Investigating the presence of mold in wood treated with chlorophenol

A common moisture-related problem in Sweden and other countries, is mold odor indoors. The general perception is that mold odor indicates hazardous hidden mold. However, some grey literature studies indicate that the source of mold odor might not be substantial amounts of mold, but rather chloroanisoles (CAs) which are biomethylated from chlorophenols (CPs) in moist conditions. Products containing CPs were commonly used world-wide as wood preservatives in the 1960-70s and problems with indoor mold odor have been reported in buildings where such products have been used. In Sweden, one of the main uses of CPs in buildings was in wooden constructions exposed to big moisture loads, such as sill plates and crawl space ceilings. Here we aimed to determine the potential presence and level of mold growth on wood treated with CPs in one school building with reported odor problems built in the stated time period. Odorous wooden samples were taken and analyzed for mold growth. No mold was detected by the naked eye, but some growth was seen using a microscope. We presently investigate more schools and samples, but so far our results question that mold odor depends on substantial amounts of mold.