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What role do “guesswork and logic” play in battling COVID-19?

Credit: Healthline 5 mins read

Several videos and sites, including the Nigerian Immigration Service, suggest wearing the coloured part of the surgical mask on your nose, as opposed to the orthodox approach. This method is perceived to prevent the breathing in of harmful particles.

The coloured part of a mask is not designed to face your nose; this means it could make breathing through the cover even more uncomfortable. Your face mask, the surgical mask, should always be worn with the coloured part out. You can see a demonstration here.

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The controversy over what side of the surgical face mask should face outward began long before the coronavirus pandemic. Back then, it was about this photo showing that masks should be worn with the coloured side in and the non-coloured side out. It seems the message got modified with the pandemic. Now, several actors claim that people should wear the shaded portion of the surgical face mask, facing inward. It further adds that wearing the white side outwards is necessary for people who are not sick.

Facebook posts amid the global lockdown have further fuelled this method of wearing face masks.

We also found an advisory on the Nigerian Immigration Service website, pointing out that the right way for healthy persons to wear a face mask is for the coloured side to face the wearer’s nose. But is this the right way to wear your surgical mask?

Credit: Nigeria Immigration Service

Surgical Mask, what is it?

Firstly, while surgical masks are essential in clinical situations, they do not provide wholesome protection from viruses. Health practitioners mostly used them during surgical procedures, to prevent wound contamination or prevent the spread of respiratory infections generally between staff and patients.


In design, these masks follow standards; separate countries have their own rules, such as the NIOSH in the USA, the EU standard, Chinese, etc. The specific filtration capacity of the mask is the reason for these standards. Going by this, there are two types of surgical masks.

The first is the thinner single-use surgical mask (China standard YY/T0969); the second, the standard surgical mask (China standard YY0469) used in surgical theatres. Both vary in their functions; while the single-use surgical mask can only trap particles 3.0micron and above, the standard surgical mask can trap up to 30% of particles 1.0micron. 

Necessity is indeed the mother of invention

Simply put, the single-use surgical mask can trap dust or larger particles, while the standard surgical mask can trap bacteria and individual virus particles. Furthermore, you would be correct to speculate that Asia’s storied history with air pollution necessitated the design of the second type. In truth, this standard of face covers is not present in other countries’ categorisations. 

In manufacture, the surgical mask consists of three layers of industrially-made fabric. The usually coloured layer (mostly coloured in green or blue)  is oily and non-absorbent, and functions to deter fluids and particles from sticking to it. The inner perforated layer traps particles, and the third (generally non-coloured) layer is more absorbent, to hold down moisture. 

Credit: Centre for Health Protection, Hong Kong

How does this design help with Infection Prevention? 

It is important to remember that the intent of the surgical mask- to control infection in the hospital setting; its purpose is not just to prevent the spread of viruses, like the coronavirus. So, the non-coloured outer part is to help trap moisture and droplets such as those of a sneeze from the wearer while the inner layer is to trap bacteria and distinct virus particles, and the coloured slippery part helps to prevent fluid splashes and particles from sticking to the mask. In this manner, theatre staff and particularly the surgeon, do not infect patients or contaminate their surgical wounds. In essence, the cover’s design is to prevent the wearer from passing on the infection. It is perhaps this revelation that has precipitated most confusion around the subject, especially during this pandemic. 

Best practices and civic responsibility

In hospital settings, doctors and other practitioners used the surgical when treating patients with highly infectious respiratory diseases such as tuberculosis to prevent these patients from passing on such infections to their caregivers. In this case, the sick person puts on the mask and the caregiver too.

However, over the years, Asian countries such as Japan, Korea, and China have popularised the wearing of surgical masks. People with the flu reportedly use these covers during the flu season to curb the transfer of the common cold; a responsible act, one might add. 

How does the Surgical Mask prevent Coronavirus spread? Don’t pass it on!

Primarily, the purpose of the surgical mask is to keep the wearer from transmitting infectious droplets to other persons. We also established that the non-coloured inner layer acts as a moisture absorbent. So, the misguided notion reasons that the practice of wearing the non-coloured inner part of the mask facing out ought to grant the wearer protection from breathing in infectious particles, as the absorbent layer would trap said particles. This hypothesis, however, is wrong because the surgical mask is not a respirator. It does not act as a single valve, allowing particles to flow in one direction. Respirators have a one-way valve, meaning they only allow filtered airflow into the mask. If the surgical mask had this one-way valve that oozed airflow out of the wearer, reversing it to filter breathed-in air would then make sense. But this is not the case. Interestingly, the one-way valve of respirators means the wearer can breathe out anything, including droplets, while the inner layer of the surgical mask can hold droplets from the wearer.

The reason for advising its use is that if we all wear a mask, the surgical mask, then everyone gets to keep their infection to themselves, not passing it on to the next person(s). It is in a way following the Japanese ethics of wearing a mask during a flu season- don’t pass it on!

Victor Ndukwe is a first-class honours graduate in Architectural Design Technology from the University of Wolverhampton. He was an Associate Member of the Chartered Institute of Architectural Technologists; and a STEM Ambassador. Additionally, he manages a health-fitness centred blog. His varied work experience gives him a unique perspective in the literary field; having worked in construction, Information Technology and conducted extensive research in various fields. He now utilizes this skill set in the field of fact-checking; aiding colleagues and teammates with research and editorial work.

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