ASTM G21 – Antifungal Test
ASTM G21 is a standard antifungal product test for determining fungal resistance of plastics and polymeric materials.
Synthetic polymers are generally resistant to fungi, but the additives (such as colorants, stabilizers, and plasticizers) used in the polymer may not be. These additives may contribute to the fungal growth and unsightly conditions.
Products made of plastics and foam are commonly tested with ASTM G21 but the method can also be used for a wide range of other materials and products.
ASTM G21 is useful for interior products including vinyl, foam, gaskets, and rubber and is often used for materials in plumbing, baths, and bedding. ASTM G21 is also used for outdoor products such as siding, shingles, pool covers, marine plastics, fishing and boating gear, footwear, sporting goods and polymeric coatings.
ASTM G21 consists of exposing plastics and other materials to a fungal inoculum over 28 days of testing. A mixed fungal inoculum is standard, but individual fungi can be requested as an alternative.
The ASTM G21 test method challenges materials with a wide variety of fungal species, ranging from common environmental fungi to agricultural pathogens and even antibacterial compound producing fungi, all of which have different growth requirements and enzymatic properties.