ASTM E2197: Standard Quantitative Disk Carrier Test Method for Determining Bactericidal, Virucidal, Fungicidal, Mycobactericidal, and Sporicidal Activities of Chemicals (modified)

Purpose and Goals

  • Evaluate and compare the antimicrobial efficacies of 6 disinfection devices against a variety of microbes in different test conditions in laboratory-controlled testing. 

Materials and Methods

  • Each test will include 6 disinfection devices: Device A and Device B. 
  • Each test will include 3 exposure times: 5 minutes, 10 minutes, and 20 minutes. 
  • 3 replicate discs will be tested for each testing condition.
  • Bacterial/fungal tests will be performed 2 independent times. ​Viral tests will be performed once.
  • Each test will include one microbial strain:
    • Methicillin-resistant ​Staphylococcus aureus​ (MRSA) bacteria
    • Clostridioides difficile (formerly known as Clostridium difficile) bacterial spores
    • Viral strain to be determined

Air Chamber Testing: 

  • This testing will utilize a biological air chamber to evaluate the device efficacy of microbes in the air. A liquid microbial suspension will be introduced to the chamber for exposure to the disinfection device. After exposure, a sample of the microbes in the chamber will be recovered to provide viable microbial burden data for each condition tested.
  • Each test will include 2 device settings:
    • Disinfection only
    • Disinfection and fan

Data Analysis

  • Data will be calculated to determine the quantifiable bacterial/fungal burden in colony-forming units per disc (CFU/disc) or viral burden in plaque- or foci-forming units per disc (PFU/disc or FFU/disc) remaining on each test location.
  • Data will be analyzed to determine the consistency between replicate discs.
  • Data will be analyzed to compare the efficacies of each device/exposure time to determine the percent reductions and log reductions of microbial burdens compared to unexposed discs. 

Typical Turn Around Time

  • Bacterial/fungal (per strain): 4-6 weeks following receipt of the test devices.
  • Viral (per strain): 6-8 weeks following receipt of the test devices