advertisement

Infectious Diseases

Updated 05 May 2020

If you’re making a DIY face mask, these are the best materials to use according to science

Wearing face masks has become mandatory as lockdown eases in South Africa, and if you plan on making your own, scientists suggest using multiple layers and mixing the fabrics for better protection.

As the Covid-19 pandemic escalates, many governments worldwide are advocating for the mandatory use of face masks in public.

When President Cyril Ramaphosa addressed the nation on 23 April, he indicated that the use of face masks in public – during all lockdown levels – would be mandatory.

And if you can't find one, you can certainly make one, but be sure to take the advice of scientists in a recent study.

Six researchers from the Argonne National Laboratory and the University of Chicago recently conducted a study and found that two simple but important features can help to stop the spread of the new coronavirus, officially named SARS-CoV-2.

These include that the mask should have multiple layers, and mixing up the fabrics. They suggest this works best to filter particles and add that an improper mask fit can seriously reduce the protection it offers.

The study was published in ACS Nano Publications.

The study

The researchers began their study by taking a variety of common fabrics, including cotton, chiffon, silk, flannel, various synthetics, and their combinations, and proceeded to test them in laboratory conditions.

Their aim was to investigate the materials’ mechanical and electrostatic filtration properties. Mechanical filtration refers to the fabric physically catching the particles, whereas electrostatic-based filtration keeps the aerosols inside the static environment, explains ScienceAlert.

"Overall, we find that combinations of various commonly available fabrics used in cloth masks can potentially provide significant protection against the transmission of aerosol particles," the researchers explain.

The process involved the use of an aerosol mixing chamber to sample the number of aerosols in the air, an article by ScienceAlert explains. The paper shows an illustration of the experiment, along with specific information on the fabrics used.

After the first step, they passed the particles through each of the fabrics and sampled the air that penetrated the fabric, and tested for a large range of aerosolised particle sizes. Although scientists are still on the fence on whether such tiny particles can cause infection, ScienceAlert further explains that ensuring the material can filter out the smallest scale of particles is a good way to ensure larger particles will also be blocked.

Ruining the entire effort

In addition to mixing up the material, the team also found that layering multiple materials, also known as "hybrid" fabrics, successfully filtered a large majority of the particles.

"We speculate that the enhanced performance of the hybrids is likely due to the combined effect of mechanical and electrostatic-based filtration," the researchers explained.

However, although making your own mask may be a quick and cheap method, the researchers cautioned that even if you get the above techniques right, wearing your mask incorrectly can ruin the entire effort – and can increase the risk of being infected with the virus.

As part of their experiment, the team poked small holes in the fabrics they were testing, and the results were surprising.

"Our studies also imply that gaps (as caused by an improper fit of the mask) can result in over a 60% decrease in the filtration efficiency," they explained.

The World Health Organization (WHO) offers simple tips for getting this right:

  • Before wearing your mask, ensure your hands were cleaned with alcohol-based hand sanitiser, or washed thoroughly with soap and water.
  • Make sure to cover both your mouth and nose with the mask.
  • Take care to check for any gaps between your face and the mask, as there shouldn’t be any.
  • Avoid touching your mask while using it.
  • In the event that you do touch your mask, clean your hands as stated above.

When removing your mask, remove it from behind and do not touch the front of it.

Once done, clean your hands thoroughly.

Of course, face masks are effective only when used in combination with frequent handwashing, notes WHO. More importantly, wash your face mask regularly, as this is just as important as wearing it correctly, in order to prevent the spread of the Covid-19 virus.

READ | Coronavirus in SA: All the confirmed cases

READ | Coronavirus morning update: Why lockdown was eased, 1 million cases in US, and experts speak out on BCG

READ | Isolation during coronavirus pandemic a trigger for depression

Image: Getty/Anna Blazhuk