Protective masks: what differences?

SARS-CoV-2 is a virus transmitted by respiratory secretions (cough, sneezing, saliva droplets…). To avoid contagion, some rules are essential, such as maintaining a safety distance of at least 1 meter (better 2), avoiding crowded places, washing our hands often with soap and water or alcohol-based gel, avoid touching our eyes, nose and mouth with our hands.

For some time, the World Health Organization has specified the best practices for wearing masks. There are many types available: surgical, FFP2, FFP3, with or without exhalation valve… but what are the differences among them? Here is a small informative and non-exhaustive summary, to illustrate the diversity of masks available to date (remembering that masks alone are not enough to protect us from contagion, and always recommending to follow the instructions of the competent authorities).

Three categories of masks

Protective masks can be divided into three categories:

The high protection masks are the so-called "FFP" (the acronym stands for "filtering facepiece particles"). These devices protect both the wearer and others, and are optimal for protecting healthcare professionals directly involved in caring for a patient who is certainly or likely to be infected with SARS-CoV-2.

They are divided into the three protection classes FFP1, FFP2 and FFP3 according to their filtering efficiency. FFP1 masks filter at least 80% of the particles found in the air down to a size of 0.6 μm; a single particle of SARS-CoV-2 is about 5 times smaller, so they are not suitable for protection from airborne pathogens. FFP2 masks are suitable, they filter at least 94% of the particles found in the air down to a size of 0.6 μm; FFP3 masks offer the highest possible protection, with a filtering capacity of at least 99% from particles up to 0.6 μm in size.

FFP masks can also be equipped with exhalation valves, which however have no effect on the filtering capacity of the device, but allow for better breathing when the mask is worn for a long time. The exhalation valve allows hot air to escape from the device, reducing the humidity that forms inside it, avoiding the formation of condensation. This system prevents the glasses from fogging and facilitates breathing, but be careful: in this way, even viral particles can escape! As such, valve FFPs protect the wearer, but not others.

Masks not certified for medical use, which can be made with any type of fabric that covers the nose and mouth. These are not considered medical or personal protective devices; they can be produced under the responsibility of the manufacturer, who must in any case guarantee their safety.

“The FFP2 and FFP3 masks are reserved for healthcare personnel engaged in certain clinical activities while, in the COVID-19 epidemic contingency, surgical masks can be useful to everyone especially when it is not possible to respect the physical safety distance” adds Prof. Carlo Signorelli, Full Professor of Hygiene and Public Health and Director of the UniSR School of Specialization in Hygiene and Preventive Medicine.

In any case, those wearing a mask must still comply with the precautionary rules on social distancing and the others introduced to deal with the Covid-19 emergency.