The Microstar Lab

Fungal Test - ASTM G21

Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi

Fungal Testing - ASTM G21 - Plastic Materials Testing
The purpose of this test is to determine the effect of fungi on the properties of synthetic polymeric materials. While the synthetic polymer portion of an item generally will not support fungal growth, other components, such as plasticizers; cellulosics, lubricants, stabilizers, and colorants may allow for fungus attack on a plastic material.
  • Test pieces are placed on the surface of a nutrient salts agar and inoculated with a mixture of 5 different fungi.
  • The nutrient salts agar provides trace nutrients for the fungus to survive. In order for the fungus to grow, it must use nutrients present in the sample.
  • The standard incubation is 4 weeks but can be extended.
  • The rating scale for the G21 is a 0-4 scale with 0 being no growth, and 4 being completely covered with growth. Ratings are determined weekly for each test piece.

ISO/IEC 17025: 2017 accredited by A2LA