Mold's hyphae (root structures) actually grow into wood and drywall like roots. The hyphae are not killed by bleach because bleach's ion structure prevents chlorine from penetrating into porous materials such as dry wall and wood. It stays on the outside surface, whereas mold has protected enzyme roots growing inside the porous construction materials. When you spray porous surface molds with bleach, the water part of the solution soaks into the wood while the bleach chemical sits atop the surface, gasses off, and thus only partially kills the surface layer of mold while the water penetration of the building materials fosters further mold growth.
Chlorine bleach causes long term breakdown of wood products like studs, sheathing, plywood, OSB, and other building materials over time.
You can verify it yourself when you are unable to find an EPA registration number for killing mold on the label of any brand of chlorine bleach. Why not? Because it is not effective at killing mold as other EPA approved chemicals.
University Study Discovers Bleach is Ineffective at Killing Mold on Wood and Other Porous Surfaces.
"While bleach is often recommended for remediation of surface mold on wood and other porous surfaces, our [university research study] study results illustrate that the treatment does not eliminate the surface microflora," is the conclusion of the Oregon State University study of the effects of chlorine bleach on mold growth on Douglas fir wood [an important timber crop in the state of Oregon]. The research study was conducted by Professor Jeffrey Morrell, Dept. of Wood Science, Oregon State University, as assisted by Adam Taylor [graduate research assistant] and Camille Freitag [Senior Research Associate], as published in Forest Products Journal, 54:4, 2004.
"The use of chlorine bleach is not recommended as a routine practice during mold cleanup." from the www.epa.gov website
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