COVID-19: Study explores which face mask combinations, modifications work best

First published by Safety+Health an NSC publication
COVID-19: Study explores face mask modifications
Photo: Centers for Disease Control and Prevention

Arlington, VA — Adding a brace or wearing a cloth face mask over a medical mask increases protection against aerosols carrying viruses – including SARS-CoV-2, the virus that causes COVID-19, results of a recent NIOSH study suggest.

Researchers tested, on a sample of humans and mannequins, two types of medical masks and three varieties of cloth masks purchased online. The researchers also looked at multiple mask fit modifications while simulating coughs and exhalations through a source control measurement system.

Findings show that using a brace over a medical mask blocked about 99% of exhaled aerosols and 95% of cough aerosols. Wearing a cloth mask over a medical mask prevented the passage of around 91% of exhaled aerosols and 85% of cough aerosols.

Nonmodified medical masks, meanwhile, blocked about 56% of cough aerosols and 42% of exhaled aerosols. Use of earloop toggles or an earloop strap, or knotting and tucking the mask enhanced aerosol-blocking performance. Crossing earloops or placing a bracket under the mask didn’t improve performance.

“Since the start of the COVID-19 pandemic, there has been considerable confusion about the most effective use of facemasks, especially among the general public, to reduce the spread of infection,” Ann Marie Pettis, president of the Association for Professionals in Infection Control and Epidemiology, said in a press release. “The NIOSH study findings are important and timely because they identify specific, practical combinations of facemasks and mask modifications that may improve mask seal and thereby measurably reduce the expulsion of infectious aerosols into the environment.”

The Centers for Disease Control and Prevention advises choosing facemasks that:

  • Have two or more layers of washable, breathable fabric
  • Completely cover the user’s nose, mouth and chin
  • Fit snugly against the side of one’s face with no gaps
  • Have a nose wire to prevent air from leaking from the top of the mask

The study was published online Dec. 15 in the American Journal of Infection Control, APIC’s official, peer-reviewed journal.

McCraren Compliance offers many opportunities in safety training to help circumvent accidents. Please take a moment to visit our calendar of classes to see what we can do to help your safety measures from training to consulting.

‘Which Mask for Which Task?’: Washington L&I offers guidance for employers


Photo: Washington State Department of Labor & Industries

Tumwater, WA — New guidance from the Washington State Department of Labor & Industries is intended to help employers select the proper masks or facial coverings for workers during the COVID-19 pandemic.

Under state safety and health requirements that went into effect June 8, workers – with some exceptions – must wear some type of facial covering to help prevent the spread of the disease. Employers must provide workers with the masks at no charge, or employees can supply their own as long as they meet state requirements.

Which Mask for Which Task? details the use of masks or, in some cases, respirators based on the job-related risk, from negligible to extremely high. The guidance also lays out the minimum level of facial coverings required if no other feasible measures can mitigate spread of the disease.

For example, small landscaping crews, a crane operator who is in an enclosed cab and delivery drivers who have no face-to-face interaction with customers are considered at negligible risk. Meanwhile, emergency medical technicians, occupational or physical therapists, and workers in long-term care facilities are categorized as extremely high risk.

For each level of risk, a photo of the appropriate facial covering, mask or respirator is included.

“We know that choosing the correct face covering, mask or respirator can be confusing,” Washington L&I Assistant Director Anne Soiza said in a June 5 press release. “It’s a new experience for most employers and people on the job. This guidance should help employers and workers understand the risk level for various tasks, and make the right choice to protect workers from the coronavirus.”

COVID-19 pandemic: OSHA answers FAQs on wearing masks at work


Photo: South_agency/iStockphoto

Washington — New guidance from OSHA answers six frequently asked questions regarding the use of masks in the workplace during the ongoing COVID-19 pandemic.

Among the agency’s answers is an explanation of the key differences between cloth facial coverings, surgical masks and respirators. Other topics include whether employers are required to provide masks, the continued need to follow physical distancing guidelines when wearing masks and how workers can keep cloth masks clean.

“As our economy reopens for business, millions of Americans will be wearing masks in their workplace for the first time,” acting OSHA administrator Loren Sweatt said in a June 10 press release. “OSHA is ready to help workers and employers understand how to properly use masks so they can stay safe and healthy in the workplace.”

The agency reminds employers not to use surgical masks or cloth facial coverings for work that requires a respirator.

COVID-19 pandemic: DOT to provide more than 15 million cloth facial coverings to essential workers


Photo: andresr/iStockphoto

Washington — The Department of Transportation has announced it will distribute about 15.5 million cloth facial coverings to transportation workers during the ongoing COVID-19 pandemic.

Previous guidance from the Centers for Disease Control and Prevention has identified transportation workers as essential and among those in “critical infrastructure” occupations.

“Transportation workers are on the front lines of keeping our transportation systems operational during this public health emergency and their well-being and safety is paramount,” Secretary of Transportation Elaine Chao said in a May 28 press release.

Distribution of facial coverings by industry is as follows:

  • Mass transit and passenger rail: 4.8 million
  • Aviation: 3.8 million
  • Maritime: 2.4 million
  • Freight rail: 2.2 million
  • Highway and motor carrier: 2.1 million
  • Pipeline systems: 258,000

FEMA secured the facial coverings, which are expected to be distributed via the U.S. Postal Service “over the coming weeks.”