On February 10, 2016, the U.S. Environmental Protection Agency (EPA) announced it was initiating an external peer review of the updated draft protocol for testing the antimicrobial efficacy of copper-containing surface products. The products in question are hard surface copper-containing surface products such as door handles, light switch panels, and bed rails, which are utilized for their antimicrobial characteristics. EPA states that “the testing described in this draft protocol is designed to support registration of copper-containing surface products (such as door knobs or other items that are not intended for food contact) that bear sanitizer claims.” Numerous changes have been made to the draft, including changes to the test microbes, culture preparation, quality control process, and product characterization. Following completion of the review, EPA states that it will evaluate the findings and revise the draft as appropriate prior to posting the final protocol.
Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA evaluates the efficacy of antimicrobial products intended to control pathogens that can be detrimental to public health. EPA indicates that antimicrobial efficacy testing of copper-containing surface products poses challenges because of the prolonged product life span, the likelihood that cleaning and disinfecting agents would be used on the surfaces, and the wide variation in potential product forms and use patterns. EPA states the following regarding the protocols and how they will affect the test results:
- This protocol is designed to address these issues by including a product characterization component that challenges the product’s physical durability and chemical stability when used as proposed;
- The efficacy assessment component of the protocol involves evaluation of the performance of two product manufacturing lots against two pathogenic microorganisms -- Staphylococcus aureus and Pseudomonas aeruginosa; and
- The efficacy test results, in combination with the product durability/stability component, will be used to determine the sanitizing activity of the copper-containing surface.
More information is available on EPA’s Antimicrobial Pesticide Registration website. Information regarding other antimicrobial pesticide issues is available in our blog items EPA Posts Revised Antimicrobial Pesticides Use Site Index and EPA Releases Guidance Document: Antimicrobial Pesticides Use Site Index.
Products that are intended to have pesticidal efficacy over a protracted period require testing that differs materially from those pesticides that are only effective for a transient period and, thus, must be used repeatedly. Some believe copper-containing surfaces have great promise as antimicrobial sanitizers, particularly in health care environments where limiting patient exposure to potential pathogens has become a critical institutional concern. EPA’s enhanced test protocols are intended to address questions EPA and others have raised concerning the continued efficacy of a copper-containing surface over a prolonged life span, and the potential impact of cleaning and disinfecting agents.