M-Xylene

Fire Extinguishing Agents Not to Be Used: Water may be ineffective.

Use water spray, powder, foam, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

Fresh air, rest. Refer 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.

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 .

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.

(General first aid procedures)

Biological Exposure Indices (BEI) [ACGIH] - Xylenes (technical or commercial grades): 0.3 g/g creatine methylhippuric acids in urine at end of shift; [ACGIH TLVs and BEIs]

100.0 [ppm]

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.

Foam, dry chemical or carbon dioxide. Water may be ineffective. Cool exposed containers with water.

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. Storage class (TRGS 510): Flammable liquids.

Protect containers against physical damage. Outdoor or detached storage is preferable. Indoor storage should be in a standard flammable liquid storage room.

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 areas. 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: 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.

SMALL SPILLS AND LEAKAGE: If you should spill this chemical, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with acetone followed by washing with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U239 and F003, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

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: 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 material; Contaminated packaging: Dispose of as unused product.

Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Ventilation. Remove all ignition sources. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations.

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

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 areas. 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.

Precautions for safe handling: Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Keep away from sources of ignition - No smoking. Take measures to prevent the build up of electrostatic charge.

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

For more Preventive Measures (Complete) data for 3-XYLENE (8 total), please visit the HSDB record page.

... m-Xylene ... /was/ detected in brain, liver, lung, vitreous fluid, kidney, and blood of two individuals who died from exposure to painting sprays by packed and open tubular gas chromatography and mass spectroscopy.

The mean concentration of 3-/4-xylene was 0.21 ng/mL in the blood of 134 school-age children that participated in the School Health Initiative: Environment, Learning, Disease (SHIELD) study in Minneapolis, MN(1). The mean concentration of 3-/4-xylene was 0.32 ng/mL in the blood of 43 children living in an inner city neighborhood of Minneapolis, MN(2). A median measured personal 3-/4-xylene concentration of 4.4 ug/cu m was determined for participants of the BEAM study which included 55 individuals employed in nonmanufacturing workplaces, including schools and offices, and living in suburban or urban locations in the greater Boston, MA area(3).

Expired air samples from 54 normal, healthy volunteers from an urban population in Chicago, IL had mean levels of 3-xylene of 0.0003 mg/cu m(1). Expired air samples from urban residents of two New Jersey cities had a mean value of 0.009 mg/cu m for combined 3-/4-xylene. Levels were higher in persons who pumped their own gasoline or were exposed to auto and truck exhaust(1). Blood samples collected from a reference group of a non-occupationally exposed US population contained combined 3-/4-xylene at a mean concentration of 0.37 ppb (median = 0.19, n = 649)(2). 100% of expired air samples from 26 smokers and 43 non-smokers contained 3-/4-xylene, combined(3). Expired air samples collected from 28 healthy human subjects contained 3-xylene at a mean concentration of 0.35 ng/L(4). Expired air samples collected from 54 healthy human subjects contained 3-xylene at a mean concentration of 0.324 ng/L (15.8% positive samples)(5). 100% of human adipose tissue samples collected for the National Human Adipose Tissue Survey, contained xylene, unspecified isomer, with wet tissue concentrations of 0.4-400 ng/g; the greatest concns were found in the South Atlantic region for people 15-45+ years of age(6).

The reported mean concentration of 3-/4-xylene measured in the personal air of 36 high school students in New York City participating in the TEACH study was 10.9 ug/cu m in the summer and 6.71 ug/cu m in the winter(1).

Personal air samples collected from 340 residents fall 1981, 150 residents in summer 1982, and 49 residents from Elizabeth-Bayonne NJ in winter 1983 contained 3-/4-xylene combined, at average concns of 52, 37, and 36 ug/cu m, respectively, for 12 hour samples. Personal air samples collected from 110 Los Angeles, CA residents in winter 1984, 50 Los Angeles, CA residents in spring 1984, and from Contra Costa, CA residents in summer 1984 contained 3-/4-xylene, combined, at average concns of 18, 12, and 5.5 ug/cu m, respectively, for 12 hour samples(1).

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.

Ingestion of ethanol (0.8 g/kg) prior to exposure to m-xylene (6.0 or 11.5 mmol/cu m) produced a marked alteration in xylene kinetics. Blood xylene level rose and urinary methylhippuric acid excretion decreased suggesting ethanol decreased metab clearance of xylene by about one-half.

Healthy male subjects were exposed at weekly intervals to m-xylene concn of 6 umol/L (145 ppm) and 11.5 umol/L (290 ppm) for 4 hr alone and in combination with prior ingestion of single doses of alcohol (0.8 g/kg). Body sway was recorded with a strain gauge transducer platform with the subject's eyes closed and open, and the eyes closed/open ratio, indicating the grade of visual compensation for body balance. Alcohol with xylene concn of 11.5 umol/L significantly incr the ratio, a finding suggesting an unexpected combined effect of xylene and alcohol, possibly of metabolic origin, on the human equilibrium system.

The metabolic interaction and disposition of methyl ethyl ketone and m-xylene after single or multiple inhalation exposures were studied in rats. Male Wistar-rats were exposed one for 6 hr to 300 ppm m-xylene or 600 ppm methyl ethyl ketone vapor alone or in combination. Other rats were exposed to 600 ppm methyl ethyl ketone and 300 ppm m-xylene, separately or together, daily for 7 days. They were then given a final exposure 18 hr later. The rats were killed 0.5 or 18 hr after the last exposure and the blood and perirenal fat /were taken and analyzed for xylene and MEK. The livers were/ removed and assayed for 7-ethoxycoumarin-O-deethylase, 7-ethoxyresorufin-O-deethylase, and 7-pentoxyresorufin-O-deethylase. Urine samples collected from other animals were analyzed for methyl-hippuric acid, 2,4-dimethylphenol, and thioethers. Blood m-xylene concentrations were slightly, significantly increased in rats exposed to the mixture compared to those exposed to xylene only. Blood methyl ethyl ketone concentrations were not significantly affected by xylene. Blood xylene concentrations were similar in rats given the single and multiple exposures. Perirenal fat m-xylene concn in rats exposed to the mixture were significantly higher than in those exposed to xylene alone 0.5 and 18 hr after exposure ended. Xylene concentrations were significantly lower after the multiple exposure than after the single exposure. Fat methyl ethyl ketone concentrations were also increased by coexposure to m-xylene. Methyl-hippuric acid excretion was decreased and 2,4-dimethylphenol excretion increased in rats exposed to the mixture relative to those exposed to m-xylene only. All m-xylene exposed rats showed sharp increase in urinary thioether excretion. Thioether excretion in controls. Multiple exposures to xylene significantly increased hepatic 7-ethoxycoumarin-O-deethylase, 7-ethoxyresorufin-O-deethylase, and 7-pentoxyresorufin-O-deethylase activity. Methyl ethyl ketone caused only a slight increase in activity of these enzymes. The combined exposures caused a synergistic increase in 7-pentoxyresorufin-O-deethylase activity and an additive increase in 7-ethoxyresorufin-O-deethylase and 7-ethoxycoumarin-O-deethylase activity. The authors conclude that methyl ethyl ketone inhibits the metabolism of xylene by suppressing side chain oxidation, but not oxidation of the aromatic ring.

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: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.

LC50; Species: Cancer magister (Crab) larvae-stage I; Concentration: 12 ppm for 96 hr /Conditions of bioassay not specified/

LC50; Species: Crangon franciscorum (Shrimp); Concentration: 3.7 ppm for 96 hr /Conditions of bioassay not specified/

LC100; Species: Tetrahymena pyriformis (Ciliate); Concentration: 3.77 mmole/L for 24 hr /Conditions of bioassay not specified/

EC50; Species: Pseudokirchneriella subcapitata (Green algae); Conditions: freshwater, static; Concentration: 4900 ug/L for 72 hr; Effect: growth, general /formulated product/

For more Ecotoxicity Values (Complete) data for 3-XYLENE (14 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values ranging from 166-275(2-4), indicate that 3-xylene is expected to have moderate mobility in soil(SRC). Volatilization of 3-xylene from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 7.18X10-3 atm-cu m/mole(5). 3-Xylene is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 8.29 mm Hg at 25 °C(6). 3-Xylene is expected to biodegrade in soil under both aerobic and anaerobic conditions(7). Biodegradation is an important process in subsurface soils and groundwater where volatilization is hindered(7). 3-Xylene has been observed to biodegade in standard biodegradability tests using various inocula(8). For example, using OECD Guideline 301F (Ready Biodegradability: Manometric Respirometry Test) with a mixture of sewage, soil and natural water inoculum, 3-xylene reached 98% of its O2 consumption in 28 days which classified 3-xylene as readily biodegradable(8). 3-Xylene, present in soil samples contaminated with jet fuel, was completely degraded aerobically within 5 days(9), suggesting that biodegradation may be an important environmental fate process in soil(SRC). In anaerobic aquifer studies, 3-xylene was degraded, usually within several weeks(10). However, under anaerobic conditions, a long lag period may be required before xylene degradation commences(11).

AQUATIC FATE: Based on a classification scheme(1), Koc values ranging from 166-275(2-4), indicate that 3-xylene is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(5) based upon a Henry's Law constant of 7.18X10-3 atm-cu m/mole(6). Using this Henry's Law constant and an estimation method(5), volatilization half-lives for a model river and model lake are 3.1 hours and 4.1 days, respectively(SRC). According to a classification scheme(7), a BCF of 14.8 measured in goldfish(8) suggest the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation is an important process in groundwater where volatilization is hindered(9). 3-Xylene has been observed to biodegade in standard biodegradability tests using various inocula(10). For example, using OECD Guideline 301F (Ready Biodegradability: Manometric Respirometry Test) with a mixture of sewage, soil and natural water inoculum, 3-xylene reached 98% of its O2 consumption in 28 days which classified 3-xylene as readily biodegradable(10). However, under anaerobic conditions, a long lag period may be required before xylene degradation commences(11). Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions(5). Irradiation studies using humic substances(12) suggest photooxidation may have some environmental importance in natural surface waters exposed to sunlight(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 3-xylene, which has a vapor pressure of 8.29 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 3-xylene 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 17 hours(SRC), calculated from its rate constant of 2.31X10-11 cu cm/molecule-sec at 25 °C(3). Vapor-phase 3-xylene is degraded slowly in the atmosphere by reaction with night-time nitrate radicals(SRC); the half-life for this reaction in air is estimated to be 138 days(SRC), calculated from its rate constant of 2.32X10-16 cu cm/molecule-sec at 25 °C(4). 3-Xylene has been detected in rainwater and snow(5,6) and, therefore, it may be removed from the air by wet deposition(SRC). 3-Xylene does not absorb at wavelengths >290 nm(7) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

3-Xylene was measured in Korean salt-fermented fish and shrimp pastes; big eyed herring, hair-tail viscera, and shrimp pastes had concentrations of 378, 124, and 99.9 ng/g 3-xylene, respectively(1). Volatile flavor components from Idaho Russet Burbank baked potatoes(2), roasted filberts(3), scrambled eggs(4), tree-ripened nectarines(10) and chicken, beef, and pork volatiles(12) contained 3-xylene. 64 of 234 table-ready food items from the FDA's Total Diet Study contained 3- and 4-xylene (reported as a combined value) with the highest concentration found in margarine (114 ppb), butter (54.8 ppb), cake doughnuts (35.0 ppb), and sandwich cookies (12.9 ppb)(5). 3-Xylene was detected in lipid fractions from raw beef(6). 3-/4-Xylene, combined value, was not detected in samples of animal milk from suburban, countryside and pasteurized sources (unreported detection limit)(7). 3-Xylene was detected in the aroma concentrate of cured beef and cured chicken at 0.04 and 0.11 mg/kg, respectively(8). 3-/4-Xylene, combined value, was detected in floured chickpea seed(9). Volatile components of water-boiled duck meat, duck fat, Cantonese style roasted duck, and Cantonese style roasted duck gravy contained 3-xylene at 0.99, 4.29, 9.61, and 18.09 ppb, wet basis, respectively(6).

As part of the US FDA Total Diet Program, monitoring of 70 foods between 1996 and 2000 detected 3-/4-xylene in the following food items(1):[Table#418]

The substance can be absorbed into the body by inhalation, through the skin and by ingestion.

inhalation, skin absorption, ingestion, skin and/or eye contact

Oral (L165) ; inhalation (L165) ; dermal (L165)

F003; When xylene is a spent solvent, it is classified as a hazardous waste from a nonspecific source (F003), as stated in 40 CFR 261.31, and must be managed according to State and/or Federal hazardous waste regulations. /Xylenes/

U239; As stipulated in 40 CFR 261.33, when xylene, 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). /Xylenes/

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. m-Xylene is included on this list. Effective date 10/4/82; Sunset date: /10/4/92.

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. 3-Xylene is included on this list.

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).

m-Xylene 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.

Permitted for use as an inert ingredient in non-food pesticide products; [EPA] Found in coal tar; Commercial xylene is a mixture of the o-, m-, and p- isomers with the m-isomer predominating; Used as a solvent, to make dyes, and to sterilize catgut; [Merck Index] Used as a solvent and to make polyester and alkyd resins, insecticides, aviation fuel, and dyes; [HSDB]

Painting (Solvents) [Category: Paint]

Solvent; intermediate for dyes and organic synthesis, especially isophthallic acid; insecticides; aviation fuel.

Most of the MX /3-xylene/ that is contained in recovered mixed xylenes is isomerized to PX /4-xylene/ and OX /2-xylene/. MX is also used to produce isophthalic acid and isophthalonitrile.

m-Xylene is used in the manufacturing of polyester and alkyl resins.

Used as a chemical intermediate for the synthesis of 5-t-butyl-m-xylene; 3,5-di-(trifluoromethyl)aniline; isophthalic acid; isophthalodinitrile; 3-(trifluoromethyl)-benzoyl fluoride; 3,5-xylenol; 2,4-xylidine; 2,6-xylidine.

(1978) 1.26X10+10 G

(1982) 1.02X10+9 G

(1986) 7.62X10+5 gal

2023: 85,000,000 - <100,000,000 lb

1,3-Dimethylbenzene is listed as a High Production Volume (HPV) chemical (65FR81686). Chemicals listed as HPV were produced in or imported into the U.S. in >1 million pounds in 1990 and/or 1994. The HPV list is based on the 1990 Inventory Update Rule. (IUR) (40 CFR part 710 subpart B; 51FR21438).

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#421]

Non-confidential 2012 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: Benzene, 1,3-dimethyl-. National Production Volume: 317,946,408 lb/yr.

The Mitsubishi Gas-Chemical Company (MGCC) has commercialized a process for separating and producing high purity MX /3-xylene/. In addition to producing MX, this process greatly simplifies the separation of the remaining C8 aromatic isomers. This process is based on the formation of a complex between MX and HF-BF3. MX is the most basic xylene and its complex with HF-BF3 is the most stable. The relative basicities of MX, OX /2-xylene/, PX /4-xylene/, and EB /ethylbenzene/ are 100, 2, 1, and 0.14, respectively. MX of >99% purity can be obtained with the MGCC process with <1% MX left in the raffinate by phase separation of hydrocarbon layer from the complex-HF layer. The latter undergoes thermal decomposition, which liberates the components of the complex.

Xylene is produced primarily by the catalytic reforming of naphtha streams, which are rich in alicyclic hydrocarbons. The aromatic reformate fractions consist mainly of benzene, toluene and mixed xylenes, xylenes representing the largest fraction. The xylene isomers are separated from the reformate by extraction and distillation on the basis of differences in boiling point ... 4-xylene is separated by continuous crystallization or adsorption from the mixed xylenes or isomerized from the 3-xylene/4-xylene distillate; 3-xylene is obtained by selective crystallization or solvent extraction of meta-para mixtures.

Grade: 95% (technical); 99%, 99.9% (research)

Present in high octane gasoline at 12.03 wt%

Wholesale and Retail Trade

Benzene, 1,3-dimethyl-: ACTIVE

The commercial product "mixed xylenes" is a technical product generally containing approximately 40% m-xylene and 20% each of o-xylene, p-xylene, and ethylbenzene, as well as small quantities of toluene ...

Xylenes will enter the atmosphere primarily from fugitive emissions and exhaust connected with their use in gasoline. Industrial sources include emissions from petroleum refining and their use as solvents and chemical intermediates ... The primary source of exposure is from air, especially at occupational sites where xylenes are used and in areas with high traffic. /xylenes/

There are some differences in the composition of commercial xylenes produced from petroleum and from coal-tar. The general composition of xylenes from petroleum is 44% m-xylene, 20% o-xylene, 20% p-xylene and 15% ethylbenzene. The xylenes from coal-tar consists of 45-70% m-xylene, 23% p-xylene, 10-15% o-xylene and 6-10% ethylbenzene. Commercial xylene may also contain small amounts of toluene, trimethylbenzene (pseu documene), phenol, thiophene, pyridine and non-aromatic hydrocarbons and has frequently been contaminated with benzene.

Concentration of 3-xylene in gasoline: 5.6% wt