ASTM G21

ASTM G21 – Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi

Overview

ASTM G21 is an internationally recognized standard that details how to assess the resistance of synthetic polymeric materials to fungal growth. This test is essential for manufacturers and developers seeking to ensure their products maintain structural integrity and performance when exposed to fungal environments.

Why Fungal Resistance Testing Matters

Polymeric materials, such as plastics, coatings, insulation, and sealants, can be susceptible to fungal growth, especially in humid environments. Fungal growth can:

Compromise material strength and flexibility
Cause discoloration and surface damage
Lead to unpleasant odors
Reduce product lifespan and safety

By performing ASTM G21 testing, manufacturers can verify that their materials are suitable for use in environments where fungal contamination is a concern.

Our ASTM G21 Testing Services

At Biosan Laboratories, we provide fungal resistance testing following ASTM G21 protocols. Our services include:

Sample preparation and inoculation with a standardized fungal spore suspension
Incubation under controlled temperature and humidity conditions
Periodic inspection for evidence of fungal growth
Grading and reporting based on ASTM G21 rating scale

Testing Procedure

Sample Preparation: Each sample consists of three 50 mm x 50 mm specimens.
Fungal Inoculation: Specimens are inoculated with a mixed spore suspension containing five common fungal organisms
Incubation: Inoculated specimens are incubated at 28-30°C and >85% relative humidity for 28 days.
Evaluation: Samples are visually inspected and rated on a scale from 0 (no growth) to 4 (heavy growth) according to ASTM G21 criteria.
Reporting: Detailed reports include growth ratings, photographic documentation, and expert interpretation.

Applications

ASTM G21 testing is applicable to a wide range of products, including:

Construction materials (panels, pipes, insulation)
Electrical components
Consumer goods
Coatings and adhesives

Why Choose Us?

Experienced microbiologists and technical staff
Modern laboratory facilities
Rapid turnaround and clear, actionable reports