The ongoing COVID-19 pandemic has resulted in a global shortage of face masks and the raw materials that go into them, driving individuals to opt for self-produce or purchase reusable cloth masks.
Face masks are an important protective item and the wide variety of types available provide different levels of protection. It is essential to choose the proper mask type for the appropriate task. For example, the highly effective protection of an FFP2 mask (high-filtration respirators, often seen worn by health workers) has meltblown layers that filter and are able to stop 94% of 0.3 micrometre particles. Although the coronavirus is expected to be about 0.08 micrometres, virus particles are usually carried in droplets bigger than this, making the 0.3 micrometre limit quite sufficient for protecting the wearer when combined with other protective equipment. Compare this with cloth fibres, of the type usually used for reusable masks. The difference between most reusable cloth fibres found in materials at home depends on weave thickness and can be 1,000 times bigger compared with the FFP2 mask – around 100 to 1000 micrometres.
Although the effectiveness of a cloth mask varies, the widespread use of cloth masks is better than no protection as it could dramatically reduce transmission by preventing droplet transmission from infected individuals. The benefits are further complicated by factors such as the fit, type of material, number of layers, frequency of adjusting, and the effect of having a moist or bacteria infested piece of cloth over your face.
Government advised behavioural economic ‘nudges’ (social distancing and hand washing) to encourage healthy behaviours could also play a role.
With the scientific perspective, the evidence does seem clear that a high filtration close fitted mask combined with the right safety equipment and behaviour has a protective effect, but homemade cloth face masks are simply too variable to be relied on for protection of yourself or others.
If personal protective equipment (PPE) supplies are scarce, wearing a cloth mask demonstrates to others that you are taking this pandemic seriously and are trying to respect the safety of others as well as your own, therefore, an important statement of camaraderie.
Wearing a reusable cloth face mask is less about science and more about unity.