The following was published in American School and University

Disinfectants and sanitizers are important tools for keeping buildings clean, safe and healthful. But as cleaning budgets and staffing levels have declined, the amount of time spent cleaning and disinfecting also has dropped.

The importance of those tools has grown amid heightened public awareness of the risks from pathogens, additional regulatory requirements, and changes to our basic understanding of how cleaning products can affect the health of students, teachers, custodial staff and the environment.

A Dirty Little Secret

Failing to follow the directions stated on the label of a disinfectant violates federal law, but it occurs regularly.

Specifically, many traditional disinfectants require a dwell time of 10 minutes; i.e., the surface must remain wet for a disinfectant to work and kill the target organisms. However, keeping surfaces wet for 10 minutes often is difficult, if not impossible. The environment and the surfaces of the areas being cleaned may present barriers to effective disinfecting.

For example, in Las Vegas where relative humidity averages 30 percent, it is more difficult to keep a surface wet for 10 minutes before the disinfectant evaporates. But in Orlando, Fla., where relative humidity averages 75 percent, disinfectant solutions may stay wet for too long and increase the potential for damage to the surface from moisture saturation.

Then there are the surfaces themselves. These include vertical surfaces such as elevator buttons and light switches, and those with a round shape such as the railings on a hospital bed or doorknobs. Buildings also have many devices such as computer keyboards and printers that can be damaged by the amount of water necessary to keep them wet for 10 minutes.

What’s The Solution?

The good news is that improved disinfectant and sanitizer technologies are available. These products kill the targeted pathogens and better accommodate the needs and limitations of cleaning processes, time constraints, surfaces, environmental factors and health concerns.

To help schools and universities make more informed choices, the U.S. Environmental Protection Agency (EPA) has changed its policy on labeling disinfectants.

Working with the Safer Choice Program (formerly the Design for the Environment program), the EPA has launched a Green Disinfectant program. It designates a number of active ingredients such as ethyl alcohol (the same active ingredient used in alcohol-based hand sanitizers), citric acid and hydrogen peroxide as safer for health and the environment compared with more traditional disinfectants such as chlorine bleach (sodium hypochlorite) or quaternary ammonium compounds (quats).

Also, avoid using those old-fashioned disinfectants with a 10-minute dwell time. Replace them with those that require only 30 seconds to do the job. This will improve cleaning effectiveness, especially in spaces with high or low relative humidity and vertical or round surfaces.

Finally, newer technologies such as ethyl alcohol do not require surfaces to be rinsed after disinfecting or sanitizing food-contact surfaces. These solutions prove to be safer for human health compared with traditional technologies that must be removed before contact, and they save time.

So look for disinfectants that carry the EPA’s Design for the Environment certification, and have a short dwell time and a no-rinse claim. For more information on the Green Disinfectant program, go to


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