Virucidal Efficacy of Laundry Additives

Purpose of Test

This test method (a modification for viral testing of ASTM E 2274 Standard Test Method for the Evaluation of Laundry Sanitizer and Disinfectants and ASTM E 2406 Standard Test Method for the Evaluation of Laundry Sanitizer and Disinfectants for Use in High Efficiency Washing Operations) is used to evaluate the disinfectant efficacy of laundry additives for registration with regulatory agencies such as the U.S. EPA. This method is intended to simulate the way in which the product is intended to be used. This test method may be performed using a wide variety of human and veterinary viruses.

Summary of Test

Each of nine fabric swatches (“carrier”) are individually inoculated with a representative test virus and the carriers are dried. The carriers are placed into a fabric wrapped spindle (three carriers per spindle) and the spindle is then placed into a jar containing an aliquot of the use dilution of the test substance. For high efficiency washing operations testing, the spindle is removed from the fabric following placement of the carriers. The jar is placed onto an agitating device to rotate the jar through a 360° vertical orbit for the requested exposure time at the requested exposure temperature. Following exposure, the carriers are removed and placed individually into a neutralizing agent. An aliquot of the test substance (“wash liquid”) is also removed and neutralized. Serial dilutions of the neutralized carriers and test substance are performed. The dilutions are then assayed for viral infectivity by an assay method specific for the test virus. Appropriate virus, test substance cytotoxicity, and neutralization controls are run concurrently. Typically, most regulatory agencies require complete inactivation of the virus in all dilutions assayed for each test carrier and the wash liquid.