Copper Care Wood Preservatives, Inc. can help you get the copper naphthenate you need. Cu-Nap Concentrate and ready-to-use Tenino Copper Naphthenate are available in a wide variety of packaging options: two-hundred and seventy gallon totes down to pint bottles. Pints of Tenino are favored by utility linemen,while single gallon containers of ready-to-use Tenino stocked by many fine retailers and 55 Gallon drums of Cu-Nap Concentrate for bulk post treaters - Copper Care has Tenino and Cu-Nap Concentrate in packaging that works for you.


27 APR

TENINO Copper Naphthenate (2% copper as metal) EPA Reg. No. 64405-22-54471


Tenino Copper Naphthenate (2% copper as metal) meets the American Wood Protection Association’s (AWPA) M4 STANDARD FOR THE CARE OF PRESERVATIVE-TREATED WOOD PRODUCTS as defined in Section 7.1.1 for field treating abrasions, cuts and holes in treated lumber, timbers, and decking.

Copper Naphthenate has been used as a wood preservative for over one hundred years with many applications for use including; fence posts, canvas, nets, greenhouses, utility poles, and wooden structures in ground contact. Tenino provides protection against wood decay and the superior water repellent qualities of an oil borne wood preservative.
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Tenino Copper Naphthenate AWPA Standard M-4 for field treatment of wood:

Copper Naphthenate preservatives containing a minimum of 2.0% copper metal are recommended for material originally treated with copper naphthenate, pentachlorophenol, creosote, creosote solution or waterborne preservatives.

AWPA Standard M4 Section 7 field treatment of wood

Copper Care Wood Preservatives' Cu-Nap Concentrate (8% Cu as metal) is a liquid Copper Naphthenate wood preservative that can be diluted with diesel or mineral spirits. It is widely used as a dip treatment for fence posts using a 24-hour soak. Cu-Nap Concentrate is labeled for the treatment of posts, poles, lumber, siding, boxes, roof shakes and shingles, fence pickets, landscape timbers, cellulose textiles and cordage. Apply by brush, dip, or pressure treatment. Cu-Nap Concentrate is a cost effective solution for large volume, commercial users. For dilution and other detailed information, refer to the product label, the product flyer, or call us.

Graphic indicating results of USDA FPL long term study results comparing CuNap and Creosote efficacy.

Performance Study

In a major 50+ year study by the USDA Forest Product Laboratories, wood treated with copper naphthenate demonstrated similar performance to that of creosote treated woods.

Copper Naphthenate is an oil-borne wood preservative classified as general use by the United States Environmental Protection Agency (EPA) under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Copper Care Wood Preservative’s Tenino, and Cu-Nap concentrate products are EPA-registered “general use” preservatives and have been standardized for use by the American Wood Protection Association (AWPA). Creosote and pentachlorophenol are used in pressure treatment for utility poles, bridge timbers and railroad crossties. Copper naphthenate is the only non-restricted use product in this market. Copper naphthenate has a low mammalian toxicity profile.


USDA Forest Service Forest Products Laboratory studies document long-term performance. American Wood Protection Association (AWPA) Standards ensure peer review and qualify intended applications.

Formosa Subterranean Termite Protection

University of Hawaii in studies demonstrates Copper Naphthenate can provide effective protection against Formosan Termites. To achieve effective, long-term protection against termites, treat to the required AWPA Use Category 4C requirements.

Time Tested

Copper Naphthenate has been used as a wood preservative for over one hundred years with many applications for use, including field boxes, benches, flats, fence posts, water tanks, canvas, burlap, ropes, nets, greenhouses, utility poles, crossarms, and wooden structures in ground contact and above ground contact.

Reveals Natural Wood Grain

The bright green color of wood freshly treated with copper naphthenate will become brown in outdoor exposure. Multiple studies demonstrate no excessive corrosion of hardware and fasteners due to contact with the preservative.

Peeled pine fence posts treated with Cu-Nap Concentrate copper naphthenate quickly faded from an inital green to natural copper tone after a briefexposure to the elements

Broad Use and Safer Handling

Copper Naphthenate provides protection against wood decay and the superior water repellent qualities of an oil borne wood preservative. Copper Naphthenate treatments result in wood that is cleaner to the touch, with minimal excess preservative coming in contact with the environment. Copper Naphthenate is the green choice in preservatives because it is not a restricted use pesticide. With durability equal to or better than other preservatives, it is a great choice for bridge timbers, barn timbers, glulam beams, salt storage domes, protector boards and highway railings. For many applications copper naphthenate is the best wood preservative available to contractors and builders. Use copper naphthenate when wood will be in contact with the ground and as an end cut treatment when applied to cut pressure treated wood.

Packaging That Lasts

Our Black Nylon fortified HDPE one-gallon jugs and our clear PET pints and quarts provide excellent resistance to aromatic hydrocarbon degradation. Our containers and copper naphthenate products have a shelf life rating of five years. Our unique induction seal uses 18 microns of copper foil which eliminates galvanic degradation of the seal. Trust Copper Care Wood Preservatives to provide the best packaging solutions for Cu-Nap Concentrate and Tenino Copper Naphthenate.

Waste Disposal

Copper Naphthenate treated wood waste is neither a listed nor a characteristic hazardous waste according to the current EPA regulations under the Resources Conservation and Recovery Act (RCRA). It may be disposed of in landfills in accordance with federal, state and local regulations.

100% Domestic

The primary constituents of the treating solution are derived and/or manufactured from domestic sources by US owned companies.