Public Restrooms and COVID-19: Guidelines for Reopening

PHLUSH, June 29, 2020
Carol McCreary

The re-opening of the economy during the continuing COVID-19 pandemic depends on the successful re-opening of toilet facilities. Retail businesses, manufacturing firms, trade workshops, food-processing units, schools and universities, and government institutions must protect people from the SARS-CoV-2 virus. And they are in a position to support and encourage social distancing, handwashing, mask wearing, and the like for customers, employees, students, and visitors.

New research by scientists and microbiologists over the past four months has highlighted ways shared bathrooms put users at risk. It has become clear that COVID-19 spreads not only through respiratory droplets which quickly fall to the floor, but through aerosol particles which remain suspended for much longer.

Viable SARS-CoV-2 virus has been shown to survive in stool, bringing risks of fecal-oral and fecal-respiratory contagion. Research has demonstrated that flushing lidless toilets typically found in restrooms sends vertical plumes several feet into the air. Studies have also demonstrated how forced-air hand dryers propel microbial material from inadequately washed hands into the surrounding spaces. Partially paneled restroom stalls bring bathroom users into close proximity within poorly ventilated spaces. There are multiple touch points – stall door locks, flush handles, and faucets. We now know that four in ten fellow restroom users are likely to be pre-symptomatic or asymptomatic who can unknowingly transmit SARS-CoV-2 virus.

It’s clear that shared restrooms need to be managed with care during this pandemic. Toilets and handwashing are essential to economic recovery, public health, and personal well-being. Based on evidence from recent studies of SARS-CoV-2 transmission, we propose the following actions:

Reopen public restrooms as they are crucial to the revival of economic and community life.

According to Asaf Bitton of Brigham and Women’s and Harvard’s School of Public Health, bathrooms are “one of the thornier issues in opening up safely.”

Restroom access to protect the health of employees is stipulated by the U.S. Department of Labor through the Occupational Safety and Health Administration (OSHA) and implemented through units in each state. As employees return to workplaces, OSHA and state agencies are developing guidelines to protect them from COVID-19. However, recommendations for the management and use of restrooms are proceeding so slowly that they are difficult to find. Given their often small enclosed spaces, shared toilet facilities present risks similar to those in health and dental care establishments.

While the general public is guaranteed none of the toilet rights that employees enjoy under OSHA, simply leaving restrooms closed is not feasible. Customers will not patronize businesses with restrooms whose design and management make them uncomfortable, particularly during this pandemic. Opening parks and recreational areas without making available public washrooms may lead people to urinate and defecate in the open. Residents of the United Kingdom are distressed that many local jurisdictions have refused to open toilets.

A significant proportion of the general public won’t leave home without assurances that restrooms are available. According to the American Restroom Association, the “restroom challenged” need to go every hour or less because of healthy status – young age, old age, pregnancy, menstruation – or medical conditions, many of which are not readily apparent. They include people with chronic conditions (Crohn’s, colitis) or temporary afflictions (food borne disease) whose need for a toilet comes urgently and without warning. For people with mobility issues, using the toilet takes time and effort. Without nearby restrooms that are clean, safe, and available, neither local economies nor community well-being can come back to life.

In the absence of restroom-specific recommendations from the Centers for Disease Control and OSHA, it’s important to look to emerging science for guidance. During the early stay-at-home months, concerns focused largely on surface contamination and the elimination of touch points. Adding foot pulls or handles large enough for one’s forearm can make door opening touchless. Sensors that activate flushing and sink taps reduce hand contacts with repeatedly touched surfaces. However, they are fairly expensive modifications and generally increase water costs. It’s likely that latching and unlatching stall doors will remain manual so it is helpful to make users aware of how they can protect themselves from surface contagion. For example, signage could suggest wearing gloves and remind users not touch their faces until they have thoroughly washed their hands.

Starting in late spring 2020, peer-reviewed studies have shifted concern from surface contagion to aerosols. University of Minnesota epidemiologist Michael Osterholm says, “the surfaces play a very little role at all in transmission…this is really all about air, breathing someone else’s air where the virus is present” (Osterman, June 17, 2020.).

Understand the longevity of SARS-CoV-2 in enclosed space. Ask users to wear masks in shared toilet facilities and to exit as soon as they have finished their business.

A COVID-19 positive person may transmit SARS-CoV-2 via droplets and aerosols from the nose or mouth.

Droplets are fairly large and affected by gravity, so they fall to the ground and dry out, becoming non-infectious…In order for an infection to be caused by droplet transmission, a susceptible individual must be close enough to the source of the infection (e.g., an infected individual) in order for the droplet (containing the infectious microorganism) to make contact with the susceptible individual’s respiratory tract, eyes, mouth, nasal passages, and so forth.

Aerosols are smaller particles that remain airborne.

In contrast, airborne transmission is defined as the transmission of infection by expelled particles that are comparatively smaller in size and thus can remain suspended in air for long periods of time. Airborne particles are particularly worrisome simply because they can remain suspended in the air for extended periods of time.

At the onset of the pandemic declared by the World Health Organization on March 11th, experts were uncertain whether the novel coronavirus could be transmitted by airborne means. Early directives referred to droplets. These were assumed to fall to the ground within six feet or two meters of the person emitting them and hence inform social distancing directives.

As the novel coronavirus became better understood, it was found viable in aerosolized form. Moreover, recent studies show droplets of 12- to 21-μm can remain suspended in indoor air between 8 and 14 minutes. During this short time period, the inhalations and exhalations of a dozen people or more determine what is suspended in the air in a restroom. Even when access is limited to one user a time, aerosols are a risk and call for face masking.

In the constrained space typical of most restrooms, traditional social distancing of six feet is simply not feasible. Coughs and sneezes have been found to travel as far as 20 feet. An early cluster of COVID-19 infections and deaths occurred among vocalists in a church choir in Washington State. Droplets are spread through normal talking. Infectious disease specialists now question whether six feet is enough distance between individuals in any interior space, especially since pre-symptomatic people can transmit the disease up to a week before they show symptoms of COVID-19.

WHO social distancing recommendations are problematic because they are based on droplet studies conducted during the 1930s. At that time, there was no technology able to detect airborne particles less than 1 μm, or one-millionth of a meter, or what are known as aerosols. According to a key study, “Increasing evidence for SARS-CoV-2 suggests the 6 ft CDC recommendation is likely not enough under many indoor conditions where aerosols can remain airborne for hours, accumulate over time, and follow air flows over distances further than 6 ft.”

Accumulating information about pre-symptomatic and asymptomatic transmission of COVID-19, argues for everyone masking throughout the time spent in a shared restroom.

Fit toilet seats with lids if they don’t have them because flushing propels aerosols that may contain infectious virus into the restroom.

It has been long known that toilet flushing generates aerosol plumes that rise to three to six feet above an open toilet depending on the energy of the flush. Sophisticated fluid dynamics are now being used to explore and visualize flushing of various toilet types and the influence of flushing on the spread of virus aerosol particles.

As for the ability for toilets to harbor live viruses, two separate patients in a French hospital contracted Legionnaires disease from aerosols expelled from a single toilet five months apart.

While there is no evidence that COVID-19 has been transmitted through toilet use, the infectious form of SARS-CoV-2 has been found in stool. As for non-infectious SARS-CoV-2 RNA, it has been shed in the feces of people a month after they have recovered from the illness. This suggests that fecal swabs may be useful to confirm results of other tests, avoiding false negatives.

As a shared toilet is repeatedly flushed, aerosols can accumulate. The potential for the density of infectious viruses to increase within a toilet room is a concern in hospital settings.

Whereas toilet lids in home bathrooms can be closed before flushing, toilets in many public restrooms are horseshoe-shaped and lack covers. This has huge implications for those who manage and use restrooms. Epidemiologists know that large numbers of people with COVID-19 who are pre-symptomatic and asymptomatic freely mix with the general population. Even a modest multi-user restroom may generate nearly a hundred flushes at peak use.

Remove forced air hand dryers that spread virus and bacteria and provide paper towels.

That restroom users do not wash their hands thoroughly is well known though casual observation and peer-reviewed academic studies. To destroy the SARS-CoV-2 virus, handwashing requires soap and systematic and meticulous lathering for at least 20 seconds. Poor handwashing leaves behind bacteria which drying can help remove. The risk of airborne dissemination of pathogens varies with the choice of drying method.

Forced air hand dryers appeared in public restrooms in an attempt to cut down on the cost and mess of paper towels. Now it’s time to remove or disable them. To address the risk of COVID-19 contagion in restrooms, nothing is better than paper towels.

Studies showing the dangers of hand dryers are not new. In 2014, researchers at the University of Leeds applied harmless bactobacilli to test subjects’ hands to mimic the incomplete washing of someone who may use soap but for less than 20 minutes. Three drying methods were tested: jet air or blade dryers, traditional warm air dryers, and paper towels. After the use of each, air samples were collected at one and two meters away. The expensive new jet air dryers proved the most contaminating. They produced airborne bacterial counts 4.5 times higher than the regular warm air dryers and 27 times higher than hand drying with paper towels.

Paper towel dispensers should be touchless. Traditional wall-mounted metal dispensers are less expensive and more resistant to abuse than plastic models with sensors. Light brown C-Fold and M-Fold paper towels are absorbent, slightly rough, and pleasant to use. Place the waste bin near the door so that people can use the towel to avoid touching the handle as they exit.

Place hand hygiene stations at the entrance restrooms and ask users to clean hands before entering to avoid surface contamination.

Wash your hands has been the mantra of the COVID-19 pandemic. Every time you wash your hands, contamination and the risk of contagion has been lessened in some way.

Having users clean their hands before entering a restroom is desirable because it limits surface contamination. One way to encourage this is to put a dispenser with hand sanitizer or a sink with running water outside the restroom.

It’s not easy to get people to wash their hands, however, even in hospitals. To control hospital infections, medical personnel should wash their hands perhaps hundreds of times a day. The desirability of this seems clear, a no brainer. But as Dr. Atul Gwande has demonstrated, it’s very difficult to get doctors to wash their hands as often and as thoroughly as they must if the hospital is to bring preventable infections down to zero. Faced with this predicament at Boston’s Brigham and Women’s Hospital, Gwande started developing the checklists for surgical teams. At every step where handwashing was required, it was explicitly added to the checklist. In time, Gwande was successful. Checklist approaches have since been applied to other industries with remarkable success.

Could checklists help members of the general public with hygiene? We see safe public restroom use as a series of steps. No matter how many sensors deliver automatic flushes and warm hand washing streams, not all touch points are eliminated. Take, for example, latching and unlatching a stall door. Now imagine a surge of COVID-19. Might that compel us to adopt hospital-like procedures in daily life? If you saw this list on a handwashing station at the entrance to a shared toilet facility, wouldn’t you pay heed?

☐ Stay masked.
☐ Wash or sanitize your hands before entering the restroom
☐ Avoid touching surfaces in restroom and stall.
☐ Do your business.
☐ Close toilet lid (if there is one).
☐ Flush the toilet.
☐ Wash hands with soap.
☐ Dry your hands with paper towels
☐ Leave ASAP.
☐ Remove your mask with care. Dispose it or bag it for the laundry.
☐ Sanitize your hands
☐ Put on a clean mask.

Behavior change that leads to consistent handwashing requires effective user education plus additional nudges. Consider creative signage, posters, PSAs, and verbal farewells such as “Take care. Wash your hands.”

It doesn’t make sense to encourage people to spend time in a poorly ventilated restroom breathing aerosolized SARS-CoV-2. Instead, place handwashing stations in public areas – whether out of doors or in hallways of buildings. First, this speeds the flow of users in the restroom while lowering the number inside simultaneously. Second, a designated handwashing area allows people the opportunity to scrub with soap for 20 seconds. Third, the presence of others in the public area increases the likelihood that individuals will do their part for the common good.

Establish new maintenance protocols, choose appropriate cleaning technologies, train cleaners, and provide signage to educate users.

If restrooms are opened after a closure of weeks or months, the older water that has been sitting in the pipes and in the hot water heater needs to be flushed out of the building and replaced with fresh water (Louisville Water 2020). A presentation by Virginia Tech research scientist William Rhoads summarizes water-quality concerns, introduces technologies, critiques existing guidance, and explains effective recommissioning.

Similarly, heating, ventilating, and air-conditioning (HVAC) systems need to be reactivated following long building closures and then maintained to reduce dangers of airborne SARS-CoV2 virus. Disabling these systems is not recommended. The Environmental Protection Agency (EPA) promotes resources from The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). ASHARE has formed an Epidemic Task Force to identify best practices for current buildings and to research the design of future systems to reduce dangers of airborne transmission of COVID-19.

Expert recommendations for cleaning and disinfection during the COVID-19 pandemic appear to be in flux. Once OSHA releases directives for maintaining workplace restrooms, they should be useful to those managing facilities for the general public. The agency’s current 35-page guidance on preparing workplaces for COVID-19 mentions restrooms once – handwashing signs must be placed in them. The CDC has released interim guidance for community facilities with suspected or confirmed COVID-19 cases. (Note that asymptomatic COVID-19 spreaders make moot the distinction between suspected and confirmed cases in the context of restroom maintenance.) The CDC recommendations are updated weekly with changes noted on specific webpages.

Here’s how the CDC currently defines cleaning and disinfection. Cleaning removes germs, dirt, and impurities from surfaces or objects. Soap (or detergent) and water physically remove germs from surfaces. Lowering their numbers, decreases risk of spreading infection. Disinfection kills germs on surfaces or objects. Chemicals to kill pathogens to further lower the risk of spreading infection.

CDC-recommended everyday steps for disinfecting a facility include reading product labels, checking expiration dates and following manufacturer’s instructions. Household bleach mixed 1/3 cup per gallon or 4 teaspoons per quart of water remains effective for 24 hours. Alcohol solutions are effective if at least 70% alcohol. Spraying disinfectant on outdoor fixtures “is not an efficient use of supplies and is not proven to reduce risk of COVID-19 to the public.” High touch outdoor surfaces like door handles and railings should be simply cleaned.

New information from commercial firms regarding their cleaning services and products appears regularly. A consumer’s guide to disinfecting after COVID-19, which was prepared by an insurance company, offers information on practices, equipment and legal issues. Ultra-Low Volume (ULV) application, fogging, electrostatic spraying, hand to surface wiping, and airless sprayers are compared.

For information on disinfectants, refer to the regularly-updated list of products registered with the Environmental Protection Agency. Guidelines for using disinfectants include wearing gloves, pre-cleaning dirty surfaces with soap and water, and attention to contact or dwell time, that is the time the product remains wet on the surface being cleaned.

Thanks to its strong disinfecting properties, ultraviolet light is commonly used in hospitals. UV light prevents the SARS-CoV-2 virus from reproducing by interfering with its RNA.

UV radiation constitutes about 10% of sunlight. Harmful to people, UV light is deployed robotically for purposes of disinfection. A variety of portable units on the market are able to move around an operating room, subway car, or airplane and disinfect all surfaces. Units appropriate for hospitals cost about $100,000.

Upper-room UV germicidal irradiation (UVGI) is an older technology first used to control tuberculosis in the 1930’s. Fixtures mounted on walls shine ultraviolet light across the top of a room above the heads of occupants. To draw airborne bacteria, viruses and fungi upward, ceiling fans are added.

UGVI expert Dr. William Bahnfleth of Pennsylvania State University offers an hour-long introduction to upper-room UV light to reduce transmission of various infectious diseases and its effectiveness in destroying SARS-CoV2. Use of various types of upper room fixtures are discussed. A symposium on upper-room UVGI is conducting ongoing research.

A variety of UV wands and light sanitizers are appearing on the market for individual use. With consumer devices, however, there is risk of damage to the skin and eyes. This is why new technologies use robotics to protect workers.

As for controlling airborne virus with fogging, fumigation, wide-area atomized mist or electrostatic spraying, the EPA recommends using only products specifically designated for these methods. For an overview of cleaning methods, disinfection technologies, standard operating procedures, personal protection, training of personnel, supervision and management, see Guidelines for Coronavirus Cleaning from disaster recovery firm ATI. The Cleaning Institute Research Institute (CIRI) provides an 11-page document on cleaning, disinfection, worker protection, and post cleaning and remediation assessment. Based on peer-reviewed research, it is useful for those establishing protocols and training employees.


American Restroom Association. (n.d.) Who are the restroom challenged?

American Society of Heating, Refrigerating and Air-Conditioning Engineers. (2020, APRIL 17). COVID-19 (Coronavirus) Preparedness Resources.

Anderson, J.L., Warren, C.A., Perez, E., Louis, R.I., Phillips, S., Wheeler, J., Cole, M. and Misra, R. (2008). Gender and ethnic differences in hand hygiene practices among college students. American Journal of Infection Control. 36, 361–368.

ATI Disaster Recovery. (2020) Guidelines for Coronavirus Cleaning.

Bahnfleth, W. (n.d.) Reducing Infectious Disease Transmission with UVGI. ASHARE.[email protected]?registrantKey=9203824226017402127&type=ATTENDEEEMAILRECORDINGLINK

Brooks, L. (2020, June 10). Closure of public toilets causing anxiety, distress and frustration across UK. The Guardian.

Brubaker, R. & McCreary, C. “US Public Health Mandates and the Restroom Problem in America: A Call To Action.” Presentation at World Toilet Summit, Delhi, November 1, 2007.

Capritto, A. (2020, May 23). Using UV light to kill coronavirus: The benefits and risks.

Centers for Disease Control and Prevention. (2019) Cleaning and Disinfection for Community Facilities. Interim Recommendations for U.S. Community Facilities with Suspected/Confirmed Coronavirus Disease 2019 (COVID-19).

Centers for Disease Control and Prevention. (n.d.) Disinfecting Your facility: Everyday Steps, Steps When Someone is Sick, and Considerations for Employers.

Centers for Disease Control and Prevention. (n.d.). How To Clean and Disinfect Schools To Help Slow the Spread of Flu.

Centers for Disease Control and Prevention. (n.d.). Pre-symptomatic and Asymptomatic Contribution to Disease Transmission.

Chang, K. (2020, May 7) Scientists Consider Indoor Ultraviolet Light to Zap Coronavirus in the Air. New York Times.

Chotiner, I.(2020, May 25). How to Maintain Social Distance as the U.S. Reopens. The New Yorker.

Cleaning Industry Research Institute. (2020, June 1). SARS-CoV-2 (COVID-19) Guidance for Decontamination of the Built Environment: Cleaning, Disinfection, Worker Protection, and Post Cleaning and Remediation Assessment.—Final.pdf

Couturier J, Ginevra C, Nesa D, Adam M, Gouot C, & Descours, G. (2020, July). Two patients at a French hospital contracted Legionnaires’ disease by breathing in Legionella bacteria that were aerosolized by flushing the toilet in the room. Emerging Infectious Diseases.

Environmental Protection Agency. (n.d.). 6 Steps for EPA Safe and Efficient Disinfectant Use.

Environmental Protection Agency. (n.d.). Can I use fumigation or wide-area spraying to help control COVID-19?

Environmental Protection Agency. (n.d.). Is there HVAC guidance that building and maintenance professionals can follow to help protect from COVID-19?

Environmental Protection Agency. (n.d.). List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19).

Fernstrom, A., & Goldblatt, M. (2013) Aerobiology and Its Role in the Transmission of Infectious Diseases. Journal of Pathogens. Fisher, M. (2020, May 8). The need to go is a big barrier to going out. Why public bathrooms are a stumbling block for reopening. Fisher. Marc. Washington Post, May 18, 2020.

Frum, Larry. (2020, June 16). Flushing Toilets Create Clouds of Virus-Containing Particles. Physics of Fluids News. June 16, 2020.

Gross, J. (2020, May 27) A consumer’s guide to disinfecting after COVID-19. NU Property Casualty 360. May 27, 2020.

Guzman, J. (2020, May 28) 6 feet of distance may not be enough to stop coronavirus transmission, experts now say. The Hill.

Gwande, Atul. (2007, December 10). The Checklist. The New Yorker. December 10, 2007.

Heilweil, R. (2020, May 22). How safe is it to use public bathrooms right now? It’s complicated. Vox.

Jabr, F. (2020, March 13). Why Soap Works. New York Times.

Johnson, D.L., Mead, K.R., Lynch, R.A., & Hirst, D.V.L. (2013). Lifting the lid on toilet plume aerosol: A literature review with suggestions for future research. American Journal of Infection Control.

Kimmitt, P.T. and K.F. Redway. (2015). Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods. Journal of Applied Epidemiology. 30.

Knowlton, S.D., Boles, C.L., Perencevich, E.N. et al. (2018). Bioaerosol concentrations generated from toilet flushing in a hospital-based patient care setting. Antimicrobial Resistance & Infection Control. 16.

Li, Y., Wang, J., and Chen, X. (2020). Can a toilet promote virus transmission? From a fluid dynamics perspective. Physics of Fluids. 32, 065107.

Louisville Water Company. (2020, May 12). Flushing the Water Lines. Video 2min18.

Nardell, E., Vincent, R., Sliney, & D.H.(2013) Upper-room ultraviolet germicidal irradiation (UVGI) for air disinfection: a symposium in print. Photochemistry Photobiology. 89(4):764-769.

Occupational Safety and Health Agency. (2020) Guidance on Preparing Workplaces for COVID-19. U.S. Department of Labor.

Osterman, M. (2020, June 17) “Amid Confusion About Reopening, An Expert Explains How To Assess COVID-19 Risk.” Interview with Terry Gross. NPR Fresh Air.

Parshina-Kottas,Y., Saget, B., Patanjali, K., Fleisher, O. & Gianordoli, G. (2020, April 14) This 3-D Simulation Shows Why Social Distancing Is So Important. New York Times.

Petri, William. (2020, June 5). What goes into the toilet doesn’t always stay there, and other coronavirus risks in public bathrooms. The Conversation.

PHLUSH (2015). Public Toilet Advocacy Toolkit. Pond, E. (2020, May 16). Fecal Shedding of SARS-CoV-2 Outlasts That of Respiratory Tract. Gastroenterology Advisor.

Prather, K. A., Wang, C.C., & Schooley, R.T. (2020, May 27). Reducing transmission of SARS-CoV-2. Science.

Read, R. (2020, March 29) A choir decided to go ahead with rehearsal. Now dozens of members have COVID-19 and two are dead. Los Angeles Times.

Rhoads, W. (2020, June 1) Assessing COVID-19 Building Start Up guidance after Stay at Home Orders are Lifted. (Video 44min) Municipal Water and Sewer and COLE Publishing Virtual Training Series.

Stadnytskyi, V., Bax, C.E.; Bax, A.; & Anfinrud, P. (2020, June 2) PNAS 117 (22) 11875-11877. The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission.

Trinitas Regional Medical Center. (2020, June 12). Trinitas Kills Germs with Surfacide Ultraviolet Disinfection System.

University of Leeds. (2017, September 7). Jet-air dryers should not be used in hospital toilets. Health News.

van Doremalen, N. , Bushmaker, T. & Morris, D.L. (2020, March 17). Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. New England Journal of Medicine, 382:1564-1567.

WebRestaurantStore. (n.d.). Types of Paper Towel Dispensers.

Xiao F., Sun J, Xu Y., Li F., Huang X., Li H., et al. (2020, August). Infectious SARS-CoV-2 in feces of patient with severe COVID-19. Emerging Infectious Diseases.