ISO 846 – Antimicrobial Test – Plastics

ISO 846 evaluates the effects and propagation of bacteria on plastic materials that are exposed to the environment.

The 4 options for ISO 846 (A, B, C, and D) include tests for fungi, bacteria separately and in the mixed inoculum.

The ISO 846 test method is often used for plastic exposed to the environment but is not intended to test porous materials like plastic foams.

ISO 846 determines deterioration of plastics due to fungi and bacteria and other soil microorganisms. However, this method does not determine the biodegradability of plastics.

Volume of testing and test strains used should be determined before testing and should reflect the intended application for the plastic.

Antimicrobial testing aids product development and supports a well structured Quality Control program.

It can be challenging and time consuming knowing which antimicrobial test method to use for product testing; with a variety of antimicrobial test methods available, Situ Biosciences’ product test laboratory can assist with the planning process and initiate testing based on the project requirements and the intended use or application of the product.

Inquire with the lab for guidance on the different available antimicrobial test methods and to determine which method is most appropriate for a product’s testing requirements.

For more information about ISO 846 and antimicrobial plastics, contact our antimicrobial lab at 847-483-9950 or


ISO Component A

Method A is a fungal growth test that challenges materials against a mixed fungal inoculum.  This ISO 846 method evaluates the inherent resistance of plastics to fungal attack without exposure to organic matter.


ISO Component B

Method B is an inhibition test that is composed of two components that determine the fungistatic activity of treated plastics. Similar to Method A, Method B exposes the test samples to a mixed fungal inoculum; however method B includes a carbon source in the testing media.  It is recommended to perform Method A and both components of Method B simultaneously for testing.

ISO Component C

Method C determines a materials resistance to bacteria using an incomplete media.  If there is no growth in the agar around the test sample, then the test sample does not contain any nutrients.

ISO Component D

Method D determines a materials resistance to microbially active soil in a soil burial test. This component was included in the ISO standard, because many plastics are used in environments where they are constantly exposed to soil and high humidities