1,2,3-Trimethylbenzene

log Kow = 3.66

3.7

3.78

0.8944 g/cu cm at 20 °C

0.89 g/cm³

Relative density of the vapour/air-mixture at 20 °C (air = 1): 1.01

0.8944 @ 20°C

0.89

Colorless liquid

Clear, colorless liquid

Miscible with ethanol, ether, acetone, benzene, petroleum ether, carbon tetrachloride

In water, 75.2 mg/L at 25 °C

Solubility in water, g/100ml: 0.005

Low

44 to 53 °C (closed cup)

111 °F (44 °C) (Closed cup)

44 °C

176.12 °C

176 °C

176.12 °C @760 [mm Hg]

349 °F

This chemical does not meet GHS hazard criteria for 2.5% (42 of 1654) of reports.

Warning

H226 (95%): Flammable liquid and vapor [Warning Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P271, P280, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 1654 reports by companies from 25 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

This chemical does not meet GHS hazard criteria for 1.8% (28 of 1532) of reports.

Chemical: Benzene, 1,2,3-trimethyl-

Hazard Traits - Neurotoxicity

Benzene, 1,2,3-trimethyl- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Benzene, 1,2,3-trimethyl- 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)

1,2,3-Trimethylbenzene: Does not have an individual approval but may be used under an appropriate group standard

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Trimethylbenzene (mixed isomers) is included on this list. Effective date 2/13/1984; Sunset date 2/13/1994.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. 1,2,3-Trimethylbenzene is included on this list. Effective date: 2/13/1984; Sunset date: 11/9/1993.

Lower flammable limit: 0.8% by volume; Upper flammable limit: 6.6% by volume

Flammable Liquid

1 - Materials that, under emergency conditions, can cause significant irritation.

2 - Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. Materials would not under normal conditions form hazardous atmospheres with air, but under high ambient temperatures or under moderate heating could release vapor in sufficient quantities to produce hazardous atmospheres with air.

0 - Materials that in themselves are normally stable, even under fire conditions.

Flam. Liq. 3 (95%)

Flam. Liq. 3 (96.1%)

Flammable liquids - Category 3

Hazardous to the aquatic environment (Acute) - Category 2

Flammable liquids - Category 3

Fresh air, rest. Refer for medical attention.

Rinse skin with plenty of water or shower.

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

Rinse mouth. Do NOT induce vomiting. Refer for medical attention .

This chemical is a flammable liquid. Poisonous gases are produced in fire. Small fires: dry chemical, carbon dioxide, water spray, or alcohol-resistant foam. Large fires: water spray, fog, or alcohol foam. Move container from fire if you can do so without risk. Spray cooling water on containers that are exposed to flames until well after fire is out. For massive fire in cargo area, use unmanned hose holder or monitoring nozzles; if this is impossible, withdraw from area and let fire burn. Isolate for one-half mile in all directions if tank car or truck is involved in fire. Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Containers may explode in fire. Storage containers and parts of containers may rocket great distances, in many directions. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position. If employees are expected to fight fires, they must be trained and equipped in OSHA 1910.156.

This chemical is a flammable liquid. Poisonous gases are produced in fire. Small fires: dry chemical, carbon dioxide, water spray, or alcohol-resistant foam. Large fires: water spray, fog, or alcohol foam. Move container from fire if you can do so without risk. Spray cooling water on containers that are exposed to flames until well after fire is out. For massive fire in cargo area, use unmanned hose holder or monitoring nozzles; if this is impossible, withdraw from area and let fire burn. Isolate for one-half mile in all directions if tank car or truck is involved in fire. Vapors are heavier than air and will collect in low areas. Vapors may travel long distances to ignition sources and flashback. Vapors in confined areas may explode when exposed to fire. Containers may explode in fire. Storage containers and parts of containers may rocket great distances, in many directions. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position. If employees are expected to fight fires, they must be trained and equipped in OSHA 1910.156. /Trimethyl benzenes/

Prior to working with this chemical you should be trained on its proper handling and storage. Before entering a confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Trimethylbenzene must be stored to avoid contact with oxidizers (such as perchlorates, peroxides, permanganates, chlorates, and nitrates), and strong oxidizers (such as chlorine, bromine, and fluorine) since violent reactions occur. Store in tightly closed containers in a cool, well-ventilated area away from heat. Sources of ignition such as smoking and open flames are prohibited where this chemical is used, handled, or stored in a manner that could create a potential fire or explosion hazard. Metal containers involving the transfer of 5 gallons or more of this chemical should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only nonsparking tools and equipment, especially when opening and closing containers of this chemical.

Prior to working with this chemical you should be trained on its proper handling and storage. Before entering a confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Trimethylbenzene must be stored to avoid contact with oxidizers (such as perchlorates, peroxides, permanganates, chlorates, and nitrates), and strong oxidizers (such as chlorine, bromine, and fluorine) since violent reactions occur. Store in tightly closed containers in a cool, well-ventilated area away from heat. Sources of ignition such as smoking and open flames are prohibited where this chemical is used, handled, or stored in a manner that could create a potential fire or explosion hazard. Metal containers involving the transfer of 5 gallons or more of this chemical should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. Use only nonsparking tools and equipment, especially when opening and closing containers of this chemical. /Trimethyl benzenes/

Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Establish forced ventilation to keep levels below explosive limit. Absorb liquids in vermiculite, dry sand, earth, peat, carbon, or similar material and deposit in sealed containers. Keep this chemical out of a confined space ... because of the possibility of an explosion ... It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations. If employees are required to clean up spills, they must be properly trained and equipped. OSHA 1910.120(q) may be applicable.

Evacuate and restrict persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Establish forced ventilation to keep levels below explosive limit. Absorb liquids in vermiculite, dry sand, earth, peat, carbon, or similar material and deposit in sealed containers. Keep this chemical out of a confined space ... because of the possibility of an explosion ... It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations. If employees are required to clean up spills, they must be properly trained and equipped. OSHA 1910.120(q) may be applicable. /Trimethyl benzenes/

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.

Incineration /SRP: with appropriate emission controls/.

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.

Incineration /SRP: with appropriate emission controls/. /Trimethyl benzenes/

Above 44 °C use a closed system, ventilation, and explosion-proof electrical equipment. Prevent build-up of electrostatic charges (e.g., by grounding).

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit 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.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit 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.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet or significantly contaminated should be removed or replaced.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

Hematologic

Eyes, skin, respiratory system, central nervous system, blood

LC50; Species: Palaemonetes pugio (Daggerblade grass shrimp); Conditions: saltwater, static, 21 °C, pH 8.1, salinity 15 parts per thousand, dissolved oxygen >5.0 mg/L; Concentration: 7000 ug/L for 24 hr

LC50; Species: Palaemonetes pugio (Daggerblade grass shrimp); Conditions: saltwater, static, 21 °C, pH 8.1, salinity 15 parts per thousand, dissolved oxygen >5.0 mg/L; Concentration: 5600 ug/L for 48 hr

LC50; Species: Palaemonetes pugio (Daggerblade grass shrimp); Conditions: saltwater, static, 21 °C, pH 8.1, salinity 15 parts per thousand, dissolved oxygen >5.0 mg/L; Concentration: 5400 ug/L for 96 hr

TERRESTRIAL FATE: Based on a recommended classification scheme(1), a Koc range of 501 to 1,445 measured in soil(2-9), suggests that trimethylbenzenes will have low mobility in soil(SRC). Volatilization of trimethylbenzenes from moist soil surfaces may be important(SRC) based on Henry's Law constants of 4.36X10-3 to 8.77 atm-cu m/mole(10). Volatilization from dry soil surfaces is expected(SRC), based on a vapor pressure range of 1.69 to 2.48 mm Hg(11). Screening studies indicate that trimethylbenzenes are slow to degrade and are not classified as readily biodegradable under aerobic conditions(12,13).

AQUATIC FATE: Based on a recommended classification scheme(1), a Koc range of 501-1,445 measured in soil(2-9), indicates that trimethylbenzenes are expected to adsorb to sediment and particulate matter in the water column(SRC). Trimethylbenzenes are expected to volatilize from water surfaces(10) based on Henry's Law constants of 4.36X10-3 to 8.77 atm-cu m/mole(11). Using these Henry's Law constants and an estimation method(3), volatilization half-lives for a model river and model lake are approximately 3 hours and 4 days, respectively(SRC). According to a classification scheme(12), BCF values of 23-342 measured in fish(13), suggests the potential for bioconcentration in aquatic organisms is moderate to high(SRC). Screening studies indicate that trimethylbenzenes are slow to degrade and are not classified as readily biodegradable under aerobic conditions(13,14).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), trimethylbenzenes, which have a vapor pressure range of 1.69 to 2.48 mm Hg 25 °C(2), will exist solely as vapors in the ambient atmosphere. Vapor-phase trimethylbenzenes are degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and nitrate radicals(SRC). The half-life for the reaction with hydroxyl radicals is estimated to be about 7 to 12 hours calculated from a rate constant ranges of 3.25X10-11 to 5.75X10-11 cu cm/molecule-sec at 25 °C(3). The half-life for the reaction in air with nitrate radicals is estimated as 10-67 days(SRC), calculated from rate constants of 2.4X10-16 and 1.60X10-15 cu cm/molecule-sec at 25 °C(4). Trimethylbenzenes do not contain chromophores that absorb wavelengths >290 nm(5) and therefore are not expected to be susceptible to direct photolysis by sunlight(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 1,096(2) and 630(3) indicate that 1,2,3-trimethylbenzene is expected to have low mobility in soil(SRC). Volatilization of 1,2,3-trimethylbenzene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 4.36X10-3 atm-cu m/mole(4). 1,2,3-Trimethylbenzene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 1.69 mm Hg(5). Biodegradation of 1,2,3-trimethylbenzene may occur in aerobic environments(6) but is likely to be slow based upon 0% theoretical BOD in the Japanese MITI test(8); it is unlikely to biodegrade in anaerobic environments(7).

AQUATIC FATE: Based on a classification scheme(1), Koc values of 1,096(2) and 630(3) indicate that 1,2,3-trimethylbenzene 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 4.36X10-3 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 3.4 hours and 4.4 days, respectively(SRC). According to a classification scheme(6), a BCF range of 133-259(7) suggests bioconcentration in aquatic organisms is high(SRC). Biodegradation of 1,2,3-trimethylbenzene may occur in oxygenated water(8) but is likely to be slow based upon 0% theoretical BOD in the Japanese MITI test(7); it is unlikely to biodegrade in anaerobic environments(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1,2,3-trimethylbenzene, which has a vapor pressure of 1.69 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1,2,3-trimethylbenzene 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 12 hours(SRC), calculated from its rate constant of 3.27X10-11 cu cm/molecule-sec at 25 °C(3). 1,2,3-Trimethylbenzene also reacts with ozone and nitrate radicals in the atmosphere; the half-life for these reactions are 20 years(4) and 60 days, respectively(5).

The substance can be absorbed into the body by inhalation.

inhalation, ingestion, skin and/or eye contact

1,2,3-Trimethylbenzene had calculated average daily intake values of 18 ug/day and 21 ug/day in Traviglio, Italy for indoor and indoor/outdoor exposure, respectively(1). In Poggibonsi AVDI values were 18 ug/day and 14 ug/day for indoor and indoor/outdoor exposure and in Valenza AVDI values were 23 ug/day and 26.5 ug/day(1). 1,2,3-Trimethylbenzene AVDI of 28.5 ug/day and 10.5 mg/yr were calculated for people in the Netherlands(2).

Confusion. Dizziness. Headache. Vomiting. Drowsiness. Cough. Sore throat.

Redness.

Redness. Pain.

irritation eyes, skin, nose, throat, respiratory system; bronchitis; hypochromic anemia; headache, drowsiness, lassitude (weakness, exhaustion), dizziness, nausea, incoordination; vomiting, confusion; chemical pneumonitis (aspiration liquid)

1,2,3-Trimethylbenzene was 0.72% of the total emissions measured in the Caldecott tunnel in San Francisco, CA June 26-28 1991(1). 1,2,3-Trimethylbenzene was emitted in Fort McHenry tunnel, Baltimore, MD from light duty trucks at 5.8 mg/mile and from heavy duty trucks at 10.1 mg/mile from June 18-24, 1992(2). 1,2,3-Trimethylbenzene was emitted in Tuscarora tunnel, PA from light duty trucks at 2.2 mg/mile and from heavy duty trucks at 3.7 mg/mile from June 18-24, 1992(2). 1,2,3-Trimethylbenzene was found at 0.5% of catalytic equipped engine exhaust(3). 1,2,3-Trimethylbenzene was found in the emissions of 30 vehicles (10 built before 1990, 20 built between 1990 and 1996) using 3 types of gas in Mexico City(4). 1,2,3-Trimethylbenzene was emitted from motor vehicles in the Van Nuys tunnel in Los Angeles at 84 mg/L on Sept 21, 1993(5). Emissions of 1,2,3-trimethylbenzene were identified in regular whole (liquid) gas (0.25%), high grade whole (liquid) gas (0.50%), roadway (0.45%), bus parking garage hot soak (1.14%), bus parking garage cold start (0.40%), motorcycle emissions (0.16%), petroleum refinery (0.07%), lead smelter (0.62%), and cast iron factory emissions (0.54%), in Cairo, Egypt(6). 1,2,3-Trimethylbenzene was found in roadway emissions, whole gas and whole gas (97 octane) at 0.532, 1.01 and 0.92 ppb% in Atlanta, GA(7).

1,2,3-Trimethylbenzene was found in 4% of trade water effluent samples at a average concentration of 2.47 ug/L in England and Wales in 1995(1). 1,2,3-Trimethylbenzene was emitted from Wyomings Hanna and Gillette coal gas power plants at 0.1 and 42 ppb, respectively, and from Morgantown rosebud coal/gas plant at 361 ppb(2). 1,2,3-Trimethylbenzene was not found in emissions from oil/shale power plants in Rock Springs, WY and DeBeque, CO(2). 1,2,3-Trimethylbenzene concentrations in leachate were 10, 20, 40, 1200 and 2450 ug/L from a hazard waste landfill and not detected, 1.0, 3.0 and 9.1 ug/L from a domestic waste landfill(3). Landfill gas from Fresh Kills (NY) municipal solid-waste landfill had an average concentration of 1.90 ppm in >250 extraction samples from the summer of 1995(4). 1,2,3-Trimethylbenzene was present in 3 landfill leachates at 10, 800 and 2000 ug/L in Germany(5).

1,2,3-Trimethylbenzene was detected in water after running a four-stroke outboard motor for 10 minutes(1). 1,2,3-Trimethylbenzene had water concentrations of 1.9 and 5 ppm after running a 7 and 10 horsepower outboard motor(2). 1,2,3-Trimethylbenzene was identified in the emission from four-stroke lawn mower engines using 2 types of gas(3). 1,2,3-Trimethylbenzene was emitted from the ferry boat Aurora at a rate of 10 mg/kWh July 12-15, 1995 and from the Stena Danica at <0.5 mg/kWh August 22-26, 1995(4).

1,2,3-Trimethylbenzene was found in 6.9% of 275 stormwater samples from 40 monitoring locations in NC with an average concentration of 0.17 ug/L(1).

1,2,3-Trimethylbenzene is emitted from vinyl cove molding, linoleum tile, tar paper, black rubber molding, vinyl edge molding, large and small diameter telephone cable, latex paint, polystyrene foam insulation, latex caulk, carpet adhesive, and carpet at rates of 0.33, 7.3, 0.32, 2.8, 0.77, 1.0, 1.8, 0.53, 0.12, 11, 4.5, and 1.3 ug/sq m-hr, respectively(1).1,2,3-Trimethylbenzene is emitted from textile floor coverings(2). 1,2,3-Trimethylbenzene was detected but not quantified in the emissions of mixed household waste(3).

1,2,3-Trimethylbenzene

Hematologic

1 x 10 ^-2 mg/kg-day

4 x 10 ^-2 mg/kg-day

6 x 10 ^-2 mg/m^3

2 x 10 ^-1 mg/m^3

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Trimethylbenzene (mixed isomers) is included on this list. Effective date 2/13/1984; Sunset date 2/13/1994.

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. 1,2,3-Trimethylbenzene is included on this list. Effective date: 2/13/1984; Sunset date: 11/9/1993.

... Ten healthy male volunteers were exposed to trimethylbenzene (TMB) vapor in an exposure chamber for 2 hr at a work load of 50 W. The subjects were exposed on four occasions, to 25 ppm of 1,2,4-TMB, 1,2,3-TMB, and 1,3,5-TMB, respectively, and 2 ppm of 1,2,4-TMB. Urine was collected from the onset of exposure until the following morning. All six possible dimethylhippuric acid (DMHA) isomers were analyzed by high-performance liquid chromatography. ... The half-times of the different DMHA isomers ranged from 4 to 16 hr.

The structure was investigated of the mercapturic acid excreted in urine of rats after the i.p. administration of 1,2,3-trimethylbenzene. Of the two regioisomeric mercapturic acids, i.e. N-acetyl-S-(2,3-dimethylbenzyl)-L-cysteine and N-acetyl-S-(2,6-dimethyl-benzyl)-L-cysteine, only the former was isolated by preparative HPLC and identified, by comparison with an authentic specimen. The excretion rate of the mercapturate was estimated to be approximately 5% of dose, not a substantial metabolic route.

Toxicity of Tri- and Tetramethylbenzenes: Material: 1,2,3-trimethylbenzene; Route of entry: oral (subacute); Species: rat; Dose or concentration: 1.2 g/kg; Results or Effects: Metabolites: 2,3-dimethylhippuric acid 17.3%, 2,3-dimethylbenzoic glucuronide 19.4%, and 2,3-dimethylbenzoic sulfate 19.9%. /From table/

Trimethylbenzene (TMB) ... is a mixture of three isomers (pseudocumene-1,2,4-TMB; mesitylene-1,3,5-TMB; hemimellitene-1,2,3-TMB). The proportion of individual isomers in the mixture differs. The aim of this study was to obtain toxicokinetic data on the absorption and elimination of trimethylbenzene and its metabolites in biological fluids and to investigate the relationship between the biological indices of exposure and the absorbed dose. Eight-hour inhalation tests were performed in a toxicological chamber, The subjects were eight volunteers aged 20-39 with no history of exposure to TMB. They were exposed to pseudocumene, mesitylene or hemimellitene at concentrations ranging from 5 to 150 mg/cu m air. Exhaled air, capillary blood and urine samples were collected before, during and after the exposure. The determinations of TMB or its metabolites were performed using gas chromatography (HP 5890 II Plus, MSD, FID). Pulmonary ventilation in the volunteers ranged from 0.56 to 1.0 cu m/hr. The retention of 1,2,4-TMB; 1,3,5-TMB; 1,2,3-TMB in the lungs was 68%, 67% and 71%, respectively. The elimination of TMB from capillary blood occurred in accordance with the open three-compartment model. Urinary excretion of dimethylbenzoic acids (DMBA) proceeded according to the open two-compartment model. Based on the toxicokinetic data, a simulation model of accretion and excretion of DMBA in urine during a 14-day period was developed. The highest rates of metabolite excretion and the highest quantities of DMBA in urine during 24-hr intervals were observed on day 5 of exposure. The relationship between the levels of TMB or DMBA in biological material and TMB air concentration or absorbed dose were determined. ...

The objective of this study was to compare the toxicokinetics of inhaled 1,2,4-trimethylbenzene (1,2,4-TMB) in man after exposure to white spirit with that observed after exposure to 1,2,4-TMB alone. ... The toxicokinetics were studied in 9 male, healthy volunteers exposed to solvent vapors in an exposure chamber for 2 hr during a work load of 50 W. The subjects were exposed to 11 mg/cu m of 1,2,4-TMB on two occasions; during exposure to 1,2,4-TMB vapor alone and during exposure to 300 mg/cu m of white spirit. The 1,2,4-TMB isomer was analyzed in blood and exhaled air by gas chromatography. In addition, a major urinary metabolite of 1,2,4-TMB, 3,4-dimethylhippuric acid (3,4-DMHA), was analyzed by high performance liquid chromatography. ... Blood levels of 1,2,4-TMB and excretion rates of 3,4-DMHA in urine were markedly elevated both during and after exposure to white spirit as compared to exposure to TMB alone. Thus, it appears that components in white spirit inhibit the metabolic elimination of 1,2,4-TMB. This should be considered in biological exposure monitoring as well as in risk assessment. No irritation or central nervous system effects were reported at these conditions.

The substance can be absorbed into the body by inhalation.

... Ten healthy male volunteers were exposed to trimethylbenzene (TMB) vapor in an exposure chamber for 2 hr at a work load of 50 W. The subjects were exposed on four occasions, to 25 ppm of 1,2,4-TMB, 1,2,3-TMB, and 1,3,5-TMB, respectively, and 2 ppm of 1,2,4-TMB. Urine was collected from the onset of exposure until the following morning. All six possible dimethylhippuric acid (DMHA) isomers were analyzed by high-performance liquid chromatography. About 22% of the inhaled amount of 1,2,4-TMB was excreted as DMHAs within 24 hr, mainly as 3,4-DMHA. The 24-hr recovery of 1,2,3-TMB as DMHAs was 11%. Only 3% of the absorbed amount of 1,3,5-TMB was excreted as 3,5,-DMHA. ... In addition to analysis of DMHAs, the excretion of unconjugated dimethylbenzoic acids in urine was estimated to account for approximately 3% of the dose of all TMBs. In conclusion, the urinary excretion of DMHA isomers may serve as a good indicator of TMB exposure. In this controlled short-term-exposure study the sum of excretion rate of several DMHA isomers reflected exposure more closely than did the excretion rate of any single DMHA.

Used as a solvent and to make dyes, perfumes, and other organic chemicals; [HSDB] Present in gasoline; [CHEMINFO]

... Used as solvents and in dye and perfume manufacture. ...

Listed as an inert ingredient in pesticide formulations; List 3-Inerts of unknown toxicity.

Raw material for chemical synthesis

... Used as solvents and in dye and perfume manufacture. ... /Trimethyl benzenes/

Hemimellitene is an intermediate in the production of fragrances.

2023: 25,000 - <50,000 lb

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#6319]

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#7254]

Trimethylbenzenes can be produced by Friedel-Crafts methylation of toluene or xylene with chloromethane in the presence of aluminum chloride.

Trimethylbenzenes are also generated in the reaction of toluene with synthesis gas over a dual catalyst consisting of a metal oxide component and an aluminum silicate, at 200-400 °C and up to 20 MPa.

Fusel oils and other fermentation products may be reacted on the zeolite catalyst HZSM-5 to form aromatic compounds, including trimethylbenzenes.

... Hemimellitene ... /is/ found in coal tar oil ... /It/ can be isolated by distillation and purified by the differential hydrolysis of ... /its/ sulfonic acids.

Information on 15 consumer products that contain 1,2,3-Trimethylbenzene in the following categories is provided:

Information on 42 consumer products that contain Trimethylbenzenes (mixed isomers) in the following categories is provided:

Petroleum Refineries

Benzene, 1,2,3-trimethyl-: ACTIVE

Occurs in some petroleums