Ask Your Pharmacist

April 9, 2020

Canada’s Chief Medical Officer said this week that Canadians can use non-medical masks in tandem with physical distancing measures to limit the transmission of COVID-19 when out grocery shopping or at a pharmacy. I thought only health-care professionals are supposed to wear masks. What’s your advice?


Thanks for this question. The recommendation this week came as a surprise to many because our Chief Medical Officers had been resisting the idea of non-medical professionals wearing masks. There are pros and cons to wearing face masks. Human transmission of COVID-19 occurs by spread of infected droplets. Evidence supports that physical distancing of two meters (six feet) and practicing meticulous hand hygiene are more effective ways to prevent infection. What many people don’t realize is face masks may block the spread of virus to someone else, but they will not protect the wearer of the mask.

What are the pros and cons of wearing a face mask?


Masks don’t offer full protection, but some protection is better than none. COVID-19 is spread when infected droplets make it into a person’s mouth, nose, or eyes. If you have a physical barrier in front of your mouth and nose, that is less likely to happen. Masks do not replace cleaning your hands often with soap and water, keeping your hands away from your face, and physical distancing.

A health care worker may recommend you wear a face mask if you are experiencing symptoms of respiratory illness (i.e. fever, cough, sneeze) while you are seeking or waiting for medical care. In this instance, masks are an appropriate part of infection prevention and control measures. The mask acts as a barrier and helps stop infected droplets from spreading to others when you cough or sneeze. The most important measure for someone with symptoms of COVID-19, is self-isolation (and in some cases quarantine).


Face masks may give a person a false sense of security and are likely to increase the number of times a person will touch their own face (i.e., mask adjustments). Any mask, no matter how efficient at filtration or how good the seal, will have minimal effect if it is not used together with good hand hygiene and maintaining physical distancing.

Face masks do not protect the eyes if you were to rub your eye with an infected hand. If worn improperly or if not tight enough, face masks may allow infected droplets to enter and escape the sides of the mask.

As a care health worker during the 2002 SARS outbreak in Ontario, what I remember most is that wearing a face mask is not fun. I found the mask irritating, and hot, and generally uncomfortable. I was constantly checking to make sure I had a proper seal and making adjustments. This made it tough for me to keep my hands away from my face, which is essential to minimize the risk of infection. Wearing the mask for any prolonged period causes sweat and condensation to build up inside the mask. This moisture can lead to facial skin break down, and once the skin - our body’s physical defense barrier - is down, we are susceptible to many bacterial and viral infections. I also got headaches wearing a mask because of the carbon dioxide buildup. There is a potential risk of infection with improper mask use and disposal. They also need to be changed frequently.

Who should wear a face mask?

Evidence is still emerging on this question, but the Canadian Special Advisory Committee on COVID-19 now indicates that wearing a non-medical mask is an additional measure that may be taken to protect others from infection when physical distancing is a challenge (i.e. the grocery store or public transit). If you do choose to wear a mask, ensure you take all the necessary precautions to use it correctly.

Dr Kevin Duplisea (PharmD BSc. Pharm, BSc. ACPR) is a pharmacist at Sharp’s Corner Drugstore in Sussex, New Brunswick. His opinions expressed in this newspaper are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment. Send your questions to