1,6-Dimethylnaphthalene

Other Classes -> Naphthalenes

Volatile Organic Compound (VOC)

1.009 at 61.3 °F (NTP, 1992) - Denser than water; will sink

1.003 @ 20 °C

less than 1 mg/mL at 68.9 °F (NTP, 1992)

Insoluble in water; sol in ether and benzene

greater than 230 °F (NTP, 1992)

This chemical has a flash point of >110 °C (>230 °F).

509 to 511 °F at 760 mmHg (NTP, 1992)

264 °C

1.6 °F (NTP, 1992)

-16.9 °C

0.01 [mmHg]

1.46X10-2 mm Hg @ 25 °C

This chemical does not meet GHS hazard criteria for 100% (3 of 3) of all reports.

Not Classified

Aggregated GHS information provided per 3 reports by companies from 1 notifications to the ECHA C&L Inventory.

May cause skin irritation and photosensitization; [HSDB] May cause irritation; [MSDSonline]

The major hazards encountered in the use and handling of 1,6-dimethylnaphthalene stem from its toxicologic properties. Toxic primarily via dermal contact and inhalation. Exposure to this substance may occur from its presence as a combustion product of fossil fuels such as coal, gasoline, and heating oil. Effects from exposure include skin irritation and photosensitization. Before implementing land disposal of waste 1,6-dimethylnaphthalene, 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/

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/

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.

If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed 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.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed 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: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. 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 soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

The following wastewater treatment technology has been investigated for dimethylnaphthalene: Activated carbon. /Dimethlynaphthalene/

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

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)

80 male and female young adult golden Syrian hamsters were divided into groups. Group A was the control group. Groups B, C, and D were treated by painting of the left buccal pouch 3 times/wk with a 0.5% solution of 7,12-dimethylbenz(a)anthracene in heavy mineral oil. Group C was painted with mineral oil containing 0.3% 1,4-dimethylnaphthalene. This group showed intermediate tumor numbers and sizes. Apparently 1,4-dimethylnaphthalene retards development of epidermoid carcinomas in hamster buccal pouches induced by 7,12-dimethylbenz(a)anthracene. /1,4-Dimethylnaphthalene/

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 4,900(SRC), determined from a structure estimation method(2), indicates that 1,6-dimethylnaphthalene is expected to have slight to no mobility in soil(SRC). Volatilization of 1,6-dimethylnaphthalene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.2X10-4 atm-cu m/mole(SRC), using a fragment constant estimation method(3). 1,6-Dimethylnaphthalene is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.46X10-2 mm Hg(4). A 54.5% loss after 7 days in a marine water die-away study with sediment inoculum from Dunstaffnage Bay, Scotland(5), indicates that biodegradation may be an important fate process in the terrestrial environment.

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 4,900(SRC), determined from a structure estimation method(2), indicates that 1,6-dimethylnaphthalene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 4.2X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 6 hrs and 6 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 51 days if adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 520(SRC), from an estimated log Kow of 4.3(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is high(SRC). A 54.5% loss after 7 days in a marine water die-away study with sediment inoculum from Dunstaffnage Bay, Scotland(9), indicates that biodegradation may be an important fate process in the aquatic environment.

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,6-dimethylnaphthalene, which has a vapor pressure of 1.46X10-2 mm Hg at 25 °C(2), is expected to exist primarily as a vapor in the ambient atmosphere. Vapor-phase 1,6-dimethylnaphthalene 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 5 hrs(SRC), calculated from its rate constant of 6.34X10-11 cu cm/molecule-sec at 25 °C(3). Based upon aqueous photolysis data for 1- and 2-methylnaphthalene(4), 1,6-dimethylnaphthalene may undergo direct photolysis in the atmosphere(SRC).

1,6-Dimethylnaphthalene was found to be a volatile component in steamed meat from a southeast Asian crab, Charybidis feriatus. Concentrations in the leg, body, and carapace were 1.9, 1.1, and 18.9 ug/g, respectively(1).

1,6-Dimethylnaphthalene was identified in stored liquid smoke flavorings obtained from oak, cherry, beech, poplar, and vine shoots at concns of 3.38, 2.28, 1.84, 15.03, and 4.22 ug/kg, obtained at max temps of 530, 550, 532, 536, and 559 °C, respectively(1). Concns decreased when stored in polyethylene flasks - 1.60 for beech, 1.09 for poplar, and 1.36 ug/kg(1).

1,6-Dimethylnaphthalene was identified as a stack emission(1) and a component of fly ash(2) from waste incinerators. The compound was detected at a total concn of 0.16 mg/mile in conjunction with the 1,7- and 1,3-isomers from gasoline-fueled high-emitter light duty motor vehicle exhaust sampled during summer near Denver, CO(3).

Alkylaromatics, alkanes, aldehydes, dimethyl polysulfides and miscellaneous compounds were determined over 15 months at a coastal site, Vineyard Sound, Massachusetts. Alkylnaphthalenes showed a contrasting pattern with highest levels occurring during the winter months and the lowest in summer; this was best explained by a dominant wintertime source such as space heating oil use(1). A mean seawater concentration of 1.9 ng/liter and a range of 0.0-4.2 ng/liter was reported for 1,6-dimethylnaphthalene(1).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for 1,6-dimethylnaphthalene can be estimated to be 4,900(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1,6-dimethylnaphthalene is expected to have slight to no mobility in soil.

1,6-Dimethylnaphthalene is a natural component of crude oil(1). 1,6- Dimethylnaphthalene is also a product of combustion and can be released to the environment via natural fires associated with lightening, volcanic activity, and spontaneous combustion(SRC).

1,6-Dimethylnaphthalene's formationtion during petroleum refining and coal tar distillation(1), as a result of gasoline, diesel, and heating fuel combustion(2), and from municipal waste incinerator activities(3,4) may result in its direct release to the environment(SRC).

A marine water die-away study with sediment inoculum from Dunstaffnage Bay, Oban, Scotland showed a 54.5% loss of 1,6-dimethylnaphthalene contained in crude oil after 7 days at 20 °C(1). No other data regarding the biodegradation of 1,6-dimethylnaphthalene was available. However, based on information pertaining to 1- and 2-methylnaphthalene, the biodegradation of 1,6-dimethylnaphthalene should be an important fate process in the environment(SRC).

SEDIMENT: Of 492 streambed sediments sampled in the US from 1992-1995, 1,6-dimethylnapthalene was detected in 6.3% of the samples, with <50, <50, 56, and 680 ug/kg measured at the 75th percentile, 90th percentile, 95th percentile, and maximum, respectively(1). 1,6-Dimethylnaphthalene was detected in sediment samples at a concn of 65 ng/g dry wt 400 m downstream from a discharge of produced water at midchannel at Pass Fourchon, LA(2). Produced water is a complex chemical mixture that can contain petroleum organics, heavy metals, radionuclides, treating chemicals, salts, and dissolved nonvolatile organic matter of unknown chemical composition at concns as high as 750 mg Carbon/liter, and is generated as a result of petroleum production(3).

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/

Yields 5-methyl-2-naphthoic acid in Nocardia... /from table/

In /rat/ urine, the following substances were identified and quantified by GC peak areas: unchanged 1,6-dimethylnaphthalene, 1-methyl-hydroxynaphthalenes, 1-hydroxymethyl-6-methylnaphthalene, 1,6-dimethyl-thionaphthalene, 6-methyl-1-naphthoic aldehyde, 6-methyl-1-naphthoic acid, 1,6-dimethyl-thionaphthalene and 1,6-dimethyl-methylthionaphthalene.

The distribution, excretion and metabolism of 1,6-dimethylnaphthalene following i.p. administration of a single dose of 20 mg/kg to rats, was investigated using radiotracer (3H) and a gas chromatography-mass spectrometry technique (GC-MS). After 72 hr, about 94% of the given dose was excreted in urine and feces. In organs and tissues, the highest concentration during the first hours after administration was detected in fat, liver, spleen and kidneys. Then gradual decline of tritium was noticed in all examined tissues.