Scope:

ASTM D3273 test is used for evaluating fungal defacement on the surface of interior coatings in an accelerated manner. This test mainly focuses on establishing the relative resistance of paint films to the propagation of mold and mildew under perfect fungal growth parameters. Different species of fungus, for various custom projects, can easily be adjusted by using this test. Also, the test provides an easy and direct procedure to control extraneous variation. This test method is designed mainly for testing paints and varnishes. For a standardized rating system, ASTM D3274 is used as a complementary method.

Test Procedure:

For ASTM D3273, the growth chamber is made ready with proper soil and water content and is equilibrated for 24 hours at about 32°C. Then, the suspensions are molded from three fungi cultures that are spread uniformly over the soil surface. They are incubated for about 14 days. Different species are used, such as Aureobasidium, Aspergillus niger, and Penicillium. The non-coated substrates and coated test panels are established randomly to a sporulating chamber by vertical hanging. The panels are rated for mold growth each week for four weeks on a 0-10 rating scale using photographic standards as specified by ASTM D3274.

Sample size:

The samples are used as stated by the ASTM D3273 test method. 

Data:

The results for ASTM D3273 are reported at the end of the four-week exposure providing the mean and range of the three panels.

Conclusion:

Resistance to the growth of mold on the surface of interior coatings (paints and varnishes) in an environmental chamber is evaluated by ASTM D3273.