HuagongsheHuagongshe Chemistry Print Report · For research reference only
Toluene
TOL · METHYLBENZENE · TOLUNE · TOLUOL · Toluen · tolueno · JB · PHENYLMETHANE
Identifiers & Physical Properties
| CAS No. | 108-88-3 |
|---|---|
| Molecular formula | C7H8 |
| Average molar mass | 92.14 g/mol |
| Monoisotopic mass | 92.06260026 g/mol |
| SMILES | Cc1ccccc1 |
| InChIKey | YXFVVABEGXRONW-UHFFFAOYSA-N |
| PubChem CID | 1140 |
| ChEMBL | CHEMBL9113 |
| ChEBI | CHEBI:17578 |
| EC No. | 203-625-9 |
| DTXSID | DTXSID7021360 |
Chemical & Physical Properties
| XLogP | 2.7 |
|---|---|
| Topological polar surface area | 0 |
| Hydrogen bond donors | 0 |
| Hydrogen bond acceptors | 0 |
| Rotatable bonds | 0 |
| Heavy atoms | 7 |
| Formal charge | 0 |
| Complexity | 42 |
| LogP (partition coefficient) | 2.73log Kow = 2.732.69 |
| LogS | -2.21 |
| Odor | Sweet, pungent, benzene-like odorAromatic, benzene-like odor detectable at 0.16 to 37 ppm (mean = 1.6 ppm) |
| Density | 0.867 at 68 °F (USCG, 1999) - Less dense than waterwill float0.8623 g/cu cm at 20 °CRelative density (water = 1): 0.870.8623 @25 °C0.865 g/mL at 25 °C (lit.) |
| Viscosity | 1.165 mPa-s at -25 °C0.778 mPa-s at 0 °C0.560 mPa-s at 25 °C0.424 mPa-s at 50 °C0.333 mPa-s at 75 °C0.270 mPa-s at 100 °C0.68 mm²/s at 20 °C |
| Color/Form | Colorless liquid |
| Solubility | less than 1 mg/mL at 64 °F (NTP, 1992)526In water, 526 mg/L at 25 °CMiscible with alcohol, chloroform, ether, acetone, glacial acetic acid, carbon disulfideSoluble in ethanol, benzene, diethyl ether, acetone, chloroform, glacial acetic acid and carbon disulfide0.526 mg/mL at 25 °C0.5 g/L (20 ºC) |
| Corrosivity | Noncorrosive liquid. |
| Flash point | 40 °F (NTP, 1992)4.4 °C4.0 °C (39.2 °F) - closed cup4.4 dec C (closed cup)40 °F (4 °C) (Closed cup)4 °C c.c. |
| Boiling point | 231.1 °F at 760 mmHg (NTP, 1992)110.6110.6 °C110.00 to 111.00 °C. @ 760.00 mm Hg111 °C232 °F110-111 °C (lit.) |
| Decomposition | Can react vigorously with oxidizing materials.When heated to decomposition it emits acrid smoke and irritating fumes. |
| Melting point | -139 °F (NTP, 1992)-94.9-94.9 °C-95 °C-93 °C (lit.) |
| Vapor density | 3.2 (vs air) |
| Vapor pressure | 22 mm Hg ( 20 °C) |
| Refractive index | n/D 1.496(lit.) |
| Storage conditions | 0-6°C |
| pKa (acidity coefficient) | 40(at 25℃) |
| Physical state | Liquid |
| Color | Colorless |
| Specific gravity | 0.865~0.870(20/20℃)(Ph.Eur.) |
| Relative polarity | 0.099 |
| Explosive limits | 7% |
| Odor threshold | 0.33ppm |
| Biological source | rabbit |
| Thermal conductivity | 0.1234 W/(m·K) at 25 ℃ |
| Specific heat capacity | Cp(liquid): 1.71 J/(g·K), at 25℃ |
| Merck | 14,9529 |
| BRN | 635760 |
| Henry's law constant | 1.05 at 40 °C, 1.68 at 50 °C, 2.62 at 60 °C, 3.15 at 70 °C, 3.97 at 80 °C (headspace-GC, Vane et al., 2001) |
| Exposure limits | ACGIH TLV-TWA:20 ppmTLV-STEL:150 ppmOSHA PEL-TWA:200 ppm (～750 mg/ m3)PEL-Ceiling:300 ppmPEL-peak:500 ppm/ 15 minNIOSH REL-TWA:100 ppm (～375 mg/m3) |
| Dielectric constant | 2.4(20℃) |
| Cosmetics Ingredients Functions | SOLVENTANTIOXIDANT |
| InChI | 1S/C7H8/c1-7-5-3-2-4-6-7/h2-6H,1H3 |
| InChIKey | YXFVVABEGXRONW-UHFFFAOYSA-N |
| SMILES | Cc1ccccc1 |
| EPA Primary Drinking Water Standard | MCL:1,MCLG:1 |
| LogP (partition coefficient) | 2.73 at 20℃ |
| Surface tension | 27.76mN/m at 298.15K |
| Toxicology and Carcinogenesis | Toxicology and Carcinogenesis Studies of Toluene (CASRN 108-88-3) in F344/N Rats and B6C3F1 Mice (Inhalation Studies) |
| Indirect Additives used in Food Contact Substances | TOLUENE |
| Substances Added to Food (formerly EAFUS) | toluene |
| REACH Annex XVII Substances List | Toluene (108-88-3) |
| FDA 21 CFR | 175.105175.320176.180177.1010177.1200177.1440177.1580177.1585177.1650177.2460177.2600178.3010 |
| CAS DataBase Reference | 108-88-3(CAS DataBase Reference) |
| EWG's Food Scores | 6-10 |
| NCI Dictionary of Cancer Terms | toluene |
| FDA UNII | 3FPU23BG52 |
| Proposition 65 List | Toluene |
| NIST Chemistry Reference | Toluene(108-88-3) |
| IARC | 3 (Vol. 47, 71) 1999 |
| EPA Substance Registry System | Toluene (108-88-3) |
| Toxicological Profile|ATSDR | Toluene|Toxicological Profile|ATSDR |
| UNSPSC Code | 77101502 |
| NACRES | NB.21 |
| GHS pictogram | GHS02,GHS07,GHS08 |
| Signal word | Danger |
| GHS hazard statements | H225-H304-H315-H336-H361d-H373-H412 |
| GHS precautionary statements | P201-P210-P273-P301+P310+P331-P302+P352-P308+P313 |
| Target organs | Central nervous system |
| Personal protective equipment (PPE) | Eyeshields, Faceshields, Gloves, type ABEK (EN14387) respirator filter |
| Hazard symbols | F,Xn,T |
| Risk statements (R) | 11-38-48/20-63-65-67-39/23/24/25-23/24/25 |
| Safety statements (S) | 36/37-46-62-45-16-7 |
| Occupational exposure band (OEB) | A |
| Occupational exposure limit (OEL) | TWA: 100 ppm (375 mg/m3), STEL: 150 ppm (560 mg/m3) |
| UN transport number | UN 1294 |
| Water hazard class (WGK) | 2 |
| RTECS number | XS5250000 |
| F | 3-10 |
| Autoignition temperature | 480 °C |
| TSCA inventory status | TSCA listed |
| Hazard class | 3Aquatic Chronic 3Asp. Tox. 1Flam. Liq. 2Repr. 2Skin Irrit. 2STOT RE 2 InhalationSTOT SE 3 |
| Packing group | II |
| Customs code | 29023000 |
| Storage class | 3 - Flammable liquids |
| Hazardous substances data | 108-88-3(Hazardous Substances Data) |
| Toxicity | LD50 orally in rats: 7.53 g/kg (Smyth) |
| Immediately dangerous to life or health concentration | 500 ppm |
| REACH registrations | Active |
| Limited quantities | 1.0 L (0.3 gallon) (liquid) |
| Excepted quantities | Max Inner Pack (30g or 30ml) and Max Outer Pack (500g or 500ml) |
Safety & Regulations
| GHS classification | DangerH225: Highly Flammable liquid and vapor [Danger Flammable liquids]H304: May be fatal if swallowed and enters airways [Danger Aspiration hazard]H315: Causes skin irritation [Warning Skin corrosion/irritation]H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposureNarcotic effects]H361d ***: Suspected of damaging the unborn child [Warning Reproductive toxicity]H373 **: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P271, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P318, P319, P321, P331, P332+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)This chemical does not meet GHS hazard criteria for < 0.1% (8 of 9036) of reports. |
|---|---|
| Regulatory information | Chemical: Benzene, methyl-Hazard Traits - Cardiovascular ToxicityDevelopmental ToxicityHepatotoxicity and Digestive System ToxicityImmunotoxicityNeurotoxicityRespiratory ToxicityAuthoritative List - ATSDR NeurotoxicantsCA MCLsCA TACsCWA 303(c)CWA 303(d)IRIS NeurotoxicantsOEHHA RELsProp 65Report - regardless of intended function of ingredient in the productList II Chemical: A chemical, other than a List I chemical, specified by regulation that, in addition to legitimate uses, is used in manufacturing a controlled substance in violation of the Act. (21 eCFR 1310.02)Benzene, methyl- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Benzene, 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)Status: Active Update: 02-05-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15538Status: Cease Manufacture Update: 15-04-2018 https://echa.europa.eu/registration-dossier/-/registered-dossier/24071Restricted substance: TolueneEC: 203-625-9Restriction condition document: PDF link |
| Other safety information | IMAP assessments - Benzene, methyl-: Human health tier II assessment |
| DOT label | Flammable Liquid |
| Fire hazards | Behavior in Fire: Vapor is heavier than air and may travel a considerable distance to a source of ignition and flash back. (USCG, 1999)· HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.· Vapors may form explosive mixtures with air.· Vapors may travel to source of ignition and flash back.· Most vapors are heavier than air. They will spread along the ground and collect in low or confined areas (sewers, basements, tanks, etc.).· Vapor explosion hazard indoors, outdoors or in sewers.· Those substances designated with a (P) may polymerize explosively when heated or involved in a fire.· Runoff to sewer may create fire or explosion hazard.· Containers may explode when heated.· Many liquids will float on water.Highly flammable. Vapour/air mixtures are explosive. Risk of fire and explosion on contact with strong oxidants. |
| Fire potential | Flammable liquid. A very dangerous fire hazard when exposed to heat, flame, or oxidizers. |
| Health hazards | Vapors irritate eyes and upper respiratory tractcause dizziness, headache, anesthesia, respiratory arrest. Liquid irritates eyes and causes drying of skin. If aspirated, causes coughing, gagging, distress, and rapidly developing pulmonary edema. If ingested causes vomiting, griping, diarrhea, depressed respiration. (USCG, 1999)· May cause toxic effects if inhaled or absorbed through skin.· Inhalation or contact with material may irritate or burn skin and eyes.· Fire will produce irritating, corrosive and/or toxic gases.· Vapors may cause dizziness or asphyxiation, especially when in closed or confined areas.· Runoff from fire control or dilution water may cause environmental contamination. |
| Hazards summary | Toluene is a clear, colorless liquid with a distinctive smell. Toluene occurs naturally in crude oil and in the tolu tree. It is also produced in the process of making gasoline and other fuels from crude oil and making coke from coal. Toluene is used in making paints, paint thinners, fingernail polish, lacquers, adhesives, and rubber and in some printing and leather tanning processes.Toluene is added to gasoline, used to produce benzene, and used as a solvent. Exposure to toluene may occur from breathing ambient or indoor air affected by such sources. The central nervous system (CNS) is the primary target organ for toluene toxicity in both humans and animals for acute (short-term) and chronic (long-term) exposures. CNS dysfunction and narcosis have been frequently observed in humans acutely exposed to elevated airborne levels of toluenesymptoms include fatigue, sleepiness, headaches, and nausea. CNS depression has been reported to occur in chronic abusers exposed to high levels of toluene. Chronic inhalation exposure of humans to toluene also causes irritation of the upper respiratory tract and eyes, sore throat, dizziness, and headache. Human studies have reported developmental effects, such as CNS dysfunction, attention deficits, and minor craniofacial and limb anomalies, in the children of pregnant women exposed to high levels of toluene or mixed solvents by inhalation. EPA has concluded that that there is inadequate information to assess the carcinogenic potential of toluene.Chronic abuse from glue sniffing causes permanent cerebral and cerebellar dysfunction. Liver injury has been reported in glue sniffers. [ATSDR Case Studies: Toluene Toxicity] Toluene abuse may induce acute renal failure with rhabdomyolysis documented as the precipitating event in some cases. [Rosenstock, p. 577] Birth defects similar to the fetal alcohol syndrome occur when mothers abuse toluene during pregnancy. A study of women occupationally exposed to toluene showed an increased incidence of spontaneous abortions. [Frazier, p. 184-5] TLV Basis is impairment (CNS, visual, and hearing), female reproductive toxicity, and pregnancy loss. [ACGIH] The probability of cognitive deficits due to toluene exposure below a TLV of 50 ppm remains extremely low. [PMID 14598174] |
| DOT ID and guide | 1294 130 |
| FDA requirements | Toluene is an indirect food additive for use only as a component of adhesives. |
| Reactive group | Hydrocarbons, Aromatic |
| UN classification | UN Hazard Class: 3UN Pack Group: II |
| Special Reports | Review: Benignus VANeurotoxicology (Park Forest South, IL) 2 (3): 567 (1981). Review on health effects of toluene, particularly with respect to its neurotoxic effects in humans and lab animals.NIOSHCriteria Document: Toluene (1973) DHEW Pub. NIOSH 73-11023USEPAAmbient Water Quality Doc: Toluene (1980) EPA 440/5-80-075NAS/NRCThe Alkyl Benzenes 384 pp (1981)For more Special Reports (Complete) data for TOLUENE (10 total), please visit the HSDB record page. |
| Fire fighting | Excerpt from ERG Guide 130 [Flammable Liquids (Water-Immiscible / Noxious)]:CAUTION: The majority of these products have a very low flash point. Use of water spray when fighting fire may be inefficient.SMALL FIRE: Dry chemical, CO2, water spray or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam.LARGE FIRE: Water spray, fog or regular foam. If regular foam is ineffective or unavailable, use alcohol-resistant foam. Avoid aiming straight or solid streams directly onto the product. If it can be done safely, move undamaged containers away from the area around the fire.FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: Fight fire from maximum distance or use unmanned master stream devices or monitor nozzles. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks in direct contact with flames. For massive fire, use unmanned master stream devices or monitor nozzlesif this is impossible, withdraw from area and let fire burn. (ERG, 2024)Use foam, powder, carbon dioxide, water spray. In case of fire: keep drums, etc., cool by spraying with water. |
| First aid measures | Fresh air, rest. Refer immediately for medical attention.First rinse with plenty of water for at least 15 minutes, then remove contaminated clothes and rinse again. Rinse and then wash skin with water and soap. Refer for medical attention .First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.Rinse mouth. Give nothing to drink. Do NOT induce vomiting. Refer immediately for medical attention. |
| Accidental release measures | · CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.· Keep unauthorized personnel away.· Stay upwind, uphill and/or upstream.· Ventilate closed spaces before entering, but only if properly trained and equipped.· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.· All equipment used when handling the product must be grounded.· Do not touch or walk through spilled material.· Stop leak if you can do it without risk.· Prevent entry into waterways, sewers, basements or confined areas.· A vapor-suppressing foam may be used to reduce vapors.· Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers.· Use clean, non-sparking tools to collect absorbed material.Large Spill· Dike far ahead of liquid spill for later disposal.· Water spray may reduce vapor, but may not prevent ignition in closed spaces. |
| First aid | 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.SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.INHALATION: IMMEDIATELY leave the contaminated areatake deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be usedif not available, use a level of protection greater than or equal to that advised under Protective Clothing.INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)General First Aid:· Call 911 or emergency medical service.· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.· Move victim to fresh air if it can be done safely.· Administer oxygen if breathing is difficult.· If victim is not breathing:-- DO NOT perform mouth-to-mouth resuscitationthe victim may have ingested or inhaled the substance.-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.· Remove and isolate contaminated clothing and shoes.· For minor skin contact, avoid spreading material on unaffected skin.· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.· For severe burns, immediate medical attention is required.· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.· Keep victim calm and warm.· Keep victim under observation.· For further assistance, contact your local Poison Control Center.· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.Specific First Aid:· Wash skin with soap and water.(General first aid procedures)Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.Skin: Soap wash promptly - If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water. Get medical attention promptly.Breathing: Respiratory supportSwallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. |
| Safe storage | Well closed. Fireproof. Separated from strong oxidants. Store in an area without drain or sewer access. Store only in original container. |
| Firefighting Hazards | Poisonous gases may be produced in fire.Vapors are heavier than air and may travel to a source of ignition and flash back. Liquid floats on water and may travel to a source of ignition and spread fire.Flame speed equals 37 cm/sec. |
| Exposure control and personal protection | · Wear positive pressure self-contained breathing apparatus (SCBA).· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.Biological Exposure Indices (BEI) [ACGIH] - o-Cresol in urine = 0.3 mg/g creatinine (end of shift)Toluene in blood = 0.02 mg/L (prior to last shift of workweek)Toluene in urine = 0.03 mg/L (end of shift)5300.0 [ppm]50.0 [ppm] |
| Fire fighting procedures | Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.Use water spray to cool unopened containers.To fight fire, use foam, CO2, dry chemical.For more Fire Fighting Procedures (Complete) data for TOLUENE (7 total), please visit the HSDB record page. |
| Storage conditions | Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Handle and store under inert gas.Store in a flammable liquid storage area or approved cabinet away from ignition sources and corrosive and reactive materials. ... Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Toluene must be stored to avoid contact with strong oxidizers (such as chlorine, bromine, and fluorine), since violent reactions occur. Protect storage containers from physical damage. Sources of ignition, such as smoking and open flames, are prohibited where toluene 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 toluene 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 toluene.Outside or detached storage is preferred. Inside storage should be in a standard flammable liquids storage warehouse, room, or cabinet. Separate from oxidizing materials. |
| Cleanup methods | ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areasEnvironmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoidedMethods and materials for containment and cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations.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 a similar material and deposit in sealed containers. Keep this chemical out of a confined space, such as a sewer, because of the possibility of an explosion, unless the sewer is designed to prevent the buildup of explosive concentrations. 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.Eliminate all ignition sources. Stop or control the leak, if this can be done without undue risk. Use water spray to cool and disperse vapors and protect personnel. Absorb in noncombustible material for proper disposal. Control runoff and isolate discharged material for proper disposal.1. Remove all ignition sources. 2. Ventilate area of spill or leak. 3. For small quantities, absorb on paper towels. Evaporate in safe place (such as fume hood). Allow sufficient time for evaporating vapors to completely clear hood ductwork. Burn paper in suitable location away from combustible materials.For more Cleanup Methods (Complete) data for TOLUENE (10 total), please visit the HSDB record page. |
| Nonfire spill response | Excerpt from ERG Guide 130 [Flammable Liquids (Water-Immiscible / Noxious)]:ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. All equipment used when handling the product must be grounded. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. A vapor-suppressing foam may be used to reduce vapors. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. Use clean, non-sparking tools to collect absorbed material.LARGE SPILL: Dike far ahead of liquid spill for later disposal. Water spray may reduce vapor, but may not prevent ignition in closed spaces. (ERG, 2024) |
| Disposal methods | Product: Burn in a chemical incinerator equipped with an afterburner and scrubber but exert extra care in igniting as this material is highly flammable. Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this materialContaminated packaging: Dispose of as unused product.Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste numbers U220, and F005 must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.Toluene is a waste chemical stream constituent which may be subjected to ultimate disposal by controlled incineration.A good candidate for liquid injection incineration at a temperature range of 650 to 1,600 °C and a residence time of 0.1 to 2 seconds. A good candidate for rotary kiln incineration at a temperature range of 820 to 1,600 °C and residence times of seconds for liquids and gases, and hours for solids. A good candidate for fluidized bed incineration at a temperature range of 450 to 980 °C and residence times of seconds for liquids and gases, and longer for solids.For more Disposal Methods (Complete) data for TOLUENE (11 total), please visit the HSDB record page. |
| Toxicological information | CDC-ATSDR Toxicological Profile |
| Body burden | Toluene was identified, not quantified, in 8 samples of mothers' milk from 4 urban areas(1). Toluene was detected in 250 of 250 specimens of human blood at concentrations of 0.2-38 ppb (1.5 ppb avg)(2). Toluene was detected in 91% of the samples of the National Human Adipose Tissue Survey at a maximum concentration of 250 ppb(3). Toluene was identified, not quantified, in expired breath of people at service stations during fueling(4). The mean concentration of toluene in the blood of non-occupationally exposed individuals in the US was 0.52 ppb(5). The average concentration of toluene in the blood and urine of workers in glass fiber and clutch lining plants were 911 ug/L and 2.9 mg/L, respectively(6). Toluene was detected in human blood samples collected from 292 adults aged 20-59 years old in the 1999-2000 NHANES study at a mean concentration of 0.442 ng/mL (range of 0.023-4.880 ng/mL)(7). |
| Treatment | If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally. |
| Interactions | The exposure intensity during a shift and the metabolite levels in the shift-end urine were examined in male workers exposed to either benzene (65 subjectsthe benzene group), toluene (35 subjectsthe toluene group), or a mixture of both (55 subjectsthe mixture group). In addition, 35 non-exposed male workers (the control group) were similarly examined for urinary metabolites to define background levels. A linear relationship was established between the intensity of solvent exposure and the corresponding urinary metabolite levels (i.e. phenol, catechol and quinol from benzene, and hippuric acid and o-cresol from toluene) in each case when one of the three exposed groups was combined with the control group for calculation. Comparison of regression lines in combination with regression analysis disclosed that urinary levels of phenol and quinol (but not catechol) were lower in the mixture group than in the benzene group when the intensities of exposure to benzene were comparable, indicating that the biotransformation of benzene to phenolic compounds (excluding catechol) in man is suppressed by co-exposure to toluene. Conversely, metabolism of toluene to hippuric acid was suppressed by benzene co-exposure. Conversion of toluene to o-cresol was also reduced by benzene, but to a lesser extent. The significance of the present findings on the mutual suppression of metabolism between benzene and toluene is discussed in relation to solvent toxicology and biological monitoring of exposure to the solvents.As toluene is metabolized by CYPs, ADH, and ALDH, the chemical can interact with other xenobiotics metabolized by these enzymes. Concurrent exposure to solvents metabolized by the same CYP isoforms can result in competitive metabolic inhibition. /It has been observed/ that benzene and toluene suppressed one another's metabolism in humans. ... /A study/ found that toluene greatly reduced manifestations of peripheral neuropathy caused by n-hexane in rats. Although no interaction between toluene and xylenes were seen in humans inhaling low levels of each, simultaneous exposure to higher levels results in mutual metabolic suppression. Prior exposure to P450 inducers can result in increased rates of toluene metabolism/elimination and more rapid recovery from toluene-induced CNS depression. /Another study/ observed that high concentrations of inhaled toluene moderately induced four of the six P450 isoforms that metabolize it, but inhibited the other two in rat liver.Voluntary inhalation of organic solvents, such as toluene, is particularly prevalent in adolescent populations and is considered to be a contributing factor to substance use and dependence later in life. While inhalants are often the initial "drug" experienced during this period, alcohol is another substance readily abused by adolescent populations. Although both substances are thought to have similar actions within the brain, our understanding of the implications of adolescent inhalant abuse upon subsequent exposure to alcohol remains to be investigated. Thus, this study aimed to assess locomotor responses to acute ethanol and voluntary ethanol consumption following a period of toluene inhalation throughout adolescence/early adulthood. Adolescent male Wistar rats (postnatal day [PN] 27) inhaled air or toluene (3000 ppm) for 1 hr/day, 3 days/week for 4 (PN 27-52) or 8 weeks (PN 27-80) to mimic the patterns observed in human inhalant abusers. Following the exposure period, cross-sensitization to acute ethanol challenge (0.5 g/kg, intra-peritoneally [i.p.]), and voluntary consumption of 20% ethanol in a chronic intermittent 2-bottle choice paradigm, were assessed. Hepatic ethanol and acetaldehyde metabolism and liver histopathology were also investigated. Chronic intermittent toluene (CIT) exposure throughout adolescence for up to 8 weeks did not alter the behavioral response to acute ethanol or voluntary consumption of ethanol in adulthood, although an age-dependent effect on ethanol consumption was observed (p<0.05). Both liver function and pathology did not differ between treatment groups. Thus, in the paradigm employed, CIT exposure throughout adolescence and early adulthood did not predispose rats to subsequent locomotor sensitivity or voluntary consumption of ethanol in adulthood.Caffeic acid phenethyl ester (CAPE) has antioxidant and anti-inflammatory properties. The aim of this study is to examine the negative effects of toluene on kidney tissues and functions and to investigate the protective effects of CAPE against toluene-induced nephrotoxicity in rats. A total of 21 male Wistar rats were divided into three groups of equal number in each. The rats in group I were the controls. Toluene was intraperitoneally injected into the rats in group II with a dose of 500 mg/kg. Rats in group III received CAPE daily while exposed to toluene. After 14 days of experimental period, all rats were killed by decapitation. Enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) and malondialdehyde (MDA) levels were studied in the rat kidneys. Blood urea nitrogen (BUN) and serum creatinine levels were measured for renal function. The CAT and SOD enzyme activities and serum creatinine levels were significantly increased in rats treated with toluene when compared with the controls. But GSH-Px activity, MDA, and BUN levels showed statistically nonsignificant changes. However, increased CAT and SOD enzyme activities and decreased serum creatinine levels were detected in the rats that received CAPE while exposed to toluene. The GSH-Px activity and MDA and BUN levels in the same group did not show statistically significant changes. The results of our study demonstrated that toluene damages kidney tissue and is a nephrotoxic substance. CAPE was able to prevent the renal damage as antioxidant, antitoxic, and nephroprotective agent.For more Interactions (Complete) data for TOLUENE (23 total), please visit the HSDB record page. |
| Target organs | Cardiovascular (Heart and Blood Vessels), Developmental (effects while organs are developing), Immunological (Immune System), Neurological (Nervous System), Respiratory (From the Nose to the Lungs)UrinaryEyes, skin, respiratory system, central nervous system, liver, kidneysCentral nervous system |
| Health effects | Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergi |
| Ecotoxicity values | EC50Species: Scenedesmus subspicatus (Green Algae) Exponential Growth PhaseConditions: freshwater, static, 24 °C, pH 8.0-9.3Concentration: 160000 ug/L for 48 hrEffect: population, decreased biomass /formulation/Concentration: 125000 ug/L for 48 hrEffect: population changes, general /formulation/Species: Pseudokirchneriella subcapitata (Green Algae) Exponential Growth PhaseConditions: freshwater, staticConcentration: 9400 ug/L for 8 daysEffect: growth, general /formulation/Species: Pseudokirchneriella subcapitata (Green Algae)Concentration: 12500 ug/L for 72 hrEffect: growth, generalFor more Ecotoxicity Values (Complete) data for TOLUENE (35 total), please visit the HSDB record page. |
| Environmental fate | TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 37-178 measured in soil(2,3) indicate that toluene is expected to have high to moderate mobility in soil(SRC). Volatilization of toluene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 6.64X10-3 atm-cu m/mole(4). Toluene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 28.4 mm Hg at 25 °C(5). Complete biodegradation of toluene was observed in lab microcosm tests during a 40 hour incubation period using soils previously exposed to toluene(6). The biodegradation half-life in various soils was reported as several hours to 71 days(7). These tests suggest that biodegradation is an important environmental fate process in soil(SRC).AQUATIC FATE: Based on a classification scheme(1), a Koc value of 166 measured in lake sediment(2) indicates that toluene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 6.64X10-3 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 1 hour and 4 days, respectively(SRC). According to a classification scheme(5), BCF values of 13(6) and 90(7) measured in fish suggest the potential for bioconcentration in aquatic organisms is low to moderate(SRC). The half-life of toluene in aerobic and anaerobic water was reported as 4 and 56 days(8), respectively, suggesting that biodegradation is an important environmental fate process in water(SRC).ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), toluene, which has a vapor pressure of 28.4 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase toluene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals, nitrate radicals and ozone molecules(SRC). The half-life for the reaction with hydroxyl radicals is estimated to be 2 days(SRC), calculated from its rate constant of 5.93X10-12 cu cm/molecule-sec at 25 °C(3). The half-life for the nighttime reaction with nitrate radicals is estimated as 491 days(SRC) calculated from its rate constant of 6.8X10-17 cu cm/molecule-sec at 25 °C(4). The half-life for the reaction with ozone is estimated as 27,950 days(SRC) calculated from its rate constant of 4.1X10-22 cu cm/molecule-sec at 25 °C(4). Toluene does not absorb light at wavelengths >290 nm(5) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC). |
| Food survey values | Toluene was identified, not quantified, in baked potatoes(1), mountain cheese(2), fried bacon(3), fried chicken(4), peanut oil(5) and raw beef(6). |
| Adverse effects | Neurotoxin - Acute solvent syndromeOccupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.Nephrotoxin - The chemical is potentially toxic to the kidneys in the occupational setting.Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.ACGIH Carcinogen - Not Classifiable. |
| Exposure routes | The substance can be absorbed into the body by inhalation, through the skin and by ingestion.inhalation, skin absorption, ingestion, skin and/or eye contactOral (L174)inhalation (L174)dermal (L174) |
| Milk Concentrations | Toluene was identified, not quantified, in 8 samples of mothers' milk from 4 urban areas(1). |
| RCRA requirements | U220As stipulated in 40 CFR 261.33, when toluene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).F005When toluene is a spent solvent, it is classified as a hazardous waste from a nonspecific source (F005), as stated in 40 CFR 261.31, and must be managed according to State and/or Federal hazardous waste regulations. |
| TSCA requirements | 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. Toluene is included on this list. Effective date: 10/4/82Sunset date: 10/4/92. |
| Atmospheric standards | 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. Toluene is produced, as an intermediate or a final product, by process units covered under this subpart.Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Toluene is included on this list. |
| CERCLA reportable quantities | Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 1000 lb or 454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV.D.3.b). |
| Clean Water Act requirements | Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations.Toluene is designated as a hazardous substance under section 311(b)(2)(A) of the Federal Water Pollution Control Act and further regulated by the Clean Water Act Amendments of 1977 and 1978. These regulations apply to discharges of this substance. This designation includes any isomers and hydrates, as well as any solutions and mixtures containing this substance.Maximum contaminant levels (MCL) for organic contaminants apply to community and non-transient, non-community water systems: Chemical, MCL 1 mg/L. |
| State Drinking Water Standards | (CA) CALIFORNIA 150 ug/L |
| State drinking water guidelines | (AZ) ARIZONA 2000 ug/L(ME) MAINE 1400 ug/L(MN) MINNESOTA 1000 ug/L |
| Federal Drinking Water Standards | EPA 1000 ug/L |
| Federal drinking water guidelines | EPA 1000 ug/L |
| F | 3-10 |
| Occupational exposure band (OEB) | A |
| Occupational exposure limit (OEL) | TWA: 100 ppm (375 mg/m3), STEL: 150 ppm (560 mg/m3) |
| Personal protective equipment (PPE) | Eyeshields, Faceshields, Gloves, type ABEK (EN14387) respirator filter |
| Water hazard class (WGK) | 2 |
| Immediately dangerous to life or health concentration | 500 ppm |
| TSCA inventory status | TSCA listed |
| RTECS number | XS5250000 |
| UN transport number | UN 1294 |
| Customs code | 29023000 |
| Toxicity | LD50 orally in rats: 7.53 g/kg (Smyth) |
| Risk statements (R) | 11-38-48/20-63-65-67-39/23/24/25-23/24/25 |
| Signal word | Danger |
| GHS pictogram | GHS02,GHS07,GHS08 |
| Hazard symbols | F,Xn,T |
| Safety statements (S) | 36/37-46-62-45-16-7 |
| Hazard class | 3Aquatic Chronic 3Asp. Tox. 1Flam. Liq. 2Repr. 2Skin Irrit. 2STOT RE 2 InhalationSTOT SE 3 |
| Storage class | 3 - Flammable liquids |
| Packing group | II |
| GHS hazard statements | H225-H304-H315-H336-H361d-H373-H412 |
| Limited quantities | 1.0 L (0.3 gallon) (liquid) |
| Excepted quantities | Max Inner Pack (30g or 30ml) and Max Outer Pack (500g or 500ml) |
| REACH registrations | Active |
| Autoignition temperature | 480 °C |
| GHS precautionary statements | P201-P210-P273-P301+P310+P331-P302+P352-P308+P313 |
| Hazardous substances data | 108-88-3(Hazardous Substances Data) |
Applications & Uses
Uses
Toluene is a component of gasoline, paints, inks, lacquers, paint thinners, adhesives, fingernail polish, cleaning agents, and rubber. BTX (a mixture of benzene, toluene, and xylene) is added to gasoline to improve octane ratings. Toluene is used to produce benzene, trinitrotoluene (TNT), nylon, plastics, and polyurethanes. It is also used in production of drugs of abuse. Toluene is a favorite of solvent abusers, who intentionally inhale high concentrations to achieve a euphoric effect. It is used in the production of pharmaceuticals, dyes, and cosmetic nail products. It is used against roundworms and hookworms. Detailed applications are summarized here: Industry Applications Role/Benefit Chemical manufacture Production of benzene and dimethyl benzene Main feedstock Production of benzoic acid The oxidation products of toluene Production of benzene chloromethane or benzene trichloromethane The chlorination products of toluene Production of p-nitrotoluene or o-nitrotoluene The nitration products of toluene Production of o-toluenesulfonic acid or p-toluenesulfonic acid The sulfonation products of toluene Gasoline High-octane gasoline Used as octane booster to increase the octane value of gasoline Adhesives manufacture Carpet adhesive solvents Good solubility for adhesive Chemical analysis ICP-AES, AAS, AFS, ICP-MS and ion chromatography Stander material Titration analysis Stander solution Biology <div class="span"
Description
Toluene is a clear, colourless liquid with a sweet, benzene-like odour. Toluene occurs naturally in crude oil and in the toluene tree. It is also produced in the process of making gasoline and other fuels from crude oil and making coke from coal. Toluene is used in making paints, paint thinners, fingernail polish, lacquers, adhesives, and rubber and in some printing and leather tanning processes. Toluene is also used in the production of polymers used to make nylon, plastic soda bottles, and polyurethanes and for pharmaceuticals, dyes, cosmetic nail products, and the synthesis of organic chemicals. Toluene has been reported as the most commonly abused hydrocarbon solvent, primarily through ‘glue sniffing’. The common possibilities of exposure to high levels of toluene include indoor air from the use of household products such as paints, paint thinners, adhesives, synthetic fragrances, and many other sources.
History
Toluene is a clear, flammable, aromatic hydrocarbon liquid with a smell similar to benzene. It is also called methylbenzene, indicating that a methyl group has been added to one of benzene’s carbon atoms. Toluene was first isolated by Pierre-Joseph Pelletier (1788–1842) and Philippe Walter (1810–1847) in 1837. The name toluene comes from the South American tree Toluifera balsamum. Henri-Etienne Sainte-Claire Deville (1818–1881) isolated toluene from the tree’s gum, Tolu balsam, in 1841. The main source of toluene is from the catalytic reforming of naphthas during petroleum processing. During this process cycloalkanes are dehydrated, forming aromatics such as toluene and xylene along with hydrogen. Toluene can also be obtained from the pyrolysis of gasoline. It is a by-product when styrene is produced and can also be produced from coal tar, which was its main source in the first half of the 20th century.
Uses
Toluene is derived from coal tar as well aspetroleum. It occurs in gasoline and manypetroleum solvents. Toluene is used to producetrinitrotoluene (TNT), toluene diisocyanate,and benzene; as an ingredient fordyes, drugs, and detergents; and as an industrialsolvent for rubbers, paints, coatings, andoils.
Uses
In manufacture of benzoic acid, benzaldehyde, explosives, dyes, and many other organic Compounds; as a solvent for paints, lacquers, gums, resins; thinner for inks, perfumes, dyes; in the extraction of various principles from plants; as gasoline additive.
Uses
Toluene has numerous applications in the chemical and petroleum industry, with approximately 6 million tons used annually in the United States and 16 million tons used globally. The major use of toluene is as an octane booster in gasoline. Toluene has an octane rating of 114. Toluene is one of the four principal aromatic compounds, along with benzene, xylene, and ethylbenzene, that are produced during refining to enhance gasoline's performance. Collectively, these four compounds are abbreviated as BTEX. BTEX is a major component of gasoline, forming about 18% by weight of a typical blend. Although the proportion of the aromatics is varied to produce different blends to meet geographic and seasonal requirements, toluene is one of the major components. A typical gasoline contains approximately 5% toluene by weight.Toluene is a primary feedstock used to produce various organic compounds. It is usedto produce diisocyanates. Isocyanates contain the functional group N = C = O, and diisocyanatescontain two of these. The two main diisocyanates are toluene 2,4-diisocyanate andtoluene 2,6-diisocyanate. The production of diisocyanates in North America is close to a billionpounds annually. More than 90% of toluene diisocyanate production is used for makingpolyurethanes foams. The latter are used as flexible fill in furniture, bedding, and cushions.In rigid form it is used for insulation, hard shell coatings, building materials, auto parts, androller skate wheels.
General Description
A clear colorless liquid with a characteristic aromatic odor. Flash point 40°F. Less dense than water (7.2 lb / gal) and insoluble in water. Hence floats on water. Vapors heavier than air. May be toxic by inhalation, ingestion or skin contact. Used in aviation and automotive fuels, as a solvent, and to make other chemicals.
Preparation & Synthesis
Preparation
Toluene is the starting material for the production of tolylene diisocyanate (TDI)，the process may be varied to give products of differing isomer contents. The nitration of toluene (with a nitrating mixture containing 20% nitric acid, 60% sulphuric acid and 20% water at 30-45°C) gives a mixture of 2-nitrotoluene (about 60%) and 4- nitrotoluene (40%). If this mixture is nitrated further (with a mixture of 35% nitric acid and 65% sulphuric acid at 65-80°C) without separation, the product is a mixture of2,4-dinitrotoluene (about 80%) and 2,6-dinitrotoluene (20%). If, on the other hand, the mixed mononitrates are separated (by distillation), then further nitration of the 2-nitrotoluene yields a mixture of 2,4-dinitrotoluene (about 65%) and 2,6-dinitrotoluene (35%) whilst further nitration of the 4-nitrotoluene gives only 2,4-dinitrotoluene.