Treated Wood Products

One significant responsibility of the Missouri Department of Agriculture’s Forest Resources Program is the regulation of the wood treating industry. This regulation deals with the quality of treated products produced and is conducted by the authority of the Missouri Treated Timber Law.

Inspectors visit all wood treating facilities within the state to ensure that proper treating methods are being followed. In addition, core samples of the finished product are taken and analyzed to determine depth of penetration and net retention. Depth of penetration refers to how deep the wood preservative had actually gone into the wood. Net retention refers to the actual quantity of chemical found in the wood.

Missouri is home to a variety of wood treating facilities. Currently, CCA, pentachlorophenol, copper naphthenate and creosote are the four types of wood preservers treated and sold in the state. However, new “alternative” wood preservers will be entering the market relatively soon as a result of the CCA phase-out. Two of the predominant replacements for CCA treated lumber will be ACQ and copper azole.

In addition to monitoring the quality of Missouri’s treated wood products, the program also issues two types of licenses. Producer licenses are issued to wood treating facilities in-state and out-of-state that both sell and treat wood products into Missouri. Dealer Licenses are issued to retail and wholesale establishments that do not treat but do sell treat wood products in Missouri. Dealer licenses are only required by businesses physically located within the state.

For additional information regarding the rules and regulations associated with the Missouri Treated Timber Law or to view licensed treated timber producers or dealers, please refer to the following websites:

View the Missouri Treated Timber Law

View the Missouri Treated Timber Regulations

View list of Missouri Treated Timber Producers (Wood treaters licensed to sell products in Missouri)

View list of Missouri Treated Timber Dealers (Retail or wholesale companies currently selling treated wood products)

For additional information on treated wood products, see the website below:

AWPA - American Wood Preservers' Association