MaTestLab > Test Standards > ASTM G21 Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi
Last updated 12th March 2025
ASTM G21 Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi
This practice involves assessing how fungi affect the properties of synthetic polymeric materials, including molded and fabricated items like articles, tubes, rods, sheets, and films. Changes in optical, mechanical, and electrical properties can be determined using applicable ASTM methods. The procedure includes selecting suitable specimens, inoculating them with fungi, exposing them to conditions favorable for growth, visually assessing growth, and observing specimens for testing, either before or after cleaning and reconditioning.
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ASTM G21 Introduction
This practice involves assessing the impact of fungi on synthetic polymeric materials, including molded and fabricated items, tubes, rods, sheets, and films. Changes in optical, mechanical, and electrical properties can be evaluated using relevant ASTM methods.
ASTM G21 Test Method
Preparation of Test Samples
For fungi testing with ASTM G21, fungi are grown on solid apparatuses. A pooled spore suspension is prepared and standardized. Test samples are placed in triplicate containers with minimal salt agar, and then the pooled spore suspension is sprinkled onto them.
Incubation
These preparations are left to incubate for approximately 28 days under suitable humidity conditions.
Performance Scoring
A performance score is assigned to the samples based on fungal growth observed after 28 days, and pictures of each test sample are taken at regular intervals.
G21 Equipment and Sample Preparation
Specimen Detail
For ASTM G21 involves selecting appropriate specimens, inoculating them with suitable organisms, exposing them to conditions conducive to growth, visually examining and rating their growth, and then removing and observing them for testing, either before or after cleaning and reconditioning.
Specimen Size
For ASTM G21 testing, samples can include squares measuring 50×50 mm (2×2 inches), circles with a diameter of 50 mm (2 inches), or rods/tubing that are 76 mm (3 inches) long. Film-forming materials, such as coatings, can be tested as films with dimensions of at least 50×25 mm (2×1 inch).
G21 Test Result and Interpretation
ASTM G21 evaluates how well plastics and synthetic materials resist fungal growth. It offers a standardized procedure to assess their susceptibility to fungal colonization by subjecting them to controlled conditions. This helps gauge the risk of fungal infestation and material degradation, guiding material selection and product quality control.
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Tests Related to ASTM G21
ASTM G21 is related to tests including ASTM D149 for breakdown voltage of dielectrics, ASTM D150 AC loss features and Permeability, and ASTM D257 for conductance and resistance of materials.
Use of G21 in Various Industries
This is widely used in construction, healthcare, consumer goods, and electronics that use synthetic polymeric materials exposed to humid or fungal-prone environments. It ensures that materials meet specific requirements for fungal resistance, thus preventing their performance degradation and health hazards.
Materials Commonly Tested with G21
These tests are often utilized on materials such as polymer-based products, rubber, coatings, adhesives, and textiles for durability in resisting fungal colonization, which causes discoloration, odor, or structural damage; hence, it is suitable for the application in environments requiring such durability.
Common Challenges and Troubleshooting in G21 Testing
Testing is exposed to consistent environmental conditions for fungal growth and contamination of test specimens, which requires proper calibration, rigorous cleaning protocols, and frequent environmental monitoring to address these issues.
Safety and Best Practices in G21 Testing
Testing prioritizes safety as the pathogenic or allergenic cultures of fungi are handled. Best practices include well-ventilated biosafety cabinets, wearing PPE, sterilization protocols, and proper training in fungal culture handling and disposal to ensure that laboratory personnel are protected.
Importance of G21
It is an important test to determine the resistance of synthetic polymeric materials to fungi, ensuring long-term performance in humid environments, reducing product failures, improving consumer confidence, and minimizing health risks and maintenance costs.
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FAQ's
Where can I get the astm g21 tested?
You can share your astm g21 testing requirements with MaTestLab. MaTestLab has a vast network of material testing laboratories, spread across the USA and Canada. We support your all material testing needs ranging from specific astm g21 test to various testing techniques.
How much do I need to pay for the astm g21 test?
Please contact us for a detailed quote for your astm g21 testing needs. Cost incurred to carry out different astm g21 testing methodology depends on the type of raw material; number of samples, coupons, or specimens; test conditions, turn around time etc. Costs of some ASTM testing methods start from $100 and the final value depends upon the factors listed above. Please contact us for the best and latest prices.
How many samples are required for astm g21?
The required number of samples or specimens should comply with the procedure given in the astm g21 standard. However, the MaTestLab operations team can assist you for your special requirements once you share your testing details with us.
How much discount can I get on the astm g21 test?
MaTestLab has a vast testing laboratory network, hence we bring you the best testing facilities in a cost-effective way. We offer considerable discounts (15-20%) to our returning customers based on test volume and frequency.
How many days will it take to complete the astm g21 test?
The turnaround time for astm g21 test methodology depends upon the test procedure mentioned in the standard test document. However, we at MaTestLab understand your research requirements and hence try to get your test completed within the least possible time.
Where can I get the astm g21 tested?
You can share your astm g21 testing requirements with MaTestLab. MaTestLab has a vast network of material testing laboratories, spread across the USA and Canada. We support your all material testing needs ranging from specific astm g21 test to various testing techniques.
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