However, the reality is that many people are not properly disinfecting when using an ESS or are creating additional health risks for staff. Consider the following potential errors and issues:
- Not applying enough product. Users must apply solution in a thick enough layer to keep the product wet for the duration of its contact time as stated on the product label. Making one fast pass with an electrostatic sprayer may not release enough liquid to meet the label contact time. For a two-square meter area, it may take 20-30 seconds of continuous back and forth spraying to apply enough product for a 5-minute contact time disinfectant under typical environmental conditions. This is not much different than the time it takes to manually wipe the surface.
- Not wiping after the contact time is met. The mechanical action of wiping further adds to the overall efficacy of the process, physically removing several logs of organisms. Wiping also removes product before it builds up on the surface, which can make disinfecting more difficult and cause surface discoloration or damage over time. Even when an ESS is used to spread the disinfectant, manual wiping should be part of the disinfection process.
- Spraying too close to electrical equipment vents. Professionals need to be wary of spraying near electric equipment, as spray droplets can enter vents and potentially cause issues with a wide range of electrical equipment.
- Using the wrong chemicals. Not all disinfectants are appropriate for use in an ESS. The product label should indicate that it is acceptable to use with this system. The device can produce small droplets that can be inhaled deep into the lungs, which can create health and safety risks for the worker. Before using an ESS, the facility should conduct an exposure risk assessment to ensure the staff can use the ESS safely. Some chemicals, such as chlorine bleach, have the potential to create a significant risk when sprayed through an ESS and should not be used.
- Not wearing the appropriate personal protective equipment (PPE). An exposure risk assessment may dictate the use of PPE for staff operating an ESS. For example, minimum protection for staff may include a respirator face mask, such as an N95 mask, and gloves. Recommending or requiring the use of PPE would involve PPE fit testing and oversight to ensure employees wear it properly.
Given these points, BSCs and facility managers should be appropriately cautious when selecting new equipment.
Best practices for product selection and usage
When choosing a disinfectant, there are a number of features to consider:
Check that the product is approved for the pathogens of concern. For COVID-19, the disinfectant needs to be able to inactivate SARS-CoV-2. The U.S. Environmental Protection Agency (EPA) regularly updates List N, which highlights disinfectants the agency expects to kill SARS-CoV-2 when used according to the label directions.
Select a one-step disinfectant with a shorter contact time—preferably five minutes or less. Cleaning and disinfecting in one step will accomplish your goal without sacrificing performance and a short contact time helps ensure the product is used in compliance.
Look for a product range that offers solutions in wipe, concentrate, and ready-to-use formats to meet a variety of needs. Not all product forms are appropriate for all situations. Having flexibility in how the product is applied is important.
The best products are gentle on skin and surfaces while tough on pathogens. Look for products with accelerated hydrogen peroxide that offer high efficacy and low toxicity.
Once you’ve selected products, conduct training to avoid common cleaning and disinfecting mistakes. For example, skipping the pre-cleaning phase when there is gross soil or ignoring the disinfectant contact time will impact efficacy. Mandate that employees follow the manufacturer’s instructions and keep surfaces wet for the full duration of the contact time.
Failing to wipe the surface is another common mistake. The cleaning process selected should include physical wiping of surfaces.
Consider supplying staff with microfiber or cotton cloths, or disposable wipes, as disinfectants can bind with certain materials. Be sure to train employees to follow proper cleaning procedures to avoid cross contamination or equipment and surface damage.
If you choose to use electrostatic sprayers, select one tested for use with your disinfectant so you know it is safe for workers and will perform as expected. Also, look for equipment that produces reasonably sized droplets and consider whether an exposure risk assessment is needed. In addition to droplet size and the droplet-size distribution, there are other points to consider.
Different types of unit—handheld, backpack, and cart-based—are appropriate for different sized areas. Determine whether the spray is air-assisted, which allows spraying from longer distances, and the grounding implications. Corded systems are self-grounding while battery systems ground through the workers, which can be affected by their shoes and the flooring surface. Review the nozzle design, which can impact the volume of liquid delivered and the spray pattern.
You will also want to understand the charge distribution. Higher charged droplets are capable of covering larger areas. Additionally, some ESS units can disable the electrostatic function, allowing the sprayer to be used as a more traditional sprayer. This typically allows for higher volumes of liquid to be used in larger areas. Lastly, train staff on disinfecting procedures, including applying the proper thickness of product and wiping surfaces to maintain efficacy.
Cleaning in a new world
Employees need to know how to properly clean, sanitize, and disinfect surfaces, especially during and after the pandemic. When in the market for disinfectants, BSCs and facility managers should pick a product that is fast-acting, effective, and less likely to cause irritation and surface damage.
by Peter Teska