Termites and mold are two of the most destructive threats to wood. Chemicals, treatments and insecticides that are used to protect lumber from these organisms are usually relatively hazardous to humans. Now a substance used in a number of consumer products is gaining attention as a wood-protecting tool.
Propylene glycol has been found effective against mold and termites. It has proven mostly safe for people in low doses, though large concentrations can have negative effects. It is used as a moisturizing agent in lotions and beauty products, and in food and tobacco. Propylene glycol is an "organic compound (a diol alcohol), usually a tasteless, odorless, and colorless clear oily liquid ... ," according to Chemical.net.
In 2007 a product known as Durazol was tested on unseasoned southern pine wood. Propylene glycol is one of the main active ingredients in Durazol. The Durazol-soaked wood completely resisted mold, fungus and termites for eight weeks, while untreated specimens were nearly completely covered by mold and termites. This test was done by the Wood Protection Association in cooperation with the U.S. Forest Service, the U.S. Department of Agriculture and Forest Products Laboratory.
Bearfortlodge.com, a log-home maintenance website, offers a recipe for making a home wood treatment using one gallon of propylene glycol, 4 pounds of Borax and 3 1/2 pounds of boric acid. Soaking or spraying wood with this solution will help protect it from many kinds of damage for an extended period of time. See Resources below for a link to the recipe and instructions.
Where to Obtain Propylene Glycol
Although regular stores usually don't sell propylene glycol, a few places online do. Among them are Chemical.net and QualiChem Technologies.