Food Storage and Preservative-treated Wood

Increasing use of preservative-treated wood for housing foundations in the north leads to a question posed by Doug Yates of Fairbanks: Is it safe to store vegetables in a root cellar constructed of the treated wood?

There are several different types of preservative used to treat wood. Dr. Don Dinkel of the University of Alaska's Agricultural Experiment Station says that it is safe to grow plants treated in the chemical copper-naphthanate sold under the brand name Cuprinol. When first treated, the wood will give off fumes toxic to plants, but the fumes soon go away.

In contrast, the preservative, pentachlorophenol, frequently used as to preserve fence posts and which may be sold under the name Woodlife, is definitely poisonous to plants and will kill them.

Thanks to Jack Babcock of Fairbanks Lumber Supply I was able to contact a representative for a firm that pressure-treats wood sold in Alaska. This representative recommends that no foodstuffs be stored in contact with wood treated with his firm's product. It has the brand name Chemonite and the chemical formula ammoniacal- cupric-arsenate. According to him, the only safe wood preservative for food storage containers is one called copper-8-quinolinolate. It is the only wood preservative recommended by the U.S. Department of Agriculture for the storage of food.

The bottom-line answer to Doug Yates' question is a positive yes if the food is to be stored in a root cellar having wood treated with copper-8-quinolinolate; the vegetables can even be stored in contact with the wood. It probably is quite safe to store in root cellars where other wood preservatives are used, but the stored food must not come in contact with the treated wood.