Unlike creosote, pentachlorophenol, and arsenic-containing preservatives, copper naphthenate has been classified by the US EPA as a "General Use" (not "Restricted Use") pesticide due to its relatively benign toxicity profile, i.e., its use and application is not restricted to only by or under the direct supervision of trained and certified applicators. As such, copper naphthenate is available over the counter in ready-to-use formulations for consumer/residential use. It is also used in non-pressure applications for preserving textiles and cordage, and is widely used for remedial treatment of utility poles in service and for treating end cuts, holes, and other damage to the surface of treated wood. Copper naphthenate in both oil-borne and waterborne formulations has been adopted by the American Wood Protection Association as an AWPA-standardized wood preservative. Commercial application for heavy duty commodities such as poles, ties and timbers is predominantly by pressure treatment. Non-pressure methods such as thermal (non-pressure) dipping of utility poles from the butt to above the ground line has also been used, particularly for naturally durable species such as western red cedar. Consumer methods of application include dip, brush or spray; specific directions for use are found on the pesticide label on the container. The color of CuN-treated wood may vary from light brown-green to dark brown depending on the type of oil and the treating process. Exposure to sunlight gives the wood a medium brown color over time. Copper naphthenate is also used as the antimicrobial active ingredient and drying agent in FDA-approved hoof thrush treatments for horses. As an inert ingredient, copper naphthenate is used mainly in insecticide and nematicide formulations when applied to soil and/or growing crops (prior to formation of edible parts) Metal naphthenates have been used as additive driers in alkyd paints. They increase the rate of drying of the applied paint on surface . The antimicrobial properties of copper compounds have long been exploited as pesticides due to their broad activity against a variety of decay fungi and wood-destroying insects, including termites. Copper naphthenate, when used as a preservative for wood and other cellulosic materials such as cotton fabric and cordage, is by definition a pesticide and thus must be registered with the U.S. Environmental Protection Agency (EPA). Copper naphthenate has been registered with EPA since October 29, 1951.