As things stand, over the next few months everybody will have to use masks daily. This new situation has all kinds of impacts: difficulties in supply, which have been resolved to a certain extent, the extra cost in families’ budgets (the Organization of Consumers and Users [OCU] calculated at least 70 euros a month for a family of four) and the environmental impact of the waste that is generated. If 47 million Spaniards consumed two surgical masks a week, this would lead to 220 tons of waste per week. This calculation is really an underestimate, as the life of disposable masks is around four hours, in principle.
There are three types of mask. Personal protection equipment (PPE), also called filtering facepieces, protect from inside out (they prevent us from emitting the virus outside the mask) and from outside in (the mask prevents the virus from entering our respiratory system). They are indicated for health staff who are directly exposed to the COVID-19 virus. The main property is that they can filter particles at a size of 0.3 microns or larger. However, the filtering capacity varies depending on the model. FFP1 filter 78% of the particles of this size; FFP2, filter 92%, and FFP3 98%. These models may or may not have an exhalation valve. Those that have a valve are completely inadequate for current needs in the pandemic because they do not filter the exhaled air and may therefore contaminate. In addition, FFP2 and FFP3 protect from aerosols that are microdroplets that we project when we cough, sneeze, shout or sing. The COVID-19 virus could be present in these droplets.
Surgical masks. These protect from inside out but only partially from outside in. They were initially designed for health staff who work in surgery to avoid exposing patients to any viruses or bacteria in the breath of operating theatre staff. They have a water-repellent exterior coating so that any splashes of fluids during an operation do not affect health staff. They are recommended for health staff, patients with confirmed COVID-19 and suspected carriers. They filter particles of a size greater than 3 microns and have anti-bacterial efficacy between 95% and 98% according to the model, and breathability between 40 and 60 Pa/cm2. Microbial cleaning must be equal or less than 30 ufc/g. In principle, they are disposable, and they should not be used for over 4 hours consecutively, approximately.
Non-medical masks. This is a new category that did not exist prior to COVID-19. They are designed for healthy people and are recommended by the Ministry of Health for the general public during daily life. They protect from inside out, but not totally from outside in. If a person does not know that they have COVID because they are asymptomatic, this mask stops them from infecting healthy people. If everyone wears one, everyone will be protected. There are disposable and reusable versions. Reusable masks must have anti-bacterial efficacy of 90% or more and breathability of less than 60 Pa/cm2.
In Spain, only two centres have been recognised by the National Accreditation Body (ENAC) to carry out tests to certify these masks (AITEX and LEITAT). As these centres are overwhelmed with requests for tests, many companies have obtained certificates from unauthorised centres that are not known in the textile sector. This has contributed to generating dangerous confusion. In fact, to date, a considerable part of the offer of reusable non-medical masks sold in Catalonia have not been certified by the only two centres authorised to do this.
The best mask is not the most striking or that which matches our clothes, but the one that offers the most protection and can withstand the most washes without losing its properties. Functionality rather than aesthetics is the requirement that we should focus on first when we buy a mask. I say this because lately, with a certain degree of frivolity, there has been a proliferation in the market of a wide range of masks for which aesthetics takes almost exclusive precedence, with flashy prints, logos of football teams, drawings of animals, flags and comics; I even saw some printed paintings of Van Gogh. Most of these have little or no information about the protection that they provide or how long they last, and there is no laboratory certificate recognised by ENAC that accredits compliance with the UNE 0065-2020 standard. It is like advertising a car by its body without providing any information about the features of the engine, the safety systems, the fuel consumption or the emissions per km.
Some fabric masks are certified correctly, but they are effectively just outside casing: what protects is an extractable interior filter. The maintenance and cleaning of these masks requires a type of handling that is not recommendable.
Various recent studies have shown the efficacy of the widespread use of masks, even non-medical reusable masks, to reduce the propagation of COVID-19.
A mask is not a cloth that we put on our face to protect ourselves from dust when we paint of do building work at home. Instead it is a tool for protection, as an act of solidarity, and it has highly specific technical requirements.
If we all wear the right mask, we will contribute effectively to preventing propagation of the COVID-19 virus and its effects.
* The author is the director of the Terrassa Institute of Textile Research and Industrial Cooperation (INTEXTER) and professor of the Terrassa School of Industrial, Aerospace and Audiovisual Engineering (ESEIAAT), Universitat Politècnica de Catalunya (UPC).
Article published on the website of the Diari de Terrassa.