Even though the world has been contending with COVID-19 and its consequences for nine months and counting, the routines and practices we’ve adopted to prevent its spread and minimize personal risk of infection are still evolving. With new data come new recommendations, inventions, and adaptations. If nothing else, this pandemic keeps us on our toes. Vigilance and flexibility, which might seem like oxymorons, have equal importance in the global effort to restore some form of normalcy in our lives. 

So it is with cleaning, especially in multifamily buildings and communities where comings and goings—however limited to reduce social proximity and interpersonal contact—necessitate passage through and interaction with common areas. According to the website of the Centers for Disease Control and Prevention (CDC), “Communal spaces, community activities, and close living quarters in multifamily housing increase the risk of getting and spreading the [corona]virus”—making the cleaning and sanitation procedures in these settings all the more important for the health and safety of the approximately 74 million Americans who live in such homes, according to the Community Associations Institute (CAI), as well as the staff who service them. Those responsible for keeping these areas clean and free of hazards—including viral pathogens—have to contend with the ever-changing protocols, products, and processes in place to protect the public—and themselves—from the spread of COVID-19.  

But is there a point where cleaning and disinfection can go overboard?

Sanitizer Insanity

In the beginning of the coronavirus crisis, hand sanitizer became such a hot commodity that the federal government took to usurping shipments headed for hospitals and hard-hit areas because supplies were so limited and demand was so high. If you were lucky enough to even locate a bona fide product with the CDC-recommended percentage of alcohol content (the CDC recommends that a hand sanitizer with at least 60% alcohol be used in situations when soap and water are not available), you would be faced with unimaginable markups and strict quantity limits. Even bottles of pure isopropyl alcohol and glycerin gel became scarce as citizens resorted to homemade Purell-type concoctions and alternative topical disinfectants—a method neither recommended by the U.S. Food and Drug Administration (FDA) nor endorsed by this publication, it should be noted... but desperate times call for desperate measures. 

Whether the supply chain got its act together or the public heeded the exhortations of the CDC (and pretty much any medical professional) that the best way to prevent the spread of COVID-19 is by washing your hands with plain soap and water for 20 seconds, hand sanitizing products can again be found on store shelves and online retailers. They’ve also become a fixture in condos, co-ops, and other multifamily housing sites in common locations where residents, visitors, vendors, and staff don’t have access to a sink. 

Why is this important? While the coronavirus is transmitted mainly through respiratory droplets expelled when an infected person is talking, sneezing, coughing, singing, or the like, it can also be acquired when someone touches a surface that has the virus on it and then touches their nose, mouth, or eyes. So washing one’s hands not only helps prevent the virus from transmitting from a surface to a person; it also prevents a person from transmitting the virus to a surface where it can infect other people. 

Beyond Soap and Sanitizer

Unfortunately, it’s hard to trust that everyone coming into contact with our communities is washing their hands with the frequency and duration that are known to prevent viral spread to surfaces. The next level of sanitation is to wash those surfaces regularly and safely. Again, according to health agencies, regular soap and water should be employed for keeping surfaces clean—and looking nice, which is always an important consideration in residential communities with shared common spaces. 

Following a thorough washing, surfaces can be disinfected using a variety of products, each with its own instructions for safe and effective handling and use. While these products are known to kill viruses that are harder to kill than the one that causes COVID-19 when used properly, according to the CDC, they are only as effective as their timing of application vis-à-vis an infected person coming into contact with that surface. Therefore, boards and managers of multifamily communities have implemented robust schedules of cleaning and disinfection of high-touch surfaces and frequently used common areas, such as railings, elevator buttons, laundry facilities, mailboxes, door knobs, and lightswitches.  

According to the CDC, there are a variety of considerations when determining which disinfectant product to use on which surfaces and when. Porous surfaces require different types and methods of application than non-porous surfaces. Outdoor environments pose less risk and therefore do not necessarily need disinfection after routine cleaning. Disinfectants should not be used on objects or surfaces touched by children, especially objects or surfaces that children can put in their mouths. Caution must be taken with indoor use of disinfectants that produce dangerous fumes or other toxic effects. Custodial staff and other people who are carrying out the cleaning or disinfecting are at increased risk of being exposed to the virus—and to any toxic effects of the cleaning chemicals—and should therefore wear appropriate personal protective equipment (PPE) and be instructed on how to apply the disinfectants according to the label. Information on concerns related to cleaning staff can be found on the Occupational Safety and Health Administration’s (OSHA’s) website on Control and Prevention: www.osha.gov/SLTC/covid-19/controlprevention.html.

Surface to Air

The aerosolized transmission of coronavirus presents another consideration for multifamily properties that share common elements. Its viral particles can linger in and travel through the air in respiratory droplets—including through heating, ventilation, and air conditioning (HVAC) systems of a multifamily building, or through the air flow systems that are designed to mitigate spread of smoke and fire between and into apartments. The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) has therefore developed indoor air management strategies aimed to reduce occupant exposure to infectious aerosols. 

Recommendations vary depending on the climate where a building is located, whether it uses a forced-air system for HVAC, and other building-specific features, but generally, to optimize indoor air quality, “thermal comfort conditions” (the industry’s term for temperature and humidity levels) should be maintained at normal levels: 68–78ºF (20–25ºC) and 40–60% relative humidity (RH). This might be easier to accomplish with a forced air system, but in buildings where a central system services multiple units, measures to filter and purify the air should be considered.

Professor Max Sherman, Residential Team Lead for ASHRAE’s Epidemic Task Force, tells New England Condominium, “Central systems in any homes give more options for doing filtration. Homes without central forced air systems may need to use more portable air cleaner options. In apartments with common centralized ventilation systems, it is important to make sure that air from one apartment cannot flow to another. Fortunately, most [building] codes in the U.S. do not allow this.”

 Much of New England’s older housing stock does not have a centralized HVAC system, but instead uses radiators to heat in the winter and window-mounted or through-wall air conditioning units—or simply open windows—to cool in the summer. In fact, those of us that live in such units know that opening windows and running A/C are year-round “thermal comfort mechanisms” (to borrow the industry’s term)—methods that have an outsized energy cost, to be sure, but also might have virus-spreading potential as well. 

 “The issue here,” explains Sherman, “is that we don’t want air to move from an individual apartment to the corridor. Because if there happens to be an infected person in that apartment, then their virus-containing aerosol particles (i.e., small droplets) can get into the corridor to spread the infection to the larger community. Corridors in larger apartment buildings are required to be pressurized to keep that situation from happening, [but] if someone opens their window and a lot of air blows in from that window, it will make the apartment be at a higher pressure and force air into the corridor, and maybe to adjacent spaces as well.”  

 If it seems counter-intuitive that fresh air would be a vector for the virus, it’s because open windows can have a mitigating effect on virus transmission as well, according to Sherman. “Of course,” he continues, “opening a window can help dilute the amount of virus in that given apartment, so it is not so simple.” 

As for window-mounted A/Cs, Sherman says, “the issue is simpler. Generally speaking, these things recirculate air and do not ventilate. Some units have a damper that allows for some outside air to come in. That amount is rather small and does not have the risks of [over-pressurization] and so is not a problem and could be a benefit.” Also, according to ASHRAE’s Technical Resources for Multifamily Buildings, “Strategic window fan placement in exhaust mode can help draw fresh air into room via other open windows and doors without generating strong room air currents.”

Since ventilation is one of the keys to maintaining indoor air quality and reducing the chances of viral spread, needing to keep windows open or A/C running this winter might not be such a bad thing, in spite of the inefficiency and energy cost.

Simple Is Best

As the New York Times detailed in a recent article, fancy, high-tech, expensive products promising super-clean surfaces and particle-free air are being marketed as panaceas for a public concerned about indoor transmission of the coronavirus—especially as winter approaches and fewer activities can be enjoyed outdoors. 

But, as the Times indicates, most of those products are overkill and may even have unintended harmful consequences, including respiratory hazards and production of “dangerous hydroxyl radicals that may injure cells.” The Times cites a number of experts who advise against their use, recommending instead the simple risk-reduction measures of hand-washing and mask-wearing. 

The recommendations for multifamily buildings and communities are the same: Limit interaction with people outside of your household. Wear a mask in common indoor areas and anywhere that six-foot separation cannot be maintained. Wash hands with soap and water or use a sanitizer with 60% alcohol content if those aren’t available. And—lest we forget—remember to breathe. Keeping common indoor air and surfaces clean in a pandemic should not add too much stress, complexity, or expense to an association’s or a cooperative’s daily operations.

Darcey Gerstein is Associate Editor and Staff Writer for New England Condominium.