April 16, 2020

COVID-19 Weekly Roundup: N95 Decontamination Methods, Elastomeric Respirators Webinar, and More

News briefs related to the COVID-19 pandemic from The Synergist:

FDA authorizes decontamination systems for N95s. The U.S. Food and Drug Administration has authorized the use of sterilization systems produced by Advanced Sterilization Products, Inc. for decontaminating N95 respirators. The STERRAD 100S, NX, and 100NX Sterilization Systems use hydrogen peroxide vapor to sterilize approximately 480 respirators per day, according to an FDA press release. Each respirator may be decontaminated no more than twice via this method, per FDA’s “emergency use authorization.” The agency says that approximately 10,000 STERRAD Sterilization Systems are in use in 6,300 hospitals across the country.

NIH validates four decontamination methods. A study conducted by the federal government has validated that four decontamination methods remove detectable viable SARS-CoV-2 virus from small sections of N95 respirator filter fabric, according to a news release from the National Institutes of Health. Investigators tested methods involving vaporized hydrogen peroxide, 70-degree Celsius dry heat, ultraviolet light, and 70 percent ethanol spray, then treated fully intact respirators with each method to determine their effects on reuse durability.

Vaporized hydrogen peroxide, or VHP, was found to be the most effective method. After a ten-minute treatment, no viable virus could be detected. Respirators treated with VHP experienced no failures, which suggests they can be reused up to three times.

Ultraviolet light and heat treatments caused fit and seal problems after three decontaminations, which suggests these treatments can allow respirators to be used twice.

Ethanol spray damaged the respirators’ fit and the integrity of their seal after two decontamination sessions, according to NIH, and therefore is not recommended.

The investigators urge anyone decontaminating a respirator to test the fit and seal before each reuse.

Industry-specific fact sheets available. Workers for airlines and airports, as well as bus and rail operators and maintenance staff, can find information about actions they can take to prevent exposure to COVID-19 on the NIOSH website.

NIOSH creates “PAPR100” class of respirator. An interim final rule published April 14 in the Federal Register creates a new class of powered air-purifying respirator (PAPR) that may be better suited to the needs of workers in the healthcare and public safety industries who require protection from COVID-19. Read more.

Webinar on elastomeric respirators. A recorded NIOSH webinar available on YouTube provides a broad overview of the use of elastomeric respirators in healthcare and discusses infection prevention measures as well as strategies for optimizing the supply of N95 respirators.

Study suggests healthcare workers can be rapidly trained to use elastomeric respirators. A study published in the Journal of the American Medical Association found that healthcare workers can be quickly fit tested and trained to use elastomeric half-mask respirators. EHMRs are widely used in construction and manufacturing, but uncertainty about their costs and disinfection methods has limited their adoption in healthcare, according to the authors.

IH shares best practices for protecting healthcare workers. A webinar held April 15 by the National Institute of Environmental Health Sciences featured practical information for minimizing healthcare workers’ exposure to COVID-19. Jim Chang, CIH, of the University of Maryland Medical Center in Baltimore, discussed ways to isolate COVID-19 patients and minimize contacts between patients and healthcare workers. Read more.

National Academies committee reviews science on effectiveness of homemade masks. Only limited, indirect evidence exists regarding the ability of homemade cloth masks worn by members of the general public to suppress the spread of COVID-19, according to a brief review conducted by the National Academies Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats.

A press release accompanying the report states, “The evidence from these laboratory studies suggests that while fabric masks may reduce the transmission of larger respiratory droplets, there is little evidence regarding transmission of small aerosolized particulates of the size potentially exhaled by asymptomatic or presymptomatic individuals with COVID-19.”

CDC permits “critical” workers to continue working after exposure to COVID-19. Interim guidance issued by CDC on April 9 allows “critical infrastructure workers” to continue to work following potential exposure to COVID-19 as long as they do not exhibit symptoms of the disease and additional precautions are taken to protect them and the community. Read more.

Labor department releases interim recordkeeping guidance. The U.S. Department of Labor has released interim guidance for enforcing OSHA’s recordkeeping requirements relating to cases of COVID-19. Under the new guidance, employers are responsible for recording confirmed cases of COVID-19 contracted under circumstances related to the employees’ work. Read more.

Occupational hygienist group criticizes messaging about COVID-19 transmission. In a letter (PDF) to Canadian health authorities, Workplace Health Without Borders expresses concern about statements from the Canadian government and the World Health Organization that WHWB says “is not consistent with the science on the transmission of influenza and coronavirus, which strongly indicates that aerosol transmission is a route of infection.”

The letter quotes statements on the WHO website and guidance from the Ontario public health department that describe the possibility of COVID-19 transmission via respiratory droplets and fomites. The text does not mention the possibility of aerosol transmission.

“Unfortunately the current messaging being provided at the national and international level is behind the known emerging science about the transmission of COVID-19, including as an aerosol,” the letter states.

Donations of cloth facemasks encouraged for healthcare workers. The American Association of Occupational Health Nurses and the Association for Creative Industries have launched a public awareness campaign encouraging donations of homemade face coverings to essential and front-line workers. More information is available from AAOHN and AFCI.