Think back to the first couple of months of the year when face masks were not yet a part of our daily lives. In fact, medical experts advised people not to wear face masks because they had very little information on the novel coronavirus.
That directive, however, was changed when research provided insight into the respiratory nature of Covid-19. In Canada, 6 months after the first case of Covid-19 was reported, over 170,000 were infected with nearly 10,000 people losing their lives to the virus.
Now as we learn new facts about the disease every day, we’re gradually adjusting to a new world where a face mask is an important tool as we go about our day to day routines.
The Centers for Disease Control and Prevention (CDC) advised that everyone wear face masks in public settings such as grocery stores and while using public commuter transport. In May 2020, Chief Public Health Officer of Canada Theresa Tam advised Canadians to wear masks for extra protection whenever social distancing was impossible.
This is largely in part due to a growing body of evidence supporting the notion that public use of face masks can help curb the spread of the Covid-19. But with all the types of masks available today, what kind of mask will best protect the wearer?
Here’s a look at surgical masks and how effective they are at protecting the wearer and others from Covid-19.
For the past century or so, surgical masks have been the symbol of a sanitary and safe medical environment. A surgical or medical mask is a disposable face covering that covers the mouth and bridge of the nose. In a nutshell, they perform two functions.
The first function they serve involves preventing biological particles such as droplets of saliva or secretions released by the upper respiratory tract when the wearer exhales, coughs, speaks, or sneezes, from contaminating the environment around them.
If worn by an infected patient, a surgical mask will prevent the patient from contaminating the breathable air and surfaces around them. If worn by a healthcare worker, they protect the patient and the environment around them from possible infection.
The second function they serve is to protect the wearer from possible infection through droplets or biological fluids. This is possible through their design which makes them resistant to fluids such as blood or any other infectious liquids.
There are currently three types of surgical masks; Type I, Type II, and Type IIR.
Type I surgical masks offer no resistance to fluids but are designed to help reduce the risk of spreading infections from respiratory droplets. The type I masks are worn primarily by healthcare workers and patients.
Type II surgical masks offer no resistance to fluids. They are primarily made for use by healthcare professionals working in an operating theater or similar environment.
Just like Type II surgical masks, type IIR surgical masks are designed for use by healthcare workers in an operating theater. The difference is that type IIR surgical masks offer resistance to fluids and droplets.
Surgical masks are made from nonwoven fabric because it is slightly slicker than woven material and offers better filtration of bacteria and pathogens. The cost of the nonwoven fabric is also cheaper, cleaner, and made with 3 or 4 layers.
The nonwoven fabric is mostly made from polypropylene, polyester, polycarbonate, or polystyrene, usually between 20 to 25gms (grams per square meter) in density.
The nonwoven material is made through spun bonding, a process that involves extruding melted plastic onto a conveyor belt. The nonwoven fabric is extruded in a web where the strands and fibers bond gradually as they cool down.
The spun bonding process involves the use of melt-blown technology where the plastic is passed through a die with tens of small nozzles. The material is then blown by hot air to become small fibers, less than a micron in diameter, that are then cooled and bound on a conveyor.
Surgical masks are made up of multiple layers of the nonwoven fabric which covers a layer of textile on either side. The layers are highly effective at filtering out particles larger than a micron in size. The filtration efficiency, however, is dependent on the web’s structure, on the fiber used, its manufacturing process, and the fiber’s cross-sectional shape.
After the material is made, the manufacturing process is completed by a machine that welds the layers together using ultrasonic technology, assembles the nonwovens, and places nose strips and ear loops on the mask. The completed product is then sterilized and tested before it’s released for public use.
Surgical masks have received their fair share of criticisms from health experts for various reasons, and rightly so.
One reason people have been discouraged from using surgical masks is their inability to place a tight seal around the nose and mouth. Surgical masks tend to leave a lot of space around the borders which means unfiltered air can either penetrate or leak through.
Although some people would argue this design highly favors breathability for the wearer, the design leaves them highly vulnerable to infection. If they are already coronavirus positive, they could pose a health risk to other people. Surgical masks have also been criticized for having poor filtration efficiency despite them going through rigorous bacteria and particle filtration efficiency tests.
A lot of people have been misinformed that surgical masks provide full-proof protection from Covid-19. The truth is they will not directly prevent you from coming into contact with infectious airborne pathogens.
For surgical masks to be effective in trapping the wearer’s respiratory droplets, they have to be worn in the right manner. The wearer also needs to maintain proper hand hygiene and practice social distancing especially considering the structure of surgical masks does not allow them to place a tight seal on the wearer.