Evaluation Methods of Mold Growth Inhibition

摘要

Mold growth inhibition of numerous biocide combinations in pressure treated wood was tested using three different protocols: two laboratory methods and one field study. Cue lab method was a modified ASTM D3273 ("Standard Test Method for Resistance toGrowth of Mold on the Surface of Interior Coatings in an Environmental Chamber"), in which blocks of pressure treated wood were suspended in an environmental chamber containing soil and inoculated with fungal spores. Fungal growth on the surface of the samples was examined under a dissecting microscope at intervals during the test. A second lab method, intended to simulate field conditions of bundles of lumber, was also developed. Rather than suspending individual blocks and inoculating them with preselected cultures, this method assembled test blocks into simulated packs of dead-stacked treated wood and mold spores from the surrounding air were allowed to colonize. Finally, attempts were made to correlate the results of these two tests with field testresults. Treatments were conducted on 2" x 6" x 4' southern yellow pine boards, which were stored as unwrapped packs in San Juan, Puerto Rico and were evaluated on three-month intervals for mold growth. Correlation was observed among the three studies in some, but not all, instances.