What types of masks are there?

In general, there are three types of masks based on their ability to filter inspired or exhaled air, and therefore, based on their ability to protect the user of the mask and / or the rest of the population from contagion in the event from an airborne infection:

 Surgical masks.

They are masks for medical use, used by healthcare professionals in surgery and other procedures in order to protect the patient from possible infectious agents present in the nasal or oral cavity of the user of the mask. These surgical masks may also be intended to be worn by patients and others in order to reduce the risk of spreading infections, particularly in pandemic situations such as COVID-19. They basically act as a barrier to prevent the emission of respiratory droplets when sneezing or coughing.

Based on their Bacterial Filtration Efficiency (BFE), they are divided into Type I (BFE ≥ 95%) or Type II (BFE ≥ 98%) surgical masks. There is a third type, called IIR, for those type II masks that are also resistant to splashes of blood and other biological fluids from the patient that could be contaminated by microorganisms.

These masks, therefore, can prevent the transmission of the infectious agent from an infected person to other healthy people, but their effectiveness in preventing contagion to the user of the same seems more limited, with less scientific evidence in this regard.

They are authorized as medical devices, based on the provisions of Royal Decree 1591/2009, of October 16, which regulates medical devices and is governed by the European standard UNE-EN 14683.

 Filtering masks.

They contain a microparticle filter thanks to which they can protect the user of the mask against the inhalation of environmental pollutants – in particles or aerosols – such as pathogens, chemical agents, antibiotics, cytostatics, etc. They do not protect against gases or vapors, although there are masks with specific filters for those cases.
Masks with a microparticle or self-filtering filter are considered Personal Protective Equipment (PPE),
regulated by Regulation (EU) 2016/425 of the European Parliament and of the Council, of March 9, 2016, regarding personal protective equipment and are governed by the European standard UNE-EN 149. They are classified based on their
performance in:

FFP1

(particle filter type P1): they have a minimum filtration efficiency of 78% and a maximum inward leakage percentage of 22%. They are usually used against particles of inert material, and are not recommended for medical use.

FFP2

(Particulate filter type P2): they have a minimum filtration efficiency of 92% and a maximum percentage of leakage into the interior of 8%. They are used against aerosols of low or moderate toxicity.

FFP3

(Particle filter type P3): they have a minimum filtration efficiency of 98% and a maximum percentage of leakage into the interior of 2%. They are used against highly toxic aerosols.

Self-filtering masks may or may not have an exhalation valve to reduce moisture and heat within the mask, providing greater comfort to the user and offering the sensation of less breathing resistance. These valve masks should not be used in sterile environments, nor in the case of patients infected with COVID19, since they could transmit the virus through the valve, except in the case that the valve is protected or designed to prevent said transmission outward.

These FFP2 and FFP3 filter masks will therefore protect the user against COVID-19 infection. In addition, they could prevent transmission from the user to the outside, if they were designed to do so. However, the use of a mask must be accompanied by other measures such as frequent hand washing and interpersonal distance in order to achieve greater protection.

 Community hygienic masks or face covers.

They are both reusable (that can be washed or sanitized) and non-reusable (single-use) products, with or without accessories, designed to cover the mouth, nose and chin, equipped with a fastening system normally to the head or ears, whose intended use is to minimize the projection of respiratory secretions (including
aerosolized particles), which contain saliva, sputum or respiratory secretions when the user speaks, coughs or sneezes, and may also limit the penetration of these secretions of external origin (including aerosolized particles) in the nasal and oral area of ​​the user without declaring protection of the user, as long as it is not considered a sanitary product, or Personal Protective Equipment (PPE).