Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

NAPHTHENIC ACID

NFPA

PRODUCT USE

Any group of saturated higher fatty acids derived from the gas- oil fractionation of
petroleum. Still residues from the so- called " naphthenic base crudes" (oils typically
found in Romania, the Caribbean, Gulf and the West Coast) contain considerable acid
fractions. These are removed by extraction with caustic soda solution and subsequent
acidification. Vacuum distillation yields refined naphthenic acid of quality suitable for
drier manufacture. Driers are metal salts of naphthenic acid (e.g. lead- , cobalt,
manganese- naphthenates). The term " chemically pure naphthenate" refers to a substance of
variable composition and means " made only from naphthenic acid" . By reason of its lower
acid value compared to synthetics such as octoates and neo- decanoates the maximum metal
content of solid naphthenates is lower than that of synthetic- based driers. Other uses
for naphthenic acid include solvents, detergents, rubber- reclaiming agents.

SYNONYMS

"saturated higher fatty acids", "naphthenic base crude", "drier precursor", Agenap,
Naphid, "Sunaptic acid b", "Sunaptic acid c", "naphthenic acids, ", "petroleum crude"

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  The material has NOT been classified as "harmful by ingestion". This is because of the lack of corroborating animal or human evidence. The material may still be damaging to the health of the individual, following ingestion, especially where pre-existing organ (e.g. liver, kidney) damage is evident. Present definitions of harmful or toxic substances are generally based on doses producing mortality (death) rather than those producing morbidity (disease, ill-health). Gastrointestinal tract discomfort may produce nausea and vomiting. In an occupational setting however, unintentional ingestion is not thought to be cause for concern.  The LD50s of naphthenic acids (a mixture of isomers of dimethylcyclohexanecarboxylic acid) in mice and rats were 1770 and 1750 mg/kg, respectively. Cumulative properties of naphthenic acids were mild. The oral LD50 in male mice of commercial sodium salts of naphthenic acids was found to be 3550 mg/kg body weight. Symptoms included central nervous system depression, convulsions and respiratory arrest. For rats the oral LD50 value for commercial naphthenic acids was 3000 mg/kg, while for mixtures of dicyclohexane (a specific naphthenic acid), the oral LD50 was 1750 mg/kg.  Exposure of Wistar rats to single or repeated oral doses of naphthenic acids produced a number of treatment-related effects, particularly in the highest dose groups. Marked reduction in food consumption was observed immediately following dosing in the high-dose group of the acute toxicity study. A similar decrease in food consumption was observed in the subchronic study, but in both cases the effect was short-lived. Appetite suppression was probably not due to direct irritation of the gastrointestinal lining, since repeated exposure did not sustain the effect in the subchronic study. In addition, there was no histopathological evidence of gastrointestinal irritation in either study. The mechanism of toxicant-induced anorexia has yet to be determined.  The results of the acute toxicity test suggested exposure to naphthenic acids at levels of 300 mg/kg in rats had both cardiovascular and hepatic effects. A single oral dose of 300 mg/kg produced significant cerebral hemorrhage in male rats. Vasoactive effects of naphthenic acids were also noted study by following intramuscular injection with 150 mg/kg cyclopentane naphthenic acid for 10 days; increased vascular permeability of cerebral capillaries was seen. Such an effect could be linked to the cerebral hemorrhaging or periarteriolar necrosis/fibrosis in the heart that was apparent following acute exposure to naphthenic acids. It is unclear why the cerebral hemorrhage was more prevalent in male than in female rats. It is unknown whether the effects of acute naphthenic acid dosing on cardiac tissue (periarteriolar necrosis/fibrosis) are attributable to parent naphthenic acids or their metabolites.  The clearest demonstration of a target organ in the acute toxicity test was the liver, where the inflammation of tissues around the bile duct (pericholangitis) was consistent between sexes and highly dose-dependent.  

EYE

  Although the liquid is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn).  

SKIN

  The material is not thought to produce adverse health effects or skin irritation following contact (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  The liquid may be miscible with fats or oils and may degrease the skin, producing a skin reaction described as non-allergic contact dermatitis. The material is unlikely to produce an irritant dermatitis as described in EC Directives .  Open cuts, abraded or irritated skin should not be exposed to this material.  

INHALED

  The material is not thought to produce adverse health effects or irritation of the respiratory tract (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting.  There is some evidence to suggest that the material can cause respiratory irritation in some persons. The body's response to such irritation can cause further lung damage.  Inhalation hazard is increased at higher temperatures.  The material has NOT been classified as "harmful by inhalation". This is because of the lack of corroborating animal or human evidence. In the absence of such evidence, care should nevertheless be taken to ensure exposure is kept to a minimum and that suitable control measures be used, in an occupational setting to control vapors, fumes and aerosols.  Acute effects from inhalation of high vapor concentrations may be chest and nasal irritation with coughing, sneezing, headache and even nausea.  

CHRONIC HEALTH EFFECTS

  Long-term exposure to the product is not thought to produce chronic effects adverse to the health (as classified using animal models); nevertheless exposure by all routes should be minimized as a matter of course.  In dogs and rabbits that received naphthenic acids (10 mg/kg, intravenously, and 5-15 mg/kg, intramuscularly, respectively), a notable effect was observed on haemopoiesis of both the red and white cells and a greater effect was observed on platelet formation.  In a one generation reproduction study naphthenic acid in a carrier oil was administered dermally to 12 proven male New Zealand White rabbits at 2 ml/animal for 6 hrs, 5 days each week over 10, weeks and observed for an additional 12 week post-exposure period. There were no significant differences between treated and control animals in the following: survival, body weights, testes weights, numbers of animals achieving 1 or 2 viable litters or pregnancies, numbers of implantations, pre- or post-implantation losses,  numbers of viable fetuses. There were no signs of toxicity either systemically or at the site of application and no macroscopic or microscopic pathological findings.