Before 2020, only specialists needed to know the ins and outs of cleaning and disinfecting surfaces. Now it is more important than ever before. The surfaces that we touch frequently in indoor spaces can harbor harmful microbes and toxins, turning them into vectors for contagious diseases. To prevent infection, in addition to washing hands frequently and not touching your face, the United States Centers for Disease Control and Prevention (CDC) recommends cleaning and disinfecting these high-touch surfaces. Design and building professionals have a role to play here—they can choose materials that facilitate easy cleaning. The information that follows will explain what this means for different surfaces in a variety of contexts.
Cleaning Versus Disinfecting
Both cleaning and disinfecting surfaces can help to prevent infectious diseases, but they play different roles. Cleaning—using detergent or soap and water—works by physically removing germs, dirt, dust, and impurities from surfaces. Removing germs isn’t the same as killing them, but it does lower their numbers and reduces risk of spreading infection, since a clean surface is one that inhibits growth of bacteria and other microbes. Cleaning surfaces is important not only because it prevents infection, but also as part of regular maintenance and care that extends a product’s longevity.
Disinfecting uses chemicals to kill germs and other microbes on surfaces. It doesn’t clean the surfaces—it won’t wash away dirt or physically remove germs, but it supplements cleaning by killing germs and reducing risk of spreading infection. Disinfectants typically come as ready-to-use sprays, concentrates, and wipes. In order to be effective, most disinfectants need to remain on the surface for a period of time (many recommend at least one minute), depending on the manufacturer’s application instructions. Before any surface is disinfected, it should always be cleaned.
It’s important to note that disinfectants kill microbes that are present on a surface at the time they are used. This means that a previously applied disinfectant can’t protect surfaces from microbes that come into contact with the surface after their use. The US Environmental Protection Agency (EPA) has a list of approved surface disinfectants, but they haven’t approved any products that claim to have long lasting or residual efficacy against viruses. EPA-approved disinfectants include hydrogen peroxide, citric acid, ethanol, and quaternary ammonium (among others). Diluted household bleach solutions can also be used, as can alcohol solution with at least 70 percent alcohol. Not all disinfectants are compatible with all surfaces, so make sure to check manufacturer instructions before applying.
Practice Routine Cleaning of Frequently Touched Surfaces
Frequently touched surfaces, particularly those touched by multiple people, need to be both cleaned and disinfected regularly. Surfaces such as door handles, light switches, phones, and faucets should be cleaned and disinfected at least daily or more, depending on level of use. For example, in public or commercial spaces, surfaces like touch screens or shopping carts should be cleaned and disinfected between each use.
Be Careful When Disinfecting
Not everything needs to be disinfected—some surfaces only need to be cleaned with soap and water. The CDC recommends that surfaces or objects that aren’t frequently touched, or that come into contact with children, should be cleaned, but usually don’t require additional disinfection. WELL Certification suggests that projects identify all high-touch surfaces and limit disinfection to these surfaces. This is because many disinfectants are toxic if ingested, inhaled, or through skin contact, and unnecessary disinfection and sanitization can harm immune health. Although they can kill disease-causing microbes, the EPA does not evaluate disinfectants for all possible health risks. For this reason, in a household setting it’s particularly important to avoid disinfecting objects that children might put in their mouths or otherwise come into contact with. And when applying disinfectants, always use gloves and eye protection and make sure the space is well ventilated. Choose from the EPA’s online list of hundreds of disinfectants —and their Design for the Environment label, which integrates health and environmental risks of disinfectants.
What Are High-Touch Surfaces?
In different sectors, including residential buildings, schools, commercial buildings, and hospitals, frequently touched surfaces include some of the following:
- Light switches
- Handles and fixtures
- Bathtubs and shower walls and floor
- Drinking fountains
- Touch screens
- Elevator buttons
- Rugs and carpets
In a hospital setting, high-touch surfaces may also include non-disposable medical devices, bed railings, serving trays, bed tables, and bedding. These surfaces can be divided into two categories: hard/nonporous and soft/porous.
Hard, Nonporous Surfaces
These include materials like glass, metal, plastic, high pressure laminate (HPL), some hardwood, and some stone. WELL Certification specifies that nonporous surfaces are by definition smooth, with no visible defects; finished with smooth welds and joints; and free of crevices and hard-to-reach places. The CDC recommends cleaning these surfaces with soap, water, and a cloth. The EPA provides a list of hundreds of disinfectant products that are published online, searchable by registration number, active ingredient, use, contact time needed, and surface type.
But manufacturers will always be able to provide the most complete information about what kind of cleaning and disinfection practices are best for their products. For example, Arborite recommends using alcohol and bleach for their HPL surfaces, as well as EPA-registered chemical disinfectants. Formica’s solid surfacing products can also be disinfected with products on the EPA list, including isopropanol, sodium hypochlorite, and bleach—but they do not recommend using hydrogen peroxide or phenolic. Nydree hardwood is bleach cleanable with a 48:1 water/bleach solution, using a sprayable mist—and is compatible with other disinfectants such as ammonia, hydrogen peroxide, and quat disinfectant. And finally, HanStone manufactures quartz countertops which can be disinfected using a solution of 70 percent denatured alcohol and 30 percent water.
Soft, Porous Surfaces
Soft, porous surfaces like carpets, rugs, and upholstery, are typically a bit more complicated to disinfect. CDC recommends vacuuming, cleaning the surface with soap and water, and laundering items according to manufacturer instructions, using the warmest appropriate setting and drying them completely. See the EPA’s List N for products that can be used to disinfect soft and porous materials. Keep in mind that if a soft, porous material isn’t frequently touched, it should only be cleaned or laundered, rather than disinfected.
Several manufacturers of porous materials provide examples of cleaning and disinfecting protocol. For example, Kvadrat is a textile manufacturer that recommends disinfecting by steaming, dry cleaning, or using 70 percent alcohol-based solutions. Kvadrat’s polyester and Trevira CS textiles are washable up to 60o C and can be disinfected using a 10:1 water/bleach solution. Another case is Chilewich, which produces woven products. All woven products (except printed designs) and all tufted mats can be disinfected with a 50:1 water/bleach solution left on the surface for at least one minute. Chilewich printed, metallic, and pressed table mats should be disinfected with hydrogen peroxide.