination. They protect against larger particles with a diameter of more than 1 micrometer (μm) and not against viruses with a diameter measured in nanometres (in the case of coronavirus it is 60-140 nm). However, they are an effective barrier to aerosols in which viruses may be present. A virus needs a carrier. The virus spreads by droplets when a sick person coughs or yawns, and also through saliva and nasal discharge. As far as the degree of filtration is concerned, the standards for such masks are laid down in the European standard EN 14683, according to which surgical masks are divided into three types: Type I (filtration efficiency ≥ 95), Type II (filtration efficiency ≥ 98) and Type IIR (filtration efficiency ≥ 98)
During surgical operations, doctors use type II and IIR masks. They consist of three layers of polypropylene non-woven fabric. IIR type masks differ from type II masks in that they are resistant to splash permeation, i.e. they have hydrophobic properties.
Disposable surgical masks soak up moisture and are therefore not suitable for prolonged wear. They should be discarded after after each use. People with symptoms should wear such masks to prevent the spread of the virus, which is present in micro-dropletss of exhaled air, or being sprayed when talking or coughing. However, it should be remembered that surgical masks do not provide full protection as they are loosely fitted to the face.
Masks type FFP1, FFP2, FFP provide a much higher degree of filtration as well as much better adherence to the face. D Type can be used for an entire shift, as D indicates that maks has passed a Dolomite clogging test. This means that breathing in such mask does not become restricted in a short period of time.
