A Look Back on One Year of Changing Mask Rules


The World Health Organization declared COVID-19 to be a global pandemic on March 11, 2020. Since then, as we’ve learned more about the disease and how to stop its spread, the rules and advice about masks have kept changing. Here’s a look back at some milestones in one year of mask-wearing in Canada.

March 28, 2020: Canada’s chief medical officer of health, Dr Theresa Tam, discourages mask use for the general public. She mentions that the guidance is based on the best available science - including the official position of the World Health Organization at that point - but that it is flexible and may change if new information comes to light. Over the next few days she holds several additional press conferences where she highlights the importance of reserving the available masks for healthcare workers, people with COVID-19 symptoms, and close contacts of infected people. 

April 2, 2020: Based on new data, the World Health Organization warns that it is possible for COVID-19 to be transmitted by people who are infected but have no symptoms or who are not yet experiencing symptoms. The same week, it updates its guidance on masks but still does not recommend them for routine use by healthy people in the community.

April 6, 2020: Dr Tam and the Canadian government change their advice on mask-wearing, now saying that wearing a non-medical mask is “an additional measure that you can take to protect others” in situations where it might be difficult to maintain physical distancing. At his news conference the following day, Prime Minister Justin Trudeau encourages people to wear masks in public when they may not be able to maintain a 2-metre distance from others, and utters the infamous phrase about “speaking moistly” that inspires one of our most popular mask designs, as well as an auto-tuned song that would go on to be covered by several bands and artists (including one very Moist one). 

April 20, 2020: The Canadian Ministry of Transportation makes mask-wearing mandatory for passengers on any airline flight arriving or departing in Canada. Flight attendants and other airline staff won’t be required to wear masks until June.

May 20, 2020: Canada’s official guidance on masking changes again, with Dr Tam and her colleagues now recommending mask-wearing in busy public spaces rather than leaving it as a suggested personal choice. They still recommend wearing a non-medical cloth mask, so that the limited supply of medical-grade protective equipment can be reserved for frontline health workers.

Summer, 2020: Evidence is starting to mount that mask-wearing in public spaces is an effective way to prevent virus transmission. A study based on an incident at a hair salon in Missouri shows that even though two hair stylists were infected with COVID-19, they didn’t pass it on to any of the 139 customers they served that day, because everyone was wearing masks. Several observational studies also note differences in infection rates between regions where masks are mandatory and those where it is left as a choice. 

July, 2020: Individual cities around Canada start instituting their own mask mandates. The Montréal borough of Côte Saint-Luc is one of the first, on July 1st. On July 7, the City of Toronto makes it mandatory to wear a mask in indoor public spaces. On July 18th, the province of Québec becomes the first Canadian province to require masks in all publicly accessible buildings.

Fall, 2020: With mandatory masking now in place in most regions and new, more contagious variants of the virus on the rise, the changing advice now turns to what type of masks people should be using, or whether we should double up on masks. Prominent figures in the United States are seen wearing or advocating for a surgical mask underneath a cloth mask. The Public Health Agency of Canada now recommends triple-layer, non-medical masks with a filter, but does not recommend double-masking in most situations.

November 12, 2020: Up until now, the position of the US Centers for Disease Control and Prevention (CDC) has been that the main reason for mask use is to protect others rather than yourself, a recommendation based on data that showed masks to be effective at stopping an infected person from passing on viral particles. Now they update their guidance, based on new scientific findings, to confirm that mask-wearing also protects an uninfected wearer from picking up an infection.

February 10, 2021: A CDC study shows that wearing two masks at once - a reusable cloth mask over a disposable surgical one - is more effective at protecting the wearer than either mask alone. The researchers used artificial heads to test several different mask scenarios. When viral particles were being blasted straight at the mask-wearer, a single mask stopped about 40% of the virus, compared with about 80% for two masks. But when both the exhaling and inhaling heads were double-masked, more than 95% of the viral particles were blocked. So while you may feel reassured by adding another layer of protection to your own cloth mask, it’s also important to make sure that other people around you are also doing their part! 

And today… even though vaccines are being rolled out more and more rapidly in Canada and other countries, it’s still important to keep up with mask-wearing and other public health measures. Among its recommendations for people who are fully vaccinated, the CDC asks people to keep up their mask habits, and to respect local rules and regulations about mask-wearing in public places. We’ve learned a lot in the last year about how to use masks most effectively, and the rules and advice will probably continue to change as we get more information. For now, the best way to help yourself and others is to keep following the latest recommendations, and to be flexible when new information and guidance come to light. So keep up the good work - and maybe treat yourself to a cool new mask to keep yourself motivated?