EPA Residual Efficacy Testing Guidance Update

Get A Testing Quote

Recent Articles

November 2022

Last month the EPA released new guidance and published revised test methods for residual self-disinfection and residual antimicrobial efficacy of surfaces and coatings.

Testing initiated on or after October 7, 2023, must follow the new guidance and methods. Registrants may begin testing following the new guidance and methods at any time.
For residual self-disinfectant claims, notable changes include:
  • Reduction in the number of test substance lots from three to two for the base bacteria.
  • Reduction in the number of wear passes from four to two, which aligns with the residual self-sanitization test requirements.
  • Addition of virucidal efficacy guidance.
  • Limitation of residual self-disinfectant claims to liquid formulations and spray products. Registrants seeking to register a pre-saturated towelette product are to consult with the EPA.
  • EPA consultation requirement for efficacy claims of less than or greater than 24 hours.
For supplemental residual antimicrobial surface coatings and films, notable changes include:
  • Testing is to be performed following EPA MLB SOP MB-40 which is a revision of the 2020 protocol that now includes virucidal efficacy testing procedure.
  • Reduction of the number of test substance lots from three to two for the base bacteria.
  • Change of the microorganism growth medium from Tryptic Soy Broth to Synthetic Broth.
  • Reduction of the volume of liquid applied to the sponge during the abrasion/chemical treatment cycles.
  • Addition of alternating wet and dry abrasion/chemical treatment cycles.
  • Reduction of the number of wear passes per abrasion/chemical treatment and dry treatment cycles.
  • Substantiation of a supplemental residual claim of one week. For longer residual times, consultation with the EPA is required. This is a departure from the 2020 guidance which allowed up to a four-week residual claim without EPA consultation.
For supplemental residual antimicrobial fixed/solid surfaces including copper, other metals, and solid impregnated material and paints, changes of note include:
  • Testing to be performed following EPA MLB SOP MB-41 which is a revision of the 2020 protocol that now includes a virucidal efficacy testing procedure.
  • Reduction of the number of test substance lots from three to two for the base bacteria.
  • Change of the microorganism growth medium from Tryptic Soy Broth to Synthetic Broth.
  • Consultation with the EPA is required for products formulated with sheens, colorants, glosses, etc.

This is not an exhaustive list of all changes that have occurred. For more information regarding the new guidance or if you are interested in testing your product for residual efficacy claims, please contact Karen Ramm at [email protected].

Share This Story!

EPA Residual Efficacy Testing Guidance Update

Get A Testing Quote

Recent Articles