Historical Version s - view previous versions of standard. More G It is generally the other components, such as plasticizers, cellulosics, lubricants, stabilizers, and colorants, that are responsible for fungus attack on plastic materials. To assess materials other than plastics, use of this test method should be agreed upon by all parties involved. Other effects include preferential growth caused by nonuniform dispersion of plasticizers, lubricants, and other processing additives. Attack on these materials often leaves ionized conducting paths.
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These "materials" may include but are not limited to: paint , plastics , paper , cardboard , dry wall , etc. These materials might be in different physical forms such as tubes , rods , film materials , sheets , etc. The part of the materials that is synthetic polymer material is usually fungus resistant.
This is because the synthetic polymer material itself doesn't provide or act as a source of carbon, which is what promotes the growth of fungi. Most of the time, what allows the growth of fungus on plastic materials are the other components and constituents of the plastic materials such as lubricants, colorants, etc.
Conditions that are favorable for microbial or fungal production are important to understand when producing these plastic materials. ASTM G 21 antimicrobial test method is very commonly used to test the resistance of materials to fungal attacks. High concentration of spore suspensions of each of the five fungi is prepared. Nutrient Salt Agar is poured into sterile petri dishes.
Antimicrobial treated Test specimens are placed on the surface of solidified agar. Composite Spore suspension is sprayed onto the surface of agar and test specimens. Accugen Laboratories, Inc. Call for this and other testing services and to receive personalized and customized price quotes. All Rights reserved Last Updated On: Army Trail Rd.
ASTM G21 – Everything You Need to Know
Changes in optical, mechanical, and electrical properties may be determined by the applicable ASTM methods. The inch-pound units given in parentheses are for information only. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Your Alert Profile lists the documents that will be monitored.
The ASTM G21 is a qualitative test that employs a high concentration of spores, from five different fungal species, to determine the resistance of synthetic polymeric materials to fungal growth. Fungi are generally not able to breakdown the main resin component of synthetic polymer to use as a source of carbon sugar. However, many additives, such as plasticizers, cellulose, lubricants, stabilizers and colorants that are added to impart desirable characteristics, are very susceptible to microbial growth. Once fungi become established by breaking down the easily digested ingredients, the acids they produce as by-products of growth breakdown the resin into a more useable food source. A good analogy is how lighter fluid is used to successfully set charcoal on fire. The additives act as a quick burst of energy that unlocks the stored power in the polymer resin.