ASTM E3179-18. Standard Test Method for Determining Antimicrobial Efficacy of Ultraviolet Germicidal Irradiation against Influenza Virus on Fabric Carriers with Simulated Soil.

Test accredited by ENAC (Spanish National Accreditation Entity).

ASTM E3179-18 defines the test conditions to evaluate germicidal ultraviolet light irradiation devices (mercury vapor bulbs, light-emitting diodes or xenon arc lamps), which are designed to kill or inactivate the Influenza virus deposited on inanimate supports.

This test method is specific for the Influenza virus. The use of the Influenza A virus strain (H1N1; A/ PR/ 8/34) is recommended, but other Influenza strains and viruses can be used. The test allows the addition of soil agents to simulate actual use conditions, such as artificial saliva, a hydrophilic soil agent, or artificial sebum, a waxy hydrophobic soil agent.

The test outlined by ASTM E3179 is carried out on 2.5 cm diameter supports of any fabric material. To carry out the test, 6 supports are used per dirty condition (3 of them will be exposed to the UV light source, and the remaining three will serve as controls). On each support, the Influenza virus inoculum is deposited and, once the inoculum is dry, if applicable, the dirt simulating agent is applied. Three substrates of each condition (no dirt, watery dirt, or waxy dirt) are exposed to UV light. Exposure must be in accordance with the directions on the irradiation device label and must simulate actual use of the device. The three control supports for each condition are incubated at room temperature for the exposure time. At the end of the exposure period, viruses are removed from the exposed and unexposed cloth supports and viable viruses are quantified by titration in cell culture. The log reduction due to irradiation with the test device is calculated by comparing the number of viable viruses recovered from UV treated and untreated fabric supports.

In our laboratory, these tests are carried out in a 74 m3 chamber. In addition, cotton fabric supports are generally used. If the customer wishes to use another material for the supports to adapt the test to the actual conditions of use, he must provide the material. The client must indicate the irradiation procedure to be followed with his test device (irradiation time, distance from the UV source to the test stands, the relative angle of exposure to ultraviolet light, and the position of the stands relative to the length of the device) and the test conditions (the dirt conditions to be used, the material from which the test supports must be made, initial test temperature, and initial relative humidity range).