What You Really Need to Know About Surface Disinfectant Efficacy Claims

Infection prevention and control professionals play a key role in the selection of surface disinfectants. In today’s healthcare environment, it is critical that disinfectants be selected based on their ability to be effective against the pathogenic microorganisms that can be transmitted by direct or indirect contact with the environment.

There are many formats for surface disinfectants available including liquids, sprays and pre-moistened wipes. The type of surface to be disinfected and applications for product use must always be considered. Microorganism efficacy claims (commonly referred to as “kill claims”) made by manufacturers of surface disinfectants can be difficult to understand.

Before manufacturers can sell disinfectant products in the United States, the Environmental Protection Agency (EPA) must evaluate the disinfectant products thoroughly to ensure that they meet federal safety, efficacy and labeling standards to protect human health and the environment. The EPA grants a “registration” or license that permits a pesticide’s distribution, sale, and use only after the company meets the scientific and regulatory requirements.

In evaluating a pesticide registration application, the EPA assesses a wide variety of potential human health and environmental effects associated with use of the product. Potential registrants must provide scientific data necessary to address concerns pertaining to the identity, strength, toxicity, and environmental impact of each disinfectant product.

Once the registrant has registered their products with the states it is up to the infection control professionals and environmental service managers to select the appropriate surface disinfectant for their facility.

The following questions are frequently asked when selecting surface disinfectants.

1. What are efficacy claims?

Efficacy data are reviewed by the EPA when a pesticide (like disinfectant products) claims to control pest organisms that pose a threat to human health. Such pests include, but are not limited to, (a) microorganisms which are infectious to man in any area of the inanimate environment, (b) vertebrates (e.g., rodents, birds, bats, dogs, and skunks) that may directly or indirectly transmit diseases to or injure humans, and (c) insects that carry human diseases (e.g., mosquitoes, ticks, etc.).

Products bearing claims for control of microorganisms which pose a threat to human health require specific efficacy data to support such claims and patterns of use; products bearing claims expressly for control of microorganisms not directly related to human health do not require supporting efficacy data.

All of the efficacy claims tested for a specific disinfectant product may not be listed on the product label. Be sure to ask for a complete list of the microorganisms the product has been tested effective against.

2. What is the process for manufacturers to receive EPA acceptance in making efficacy claims for their disinfectant product?

Manufacturers marketing surface disinfectants intended for use in healthcare environments must now submit efficacy studies to the EPA that are performed by independent, GLP-certified laboratories. Once the efficacy studies are completed by the laboratory, the manufacturer submits the studies to the federal EPA for acceptance. Once accepted by the federal EPA, then the manufacturer must file with each state it intends to sell the surface disinfectant. The timing for the entire process, from the start of the efficacy studies in the laboratory, to receiving all the required federal and state acceptance of the studies could take nine months to 12 months or even longer, if any of the reviewing agencies have any questions or need more information from the manufacturer.

3. In healthcare, how important are efficacy claims for selecting the proper surface disinfectant?

There are several things that must be considered when selecting a surface disinfectant with regard to efficacy claims.

First, for a disinfectant to be considered for use in hospital or medical environments, the EPA requires the product have efficacy label claims for the following three organisms:

Salmonella enterica

Staphylococcus aureus

Pseudomonas aeruginosa

These are commonly referred to as the three target organisms. Both Salmonella enterica and Staphylococcus aureus are considered general or broad spectrum claims representing gram-positive and gram-negative bacteria, while Pseudomonas aeruginosa represents a nosocomial bacterial pathogen.

Second, in addition to the three required claims, a facility must consider other efficacy claims that are needed based on the type of facility and the population that it is treating. For example, HIV-1 and hepatitis B virus are bloodborne pathogens that need to be considered as well. There are also those efficacy claims that are wanted or needed based on microorganisms that are of public health concern such as methicillin-resistant Staphylococcus aureus (MRSA), severe acute respiratory syndrome (SARS), and avian influenza virus.

Third, a surface disinfectant product can have an exhaustive list of efficacy claims that meet the needs of the facility. Infection control practitioners (ICPs) and environmental services (ES) managers must examine their current protocols and practices in determining if they have the right tools and staff education about the disinfectants they are using to reap the products' full efficacy.

4. Are the efficacy claims for surface disinfectant wipes comparable to sprays?

The answer is yes. Wipes are comparable and in many cases more efficacious due in part to the wiping action of the pre-moistened wipe to pick up and kill the remaining microorganisms from the surface onto the wipe.

The EPA requires that disinfectant wipe manufacturers test the efficacy of certain microorganisms by using wipe efficacy protocols. The other efficacy claims that do not require off-the-wipe testing, may be bridged from the liquid to the wipe if there is a prior EPA-accepted liquid formulation and is substantially similar to the wipe liquid formulation.

Some manufacturers of surface disinfectant wipes choose to take extra steps to prove efficacy of all the microorganisms it is claiming by not bridging any liquid test claims and using the wipe protocols. This information should be available in the manufacturer’s technical information sheet.

5. Our hospital is concerned about Clostridium difficile. Are there any EPA-accepted products with this efficacy claim?

As of November 2007, there are no intermediate-level surface disinfectants allowed to make this claim. Up until November 2007, the EPA was accepting efficacy data from manufacturers for efficacy against Clostridium difficile for vegetative cells only. Any manufacturers submitting efficacy testing after this date have been denied due to the decision that having this claim on an intermediate-level surface disinfectant label is misleading. The EPA’s stance is that there are not enough studies to prove that Clostridium difficile survives on surfaces in the vegetative state long enough for any disinfectant solution to be effective against it. It takes a matter of seconds to minutes for it to become a spore once it is in-vitro and on surfaces. Additionally, having the claim on a product may provide a false-sense of security and may lead to more lax cleaning and disinfection of surfaces. The EPA is in the process of contacting those manufacturers with the claim to have it removed from all of their labeling.

Jean Fleming, RN, MPM, CIC, is clinical director of infection prevention and education for Professional Disposables International and Nice-Pak Products, Inc. She is an infection control clinical expert with more than two decades of experience in the acute-care hospital setting. Fleming has had infection control articles published in scientific journals and has presented infection control education programs at the local, national and international levels.