Fashionable, yes. Effective? Not so much.
If you spend any time on social media these days, you’re bound to see a parade of posts picturing brightly colored homemade cloth masks being donated to healthcare workers. Similarly, a quick search of “N95 Respirators” on Amazon or Google yields a vast array of “reusable” or “washable” cloth and fabric “N95s”. These are not National Institute for Occupational Safety and Health (NIOSH) approved N95 respirators and have not been tested for performance. Even in my small town on the Oregon coast, our local hospital is conducting a hand-sewn face mask drive. The Centers for Disease Control (CDC) has issued guidance suggesting that homemade masks may be used; however, this guidance emphasizes homemade alternatives should be used ONLY as a last resort. Furthermore, the CDC statement includes the caveat that these homemade alternatives should not be considered personal protective equipment (PPE).
I have been working closely with healthcare organizations requiring fit testing and training on N95 respirators since long before the virus causing COVID-19 first made headlines. The shortage of available N95s is dire. As a Certified Industrial Hygienist my job is to protect employees' health in the workplace by implementing programs, policies and procedures to measure and reduce their exposure to physical, chemical, biological and ergonomic stress factors. My years of experience coupled with research evidence leads me to have serious doubts about the effectiveness of homemade masks as a form of protection for healthcare workers. After all, companies like 3M, Honeywell and Moldex have worked for years to engineer N95s that meet NIOSH criteria (click here and view the “What is an N95” section find out the 3 mains ways an n95 is specially engineered to keep particles from entering). While I admire the volunteers’ mask-making efforts during a time of crisis, is there evidence that homemade masks are effective? Or are we simply providing healthcare workers with a false sense of security?
A quick search of PubMed yielded answers. Researchers in Vietnam compared infection rates in healthcare workers wearing homemade cloth masks to surgical masks and found that rates of clinical respiratory illness (CRI), influenza-like illness (ILI) and laboratory-confirmed respiratory virus infection were significantly higher in the cloth mask group. These results caution against the use of homemade cloth masks for protection from respiratory pathogens.
Homemade masks could be of value when placed on symptomatic patients if surgical mask supplies have been exhausted.
If homemade masks are not effective as Personal Protective Equipment (PPE), do they have any value? To answer this, we turn to another study, this one published in Disaster Medicine and Public Health Preparedness. Masks made of various materials were tested for their efficacy in reducing droplet and particle transmission when worn by a coughing individual. Two layers of cotton t-shirt material or pillowcases reduced transmission, but not as effectively as surgical masks. This suggests that homemade masks could be of value when placed on symptomatic patients if surgical mask supplies have been exhausted.
What should healthcare workers do, then, if N95 respirator stocks are limited? First, remember that PPE is the bottom rung in the ladder of controls. Wherever possible, engineering and administrative controls should be implemented first, as these controls separate workers from the hazard area. Examples of engineering controls include the use of isolation rooms and properly maintained ventilation systems. Administrative controls such as telemedicine and postponing non-urgent procedures are being implemented in hospitals around the country. The CDC lists these and other strategies for optimizing the use of N95s at various stages of capacity.
When direct patient care is necessary, if N95 stock is limited, healthcare providers should first turn to elastomeric respirators and powered air-purifying respirators (PAPR) as alternatives. These give a higher level of protection and are intended to be reusable. Proper disinfection methods should be utilized to avoid contamination.
If these alternatives cannot be obtained, industrial filtering facepiece respirators and medical N95s past their use-by date but still in their original packaging and in unused condition may be used. Call upon manufacturing and construction businesses in your local area to donate excess supplies. They may also have rubber gloves, disposable coveralls, face shields and goggles they can spare, especially if their workers are sheltering at home.
Wearing a non-medical or homemade mask to go out in public may be a good idea.
At the crisis stage, when hospitals are overrun with patients and protective equipment is scarce, extended use or reuse of N95s may be necessary. Prioritize tasks with higher risk of exposure when determining when to wear respirators. Use strategies such as wearing a face shield over your respirator to minimize splash or spray risk, and mask patients with surgical masks whenever possible. Homemade masks are not recommended over top of N95s, as this could lead to a buildup of moisture inside the respirator and significantly reduce air flow. The public can assist by creating improvised face shields. These work as a barrier to protect the N95 from aerosol spray from the patient and do not need a special fit or design.
In summary, improvised masks do not provide the protection healthcare providers need to when in close contact with patients with a suspected viral disease and may cause the health care provider to in fact spread disease, as has been seen with the spread of some COVID-19 cases in Italy. However, this does not mean homemade masks are worthless. When surgical masks are in short supply, cloth masks are a viable alternative for use by the general population to reduce transmission of the coronavirus while out in public. In a healthcare setting they may be useful (as a last resort) for masking coughing patients or for use by staff who will not have direct or close patient contact.
*** Disclaimer: This material has been prepared for general informational purposes only and is not intended to be relied upon for occupational health and safety reasons, legal or other professional advice. Please refer to your advisors for specific advice.
Written by Kirsten Romero - Certified Industrial Hygienist with Mobile Health Diagnostics