4-Methylstyrol

In water, 89 mg/L at 25 °C

Insoluble in water

Soluble in benzene

125 to 127 °F (NFPA, 2010)

52.8 °C

46 °C (115 °F) - closed cup

1.81 [mmHg]

1.81 mm Hg at 25 °C

This chemical does not meet GHS hazard criteria for 4.5% (20 of 449) of reports.

Danger

H226 (95.5%): Flammable liquid and vapor [Warning Flammable liquids]

P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P271, P273, P280, P301+P316, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P317, P319, P321, P331, P332+P317, P337+P317, P362+P364, P370+P378, P391, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 449 reports by companies from 16 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

Chemical: Benzene, 1-ethenyl-4-methyl-

Benzene, 1-ethenyl-4-methyl- is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Benzene, 1-ethenyl-4-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: 28-10-2021 https://echa.europa.eu/registration-dossier/-/registered-dossier/26002

Methylstyrene (mixture of 3- and 4-isomers), >26% in a non hazardous diluent: Does not have an individual approval but may be used under an appropriate group standard

4-Methylstyrene: Does not have an individual approval but may be used under an appropriate group standard

A skin, eye, and respiratory tract irritant; Inhalation of high concentrations may cause CNS effects; Defats the skin; May have effects on the liver and kidneys; [ICSC] Causes elevation of liver enzymes in 13 week inhalation studies of rats; [Reference #1] Vinyltoluenes, stabilized (UN2618) has warning of explosive polymerization; [ERG 2016] See Vinyl toluene.

P-METHYLSTYRENE may react vigorously with strong oxidizing agents. May react exothermically with reducing agents to release hydrogen gas. In the presence of various catalysts (such as acids) or initiators, may undergo exothermic addition polymerization reactions. May undergo autoxidation upon exposure to the air to form peroxides. These peroxides and polyperoxides are usually extremely unstable and liable to detonation. The peroxidation of butadiene has been involved in several serious industrial accidents.

/GUIDE 130P FLAMMABLE LIQUIDS (Water-Immiscible/Noxious)/ Fire or Explosion: 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 ground and collect in low or confined areas (sewers, basements, tanks). 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 are lighter than water. /Vinyltoluenes, stabilized/

/GUIDE 130P FLAMMABLE LIQUIDS (Water-Immiscible/Noxious)/ Health: 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 suffocation. Runoff from fire control or dilution water may cause pollution. /Vinyltoluenes, stabilized/

/GUIDE 130P FLAMMABLE LIQUIDS (Water-Immiscible/Noxious)/ Public Safety: CALL Emergency Response Telephone Number on Shipping Paper first. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) in all directions. Keep unauthorized personnel away. Stay upwind, uphill and/or upstream. Ventilate closed spaces before entering. /Vinyltoluenes, stabilized/

/GUIDE 130P FLAMMABLE LIQUIDS (Water-Immiscible/Noxious)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. /Vinyltoluenes, stabilized/

For more DOT Emergency Guidelines (Complete) data for 4-Vinyltoluene (8 total), please visit the HSDB record page.

Suitable extinguishing media: For small (incipient) fires, use media such as "alcohol" foam, dry chemical, or carbon dioxide. For large fires, apply water from as far as possible. Use very large quantities (flooding) of water applied as a mist or spray; solid streams of water may be ineffective. Cool all affected containers with flooding quantities of water.

Advice for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.

Use water spray to cool unopened containers.

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

Store in cool place. 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. Recommended storage temperature: 2-8 °C.

Separated from strong oxidants and strong acids. Well closed. Keep in a well-ventilated room. Store only if stabilized.

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. 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.

Ventilation. 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. Personal protection: self-contained breathing apparatus.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

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.

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.

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.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

For more Preventive Measures (Complete) data for 4-Vinyltoluene (10 total), please visit the HSDB record page.

Excerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:

Eye/face protection: Face shield and safety glasses. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

Skin protection: Handle with gloves.

Body Protection: Complete suit protecting against chemicals. Flame retardant antistatic protective clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

For more Personal Protective Equipment (PPE) (Complete) data for 4-Vinyltoluene (10 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 720(SRC), determined from a structure estimation method(2), indicates that 4-vinyltoluene is expected to have low mobility in soil(SRC). Volatilization of 4-vinyltoluene from moist soil surfaces is expected(SRC) given an estimated Henry's Law constant of 3.2X10-3 atm-cu m/mole(SRC) based upon its vapor pressure, 1.81 mm Hg(3), and water solubility, 89 mg/L(4). 4-Vinyltoluene is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Biodegradation data in soil were not available(SRC, 2018).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 720(SRC), determined from a structure estimation method(2), indicates that 4-vinyltoluene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 3.2X10-3 atm-cu m/mole(SRC) derived from its vapor pressure, 1.81 mm Hg(4), and water solubility, 89 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3.5 hours and 4.4 days, respectively(SRC). 4-Vinyltoluene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(3). According to a classification scheme(6), a BCF of 32 measured in goldfish(7), suggests bioconcentration in aquatic organisms is moderate. Biodegradation data in water were not available(SRC, 2018).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 4-vinyltoluene, which has a vapor pressure of 1.81 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 4-vinyltoluene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals and ozone(SRC); the half-lives for these reactions in air are estimated to be 12 and 13 hours(SRC), calculated from its respective rate constants of 3.15X10-11(3) and 2.1X10-17(4) cu cm/molecule-sec. 4-Vinyltoluene absorbs weakly at wavelengths >290 nm(5) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: 4-Vinyltoluene is used in mixtures with other vinyltoluene isomers (3-vinyltoluene) as monomers for producing poly(vinyltoluene). It is used as a monomer in the production of polyester resins and is co-polymerized with isobutylene to produce synthetic elastomers. It is used in the coatings industry as a modifier for drying oils and oil-modified alkyds, used as a replacement for styrene in unsaturated polyester resins, as a copolymer with styrene to increase the operating temperature range of paints, coatings and varnishes. HUMAN STUDIES: 4-Vinyltoluene is irritating to the eyes, skin and respiratory tract. It may also cause effects on the central nervous system. Repeated or prolonged contact with skin may cause dermatitis. 4-Vinyltoluene defats the skin, which may cause dryness or cracking. It may have effects on the liver and kidneys, which may result in tissue lesions. Contact allergy to styrene related compounds was studied in a human subject. A patient known from previous studies to be sensitive to styrene was patch tested with styrene and 18 compounds structurally related to styrene. Positive results were obtained with 4-vinyltoluene among others. Significant increases in the frequencies of sister chromatid exchange were observed in human lymphocyes exposed in whole blood cultures to 4-vinyltoluene. ANIMAL STUDIES: There are no data available.

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of February 4, 2019: http://actor.epa.gov/dashboard/]

Motorboats emitted 4-vinyltoluene to canal water; concentrations were not reported(1). Use of unleaded gasoline by a four-stroke outboard motor emitted 4-vinyltoluene to test water at 2.2 mg/10 min(2). The removal of lead from gasoline and its subsequent replacement with aromatic compounds has caused an increased release of compounds such as vinyltoluenes to the atmosphere via fossil fuel combustion(3). The emission factor of 3-/4-vinyltoluene measured in the Caldecott tunnel in Oakland, CA July 2010 was 156 and 176 ug/L for gasoline and diesel exhaust, respectively(4).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of 4-vinyltoluene can be estimated to be 720(SRC). According to a classification scheme(2), this estimated Koc value suggests that 4-vinyltoluene is expected to have low mobility in soil(SRC). [

para-Methyl styrene (CAS # 622-97-9) was evaluated for clastogenicity in male Sprague-Dawley rats (5/dose group) given doses of 0 (Methocel K4M vehicle control), 0.134, 0.045, 0.0134, or 0.006 gm/mL daily for 5 days. Two high-dose rats died during dosing and were replaced. Treatment-associated clinical signs included slight oral discharge and decrease activity among several high dose animals, slight nasal discharge in 1 mid-dose rat, and decreased activity in 1 low-dose rat. Blood levels of para-methylstyrene correlated to doses administered. No significant (Chi square analysis, p< 0.001) increased numbers of total aberrant cells, including those with chromosome breaks, chromatid breaks, exchanges, fragments, or pulverized contents, were observed in any treated group relative to controls.

/HUMAN EXPOSURE STUDIES/ Contact allergy to styrene related compounds was studied in a human subject. A patient known from previous studies to be sensitive to styrene was patch tested with styrene and 18 compounds structurally related to styrene. Positive results were obtained with 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, styrene-epoxide, and 4-hydroxystyrene. The reaction to styrene-epoxide was stronger than that obtained by patch testing with an equimolar concentration of styrene, 0.1 percent weight per volume in ethanol. Twenty one comparisons were subsequently patch tested with styrene-epoxide. All responses were negative. The authors note that the stronger reaction to styrene-epoxide, as compared to an equimolar concentration of styrene, may indicate that styrene-epoxide is the hapten and styrene is the prohapten, which has to be oxidized in the skin in order to be converted into styrene-epoxide. Styrene-epoxide can be formed from styrene by enzymatic transformation by aryl-hydrocarbon-hydroxylase in the skin. They conclude that it is important to patch test with chemically related substances in order to evaluate the total sensitivity pattern of a patient.

/SIGNS AND SYMPTOMS/ Central nervous system effects, such as depression, poor memory, slow visuomotor performance and electrophysiological changes, have often been associated with heavy occupational exposures to vinyl toluenes. Information is not available on human exposure to vinyl toluene alone. /Vinyl toluenes/

/SIGNS AND SYMPTOMS/ The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the central nervous system.

/SIGNS AND SYMPTOMS/ Repeated or prolonged contact with skin may cause dermatitis. The substance defats the skin, which may cause dryness or cracking. The substance may have effects on the liver and kidneys. This may result in tissue lesions.

/GENOTOXICITY/ ... In human lymphocytes exposed in whole blood cultures, vinyl toluene induced both sister chromatid exchange and chromosomal aberrations in a dose-dependent manner, in the absence of exogenous metabolic activation. The induction of sister chromatid exchange was dependent on the number of erythrocytes present. Significant increases in the frequencies of sister chromatid exchange were observed in human lymphocytes exposed in whole blood cultures to ortho, meta and para isomer. The strongest responses were seen with the meta and para isomers, which are the dominant species in vinyl toluene.

The Henry's Law constant for 4-vinyltoluene is estimated as 3.2X10-3 atm-cu m/mole(SRC) derived from its vapor pressure, 1.81 mm Hg(1), and water solubility, 89 mg/L(2). This Henry's Law constant indicates that 4-vinyltoluene is expected to volatilize rapidly from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 3.5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 4.4 days(SRC). 4-Vinyltoluene's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). 4-Vinyltoluene is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

The rate constant for the vapor-phase reaction of 4-vinyltoluene with photochemically-produced hydroxyl radicals has been reported as 3.2X10-11 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 12 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(2). The rate constant for the vapor-phase reaction of 4-vinyltoluene with ozone has been estimated as 2.1X10-17 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). This corresponds to an atmospheric half-life of about 13 hours at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(3). 4-Vinyltoluene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). 4-Vinyltoluene absorbs weakly at wavelengths >290 nm(5) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

o-Vinyltoluene, m-vinyltoluene and p-vinyltoluene were given i.p. to rats and urine was analyzed for acidic metabolites by gas chromatography mass spectrometry. Different derivatives were prepared and used to identify the structure of the metabolites. Different types (11) of metabolites were found, although all metabolites were not produced from each vinyltoluene isomer. The metabolites identified were: methylphenylethylene glycol, methylmandelic acid, methylphenylglyoxylic acid, hydroxymethylphenylethylene glycol, carboxyphenylethylene glycol, hydroxymethylphenylglyoxylic acid, methylbenzoylglycine, methylphenylacetylglycine, vinylbenzoylglycine, N-acetylcysteine conjugate of methylphenylethanol and glucuronide of methylphenylethylene glycol. Metabolites (> 90%) recovered were excreted during the 1st 24 hr. For the sum of all metabolites, there was an approximately linear relation between given dose and recovered amount of metabolites. Repeated daily administration was not followed by any appreciable increase in metabolite excretion and no enzyme induction phenomenon was apparent.

The role of cytochrome-P-450 in initiating the metabolism of styrene derivatives was investigated in Holtzman-rat liver homogenates. Six parasubstituted styrenes were prepared from the corresponding acetophenones by borohydride reduction to p-bromostyrene, p-chlorostyrene, p-cyanostyrene, p-methylstyrene, p-phenylstyrene, and p-methoxystyrene. Styrene derivatives were incubated with liver homogenates with the addition of reduced nicotinamide-adenine-dinucleotide-phosphate (NADPH) or carbon-monoxide (CO). The conversion of tritiated beta-4-phenylstyrene to alpha-beta-diolstyrene depended on an oxygen source and the presence of NADPH in the microsomal system in order to catalyze the substrate. With p-methylstyrene, p-methoxystyrene, and p-phenylstyrene, metabolic attack was confined to the vinyl group. All six styrenes gave a type 1 difference binding spectrum in the microsomal substrate. The metabolism of p-phenylstyrene was confirmed by its inhibition by the addition of CO and by its stimulation and phenobarbital. The substituents did not affect the spectral dissociation constants or the values for enzymatic epoxidation. The authors conclude that the lack of significant polar substituent effects on enzymatic epoxidation of styrenes is not consistent with earlier studies in which it was determined that the reagent is electrophilic. The discrepancy may be due to the involvement of different species of cytochrome-P-450 enzymes or different modes of substrate action.

Used in isomeric mixture with 3-vinyltoluene as monomers for producing poly(vinyltoluene); in the production of polyester resins; to produce synthetic elastomers (co-polymerized with isobutylene); as a reactive monomer; in the coatings industry as a modifier for drying oils and oil-modified alkyds; as a replacement for styrene in unsaturated polyester resins; as a copolymer with styrene to increase the operating temperature range of paints, coatings and varnishes; [HSDB]

Plastic Composites Manufacturing [Category: Industry]

Use in mixtures with other vinyltoluene isomers (3-vinyltoluene) as monomers for producing poly(vinyltoluene)

Used as a monomer in the production polyester resins

Co-polymerized with isobutylene to produce synthetic elastomers

Reactive monomer; used in the coatings industry as a modifier for drying oils and oil-modified alkyds; used as a replacement for styrene in unsaturated polyester resins; used as a copolymer with styrene to increase the operating temperature range of paints, coatings and varnishes. /Vinyltoluene/

2023: 13,021,700 lb

NO DATA (1992)

Non-confidential 2016 Chemical Data Reporting (CDR) information on the production and use of chemicals manufactured or imported into the United States. Chemical: 1-ethenyl-4-methylbenzene:

PMS /(p-Methylstyrene)/ is made by alkylation of toluene with ethylene to p-ethyltoluene, followed by dehydrogenation of p-ethyltoluene.

p-Methylstyrene is prepared from p-chlorotoluene by a vinylation reaction using ethylene as the reagent and a catalyst derived from zinc, a triarylphosphine, and a nickel salt.

4-Methylstyrene is commercially produced by the catalytic dehydrogenation of 4-ethyltoluene.

The advent of a para-specific route to ethyltoluene using zeolite technology has made available a 97% /vinyltoluene/ para-isomer product called PMS ... .

The typical product contains 97% p-vinyltoluene, 3% m-vinyltoluene, and 0.2% o-vinyltoluene.

Commercial vinyl toluene is primarily a mixture of meta- and para-vinyl toluene, usually with 56-60% meta, 40-45% para and 1% ortho. It is available as a commercial product with the following characteristics: purity, 99.2 wt% minimum; polymer, 25 ppm maximum; and para-tert-butylcatechol (inhibitor), 10-15 ppm or 45-55 ppm.

Plastics Material and Resin Manufacturing

Benzene, 1-ethenyl-4-methyl-: ACTIVE

A plant for the alkylation of toluene to 4-ethyltoluene by the Mobil Process was opened in 1982 by Hoechst (now Hoechst-Celanese) in Baton Rouge, LA; the plant has an annual capacity of 16,000 tons of 4-methylsytrene /4- vinyltoluene/ and was purchased by Deltech in 1989

Vinyltoluene, comprising a mixture of about 33% para- and 67% meta- methylstyrene, was marketed for about 30 yr by Dow Chemical and also by Cosden.