2-Methylnaphthalene

Other Classes -> Naphthalenes

Flammable agents - 2nd degree

Semi-Volatile Organic Compound (SVOC) and(or) Waste-water effluent contaminant

log Kow = 3.86

3.86

3.96

1.0058 at 68 °F (NTP, 1992) - Denser than water; will sink

1.0058 at 20 °C/4 °C

Relative density (water = 1): 1.00

1.0058

1.0058 @ 20°C

Monoclinic crystals from alcohol

Solid or crystalline

less than 1 mg/mL at 70 °F (NTP, 1992)

In water, 24.6 mg/L at 25 °C

Miscible with alcohol and ether

Solubility in water, g/100ml at 25 °C: 0.003

208 °F (NTP, 1992)

98 °C (208.4 °F) Closed cup

208 °F

466 to 468 °F at 760 mmHg (NTP, 1992)

241.1 °C

241 °C

466-468 °F

241.1 °C @760 [mm Hg]

This chemical does not meet GHS hazard criteria for 3.2% (50 of 1564) of reports.

Warning

H302 (95%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P273, P301+P317, P330, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 1564 reports by companies from 13 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Warning

Chemical: Naphthalene, 2-methyl-

Hazard Traits - Environmental tox; Neurotoxicity

Commission Regulation (EC) No 1565/2000 (Repealed by Com. Implementing Reg. (EU) No 872/2012)

Naphthalene, 2-methyl- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Naphthalene, 2-methyl- are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

REACH registered substance: 2-methylnaphthalene (EC: 202-078-3)

2-Methylnaphthalene: Does not have an individual approval but may be used under an appropriate group standard

This chemical is combustible. (NTP, 1992)

Combustible.

SYMPTOMS: Symptoms of exposure to this compound may include irritation of the skin, eyes, mucous membranes and upper respiratory tract. It may also cause headaches, nausea, vomiting, diarrhea, anemia, jaundice, euphoria, dermatitis, visual disturbances, convulsions and comatose.

There are no studies of humans exposed to 1-methylnaphthalene or 2-methylnaphthalene. [ATSDR ToxFAQs] Minimal Risk Level (oral chronic) = 0.4 mg/kg/day (Resp.); [ATSDR] 1-Methylnaphthalene (1-MN) and 2-Methylnaphthalene (2-MN) are respiratory tract irritants. [ACGIH] See Naphthalene.

The major hazards encountered in the use and handling of 2-methylnaphthalene stem from its toxicologic properties. Toxic by all routes (ie, ingestion, inhalation, and dermal contact), exposure to this crystaline substance may occur from its production or use as a chemical intermediate in organic syntheses, in insecticides, or as a dye carrier. Effects from exposure may include facial flushing, fever, headache, skin irritation, corneal damage, nausea, anorexia, hemoglobinuria, hepatocellular injury, convulsions, and coma. Before implementing land disposal of waste 2-methylnaphthalene, consult with environmental regulatory agencies for guidance.

Schmeltz i et al; vol 3, Polynuclear Aromatic Hydrocarbons. Second International Symposium on Analysis, Chemistry, & Biology. Sept 1977, ISBN 0-89004-241-1: 47-60 (1978). Bioassays of naphthalene for cocarcinogenic activity relation to tobacco carcinogenesis was discussed. /Naphthalene & alkyl naphthalenes/

U.S. Dept Health & Human Services/Agency for Toxic Substances Disease Registry; Toxicological Profile for Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene (Update) (1995) NTIS# PB/95/264362

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Methylated naphthalenes is found on List C. Case No: 3088; Pesticide type: insecticide, fungicide; Case Status: No products containing the pesticide are actively registered. Therefore, we are characterizing the case as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): methylated naphthalenes; AI Status: The active ingredient is no longer contained in any registered products ... cancelled." /Methylated naphthalenes/

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Alkyl naphthalenes is produced, as an intermediate or a final product, by process units covered under this subpart. /Alkyl Naphthalenes/

Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. A water spray may also be use. (NTP, 1992)

Use powder, foam, carbon dioxide.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give a slurry of activated charcoal in water to drink. Rest. Refer for medical attention .

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.

Conditions for safe storage, including any incompatibilities: Keep container tightly closed in a dry and well-ventilated place.

Safe storage: Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing.

Accidental Release Measures. Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

Control of environmental exposure: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations. Do NOT let this chemical enter the environment.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with 60-70% ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with 60-70% ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

The following wastewater treatment technology has been investigated for naphthalene: Biological treatment. /Naphthalene/

Waste treatment methods. Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contaminated packaging: Dispose of as unused product.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

Precautions for safe handling: Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed.Normal measures for preventive fire protection.

Appropriate engineering controls Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.

Pretreatment of rainbow trout with 2,3-benzanthracene resulted in an increase in the metabolism and biliary excretion of 2-methylnaphthalene in vivo.

Mixed function oxidase inducers... affect the metabolism of 2-methylnaphthalene. Inducers that influence cytochrome P-450 increase the oxidation of the side chain and the concentration of one dihydrodiol. Induction of cytochrome P-450 increased the production of two other dihydrodiols. The production of naphthoic acid in preference to the diols may explain why 2-methylnaphthalene is less toxic to Clara cells than naphthalene.

PAHs are carcinogens and have been associated with the increased risk of skin, respiratory tract, bladder, stomach, and kidney cancers. They may also cause reproductive effects and depress the immune system. Exposure to large amounts of 2-methylnapthalene may damage or destroy the red blood cells, resulting in hemolytic anemia. (L10, L12)

EC50; Species: Daphnia magna (Water flea) age 4-6 days, length 1.5 mm; Conditions: freshwater, static, 23 °C, pH 6-7, dissolved oxygen 5-9 mg/L; Concentration: 13 mmol/cu m (95% confidence interval: 5-35 mmol/cu m); Effect: intoxication, immobilization /> or = 97% purity/

LC50; Species: Cancer magister (Dungeness crab) larvae; Concentration: 5.0 mg/L for 48 hr /Conditions of bioassay not specified in source examined/

LC50; Species: Cancer magister (Dungeness crab) larvae; Concentration: 1.3 mg/L for 96 hr /Conditions of bioassay not specified in source examined/

LC50; Species: Palaemonetes pugio (Daggerblade Grass Shrimp) adult; Conditions: saltwater, static, 21 °C, pH 8.1, dissolved oxygen >5 mg/L; Concentration: 1100 ug/L for 96 hr

For more Ecotoxicity Values (Complete) data for 2-METHYLNAPHTHALENE (9 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), log Koc values of 3.00-5.96 reported in soil and sediment(2-3) indicate that 2-methylnaphthalene is expected to have slight to no mobility in soil(SRC). Volatilization of 2-methylnaphthalene from moist soil surfaces is expected given a Henry's Law constant of 5.18X10-4 atm-cu m/mole(4). However, adsorption to soil is expected to attenuate volatilization(SRC). 2-Methylnaphthalene is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.055 mm Hg at 25 °C(5). A lag-period of two weeks was observed followed by rapid degradation to 17% residual in the two weeks following the lag period and was not detected after 25 weeks, using microcosms filled with soil material and a coal derived wood-preservative(6).

AQUATIC FATE: Based on a classification scheme(1), log Koc values of 3.00-5.96 reported in soil and sediment(2-3) indicate that 2-methylnaphthalene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(4) based upon a Henry's Law constant of 5.18X10-4 atm-cu m/mole(5). Using this Henry's Law constant and an estimation method(4), volatilization half-lives for a model river and model lake are 5.5 hours and 5.3 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 41-78 days if adsorption is considered(6). 2-Methylnaphthalene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). According to a classification scheme(7), BCF values of 30-2921 in Coho salmon(8), Starry flounder(8), sheepshead minnow(9) and bluegill sunfish(10), suggest bioconcentration in aquatic organisms is low to very high, the compound may be metabolized by the organism decreasing the BCF(SRC). The direct aqueous photolysis half-life for midday, midsummer sunlight at 40 deg N latitude was predicted to be 54 hours for 2-methylnaphthalene(11). 2-Methylnaphthalene was completely removed within <7-14 days from acclimated groundwater aquifer grab samples(12-13). Unacclimated material from the aquifer degraded 2-methylnaphthalene at an average rate of 3.5% per week(13).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 2-methylnaphthalene, which has a vapor pressure of 0.055 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 2-methylnaphthalene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 7.4 hour(SRC), calculated from its rate constant of 5.23X10-11 cu cm/molecule-sec at 25 °C(3). The rate constant for the vapor-phase reaction of 2-methylnaphthalene with ozone has been reported as <4X10-19 cu cm/molecule-sec at 25 °C(3). This corresponds to an atmospheric half-life of >29 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(4). The rate constant for the vapor-phase reaction of 2-methylnaphthalene with nitrogen pentoxide has been measured to be 4.2X10-17 cu cm/molecule-sec at 25 °C which corresponds to an atmospheric half-life of about 9.6 days at an atmospheric concentration of 2X10+10 nitrogen pentoxide molecules per cu cm(3). 2-Methylnaphthalene contains chromophores that absorb at wavelengths >290 nm(5) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

2-Methylnaphthalene was identified as a volatile component of cassava(1), roasted filberts(2), nectarines(3), and cooked meat (mutton, beef, chicken and pork)(4). Assorted types of lima, pinto, red kidney, black, navy and mung beans, soybeans, split peas and lentils were found to contain 2-methylnaphthalene at 2.8-49.2 ppb(5). Crab (Charybdis feriatus), commonly consumed in Asia, contained 2-methylnaphthalene concentrations of 404.4, 344.3 and 4800.5 ug/kg dry weight in meat from legs and claws, body and carapace, respectively(6). 2-Methylnaphthalene concentrations in wood smoke flavorings were 11.70, 9.27, 8.58, 109.02 and 28.43 ug/kg in oak, cherry tree, beech, poplar and vine shoots, respectively(7). 2-Methylnaphthalene was detected in five commercial olive pomace oil samples from Spain at 1.58-22.05 ug/kg; samples were collected 2001-2002(8). 2-Methylnaphthalene was detected in 35 milk samples collected from 8 grocery stores in Las Vegas, NV from Jan to Feb 2002; concentrations were 0.02-1.12, 0.04-0.69 and 0.03-1.39 ng/mL for whole, 2% and 1% milk, respectively(9).

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.

Oral (L10) ; inhalation (L10)

IDENTIFICATION AND USE: 2-Methylnaphthalene is a solid. It is used in organic synthesis; insecticides, pesticide adjuvant. It is also used as dye carrier. Pure 2-methylnaphthalene is used primarily as a raw material for the production of vitamin K preparations. HUMAN EXPOSURE AND TOXICITY: In contrast to naphthalene, the only reported effects of methylated naphthalene in man are skin irritation and skin photosensitization. It is not a human carcinogen. Chromosome analyses were carried out in human lymphocytes treated in vitro with 2-methylnaphthalene in the presence and absence of the mammalian metabolic activation system. Without metabolic activation there was no indication of induction of any significant cytogenetic effect by either compound. With metabolic activation a weak clastogenic effect was apparent at 4 mM 2-methylnaphthalene and sister-chromatid exchange frequencies were significantly increased at each dose of 2-methylnaphthale, yet always less than twice the control level. The present observations do not indicate that 2-methylnaphthalene must be classified as potential genotoxic substance. ANIMAL STUDIES: 2-Methylnaphthalene is an eye and skin irritant in rabbits. Single doses of 0 or 300 mg/kg 2-methylnaphthalene were administered to male mice by intraperitoneal injection, with sacrifice 24 hours later. Histological examinations identified bronchiolar necrosis in all treated animals, and no lesions among controls. 2-methylnaphthalene produced depression of the respiratory rate in rats under acute inhalation exposure. In mice treated by i.p. injection naphthalene and 2-methylnaphthalene were about equally toxic. In all cases the first evidence of cytotoxic effects was seen in the Clara cells of the bronchiolar epithelium, and, at the highest doses, toxic effects were found in the adjacent ciliated cells. Changes could be detected at the ultrastructural level at all doses, and within 6 hours after treatment. Only slight effects were seen in other cell types. Other studies demonstrated that a pulmonary toxic dose of 2-methylnaphtalene (400 mg/kg, i.p.) administered to mice significantly depleted reduced GSH in the liver and lung and to a lesser extent, in the kidney. Carcinogenicity studies in mice indicated that 2-methylnaphthalene induces pulmonary alveolar proteinosis but does not possess unequivocal carcinogenic potential in mice. 2-Methylnaphthalene was tested quantitatively using S. typhimurium TA98 and TA100 with and without metabolic activation, the concentration used was 3 umol/plate. 2-Methylnaphthalene was not mutagenic. ECOTOXICITY STUDIES: 2-Methylnaphthalene was toxic to Dungeness crab (C magister) larvae LC50 5 mg/L at 48 hr, LC50 1.3 mg/L at 96 hr.

The ability of PAH's to bind to blood proteins such as albumin allows them to be transported throughout the body. Many PAH's induce the expression of cytochrome P450 enzymes, especially CYP1A1, CYP1A2, and CYP1B1, by binding to the aryl hydrocarbon receptor or glycine N-methyltransferase protein. These enzymes metabolize PAH's into their toxic intermediates. The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. (L10, L23, A27, A32)

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their continued use. Under this pesticide reregistration program, EPA examines newer health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether the use of the pesticide does not pose unreasonable risk in accordance to newer saftey standards, such as those described in the Food Quality Protection Act of 1996. Pesticides for which EPA had not issued Registration Standards prior to the effective date of FIFRA '88 were divided into three lists based upon their potential for human exposure and other factors, with List B containing pesticides of greater concern than those on List C, and with List C containing pesticides of greater concern than those on List D. Methylated naphthalenes is found on List C. Case No: 3088; Pesticide type: insecticide, fungicide; Case Status: No products containing the pesticide are actively registered. Therefore, we are characterizing the case as "cancelled." Under FIFRA, pesticide producers may voluntarily cancel their registered products. EPA also may cancel pesticide registrations if registrants fail to pay required fees or make/meet certain reregistration commitments, or if EPA reaches findings of unreasonable adverse effects.; Active ingredient (AI): methylated naphthalenes; AI Status: The active ingredient is no longer contained in any registered products ... cancelled." /Methylated naphthalenes/

This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Alkyl naphthalenes is produced, as an intermediate or a final product, by process units covered under this subpart. /Alkyl Naphthalenes/

The tissue distribution of 2-methylnaphthalene was measured in guinea pigs 3, 6, 24, and 48 hours after oral administration of tritium-labeled 2-methylnaphthalene (10 mg/kg; 59 uCi/kg). ... The half-life of 2-methylnaphthalene in the blood was 10.4 hours.

The uptake, disposition, biotransformation, and elimination of (14)C-labeled 2-methylnaphthalene was studied in several species of fish. Half-lives of elimination of (14)C-2-methylnaphthalene from tissues, following exposure of rainbow trout fingerlings for 8 hr, were <24 hr. After exposure for 4 wk, half-life of elimination of (14)C was biphasic: half-life of rapid phase <24 hr; slow phase hundreds of hours.

Yields cis-1,2-dihydro-1,2-dihydroxy-7-methylnaphthalene and trans-1,2-dihydro-1,2-dihydroxy-7-methylnaphthalene in pseudomonas. /from table/

Yields 2-naphthylcarbinol in pseudomonas. /from table/

Metabolism of 2-methylnaphthalene in rats (in vivo and in vitro) ... was investigated. Conversion of 2-methylnaphthalene to both monohydroxylated compound and dihydrodiols was decreased by incubation with carbon monoxide, omission of NADPH or use of denatured microsomes, implying involvement of cytochrome(s) p450-linked mixed function oxidase activity. Pretreatment ... with phenobarbital and beta-naphthoflavone selectively altered the rate of formation of specific dihydrodiols by rat liver microsomes. Although phenobarbital had no significant effect on rate of dihydrodiol formation, beta-naphthoflavone was strong inducer.

The NADPH-dependent metabolism of naphthalene and 2-methylnaphthalene to covalently bound metabolites in lung or liver microsomal incubations occurred at easily measurable rates. Renal microsomal NADPH-dependent metabolism of either substrate was not detected. The formation of covalently bound naphthalene or 2-methylnaphthalene metabolites was dependent upon NADPH and was inhibited by the addition of reduced glutathione, piperonyl butoxide, and SKF 525A. Covalent binding of radioactivity from (14)C2-methylnaphthalene also was strongly inhibited by incubation in a nitrogen atmosphere or at 2 degree. The arachidonic acid-dependent formation of reactive metabolites from naphthalene or 2-methylnaphthalene was undetectable in microsomal incubations from lung, liver or kidney. Indomethacin, 1 hr before and 6 hr after the administration of 300 mg/kg naphthalene or 2-methylnaphthalene, failed to block the pulmonary bronchiolar injury induced by these aromatic hydrocarbons. These studies suggest that the major enzymes involved in the metabolic activation of naphthalene or 2-methylnaphthalene in vitro are the cytochrome P-450 monooxygenases and that cooxidative metabolism by the prostaglandin synthetases appears to play little role in the formation of reactive metabolites in vitro.

For more Metabolism/Metabolites (Complete) data for 2-METHYLNAPHTHALENE (10 total), please visit the HSDB record page.

PAH metabolism occurs in all tissues, usually by cytochrome P-450 and its associated enzymes. PAHs are metabolized into reactive intermediates, which include epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations. The phenols, quinones, and dihydrodiols can all be conjugated to glucuronides and sulfate esters; the quinones also form glutathione conjugates. (L10)

English sole were exposed to oiled (Alaskan north slope crude oil) sediments over 4 months to assess bioavailability and tissue hydrocarbon distribution kinetics in flatfish. Crude oil was mixed with aromatic hydrocarbon free sediments to a concentration of 700 ug/g dry weight at the beginning of the experiment. During the first month, this concentration decreased to 400 ug/g dry weight, and remained relatively stable during the remainder of the 4 month period. Flatfish accumulated alkane and aromatic hydrocarbons in skin, muscle and liver. 1- and 2-methylnaphthalene was accumulated to greater extent than other aromatic hydrocarbons. Tissue levels decreased with time, after 27 day continuous exposure only liver contained detectable levels.

The accumulation and elimination of (14)C in rainbow trout tissues following short and long term exposures to aqueous (14)C-labeled 2-methylnaphthalene was studied.

... Single intraperitoneal injections of 400 mg/kg (14)C-2-methylnaphthalene /were administered/ to male C57BL/6J mice. Groups of 4 mice were sacrificed at 0.5, 1, 3, 6, 12, or 24 hours after injection for measurement of radioactivity in fat, kidney, liver, and lung. Blood 2-methylnaphthalene concentrations decreased with a reported elimination half-life of 3 hours, indicative of rapid distribution to other tissues or elimination from the body. Peak tissue concentrations of 2-methylnaphthalene equivalents (nmol/mg wet weight) were attained about 1 hour after injection in the liver, 2 hours after injection in the fat, and 4 hours after injection in the kidney and the lung. Peak concentrations were highest in fat (13 nmol/mg), followed by lower concentrations in liver (3.5 nmol/mg), kidney (2.9 nmol/mg), and lung (0.7 nmol/mg). The results demonstrate that 2-methylnaphthalene did not preferentially accumulate in the lung although the lung was the only site of toxicity. Histological examination found that the single 400 mg/kg dose induced bronchiolar necrosis (minimal to prominent sloughing of lining cells in the bronchiolar lumen as revealed by light microscopy) in all exposed mice. No lesions were found in the liver or kidney of exposed mice at any time point. Consistent with the attainment of peak lung tissue concentration at 4 hours after injection, no lesions were evident until 8 hours after injection. The authors also evaluated distribution by measurement of irreversible binding of label from (14)C-2-methylnaphthalene to various tissues over a dose (0, 50, 100, 300, and 500 mg/kg; intraperitoneal injection) and time course (1, 2, 4, 8, 12, and 24 hrs). Maximum irreversible binding of 2-methylnaphthalene metabolites was observed in lung, liver, and kidney tissues at 8 hours post administration. The binding was dose- dependent in all tissues between 50-500 mg/kg and concentrations of bound radioactivity were higher in the liver and kidney than in the lung (the only tissue where lesions were found).

The available animal data indicate that 2-methylnaphthalene is absorbed rapidly following ingestion (approximately 80% within 24 hours). Once absorbed, it is widely distributed among tissues, reaching peak concentrations in less than 6 hours. It is quickly metabolized by the liver, lungs, and other tissues. 2-Methylnaphthalene is rapidly excreted (approximately 70-80% within 48 hours in guinea pigs and 55% in rats), primarily as urinary metabolites.

For more Absorption, Distribution and Excretion (Complete) data for 2-METHYLNAPHTHALENE (7 total), please visit the HSDB record page.

Produced from coal tar and used to make dyes and resins; Used to make vitamin K; Present in asphalt and smoke from burning cigarettes and wood; [ACGIH]

The active ingredient is no longer contained in any registered products ... cancelled." /Methylated naphthalenes/

Organic synthesis; insecticides.

Used as dye carrier. /From table/

It is used in small quantities for the production of alkylmethylnaphthalene sulfonates as textile auxiliaries, surfactants, and emulsifiers.

For more Uses (Complete) data for 2-METHYLNAPHTHALENE (6 total), please visit the HSDB record page.

2023: 1,000,000 - <8,500,000 lb

Naphthalene, 2-methyl- is listed as a High Production Volume (HPV) chemical (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

Non-confidential 2012 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: Naphthalene, 2-methyl-. National Production Volume: 30,324 lb/yr.

Petrochemical Manufacturing

Naphthalene, 2-methyl-: ACTIVE