Covid-19 contingency measures refer to several possible (or dutiful) uses of the ‘masks’. An in-depth study of FFP2 and FFP3 surgical masks and respirators (N95).
Covid-19 and the use of masks
The use of masks to cover the nose and mouth has been recommended so far, nationally and internationally (WHO):
– to the general population, to reduce the risks that people unaware that they have contracted coronavirus (in the absence or before the onset of symptoms) may infect others,
– to workers to ensure occupational health and safety with respect to the risk of contracting the SARS-CoV-2 virus. (1)
The term ‘template,’ as we have seen, is used in common parlance to designate different categories of objects, with quite different functions and technical requirements.
Surgical mask
The ‘surgical’ type mask has the sole function of decreasing the risk that the wearer may transmit the virus to other people. A risk, moreover, that can and should be minimized only by strict adherence to (a couple of meters of) interpersonal safety distance.
This is the mask that is generally worn by dentists, to protect patients (from flu viruses, for example) and act as a barrier to splashes of organic material (e.g., saliva, blood). However:
– surgical mask does not adhere perfectly to the face, leaving open several gaps (between the nose and cheekbones, cheeks and ears) through which the virus can pass,
– the ‘protective’ part, while capable of stopping liquid droplets, is ineffective in filtering finer suspensions. Which as well can carry coronavirus (within droplet nuclei, particles of diameter <5μm).
Those most at risk of infection (e.g., health care workers) must therefore wear certified respirators (see next section), the only true protective shields.
The respirators, FFP3 (or N95) and FFP2
The FFP3 or N95 respirator is used in various fields as an anti-pollution or anti-contagious mask. It is the most sophisticated PPE ( Personal Protective Equipment, or PPE):
– N95 certification, which must always accompany this device, is issued upon completion of experimental testing on the effective ability to filter out at least 95 percent of airborne particles (including those containing coronavirus),
– the most advanced devices go as high as 99 percent.
The acronym FFP3 stands for Third Level Filtering Face Piece (>95%). In contrast, the FFP2 respirator provides second-level protection, which must still guarantee-through appropriate certification-that at least 89 percent of the particles are filtered out. Both respirators can be equipped with a valve.
The valve on respirators, pros and cons
The valve-which may be present on both FFP3 and FFP2 respirators-is intended to facilitate the escape of exhalations. This entails:
– The advantage of reducing fatigue in breathing. It is therefore useful for those who have to wear the device for several hours at a time (e.g., in departments with a high risk of infection),
– the disadvantage of not filtering the respirator wearer’s exhalations. Which can consequently infect others where safety distances are not observed.
Valved devices are therefore not recommended for use by the general population, as well as for those who work in connection with the public (e.g., supermarket and store checkouts and counters, bank and post office counters). As well as to law enforcement officers, who are often forced into close contact between colleagues (e.g., in cars).
Contraindications and risks
The level of protection provided by FFP2-and FFP3 (N95) especially-creates an inevitable physical obstacle to the passage of airflow. Those not used to using these PPEs may experience shortness of breath. Their use is in the professional field after training on their appropriate use.
The most serious risk is related to the mishandling of masks, which can infect the wearer instead of protecting him or her whenever they are removed temporarily (even just a few moments, to answer a phone call or scratch the nose) or are moved and repositioned on the face.
Recommendations for appropriate use
One has to keep in mind the very point of these devices, which is always to act as a barrier to the virus (more or less effective, depending on the type). After using a mask in areas frequented by other people, it should therefore be handled as if it were contaminated:
– never lower it under the nose (as you risk bringing particles containing Covid-19 closer to the nose and mouth),
– Never touch it or move it after it has been placed and tested the first time,
– Use only the side elastic bands to remove it,
– After use, discard it in a closed container. Or, if spare parts are unavailable, wash your hands well and sanitize the device. (2)
The instruction manuals for the various devices provide for their replacement, with varying frequency, from one model to another-because their impenetrability is by no means absolute.
Never lower your attention span. The use of a face mask can inspire a sense of safety that is illusory, however, if crucial precautions, safe distances and frequent hand washing, are not followed. (3)
Tiziana Polimeno and Dario Dongo
Notes
(1) See Protocol 14.3.20, Measures to Contain the Virus in the Workplace, https://www.greatitalianfoodtrade.it/sicurezza/coronavirus-misure-di-contenimento-negli-ambienti-di-lavoro-protocollo-14-3-20
Employers’ liability, https://www.greatitalianfoodtrade.it/sicurezza/covid-19-sicurezza-dei-lavoratori-e-responsabilità
(2) How to sanitize masks when spare parts are unavailable, see https://www.greatitalianfoodtrade.it/sicurezza/mascherine-sanificazione-e-riutilizzo-procedura-stabilimento-chimico-farmaceutico-militare
(3) How to wash hands, see https://www.egalite.org/covid-19-guanti-meglio-lavare-spesso-le-mani-ecco-come/
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
