Proper Use of Disinfectants

Use them sparingly. Many pathogens are becoming immune to some of the disinfectants and sanitizers previously used to eliminate them.

• By Michael Wilson
• Aug 01, 2014

Due to the recent spread of a gastrointestinal virus in an industrial facility, the day porter maintaining the facility during the course of the business day was asked to disinfect all of the building's cafeteria tables after the mid-day lunch break. It was suspected the cafeteria was one place the virus was spreading. To do this, he brushed off any dry soils on the table, sprayed the table with a disinfectant, and then wiped the area clean with a microfiber cloth. This was repeated five days per week and, for extra measure, sometimes the evening cleaning crew repeated the same procedure at the end of the business day.

For many people--cleaning professionals and facility administrators alike--the cleaning workers performed this procedure correctly. However, a closer examination reveals several errors. For instance:

• While brushing off the dry soils was correct, the cleaning worker should not have stopped there. In most cases, disinfecting is a two-step process. The first step is to properly clean the area; the second step is disinfecting. After brushing the dry soils from the tables, the worker should have wiped each cafeteria table with an all-purpose cleaner or similar product. Then, on to step two.
• Spraying the disinfectant on the tables simply applies it to them. In order for the disinfectant to actually work and begin "killing" pathogens on the table, it must dwell on the table for about 10 minutes without drying. This means the worker should have sprayed a few tables with the disinfectant and then returned to the first one to wipe it clean. If the disinfectant dries, it needs to be reapplied.
• How do we know this is the type of disinfectant that should be used to kill influenza-type viruses? It is possible the disinfectant used to clean these tables was not, and if so might prove to be ineffective. Every EPA-registered disinfectant in the United States has a "kill claim" on the product's label or packaging materials identifying exactly what pathogens it is designed to eliminate.
• Microfiber tends to be more effective at cleaning and disinfecting than conventional terry cloths, and using a clean microfiber cloth is correct--but it must stay clean. The cleaning worker should have used a fresh quadrant of the cloth for each table and, after cleaning two to four tables, replaced the cloth.
• Having the evening cleaning staff clean and disinfect the tables once again is not necessary and may prove costly in terms of labor, time, and chemicals and can have a negative impact on the environment. If the procedure was performed correctly after the lunch break, an evening cleaning/disinfecting is not necessary.

From this example, we have learned some very important things about the use of disinfectants. One item at the top of the list is that unless the disinfectant's label says it both cleans and disinfects, then cleaning and disinfecting are, as above, a two-step process. Another item is that selecting the proper disinfectant is imperative. A disinfectant known to eliminate the type of pathogens and microorganisms suspected to be on a surface must be used to protect human health. (There are broad-spectrum disinfectants, which can be viewed as all-purpose disinfectants and can be used when there is no specific pathogen or it is unknown. However, for a known pathogen, it is best to select a disinfectant designed to kill those microorganisms.)

Label Reading
We should delve a bit further into understanding disinfectants, and this starts with knowing how to read a product's label. Of course, reading labels on any type of cleaning chemicals is always recommended, but it is even more important when it comes to disinfectants.

As mentioned earlier, disinfectants have kill claims posted on their labels indicating they can be used to kill, for example, the TB (tuberculosis) bacterium, HIV, MRSA (methicillin-resistant Staphylococcus aureus), or some other pathogen. However, the disinfectant that kills HIV may not work against the TB bacterium.

While these three examples may not apply to disinfection procedures in an industrial facility, this helps show the importance of selecting the disinfectant that is effective against a particular pathogen. Other items typically listed on disinfectant's label that cleaning professionals and administrators should be aware of include the following:

• An EPA registration number. Every "approved" disinfectant used in the United States is assigned a number by EPA. This number indicates the product has been reviewed and proven effective with minimal risk to users when used per instructions.
• Active ingredients. This is a list of all of the ingredients in the product responsible for killing pathogens.
• Inert ingredients. While these ingredients do not play an active role in killing pathogens, they serve other purposes, such as ensuring that active ingredients perform effectively.
• Precautionary statements. Precautionary statements provide information on a product's potential hazards, as well as how to prevent these hazards from occurring. This information can include proper dilution, disposal, first aid, and storage instructions.
• Efficacy. This refers to the how effective the disinfectant is. "Limited efficacy" disinfectants are typically used for household cleaning, whereas the most powerful disinfectants, "hospital-grade" disinfectants, are used wherever health risks are most serious. (Limited efficacy disinfectants are typically used against a specific group of pathogens.)

Selecting Sanitizers and Disinfectants
So far we have not discussed sanitizers at all. But in many situations, a sanitizer will suffice in keeping an industrial facility healthy. While a disinfectant is designed to eliminate or inactivate all disease-causing germs on a surface (when used properly), a sanitizer is designed to reduce them, eliminating 99.9 percent of pathogens when compared to an untreated surface.

In the example above about the industrial facility influenza outbreak, a sanitizer likely would suffice as long as it was used properly. (Just as disinfectants must be used properly, so must sanitizers. In most cases, the surface should be cleaned first using an all-purpose cleaner and then the sanitizer can be applied. After recommended dwell time, the surface should be wiped with a clean cloth.) However, if the outbreak continued or worsened, cleaning workers/administrators would need to select a disinfectant designed specifically to eliminate gastrointestinal-type pathogens.

This leads us to our next issue: how to select disinfectants and sanitizers. There are dozens of professional-grade disinfectants and sanitizers on the market made by scores of different manufacturers. Selecting the right product for the right situation can prove daunting. In such cases, working with an astute janitorial supplies distributor is crucial. However, even the distributor may need guidance.

For help in selecting disinfectants, sanitizers, and most other types of chemicals, plus paper goods and cleaning equipment for their clients, some distributors now turn to web-based analytical tools. Some of these systems resemble a computer dashboard. Products currently used in a facility are entered into the system, and the tool suggests other products that may be more effective, less costly, or higher-performing. When it comes to selecting disinfectants and sanitizers specifically, these tools can prove invaluable because they provide "fact based" suggestions. They have ready access to the products' efficacy, kill claims, and other information that helps purchasers make the proper selection right from the start.

Use Sparingly
While disinfectants and sanitizers are here to help protect human health, they should be used only when needed. What we are discovering is that many pathogens are becoming immune to some of the disinfectants and sanitizers previously used to eliminate them. This overuse effect is similar to that of antibiotics, and it means that ever-stronger disinfectants and sanitizers may be needed to kill pathogens. Additionally, sanitizers and disinfectants can have a negative impact on the user and the environment and are often costly compared with lighter cleaning chemicals. To ensure their efficacy, to protect the health of users and the environment, and to contain cleaning costs, they should be used only when and where needed.

This article originally appeared in the August 2014 issue of Occupational Health & Safety.