Registration of disinfectants based on relative microbicidal activity.

Abstract

Along with proper hand hygiene, disinfection of contaminated surfaces and medical instruments has been a key method of preventing patient-to-environment-to-patient transmission of infectious agents via the hands of healthcare workers.1-3 However, there is growing concern regarding the increase in antibiotic-resistant pathogens for which environmental and device contamination may play a role in disease transmission, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), Clostridium difficile, and multidrugresistant aerobic gram-negative bacilli (eg, Pseudomonas aeruginosa and Acinetobacter).1 Proper use of disinfectants plays an important role in reducing person-to-person transmission of these pathogens. For decades, the medical community in the United States has relied on the federal government’s disinfectant testing and registration program for assurance that registered disinfectants meet their label claims. However, recognized flaws in test methodologies could result in registration of ineffective disinfectants.4 Control measures should be instituted at the federal level to improve the test methodology and reduce the frequency of contaminated or ineffective disinfectants and the threat of serious healthcare-associated infections related to disinfectant use. We have previously reviewed the issues surrounding the selection and registration of high-level disinfectants and chemical sterilants.5 However, there are several unique aspects of testing and registration of low-level and intermediate-level disinfectants (eg, microbicidal testing methods) that warrant separate discussion. This article proposes a scheme for testing and registration of low-level and intermediate-level disinfectants that could be used by the U.S. Environmental Protection Agency (EPA). BACKGROUND Chemicals formulated as disinfectants in the United States are registered and regulated in interstate commerce by the Antimicrobial Division, Office of Pesticides Program, EPA. The authority for this activity was mandated by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) in 1947. In June 1993, the U.S. Food and Drug Administration (FDA) and the EPA issued a “Memorandum of Understanding” that divided responsibility for review and surveillance of chemical disinfectants between the two agencies. Under the agreement, the FDA regulates disinfectants used on critical or semicritical medical devices and antiseptics and the EPA regulates disinfectants used on noncritical surfaces. In 1996, Congress passed the Food Quality Protection Act (FQPA). The Act amended FIFRA regarding several products regulated by both the EPA and the FDA. One provision of FQPA is that regulation of disinfectants used on critical and semicritical medical devices (the EPA continues to regulate non-medical disinfectants) was removed from the jurisdiction of the EPA and now rests solely with the FDA.1,6 Examples of disinfectants that are registered by the EPA with the intent of providing a public health benefit, therefore requiring efficacy data as a condition of their registration, include disinfectants used in hospitals and other healthcare settings on floors, walls, and medical equipment surfaces and household products claiming to have disinfectant activity. There are three types of disinfectant products that the EPA registers based on submitted efficacy data: limited, general or broad-spectrum, and hospital disinfectants. When a disinfectant is represented in its labeling for use in hospitals, medical clinics, dental offices, or any other medical-related facility, it must show