7-Methylbenz(a)anthracene

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

Advice for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. 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.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

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.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber; Contaminated packaging: Dispose of as unused product.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, 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.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

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.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

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.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

For more Preventive Measures (Complete) data for 7-Methylbenz(a)anthracene (8 total), please visit the HSDB record page.

8 Hr Time Weighted Avg (TWA): 0.2 mg/cu m. /Coal tar pitch volatiles, as benzene soluble aerosol/

Peak Exposure Recommendation: Transient increases in workers' exposure levels may exceed 3 times the value of the TLV-TWA level for no more than 15 minutes at a time, on no more than 4 occasions spaced 1 hour apart during a workday, and under no circumstances should they exceed 5 times the value of the TLV-TWA level. In addition, the 8-hour TWA is not to be exceeded for an 8-hour work period. /Coal tar pitch volatiles, as benzene soluble aerosol/

A1; Confirmed human carcinogen. /Coal tar pitch volatiles, as benzene soluble aerosol/

Biological Exposure Index (BEI): Determinant: 1-Hydroxypyrene (1-HP) in urine (with hydrolysis); Sampling Time: end of shift at end of workweek. BEI: None.; Biological monitoring should be considered for this compound based on the review; however, a specific BEI could not be determined due to insufficient data. /Polycyclic aromatic hydrocarbons/

For more Threshold Limit Values (TLV) (Complete) data for 7-Methylbenz(a)anthracene (6 total), please visit the HSDB record page.

Eye/face protection: Safety glasses with side-shields conforming to EN166. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

Skin protection: Handle with gloves.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

Body Protection: Complete suit protecting against chemicals. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

Respiratory protection: For nuisance exposures use type P95 (US) or type P1 (EU EN 143) particle respirator. For higher level protection use type OV/AG/P99 (US) or type ABEK-P2 (EU EN 143) respirator cartridges. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

For more Personal Protective Equipment (PPE) (Complete) data for 7-Methylbenz(a)anthracene (6 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 3.0X10+5(SRC), determined from a structure estimation method(2), indicates that 7-methylbenz(a)anthracene is expected to be immobile in soil(SRC). Volatilization of 7-methylbenz(a)anthracene from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.9X10-6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). However, adsorption to soil is expected to attenuate volatilization(SRC). 7-Methylbenz(a)anthracene is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.1X10-7 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation half-lives of 20 and 28 days for analogous 7,12-dimethylbenz(a)anthracene in Kidman sandy loam and McLaurin sandy loam, respectively(4), suggest that biodegradation may be an important environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 3.0X10+5(SRC), determined from a structure estimation method(2), indicates that 7-methylbenz(a)anthracene 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 1.9X10-6 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 30 and 220 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 volatilization half-life from a model pond is about 890 years when adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 4700(SRC), from an estimated log Kow of 6.07(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is very high, provided the compound is not metabolized by the organism(SRC). Analogous 7,12-dimethylbenz(a)anthracene's slow biodegradation in water, exhibiting 12% CO2 production after 62 days(7), suggests that biodegradation is not expected to be an important fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 7-methylbenz(a)anthracene, which has an estimated vapor pressure of 3.1X10-7 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases is expected to exist solely in the particulate phase in the ambient atmosphere. Vapor-phase 7-methylbenz(a)anthracene 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 0.08 days(SRC), calculated from its rate constant of 1.3X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase 7-methylbenz(a)anthracene may be removed from the air by wet and dry deposition(SRC). Analogous anthracene contains chromophores that absorb at wavelengths >290 nm(4), suggesting that 7-methylbenz(a)anthracene may be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: 7-Methylbenz(a)anthracene (7-MBA) is a solid. It can be formed from incomplete combustion of organic materials. it is used mostly in biochemical research. HUMAN EXPOSURE AND TOXICITY: There are no data available. ANIMAL STUDIES: DNA adducts formed in mouse epidermis following topical application of 7-MBA. In other experiment, mice received sc administration of 230 ug of 7-MBA three times per week for 12 months (100 mg/single dose). Out of 35 mice, 13 had carcinomas. The 12 possible monomethylbenz[a]anthracenes (MBAs) were examined for their tumor-initiating activity in the classical two-stage initiation-promotion experiment. Based on the average number of tumors/mouse, 7-MBA was the most tumorigenic compound of the series causing 4.9 papillomas/mouse at an initiating dose of 400 nmol/mouse. When given to newborn male and female mice 7-MBA gave rise to sc sarcomata at injection site, and multiple lung tumors and liver tumors. Dihydrodiol dehydrogenase decreased the mutagenicity of 7-MBA in Salmonella typhimurium TA 100 with metabolic activation. There appeared to be little quantitative correspondence between carcinogenic and mutagenic potency in this group of chemicals.

7-Methylbenz(a)anthracene release sources include oil refinery emissions, gasoline exhaust and cooking emissions(1). Methylbenz(a)anthracenes, including 7-methylbenz(a)anthracene, were reported at a concentration range of 30-50 ng/mg extract in diesel engine exhaust of passenger cars(2). 7-Methylbenz(a)anthracene was detected, not quantified in boiler emissions at the coastal Powell River Pulp Mill, British Columbia, Canada; sampling conducted September, 1996(3). Methylbenz(a)anthracenes are found in airborne particulates from cigarette smoke condensate, stack gases, roofing tar extracts, and industrial effluents(4).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 7-methylbenz(a)anthracene can be estimated to be 3.0X10+5(SRC). According to a classification scheme(2), this estimated Koc value suggests that 7-methylbenz(a)anthracene is expected to be immobile in soil.

7-Methylbenz(a)anthracene is one of many polycyclic aromatic hydrocarbons (PAH), a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances. PAHs generally occur as complex mixtures, for example as part of combustion products such as soot, not as single compounds. PAHs occur naturally in volcanoes and forest fires. They can also be found in substances such as crude oil and coal. They are found throughout the environment in the air, water, and soil(1). /Polycyclic aromatic hydrocarbons/

7-Methylbenz(a)anthracene is a product of incomplete combustion. Its presence in oil refinery emissions, gasoline exhaust and cooking emissions(1) will result in 7-methylbenz(a)anthracene's release to the environment through various waste streams(SRC). Methylbenz(a)anthracenes are found in airborne particulates from cigarette smoke condensate, stack gases, roofing tar extracts and industrial effluents(2).

AEROBIC: Biodegradation of 7-methylbenz(a)anthracene data were not available(SRC, 2017). Biodegradation of 7-methylbenz(a)anthracene in soil is expected to be slow(SRC) based upon half-lives of 20 and 28 days for 7,12-dimethylbenz(a)anthracene in Kidman sandy loam and McLaurin sandy loam, respectively(1). Biodegradation in water is not expected to be an important fate process(SRC) based upon analogous 7,12-dimethylbenz(a)anthracene's slow biodegradation in water, exhibiting 12% CO2 production after 62 days(2).

PURE CULTURE: 7-Methylbenz(a)anthracene was oxidized by the fungus Cunninghamella elegans to trans-8,9-dihydroxy-8,9-dihydro-7-hydroxymethylbenz(a)anthracene and trans-3,4-dihydroxy-3,4-dihydro-7-hydroxymethylbenz(a)anthracene(1).

An estimated BCF of 4700 was calculated in fish for 7-methylbenz(a)anthracene(SRC), using an estimated log Kow of 6.07(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is very high, provided the compound is not metabolized by the organism(SRC). However, bioconcentration studies on compounds which are structurally similar suggest that bioconcentration may be lower than that indicated by the regression-derived equations due to the ability of some aquatic organisms to readily metabolize this class of compounds(3).

The Henry's Law constant for 7-methylbenz(a)anthracene is estimated as 1.9X10-6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 7-methylbenz(a)anthracene is expected to volatilize from water surfaces(2). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(2) is estimated as 30 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 220 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The volatilization half-life from a model pond is about 890 years when adsorption is considered(3). 7-Methylbenz(a)anthracene's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 7-Methylbenz(a)anthracene is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.1X10-7 mm Hg(SRC), determined from a fragment constant method(4).

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ /Mice received sc administration of 230 ug of 7-methylbenz(a)anthracene three times per week for 12 months (100 mg/single dose). Out of 35 mice, 13 had carcinomas./ /From table/

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ 7-Methylbenz(a)anthracene given to newborn male and female Swiss mice gave rise to sc sarcomata at injection site, and multiple lung tumors and liver tumors.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ 7-Methylbenz(a)anthracene and some dihydrodiols tested for carcinogenic activity in mouse lung tissue incubated with compd for 1 hr. Then implanted into isologous mice. All gave small yields of ademonas.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity: Initiation-Promotion/ As an approach for elucidation of structure activity relationships that underlie the exceptionally large difference in carcinogenic activity between benz[a]anthracene and 7,12-dimethylbenz[a]anthracene (7,12-DMBA), 11 methyl- and/or fluorine-substituted benz[a]anthracenes were evaluated for tumor-initiating activity on mouse skin. Outbred CD-1 and outbred Sencar mice received a single topical application of the hydrocarbons followed by twice weekly applications of the tumor promoter 12-O-tetradecanoylphorbol 13-acetate for 16-26 weeks. 7,12-DMBA was almost two orders of magnitude more active as a tumor-initiator than 7- and 12-methylbenz[a]anthracene. Methyl substitution at the 7- and 7,12-positions of benz[a]anthracene was significantly more effective in the enhancement of tumorigenic activity than fluorine substitution at these positions. Although 7-fluorobenz[a]anthracene, 12-fluorobenz[a]anthracene, and 7,12-difluorobenz[a]anthracene had only 0.15, 0.26, and less than 0.005 times the tumor-initiating activity of their respective methyl-substituted derivatives, they were severalfold more active than benz[a]anthracene. 7-Fluorobenz[a]anthracene was slightly less active than 12-fluorobenz[a]anthracene, whereas 7-methylbenz[a]anthracene was about twofold more than 12-methylbenz[a]anthracene. For 7,12-di-substituted benz[a]anthracenes, 7-methyl-12-fluorobenz[a]anthracene was more than twice as tumorigenic as 7-fluoro-12-methylbenz[a]anthracene, but each was individually more active than 7-methylbenz[a]anthracene and 12-methylbenz[a]anthracene, respectively. Both fluorinated compounds were much less active than 7,12-DMBA. Substitution of fluorine or methyl at the 5-position of 7-methylbenz[a]anthracene and substitution of fluorine at the 5-position of 12-methylbenz[a]anthracene dramatically reduced their tumorigenic activity.

For more Non-Human Toxicity Excerpts (Complete) data for 7-Methylbenz(a)anthracene (24 total), please visit the HSDB record page.

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Polynuclear aromatic hydrocarbons (including benzanthracenes, benzopyrenes, benzofluoranthene, chrysenes, dibenz-anthracenes, and indenopyrenes)/

For the maximum protection of human health from the potential carcinogenic effects of exposure to polynuclear aromatic hydrocarbons through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentration should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at 1X10-5, 1X10-6, and 1X10-7. The corresponding recommended criteria are 28.0 ng/L, 2.8 ng/L, and 0.28 ng/L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 311.0 ng/L, 31.1 ng/L, and 3.11 ng/L, respectively. /Polynuclear aromatic hydrocarbons/.

Used in biochemical research; Produced from the incomplete combustion of organic material; Not commercially produced in the US; [HSDB]

Laboratory chemicals, manufacture of substances.[Sigma-Aldrich; Safety Data Sheet for 7-Methylbenz

(1975) NOT PRODUCED COMMERCIALLY IN US

(1977) NOT PRODUCED COMMERCIALLY IN US