Appendix
A: Chemicals-At-A-Glance
| Copper
Naphthenate penta arsenicals creosote copper naphthenate |
Identity
And Uses
Copper
naphthenate is a copper salt of naphthenic acid. Naphthenic acid is
a complex natural mixture of fatty acids found in petroleum. It is
a by-product of petroleum refining and has a variable composition.1
Ingredients, including contaminants, inerts, and by-products A typical
copper naphthenate product would be about 19% copper naphthenate and
81% secret ingredients.2 The copper naphthenate portion is itself
poorly characterized. Its composition depends on the composition of
the source petroleum. The naphthenic acids may contain such constituents
as cyclopentylacetic acid, alkyl-substituted cyclopentylacetic acids,
fused chains of cyclopentylacetic acids, cyclohexylacetic acids, cyclopentanoic
acids, and various low-molecular-weight fatty acids.3 It may also
be contaminated up to 25% with hydrocarbons such as benzene from the
petroleum source.4
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| Toxicology The toxicology of copper naphthenate has not been well documented. EPA reports that little of the required data has been submitted--very little acute toxicity data, no chronic toxicity data, and no inhalation data. Similarly, the Canadian Centre for Occupational Health and Safety has no information for most health effects of copper naphthenate.7 AbsorptionLittle is reported. However, one study of a family living in a home with a foundation treated with copper naphthenate speculated that the increased blood levels of copper may have arisen from copper volatilized by the copper naphthenate formulation.8Clearing, detoxification, and metabolismCopper is generally cleared from the body unless in acutely toxic quantities. It is stored in the liver and marrow.9Acute toxicityInhalation of copper salts in dusts can lead to congestion of nasal membranes, congestion of the upper digestive, and perforation of the nasal septum. Very high concentrations can cause extreme symptoms of irritation.10 Very little information is available about the toxicity of naphthenic acids.Although as much as 25% of copper naphthenate may be hydrocarbon contaminants from petroleum, we know very little about these contaminants, except that they are variable in identity and quantity. Petroleum does contain many acutely toxic, chronically toxic, and carcinogenic compounds such as benzene, however, and we must assume that some of them are present in copper naphthenate.Critical dosesEPA does not have enough information to establish a LD50 (lethal dose for half of the test population).Chronic health effectsChronic exposure to copper salts may result in anemia.11 Exposure to naphthenic acids increases the permeability of membranes, which could increase uptake of other toxic substances.12 Although as much as 25% of copper naphthenate may be hydrocarbon contaminants from petroleum, we know very little about these contaminants, except that they are variable in identity and quantity. Petroleum does contain many acutely toxic, chronically toxic, and carcinogenic compounds such as benzene, however, and we must assume that some of them are present in copper naphthenate. We also know nothing about the effects of the secret ingredients that make up 80% of copper naphthenate products.Organ damageBoth copper salts and naphthenic acids are skin irritants.NeurotoxicityExposure to naphthenic acids increases the permeability of membranes to potassium, which could affect nerve transmission.13 Although as much as 25% of copper naphthenate may be hydrocarbon contaminants from petroleum, we know very little about these contaminants, except that they are variable in identity and quantity. Petroleum does contain neurotoxic compounds such as benzene, however, and we must assume that some of them are present in copper naphthenate.Reproductive toxicity and teratogenicityNo data.ImmunotoxicityNo data.Critical dosesEPA has not set levels because of inadequate information.CancerChronic exposure to copper salts has produced lung and liver damage which sometimes progressed to cancer.14MutationsTests submitted to EPA found copper naphthenate induces DNA damage.15Endocrine disruptionNo data. |
Ecological EffectsBioaccumulation/bioconcentration potentialExcept in extreme exposure conditions, excess copper is cleared from organisms. Mollusks accumulate more naphthenic acids than less toxic components of oil.16Leaching potential and environmental fateCopper salts have been found to leach from wood treatment sites. More leaches under acidic conditions.17 No data is available on the environmental fate of naphthenic acids.EcotoxicityCopper naphthenate is toxic to a wide variety of organisms. It kills microorganisms, fungi, and plants.18 It is toxic to aquatic life--including invertebrates, algae, and fish--in very low concentrations.19 Naphthenic acids reduced the fertility of sturgeon roe and the survivability of adults.20 |