• As the coronavirus pandemic spreads, and lockdown measures are being lifted, some governments have advised citizens to create their own face coverings.
  • Research has found the most effective homemade masks were made with double-layer, high-quality, heavyweight “quilter’s cotton” cotton.
  • As face masks are in high demand, if you are using one for personal and non-essential protection, here are 4 masks you could make at home.

Slowing the spread

Like other coronaviruses, the newly identified SARS-CoV-2 is being transmitted from person-to-person via airborne droplets when an infected person breathes out, coughs or sneezes.

A mask can stop virus particles spreading from an infected person. Wider use could stop the spread of the virus from those who have no symptoms or have not begun to experience symptoms.

The most effective face covering to block the transmission of the novel coronavirus is the N95 respirator mask, according to at least one study. With those in short supply and reserved for protecting healthcare professionals, many people have turned to homemade masks to protect themselves and others.

Constructing with caution

Although face coverings can slow the spread of the virus, the most effective actions are to avoid being exposed to the virus, maintain social distancing and hand washing.

U.S. Surgeon General Jerome Adams cautioned that wearing surgical-type cotton masks may not protect healthy Americans from contracting coronavirus and may even put them more at risk, since people who wear masks were likely to touch their face to make adjustments.

Finding the fit

A 2013 study published in Cambridge University Press’ Disaster Medicine and Public Health Preparedness journal on the efficiency of face masks against an influenza outbreak recommended face coverings constructed with pillowcases and cotton t-shirts when factoring in filtering, fit and easy access to materials. The study tested two microorganisms that represented a range of sizes similar to influenza viruses.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
Surgical masks top the list.
Image: Reuters Graphics

The exact size of novel coronavirus, SARS-CoV-2, is unknown, but tests at Wake Forest Baptist Health in North Carolina measured the percentage of particles 0.3 – 1.0 microns in diameter — the size of many viruses and bacteria — that were trapped in 13 different designs of homemade masks.

The tests found the most effective homemade masks were made with double-layer, high-quality, heavyweight “quilter’s cotton” cotton. But face coverings with a single layer of open weave cotton trapped as little as 1% of microscopic particles the same size of many viruses.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
While homemade masks perform lower than medical equipment, they are better than nothing.
Image: Reuters Graphics

Not sure if your fabric is a good filter? Scott Segal, M.D., chair of anesthesiology at Wake Forest Baptist, has an easy solution. Hold your fabric up to a light – the more light blocked by the fabric, the more particles that are likely blocked – but make sure the thicker fabrics are breathable.

Designs should result in a good fit. Wake Forest Baptist Health didn’t test for fit, but testers preferred designs with ties to customise the fit versus those that rely on elastics or hair bands. Supports on the bridge of the nose could enhance the fit of the mask.

If the mask is performing well, it will stop the wearer from emitting corona-size viruses, so make sure it’s washable or disposable.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
The bandana mask.
Image: Reuters Graphics

Construction of this face covering from a bandana is simple and the materials are easy to come by. A bandana could be replaced by another piece of close-weaved cotton, and elastics could be swapped for string, ribbon or fabric strips. The folding of the single piece of fabric results in a two-layer protection for filtering particles.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
How to make the bandana mask.
Image: Reuters Graphics
coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
The t-shirt mask.
Image: Reuters Graphics

The mask pattern from an old t-shirt takes advantage of easy-to-access and low-cost materials. Tests at Wake Forest Baptist Health found that masks made from high-quality and ticker t-shirts performed well at filtering microns a similar size to that of the coronavirus, but a single layer of cotton isn’t the best defense.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
How to make the t-shirt mask.
Image: Reuters Graphics
coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
The shield mask.
Image: Reuters Graphics

In order to relieve public demand for surgical face masks, a Hong Kong task force of research institutions tested and designed a 3-layer unconstructed medical face mask. Like the water-resistant nature of a surgical mask, the shield’s plastic outer layer defends against droplets from sneezing and coughing, and the task force reports that the paper towel and tissue layers filter 90% effectively as surgical masks.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
How to make the shield mask.
Image: Reuters Graphics
coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
The sewn inset.
Image: Reuters Graphics

Using inserted HEPA filters, nose bridge support in the filter pocket and adhesive seal, UnityPoint Health believes this 3-layer mask can achieve similar levels of filtration as the N95 mask. Wake Forest Baptist Health tested coffee filters as an insert and found it did not improve performance and vacuum bags hindered breathing, but other materials may improve filtering.

coronavirus fears epidemic pandemic disease infection contamination sanitation spread virus health care
How to make the sewn inset mask.
Image: Reuters Graphics

Endorsing the masks

The World Health Organization said that medical masks should be prioritised for health workers, but it opened the door to greater public use of homemade masks or other mouth coverings as a way to reduce the spread of the coronavirus.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, who is at the forefront of the U.S. fight against the coronavirus outbreak, said that Americans should cover their face if they have to go out in public, but they should still stay isolated as much as possible.

The United States Center for Disease Control recommends the use of cloth face coverings to help reduce transmissions, and Austria, Germany, Switzerland, Czech Republic, Morocco and Israel have all made the wearing of face masks in public compulsory as an additional defense against spreading the coronavirus.

Social distancing and isolation are considered the primary defender against the spread of the virus until a vaccine is developed.