Chances are that you’ve come across these face shields and mistook them for a Special Weapons and Tactics [SWAT] officer. Fear not, they are just some of the outcomes of this pandemic. And it seems the public is even taking more to face shields, than face masks, for preventing the novel virus. But how well would a face shield protect and offer you a sufficient cover, and do you even need it?
Enter scene, face shield
The (surgical) face shield is a Personal Protective Equipment (PPE) designed to protect against fluid splashes to the face during medical procedures that may be infectious. In other areas such as in engineering works, face shields protect against particles such as metal bits that fly off during welding processes, for instance.
Similarly, firefighters, scientists and law enforcement utilise diverse variations of face shields. In general, face shields are classified based on their ability to withstand impacts. The American National Standards Institute (ANSI) ranks face shields based on their impact capabilities (low or high impact shields). The European (EN 166) and Canadian (CSA) Standards Organisations also use similar criteria.
In manufacture, the face shields are commonly made from polycarbonate and cellulose acetate. And the material choice is premised on the translucent/transparent nature of these plastics as well as their durable and non-reactive properties.
What then is the difference between the face shield & the face mask?
In general, face shields protect against substances coming into contact with the face; in contrast, face masks filter the air you breathe in or breathe out. The manufacture or material choice for face shields were not premised on filtration, but protection against impact.
Functionality vs aesthetic and comfort
Face shields like the ones in this picture are rather fashionable & only have the effect of perhaps preventing one from touching their mouth, nose or eyes to protect against covid-19
At the beginning of the coronavirus pandemic, there was a shortage of PPE supply to healthcare workers, face shields and face masks mostly. Furthermore, scientists knew little about the transmission of the virus. Hence, fears fueled by misinformation made people improvise on presumed rational practices. Regardless, studies, like this finding from the lancet, have shown that face masks protect people against spreading or getting infected with the coronavirus. In contrast, studies on face shields show that, in fact, they offer no protection against the virus – the vital difference being their functionality. While the former acts as a filter, the other works as a protection against direct impact to the face. Notwithstanding, the function of face shields in preventing one from touching their face is undeniable. Regardless of the growing concern of the coronavirus transmission through circulating air in closed/poorly ventilated areas, there is still strong support, through studies, on the very minimal transmission of the novel virus between infected and healthy parties utilising facemasks.
Health authorities have also repeated the need to wear a mask alone or with a face shield if one longs for more security. The increasing showboating with respect to rising demands for shields have merely spiked the price of PPEs, draining much-needed resources away from health workers.
Health authorities like the Nigeria Federal Ministry of Health & Nigeria Centre for Disease Control (NCDC) discourage the use of face shields alone if they must be used.
So always wear a face mask, and not a face shield!