The EPA has released a draft strategy to evaluate the effectiveness of hospital-level antimicrobial disinfectants after they have been registered. The strategy describes a risk-based approach intended to help the Agency prioritize and select hospital-level disinfectants and label claims for testing. The strategy would replace the  Antimicrobial Testing Program (ATP) the Agency suspended in November 2017 in response to a recommendation from the EPA’s Office of Inspector General (OIG). The OIG had reported that the ATP provided no assurance that hospital-level disinfectant products continue to be effective after they are registered. The OIG recommended that the Agency develop the risk-based strategy and include in it a framework for periodic testing. The EPA agreed with the OIG’s recommendations.

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Efficacy testing

Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the EPA must ensure that pesticides registered for use in the United States will not have unreasonable adverse effects on humans and the environment. For antimicrobial disinfectants, the Agency must also review efficacy test data submitted by registrants to verify that products with a public health claim are effective. Antimicrobial disinfectants are used on nonliving surfaces and objects to destroy or irreversibly inactivate infectious fungi and bacteria. Disinfectant products are divided into hospital-level products that are used on medical and dental instruments, floors, toilet seats, and related surfaces and general-use disinfectants that are intended for households and swimming pools.

Assessing efficacy data

According to the EPA, a public health antimicrobial pesticide product is registered only after the Agency determines that submitted efficacy data support a finding of product efficacy and the product meets all other applicable requirements. To accomplish its reviews, the EPA initiated its ATP in 1991. The program complemented the registration process by determining whether hospital disinfectants and tuberculocides are formulated correctly and continue to meet the agency’s efficacy standards once the products are in the marketplace. The EPA reported that the ATP found that more than one-third of tested hospital disinfectant products failed efficacy tests. Products that did not meet the ATP standards were subsequently brought into compliance through regulatory or enforcement measures.

OIG’s findings

In its September 2016 report, the OIG determined that:

• The ATP was not administered in a way to ensure that products continued to meet efficacy standards. Once the EPA tested a product and it passed, the product was listed as Agency Confirmed Efficacy on the agency’s website and typically was not tested again.
• The number of ATP tests conducted and the source of test samples fluctuated over the course of the program.
• The reregistration of antimicrobial pesticide products is a more comprehensive approach to ensure product efficacy rather than only testing a few products a year under the ATP.
• The ATP did not consider risk to prioritize and select antimicrobial products for testing.

Based on these findings, the OIG recommended that the EPA suspend administering the ATP until completion of the onetime reregistration process and also develop a risk-based testing strategy.

Draft elements

In the draft, the Agency says it plans to use a variety and combination of approaches to achieve the goals of what it calls its Antimicrobial Performance Evaluation Program (APEP), including postregistration testing. The draft contains two main components:

• Risk-based criteria to determine order of testing. The criteria are (1) product label claims for specific microbes and disease prevalence data; (2) evaluation of uncommon label claims and unique product application processes; and (3) evaluation of products tested using new and/or recently revised methods.
• Two options for sample collection—the EPA itself makes the purchases from the marketplace, and/or samples are provided by the product registrant.

The strategy also notes that the entity that will conduct testing will depend on available resources. Options include the EPA’s Microbiology Laboratory Branch and Analytical Chemistry Branch, other federal labs, third parties selected by the registrant, and the registrant itself. 

The EPA adds that it plans to begin implementation of the new risk-based testing program by 2022 when the initial round of registration review is completed.

In a Federal Register notice, the Agency is soliciting public comment on the draft. The draft strategy is available here.