Bacterial Test - ISO 20743/JIS L1902
Textiles – Determination of antibacterial activity of textile products
ISO 20743 Textiles – Determination of antibacterial activity of textile products
JIS L1902 Textiles – Determination of antibacterial activity and efficacy of textile products
The current version of JIS L1902 is based on ISO 20743. These tests are technically identical methods published by two different organizations: Japanese Industrial Standard (JIS) and International Organization for Standardization (ISO). The ISO 20743 does not include the Halo Method found in JIS L1902.
These standards specify test methods to determine the antibacterial activity of all antibacterial textile products including nonwovens. There are 3 methods plus the Halo Method included in JIS L1902.
- Absorption Method – An evaluation method in which test bacteria is inoculated directly onto the samples. The number of bacteria immediately after inoculation and after a contact time is determined and used to calculate the antibacterial activity value. Standard contact time is 18 – 24 hours.
- Transfer Method – An evaluation method in which test bacteria are placed on an agar plate and then transferred onto the samples. Samples are held in contact with the bacteria for 5 minutes then allowed to incubate for 18 – 24 hours. The number of bacteria immediately after inoculation and contact is determined and used to calculate the antibacterial activity value.
- Printing Method – An evaluation method in which test bacteria are placed on a filter and printed onto samples. MicroStar does not perform this method.
- Halo Method – JIS L1902 – A qualitative method that evaluates the antibacterial activity by the existence of halos, or a clear area of growth around the sample. A sample is placed onto the surface of inoculated agar plates. The plates are incubated for 24 to 48 hours and then evaluated for “halos”.
The standard indicates the test organisms as Klebsiella pneumoniae ATCC#4352 and Staphylococcus aureus ATCC#6538 (Gram positive and Gram-negative challenge).
Results are reported as Antibacterial Activity Value (A). The Antibacterial Activity (A) is defined by the standard as the activity of an antibacterial finish used to prevent or mitigate the growth of bacteria, to reduce the number of bacteria or to kill bacteria.
ISO/IEC 17025: 2017 accredited by A2LA