ASTM E3162-18

5.1 The durability of antimicrobial agents applied to textiles is an important attribute for many of the available technologies on the market. Antimicrobial agents that claim durability are typically fixed ionically, covalently or physically, or both, to a textile surface and are expected to retain their antimicrobial functionality after 5, 25 or 50 washes.

5.2 Textile wash standards do exist that measure features as diverse as colorfastness or softener retention, pilling, or even the appearance of the decorative coatings of a zipper; however, no wash method exists that is specific for measuring the durability of an antimicrobial agent applied directly into or onto a textile surface.

5.3 Current wash standards have been written to either closely simulate (AATCC TM135) or accelerate (AATCC TM61) the laundering conditions that would be experienced during normal home laundering. While shown to be effective when testing physical properties of textiles, these methods introduce variables to the washing protocol that can directly affect the final antimicrobial properties of a fabric. For example, many wash protocols add bleach or softeners which can build up over time and may introduce false positive results in industry standard microbiological tests. Conversely, powdered detergents if not completely rinsed after each wash can leave residual surfactants that can build up over time but are generally removed during wear. These residual detergents can potentially coat an antimicrobial surface and provide false negative results.

5.4 Very specific parameters are identified within this practice to closely replicate home launderings as identified and studied in previous wash protocols (AATCC TM61) and accepted within the textile industry. This practice uses detergents and washing conditions which limit potential cross contamination of samples during washing and unrealistic deposition of residual detergents on the test fabric. These conditions increase the reproducibility and reliability of subsequent microbiological test methods.

5.5 This practice allows for the simple washing of textile fabrics for the subsequent antimicrobial testing. Any industry accepted antimicrobial test standard could be used following this washing protocol.

5.6 This practice is appropriate for porous materials such as textiles or any porous, soft substrate that is intended to withstand multiple home washes. This practice is intended to measure the durable antibacterial properties of such materials. In most instances, further studies will be required to support and substantiate actual claims being made for the performance of treated materials in practice or as part of a regulatory process.

5.7 This standard practice has been shown to be effective at measuring the durability of polymer based antimicrobial agents to home laundering conditions. Particle based or other antimicrobial agents may require modifications of the current methodology to simulate laundering conditions in practice. The exact correlation between expressed laundry care instructions on the antimicrobial treated article and the exposure conditions identified in the standard practice must be determined separately for every antimicrobial active.

1.1 To determine the durability of standard antibacterial treatments on textile products such as apparel, piece goods, household articles, hereinafter referred to as “textile” or “textile products” to multiple home launderings.

1.2 This practice subjects textile products treated with antimicrobial agents to multiple simulated and accelerated home launderings under defined parameters such that reproducible and reliable antimicrobial analysis can be performed using standard industry accepted protocols.

1.3 For some antimicrobial agents, the durability of antibacterial properties resulting from exposure to detergent solution and abrasive action of multiple home launderings has been shown to be approximated by one 45-minute laundering cycle. The exact correlation between expressed laundry care instructions and exposure conditions identified in the practice should be determined separately for every antimicrobial agent.

1.4 The subsequent microbiological methods shall be performed by individuals experienced and adept in microbiological procedures and in facilities suitable for the handling of the microorganisms under test.

1.5 This standard may involve hazardous materials, operation, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.