By Katherine Velez
As the COVID-19 pandemic continues, health care facilities face mounting pressure to elevate surface disinfection practices. Although AORN guidelines do not specifically address residual disinfection products, because of the heightened focus on disinfection, you may encounter companies and contractors offering cleaning and disinfection services using antimicrobial products that they claim will continue to kill SARS-CoV-2 (the virus that causes COVID-19) on surfaces for days, weeks, or even months. Before you consider using these products or services in your facility, it’s important to understand what these claims really mean, what types of pathogens they relate to, and what claims the Environmental Protection Agency (EPA) does and does not allow. This article will help sort through the myths and facts around what are called residual or long-lasting claims.
What types of EPA-approved residual efficacy claims can a product have and what do they mean?
There are three types of residual, or long-lasting claims, that can appear on a product’s EPA approved master label (Table 1).
Table 1. Residual claims that may appear on a product’s EPA approved master label
|Claim||Definition||What to Look for on Label|
|Bacteriostatic, mildewstatic, or fungistatic||Non-public health claims. Claims that include the word “static” indicate that the product inhibits the growth of bacteria or fungi on surfaces, but doesn’t necessarily kill those organisms.||“bacteriostatic”, “mildewstatic”, or “fungistatic”|
|Residual sanitization||Public health claim. Residual sanitizers can kill 99.9% of bacteria on surfaces for up to 24 hours following application.||“residual sanitization” or “residual self-sanitizer”|
|Residual disinfection||Public health claim. Residual disinfectants can disinfect surfaces for up to 24 hours following application. Can apply to either bacteria or viruses.||“residual disinfection” or “continuous disinfection”|
“Static” claims like “bacteriostatic”, “mildewstatic”, and “fungistatic” are non-public health claims, meaning they do not imply a direct impact on human health. Products with “static” claims can inhibit the growth of organisms on surfaces, but do not necessarily kill those organisms. These claims do not require data submission to the EPA for approval at the federal level. However, some states may require data approval in order to make claims in that state. Residual sanitization and residual disinfection claims are considered public health claims, meaning they imply a direct impact on human health. These claims mean that the product can kill bacteria or viruses on surfaces, and they require data submission and approval before they can be listed on the product’s EPA master label.
Note that most residual claims apply only to bacteria or fungi, and not to viruses. Only products tested for residual disinfection against viruses can be used to kill viruses like SARS-CoV-2 on surfaces. However, no products on the market today have residual disinfection claims against viruses because the EPA only recently released a path for companies to add these claims to product labels.
How do I determine whether a product has EPA-approved residual efficacy claims?
To determine which residual efficacy claims a specific product carries, look up the EPA master label and search it for the key terms listed in Table 1. Products that do not make public health claims may not be EPA registered, and should not be used to kill microorganisms on surfaces. If the product is registered, here is how to find and search a product’s master label: 
- Navigate to the EPA’s Pesticide Product Labeling System (PPLS) website.
- Enter the product’s EPA registration number into the field labeled “EPA Registration, Distributor Product, or Special Local Need Number:” and click “Search”. Companies should be able to provide this number to you, or it may appear on their product website. An example of an EPA registration number is “67619-38”.
- Open the most recent master label. The EPA includes the full history of master labels for each product, but only the most recent one will have all of the currently approved claims.
- Search the label for key terms. Terms like “residual disinfection”, “continuous disinfection”, “residual sanitization”, or “residual self-sanitizer” must appear on labels that have approved residual sanitization or residual disinfection claims. Read the terms of the claim, including how often the product must be reapplied.
What is the EPA doing about residual claims in light of the pandemic?
The EPA recognizes the importance of residual kill claims against viruses in light of the COVID-19 pandemic, and they recently released guidance for adding residual disinfection claims against viruses to product labels. If approved by the EPA, these products could be used to kill viruses on surfaces, including surfaces in the operating room. The EPA also recently granted temporary emergency approval to one disinfectant for use as a residual disinfectant against viruses in specific facilities for a limited amount of time. However, until products are tested for residual efficacy against viruses and claims are added to product labels, companies should not be advertising these types of claims.
Which products can I use against SARS-CoV-2?
For a full list of products that can be used against SARS-CoV-2, see EPA List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19). List N includes products that:
- · Demonstrate efficacy against SARS-CoV-2
- · Demonstrate efficacy against at least one virus that is harder to kill than SARS-CoV-2
- · Demonstrate efficacy against a human coronavirus similar to SARS-CoV-2
All of these products are approved for disinfection of hard non-porous surfaces, but they should not be used for residual disinfection of viruses, including SARS-CoV-2.
– Dr. Katherine Velez is a Senior Scientist within Clorox Healthcare’s Clinical and Scientific Affairs team. She serves as a technical expert responsible for supporting clinical studies and product development for electrostatic spray technology and U.S. Environmental Protection Agency (EPA)-registered manual surface disinfectants. She earned her Ph.D. in chemistry from the University of California, Berkeley. She is currently a member of the Society for Healthcare Epidemiology of America (SHEA), the Association for the Healthcare Environment (AHE) and the Association for Professionals in Infection Control and Epidemiology (APIC).
 Association of periOperative Registered Nurses. Environmental Cleaning Tool Kit – AORN https://www.aorn.org/guidelines/clinical-resources/tool-kits/environmental-cleaning-tool-kit (accessed Oct 14, 2020).
 United States Environmental Protection Agency. Interim Guidance – Expedited Review for Products Adding Residual Efficacy Claims https://www.epa.gov/pesticide-registration/interim-guidance-expedited-review-products-adding-residual-efficacy-claims (accessed Oct 15, 2020).
 U.S. Environmental Protection Agency. Pesticide Product and Label System https://oaspub.epa.gov/apex/pesticides/f?p=PPLS:1 (accessed Oct 14, 2020).
 United States Environmental Protection Agency. Section 18 Emergency Exemption Requests and Coronavirus (COVID-19) https://www.epa.gov/pesticide-registration/section-18-emergency-exemption-requests-and-coronavirus-covid-19 (accessed Oct 14, 2020).
 U.S. Environmental Protection Agency. List N: Disinfectants for Use Against SARS-CoV-2 (COVID-19) https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2-covid-19 (accessed Oct 14, 2020).