Wearing a mask is critical to reducing the spread of COVID-19, but rigorous tests conducted on behalf of CBC’s Marketplace found that while some work very well, others offer little protection from the particles that transmit the novel coronavirus. One type of mask can even spread those particles to others.

Months into the pandemic, there are still no standards for consumer masks. So Marketplace opted to compare more than two-dozen masks to what is commonly considered the gold standard in protecting health-care workers from infectious diseases like COVID-19 — the N95 mask. 

Marketplace purchased the masks in stores and online from a variety of sellers. The masks were also made out of varying materials and featured different designs.

The test pulls a constant breath of air containing tiny salt particles through the mask material. The salt particles are similar in size to particles able to contain the coronavirus that might originate from droplets expelled by an infected person’s breath, cough or sneeze. During the test, samples of air inside and outside the mask are compared to see how effective the mask is at reducing the level of particles.

Previous tests on consumer masks have commonly looked at how masks can help block particles when coughing or sneezing and prevent transmission to others. But the Marketplace test shows that certain materials make some masks better at limiting wearers’ exposure by filtering what they breathe in, Scott said.

Top Performers: 3- Layer Masks like blue surgical-type, and white cotton with inner layer melt-blown non-woven. 

Good Performers: 2-Layer Masks like 100% cotton 600-680 thread count, 100% polyester with an inner layer.

Other Options Will Protect You Better: 100% rayon, 1-layer bandanas made of cotton or polyester, 1 layers sequin outer layer. 

Read more details from the tests here.