Names | |
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IUPAC names Copper salt Naphthenic acid | |
Other names QNAP, Cunapsol, CuNap, Cuprinol | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.014.234 |
EC Number |
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PubChem CID | |
RTECS number |
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UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
CuCnH2n-zO4 n: 10-24; z: 0, 1, 2 | |
Molar mass | ~346-782 |
Appearance | Blue-green amorphous solid or viscous liquid. Always formulated as a liquid solution or emulsion. |
Density | 1.055 g/cm3 (1.02 g/cm3 as 8% Cu solution in #2 diesel) |
Boiling point | Non-volatile: > 100 °C (212 °F; 373 K) |
Essentially insoluble; 46 mg/L | |
Hazards | |
Flash point | > 37.8 °C (100.0 °F; 310.9 K) as solution in mineral spirits |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Copper naphthenate is a copper derivative of naphthenic acid. Although commonly called salts of naphthenic acid, copper naphthenate is not ionic, but is a covalent coordination complex, hence its lipophilic character. Copper naphthenate is most widely used in wood preservation and for protecting other cellulosic materials such as textiles and cordage from damage by decay fungi and insects. Other metal naphthenates are used as paint driers, rubber adhesion promoters, lubricant additives, and catalysts where oil solubility is required.
Copper naphthenate has the general formula Cu(RCOO)2. Its structure is assumed to resemble that of copper(II) acetate.
Copper naphthenate is commonly prepared by treatment of naphthenic acid with copper(II) compounds such as basic copper carbonate or copper hydroxide. [1] Even copper(II) sulfate can be treated with sodium or potassium naphthenate in aqueous solutions. The reaction of copper metal with naphthenic acid, which has been used commercially, requires more forcing reaction conditions and generates excessive impurities. [2] Less commonly practiced methods of synthesis include reaction of copper acetate with naphthenic acid, [3] which generates acetic acid as a byproduct, and electrochemically using copper electrodes. [4]
Copper naphthenate is a dark-green, amorphous glassy solid, paste or viscous liquid that is freely soluble in various organic solvents including mineral spirits, diesel fuel and other fuel oils, and creosote-petroleum mixtures. Copper naphthenate free of any solvent has a copper content ranging from 10-13% by weight, depending on the acid number/molecular weight of the naphthenic acid used. The properties of copper naphthenate treating solutions are dependent on the type of oil used as the carrier. Copper naphthenate sold for pressure treatment of wood is typically supplied as an 8% copper (as metal) concentrate for dilution to 0.5-1.5% copper (as metal) treating solutions. Copper naphthenate sold at retail for consumer use is typically a 1% or 2% copper ready-to-use solution in mineral spirits or other similar solvents. Waterborne copper naphthenate formulations are also available as a 5% copper (as metal) concentrate and used after further dilution with water.
Copper naphthenate is an active ingredient used predominantly in industrial and commercial wood preservation for non-pressure (dip/brush/spray) and pressure treatments (vacuum/full cell) to protect against fungal rot, decay, termites and wood-boring insects in unfinished wood and various fabricated wood products. This preservative is also used for remedial treatments to in-service poles including internal/external surfaces at ground or below ground level via brush/trowel, mechanical injection, or bandage wrap. Wood treated with copper naphthenate is specified for exterior above ground, ground contact, below ground and fresh water contact use applications. Copper naphthenate is also used as protective wood preservative surface treatments when applied to bare seasoned wood. For this use, it is readily available to the general public and sold over-the-counter to consumers as wood protection coatings and water repellants. [5]
Copper naphthenate has been commercially produced and industry utilized as wood preservative since its first use in Europe in 1889. [6] It is typically formulated in hydrocarbon solvents such as diesel, heavier fuel oils, or mineral spirits, although waterborne formulations are also used to preserve dimensional lumber and in non-pressure applications such as wooden roof shakes and shingles. Copper naphthenate in oil is a heavy duty wood preservative used for utility poles, railroad crossties and bridge timbers, highway construction such as posts and guardrails, fence posts, and piles.
In addition to broad efficacy against decay fungi and wood-destroying insects, its low mammalian toxicity is a key reason why copper naphthenate has gained market acceptance as a proven effective wood preservative that is specified and used extensively for environmental reasons by utilities and railroads as a less toxic alternative to creosote, pentachlorophenol and arsenicals in poles, crossties and bridge timbers. [6] 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 the surface . [7]
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. [8] [9] 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. The EPA PC code for copper naphthenate is 23102, and registered pesticide products may be searched under that PC code at http://ppis.ceris.purdue.edu/ Archived 2017-10-04 at the Wayback Machine . Copper naphthenate is classified by EPA as a general use (i.e., a non-restricted use) pesticide by virtue of its relatively benign toxicity profile. [5] Copper naphthenate is the only non-restricted use wood preservative in widespread use for "heavy duty" commodities such as utility poles, railroad crossties and timbers, pilings and fence posts. The general use classification also allows copper naphthenate to be sold over the counter for consumer uses such as treated wood for fences and decking, and for brush-on application for end cuts and other areas where exposed wood may be subject to insect attack or decay. Products formulated or repackaged from these compounds must be labeled for "Exterior Use Only". Treated wood materials preserved with copper naphthenate salt preservatives are intended for exterior use-site applications only; indoor installation and uses are not allowed.
Copper naphthenate, as with all metal carboxylates, readily dissociates into free metal and free acid in a reversible process, where the portion of dissociated salt present is dependent on the pH and pKa (the dissociation constant). The degree of dissociation influences the behavior of the substance in the environment because the free acid (naphthenic acid) and corresponding free metal (copper) have different solubility, adsorption, and toxicity characteristics than the undissociated salt. Carboxylate salts are found as partially dissociated products in the ambient environment at near neutral pH; in low pH environments such as the digestive tract (e.g., pH 1.2) complete dissociation of metal carboxylates will occur. Naphthenic acid is biodegradable; indigenous bacteria present in oil sands tailings can utilize naphthenic acid as a sole source of carbon, converting about 50% of the carbon into carbon dioxide. [10]
Copper naphthenate is not listed as a hazardous air pollutant or reproductive toxin, contains no listed carcinogens, and exhibits low mammalian toxicity by oral, dermal, and inhalation routes of exposure. [11] As with all other types of preservative treatment, wood treated with copper naphthenate is not considered a hazardous waste. Unlike the other heavy duty wood preservatives that are restricted use pesticides, neither copper naphthenate nor wastes from copper naphthenate wood treatment operations are listed as hazardous wastes.
Creosote is a category of carbonaceous chemicals formed by the distillation of various tars and pyrolysis of plant-derived material, such as wood, or fossil fuel. They are typically used as preservatives or antiseptics.
Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. The word "surfactant" is a blend of surface-active agent, coined c. 1950. As they consist of a water-repellent and a water-attracting part, they enable water and oil to mix; they can form foam and facilitate the detachment of dirt.
Cedar oil, also known as cedarwood oil, is an essential oil derived from various types of conifers, most in the pine or cypress botanical families. It is produced from the foliage, and sometimes the wood, roots, and stumps left after logging of trees for timber. It has many uses in art, industry, and perfumery, and while the characteristics of oils derived from various species may vary, all have some degree of pesticidal effects.
A biocide is defined in the European legislation as a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism. The US Environmental Protection Agency (EPA) uses a slightly different definition for biocides as "a diverse group of poisonous substances including preservatives, insecticides, disinfectants, and pesticides used for the control of organisms that are harmful to human or animal health or that cause damage to natural or manufactured products". When compared, the two definitions roughly imply the same, although the US EPA definition includes plant protection products and some veterinary medicines.
Wood easily degrades without sufficient preservation. Apart from structural wood preservation measures, there are a number of different chemical preservatives and processes that can extend the life of wood, timber, and their associated products, including engineered wood. These generally increase the durability and resistance from being destroyed by insects or fungi.
A drying oil is an oil that hardens to a tough, solid film after a period of exposure to air, at room temperature. The oil hardens through a chemical reaction in which the components crosslink by the action of oxygen. Drying oils are a key component of oil paint and some varnishes. Some commonly used drying oils include linseed oil, tung oil, poppy seed oil, perilla oil, and walnut oil. Their use has declined over the past several decades, as they have been replaced by alkyd resins and other binders.
Benzyl alcohol (also known as α-cresol) is an aromatic alcohol with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is denoted as BnOH. Benzyl alcohol is a colorless liquid with a mild pleasant aromatic odor. It is a useful as a solvent for its polarity, low toxicity, and low vapor pressure. Benzyl alcohol has moderate solubility in water (4 g/100 mL) and is miscible in alcohols and diethyl ether. The anion produced by deprotonation of the alcohol group is known as benzylate or benzyloxide.
Pentachlorophenol (PCP) is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names. It can be found as pure PCP, or as the sodium salt of PCP, the latter of which dissolves easily in water. It can be biodegraded by some bacteria, including Sphingobium chlorophenolicum.
A utility pole is a column or post usually made out of wood used to support overhead power lines and various other public utilities, such as electrical cable, fiber optic cable, and related equipment such as transformers and street lights. It can be referred to as a transmission pole, telephone pole, telecommunication pole, power pole, hydro pole, telegraph pole, or telegraph post, depending on its application. A Stobie pole is a multi-purpose pole made of two steel joists held apart by a slab of concrete in the middle, generally found in South Australia.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes, such as petroleum refineries, chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers, lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter, toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants, and then discharge the partially treated wastewater to the municipal sewer system.
Lead hydrogen arsenate, also called lead arsenate, acid lead arsenate or LA, chemical formula PbHAsO4, is an inorganic insecticide used primarily against the potato beetle. Lead arsenate was the most extensively used arsenical insecticide. Two principal formulations of lead arsenate were marketed: basic lead arsenate (Pb5OH(AsO4)3, CASN: 1327-31-7) and acid lead arsenate (PbHAsO4).
The arsenate is an ion with the chemical formula AsO3−4. Bonding in arsenate consists of a central arsenic atom, with oxidation state +5, double bonded to one oxygen atom and single bonded to a further three oxygen atoms. The four oxygen atoms orient around the arsenic atom in a tetrahedral geometry. Resonance disperses the ion's −3 charge across all four oxygen atoms.
Chromated copper arsenate (CCA) is a wood preservative containing compounds of chromium, copper, and arsenic, in various proportions. It is used to impregnate timber and other wood products, especially those intended for outdoor use, in order to protect them from attack by microbes and insects. Like other copper-based wood preservatives, it imparts a greenish tint to treated timber.
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons, solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting clean ups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer modelling, and GIS in Environmental Contamination, as well as an appreciation of the history of industrial chemistry.
A wood-decay or xylophagous fungus is any species of fungus that digests moist wood, causing it to rot. Some species of wood-decay fungi attack dead wood, such as brown rot, and some, such as Armillaria, are parasitic and colonize living trees. Excessive moisture above the fibre saturation point in wood is required for fungal colonization and proliferation. In nature, this process causes the breakdown of complex molecules and leads to the return of nutrients to the soil. Wood-decay fungi consume wood in various ways; for example, some attack the carbohydrates in wood, and some others decay lignin. The rate of decay of wooden materials in various climates can be estimated by empirical models.
Naphthenic acids (NAs) are mixtures of several cyclopentyl and cyclohexyl carboxylic acids with molecular weights of 120 to well over 700 atomic mass units. The main fractions are carboxylic acids with a carbon backbone of 9 to 20 carbons. McKee et al. claim that "naphthenic acids (NAs) are primarily cycloaliphatic carboxylic acids with 10 to 16 carbons", although acids containing up to 50 carbons have been identified in heavy petroleum.
Alkaline copper quaternary, usually abbreviated ACQ, is a type of water-based wood preservative product containing a soluble copper(II) complex and quaternary ammonium alkyl- or aryl-substituted compounds ("quats"). Thus the product was originally called ammoniacal copper/quaternary ammonium.
Dry rot treatment refers to techniques used to eliminate dry rot fungus and alleviate the damage done by the fungus to human-built wooden structures.
Cyproconazole is an agricultural fungicide of the class of azoles, used on cereal crops, coffee, sugar beet, fruit trees and grapes, on sod farms and golf courses and on wood as a preservative. It was introduced to the market by then Sandoz in 1994.
Transition metal carboxylate complexes are coordination complexes with carboxylate (RCO2−) ligands. Reflecting the diversity of carboxylic acids, the inventory of metal carboxylates is large. Many are useful commercially, and many have attracted intense scholarly scrutiny. Carboxylates exhibit a variety of coordination modes, most common are κ1- (O-monodentate), κ2 (O,O-bidentate), and bridging.