Determining materials' resistance to fungi is important, especially when those materials are plastics. ASTM G-21 testing from The MicroStar Lab can test your plastics to determine if the final product will be susceptible to fungal growth.

MicroStar Lab originally started out as a facility that tested paint, paper and building materials. They've since evolved into the premier testing lab for all types of industries, putting their extensive expertise to use testing many different types of products and materials. Their world-class facilities and superior testing methods provide consistent, reliable and reproducible results. Their maintenance of this test in the ISO/IEC 17025 scope guarantees that the test is performed right.

In addition to mold testing, MicroStar still provides testing for the paper and textile industries, specializing in microbiological control of building materials, paints and paper, offering the confidence necessary when it comes to proving that certain materials will stand the test of time.

ASTM G-21 testing will determine the susceptibility of materials to 5 commonly used fungi, all of which have different growth requirements and target different substrates. This testing method is designed so that every condition for growth is present except a food source so it can be determined if a material can be used by the fungi as it nutritional source. If the test material can be used as food for the fungus, the material will eventually show degradation when it is unable to withstand a fungal attack. The spore concentration is usually very high, providing a critical challenge to common synthetic materials.

The ASTM standard test method involves placement of the test pieces on a surface of mineral salts agar and sprays them with a mixture of 5 different fungi at a concentration of 1,000,000 per mL. The test is conducted with 3 test pieces, each one typically 2" x 2". An untreated control sample can also utilized to determine if there is any fungal contamination of the test pieces when they arrive in the lab. Comparison photographs are taken of representative materials at the conclusion of the test and included in the report. Additional custom pictures of the test pieces after exposure are also available upon request.

ASTM G-21 testing requires a 4 week incubation period. Normally, MicroStar Labs sets up the test within a week of receiving samples, so results are usually available within 5 weeks of arriving at the lab. Custom modifications can also be made to the fungi used in testing particularly if there would be health concerns from other fungi, such as Stachybotrys chartarum. This test is the perfect choice during the product development stage for many different types of manufacturers. It is of the utmost importance to evaluate product susceptibility to fungal attack, and the ASTM G-21 is capable of determining this susceptibility on any synthetic polymer substrates.

The MicroStar Lab is accredited to perform a full range of testing for many different applications. We take for granted that airborne pollutants, fungi and bacteria will not harm us, and we do not realize how much work goes into the testing to make sure our risks are minimized. The process is painstaking, but the results are well worth the effort of preserving a product's integrity and ensuring that it can withstand normal environmental challenges. Working with an experienced partner like MicroStar will ensure that the job gets done right, with testing that will unearth any issues before it is too late to fix them.

For more information about The MicroStar Lab and ASTM G-21 testing, visit them online at Microstarlab. There, you can read about all the services they provide and find out how to contact them to see which mode of testing would be most effective for your unique circumstances.

For more information about The MicroStar Lab and ASTM G-21 testing, visit them online at There, you can read about all the services they provide and find out how to contact them to see which mode of testing would be most effective for your unique circumstances. For more information, please visit www.microstarlab.com.