New wood preservative satisfies EPA demands

A new wood preseruative said to be environmentally safe has been okayed for use in the U.S.

Registered with the EPA in June, ammoniacal copper quat (ACQ) has been accepted by the American Wood Preserver's Association. Accepted as an inorganic wood preservative system by the AWPA P-4 committee during the annual technical committee meetings in Clearwater Beach, Fl., Sept. 8-13, ACQ will be added to AWPA Standard P-5 (waterborne preservatives) as ACQ-Type A and ACQ-Type B. Comprised of copper oxide and quaternary ammonium, ACQ is canied in aqueous ammonia.

The AWPA has set retention levels of.25 lbs. per cu. ft. above ground and .40 lbs. per cu. ft. with ground contacr, the same as for CCA.

Following AWPA procedures, ACQ will be presented to the general membership at the May 1992 annual meeting, with inclusion in AWPA publications probably occuring in 1993, according to John Hall, AWPA executive director.

ACQ has been used in Scandinavia for two years and in Japan for a little over a year. Its use in the U.S. has been limited to technical trials. The product has a history of more than nine years ofextensive and exhaustive testing, according to a spokesman for CSI, Charlotte, N.C. CSI will make and market ACQ in the U.S. under a brand name still to be determined.

The product has many advantages, Jim Saur, vice president of marketing, explains, and penetates a wider range of softwood species than CCA. Lumber treated with it has a brown color and is easily painted or stained. A competitive warranty will be offered by CSI when marketing begins, Saur says.

The treating process will remain essentially the same as the process using CCA. Treaters will be able to use existing equipment with slight modification, although all traces of previously used chemicals will have to be purged to avoid cross-contamination. Treaters who use the product will not be subject to current EPA listing.

CSI has completed a comprehensive marketing study to determine the areas where the new product will debut. Saur estimates products treated with it will be available for the 1992 spring buying season.

The cost to consumers is expected to be l0-25Vo higher than the average CCA treated wood price, but CS['s research claims that consumers and specifiers are willing to pay more for an environmentally acceptable product.

Reaction in the pressure treating community is mixed. ACQ is not unknown to most of the chemical companies and treaters. A large chemical supplier says they tested it in their lab and found it lacking. Some express reluctance to accept a product with such a short history, while others balk at the higher cost. However, all agree that an environmentally acceptable preservative is a step in the right direction to answer increasing EPA regulatory pressures.