Evaluation of laundry sanitizers and disinfectants for high efficiency washing. ASTM E2406-16. Standard test method for evaluation of laundry sanitizers and disinfectants for use in high efficiency washing operations.
Test accredited by ENAC (National Accreditation Entity).
This method is designed to evaluate laundry sanitary products or disinfectants used in high-efficiency automated laundry processes using very small wash water volumes, applied to demonstrate the reduction or complete death of a bacterial population in tissue and laundry washing water after a single wash. This method is designed for tests with vegetative bacteria, but can be adapted for tests with fungi or viruses. The method simulates the washing conditions, for which a set of tissues inoculated with the microorganisms is placed in a small volume of the solution of the evaluated product, in the proportion indicated by the manufacturer, and shaken. After a period of contact time, the wash water, the neutralization liquid, and the tissue used are individually cultured quantitatively (cleaning efficacy), or qualitatively (disinfecting efficacy). The following species of bacteria are used: Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa, although other bacteria of choice may be included. The test can be performed under clean conditions or adding some organic matter among the alternatives indicated by the guideline (heat-inactivated fetal bovine serum, or a mixture of tryptone, bovine serum albumin and mucine). Six (6) pieces of tissue are used for each microorganism. Three pieces for the test product and 3 pieces for the controls. These inoculated pieces are inserted between the folds of a 15 g piece of cloth and subjected to the closed exposure chamber with agitation for the time specified by the manufacturer. Once the exposure time has elapsed, the supports and the inoculated tissue pieces are removed and placed in a neutralization broth. The filtrate of the neutralization broth, the neutralization broth itself and dilutions prepared from it, are cultured to detect the presence of the inoculated microorganisms, as well as their reduction, where appropriate, expressed in log10. The test includes duplicate validations of microorganism count controls. The count of the surviving microorganisms after the washing simulation process is carried out using quantitative counts in duplicate, with 5 dilutions in base 10.