ASTM E2149: 2020

The test is applicable to measuring the antimicrobial activity of non-leaching (immobilized and not water-soluble), irregularly shaped, or hydrophobic surfaces. Products tested include fabric, paper, powder, granular material, and other solids.

The test takes 3 to 4 days to complete.

The microorganisms typically include common bacteria such as Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). Other microorganisms like Pseudomonas aeruginosa, Klebsiella pneumoniae, and fungi like Candida albicans may also be used depending on the specific requirements of the test.

The shake flask method is used in a laboratory to assess the antibacterial efficacy of treated materials. In this method, treated samples are cultured in a nutrient broth containing a particular microorganism. The flask is agitated to facilitate better distribution and contact of the microorganisms with the treated material. After the incubation period, the decrease in microbial count is measured to determine the antimicrobial effectiveness.

Commodities often tested include textiles, plastics, coatings, polymers, and other substances containing antimicrobial agents. These products are especially employed in healthcare, consumer goods, food packaging, and other areas where there is a necessity to prevent microorganism growth.

Before conducting the test, ensure that the product samples are cut to appropriate sizes according to the protocol. The samples should be in a germ-free state and handled aseptically to reduce interference by unwanted organisms. Follow the specific sample preparation procedures given by the testing laboratory.

This test determines the ability of coated or treated textile samples to control microbial growth. It involves exposing the tested material to a microbial growth medium containing viable microbial cells. Each sample-containing flask is shaken to facilitate contact between microorganisms and the treated textile. Subsequently, microbial count is determined, followed by the evaluation of microbial reduction to assess the antimicrobial effectiveness of the textile.

Yes, this test can help in extending the shelf life of antimicrobial products by providing information on how effective antimicrobial treatments are over a certain period. Manufacturers can justify claims about the longevity and durability of their products’ antimicrobial properties by demonstrating sustained antimicrobial activity.

While the general principle of the test is similar across materials, certain parameters such as sample preparation, handling, and exposure conditions may vary depending on the material type. For instance, textiles may need different sample sizes and agitation speeds compared to plastics. 

Yes, some specific industries like healthcare, food packaging, and consumer products may require this test by regulations or customer requirements. These requirements ensure that antimicrobial treatments are effective in reducing microbial contamination to safe levels for product consumption.

This testing helps maintain compliance with international antimicrobial standards by providing a method to test antimicrobial performance. The data generated can be used as evidence of antimicrobial efficacy necessary for claims and compliance with these standards.

Potential limitations include the focus on laboratory conditions that cannot completely simulate real-use conditions. Factors such as degradation, climatic conditions, and complex microbial communities present in the real world are not accounted for in this test. Additionally, the test primarily assesses bacterial reduction and may not appropriately gauge antifungal or antiviral properties.