How to Understand and Utilize the EPA’s “N” List

By Rachael Sparks 

If you’re a healthcare provider or oversee infection control at your facility, you’ve probably become aware of the EPA’s “N” List, which specifies registered disinfectants approved for use against SARS-CoV-2.

However, you may have wondered how the list is developed, and how exactly to interpret its phrasing.

How Does the EPA Create the N List?

As early as March 2020, the EPA began responding to the crisis by initiating the N list and adding registered disinfectants that had, in the past, shown testing to the EPA proving efficacy against viruses which were harder to kill than SARS-CoV-2. Some examples are Rhinovirus, feline Calicivirus, Poliovirus, and Norovirus. What is the similarity between these viruses? Primarily that they are non-enveloped, meaning their viral packaging is not surrounded by a fatty lipid bilayer – one of the very reasons that basic soap and water hand hygiene effectively removes SARS-CoV-2 from our hands.

While disinfectant companies began testing their efficacy against the actual virus, the EPA continued to add more disinfectants that could kill Mycobacterium bovis, Mycobacterium tuberculosis (TB), C. diff, or other human Coronaviruses. Again, the EPA was acknowledging that efficacy against a pathogen hardier than the COVID-19 virus can be trusted to eliminate the novel Coronavirus causing this pandemic, as long as the user follows the correct instructions (i.e. 5-minute dwell time for C. diff).

Clarifying the Confusion

The EPA registers disinfectants based on their active ingredients and the concentration level provided by the manufacturer. Manufacturers often package one concentration of active ingredient, for example alcohol, in many different forms and brands. All EPA-registered disinfectants have an EPA registration number followed by a hyphen and a product number, so new brand names get the same EPA number as the primary product. Acme Disinfectant (EPA # 12345) might come in three spray bottles and two wipes, and it might have changed names over the years to now be known as Pathogen Slayer (EPA# 12345-11). The EPA’s N list does not exhaustively cover every marketing variation, so it’s best to search the list by looking for the disinfectant by manufacturer name or the primary EPA number.

To further the confusion, another category exists called the “Emerging Viral Pathogens Claim,” developed in 2016 precisely for an event like the COVID pandemic. It allowed disinfectant companies to voluntarily submit results of structured testing on a variety of hard-to-kill viruses. If the testing parameters are met and the CDC or World Organization for Animal Health identifies a new viral pathogen emerging, the EPA could then trigger a guidance allowing those disinfectants to make claims in an “off-label” manner.

It’s important to remember that the EPA approves claims supported by approved lab test results, which are then included on labels. Since an emerging virus typically isn’t available for most testing labs to quickly acquire, nor are the vetted and ideal laboratory testing methods yet determined, this “Emerging Viral Pathogens Claim” provides those manufacturers more flexibility to communicate what their disinfectants can achieve. “These off-label statements can inform the public about the utility of these products against the emerging pathogen in the most expeditious manner,” states the EPA Guidance on this process, “and can be more easily removed once the outbreak has ended than statements on a label.”

A List of Infectious History

Before the N List, there were lists designated A through M, each for a new need. A look all the lists here provides an historical tour of emerging pathogens in the United States: TB, then HIV-1, then Hepatitis B, then Hepatitis C, followed by Norovirus, MRSA and VRE, C. diff. Ebola, Avian Flu, and SARS-CoV-2 are among the latest.

With the EPA’s guidance, infection control on environmental surface disinfection has come a long way and contributed to halting the spread of dangerous pathogens. The EPA designed most laboratory testing methods to measure disinfection efficacy of a fluid, so the EPA guidance evolved to appropriately address new approaches like ready-to-use wipes and continues to evolve (e.g. no-touch disinfection or antimicrobial surfaces).

When battling a frightening new pathogen like SARS-CoV-2, the EPA’s N List can be a helpful tool to ensure patient safety and quality of care. The list is updated each month, and the search platform improved for easier use. If you’re considering a new disinfectant, a quick check can ensure the efficacy necessary to protect patients and healthcare workers.

About the Author:

Rachael Sparks, Angelini Pharma Inc.

Angelini Pharma has several sodium hypochlorite products on the EPA’s N List.