Creosote Treated Timber in the Alaskan Marine Environment

Robert Perkins
Wed, 22 Apr 2026 17:10:59 PDT

Creosote is a wood preservative that is used in marine structures in Alaska, such as piles, docks, and floating structures. Some of the PAH chemicals in creosote are toxic to marine organisms, and resources agencies and environmental groups question its use. Mesoscale testing of creosoted wood has not indicated significant negative effects of wood treated with Best Management Practices (BMP), which is now standard practice. The EPA pesticide recertification of creosote required only the use of BMP or a risk assessment. The National Marine Fisheries Service issued draft guidelines for wood preservatives, which does not preclude use of creosote, but suggest a risk assessment if the qualities of treated wood are large or they are installed in sensitive areas. This report recommends consideration of the risks of creosote and presents an algorithm for analyzing the risks. Many applications require only an overview risk assessment. Applications of large quantities of preserved wood or in sensitive areas should have a more formal risk assessment. The report and the EPA recertification suggest a screening assessment published by the Western Wood Preservers Institute. If the screening indicates further assessment is needed, the report points to more detailed assessments.