Substance profile
2-phenylpropene
2-phenylpropene is a colorless liquid with a characteristic odor.
01 · Identification
What 2-phenylpropene is
2-phenylpropene is a colorless liquid with a characteristic odor. Its molecular formula is C9H10 and its molecular weight is 118.18 g/mol. It boils at 165 °C, melts at -23.2 °C.
Under the GHS it carries the signal word Warning. It is classed as flammable agents - 2nd degree.
02 · Identifiers
2-phenylpropene identifiers and molecular data
2-phenylpropene CAS number and EC number
2-phenylpropene molecular formula and molecular weight
Other names for 2-phenylpropene
- α-methylstyrene
03 · GHS classification
2-phenylpropene hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
2-phenylpropene pictograms and signal word
2-phenylpropene hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 3 | H226 | GHS02 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 | H335 | GHS07 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 2 | H411 | GHS09 |
2-phenylpropene hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H226 | Flammable liquid and vapour. |
| H335 | May cause respiratory irritation. |
| H319 | Causes serious eye irritation. |
| H411 | Toxic to aquatic life with long lasting effects. |
This page lists only the codes assigned to 2-phenylpropene. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for 2-phenylpropene
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of 2-phenylpropene issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
2-phenylpropene precautionary statements
CLP Annex VI assigns 14 precautionary statements to 2-phenylpropene. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Disposal
What has to happen to the contents and the empty container.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
2-phenylpropene name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | 2-фенилпропен α-метилстирен |
| Spanish español | 2-Fenilpropeno α-metilestireno |
| Czech čeština | isopropenylbenzen α-methylstyren |
| Danish dansk | 2-phenylpropen α-methylstyren |
| German Deutsch | 2-Phenylpropen α-MethylstyrolIsopropenylbenzol |
| Estonian eesti | 2-fenüülpropeen α-metüülstüreen |
| Greek ελληνικά | 2-φαινυλοπροπένιο α-μεθυλοστυρόλιο |
| English English | 2-phenylpropene α-methylstyrene |
| French français | 2-phénylpropène α-méthylstyrène |
| Croatian hrvatski | 2-fenilpropen α-metilstiren |
| Italian italiano | 2- fenilpropene α- metilstirene |
| Latvian latviešu | 2-fenilpropēns α-metilstirols |
| Lithuanian lietuvių | 2-fenilpropenas α-metilstirenas |
| Hungarian magyar | 2-fenilpropén α-metilsztirol |
| Maltese Malti | 2-fenilpropen α-metilstiren |
| Dutch Nederlands | 2-fenylpropeen α-methylstyreen |
| Polish polski | 2-fenyloprop-1-en propen-2-ylobenzenizopropenylobenzen α-metylostyren |
| Portuguese português | 2-fenilpropeno α-metilestireno |
| Romanian română | 2-fenilpropenă α-metilstiren |
| Slovak slovenčina | 2-fenylpropén α-metylstyrén |
| Slovenian slovenščina | 2-fenilpropen α-metilstiren |
| Finnish suomi | 2-fenyylipropeeni α-metyylistyreeni |
| Swedish svenska | 2-fenylpropen α-metylstyren |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
2-phenylpropene GHS label elements
Everything CLP Annex VI fixes for 2-phenylpropene, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
2-phenylpropene
- Flammable liquid and vapour.
- May cause respiratory irritation.
- Causes serious eye irritation.
- Toxic to aquatic life with long lasting effects.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Keep container tightly closed.
- Use explosion-proof [electrical/ventilating/lighting/…] equipment.
- Use only non-sparking tools.
- Wash … thoroughly after handling.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF IN EYES:
- Get medical advice/attention.
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Collect spillage.
- Store in a well-ventilated place.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open 2-phenylpropene in the GHS label constructor →
07 · Health hazards
2-phenylpropene health hazards and exposure limits
2-phenylpropene hazard summary
The major hazards encountered in the use and handling of alpha-methyl styrene stem from its toxicologic properties and flammability. Toxic by all routes (ie, inhalation, ingestion, and dermal contact), exposure to this sweet-smelling, colorless liquid may occur from its use in the manufacture of acrylonitrile-butadiene-styrene resins, adhesives, waxes, and polyester resins. Effects from exposure may include irritation of the eyes, skin, and upper respiratory tract, dermatitis, and central nervous system depression. OSHA has established a 100 ppm Ceiling limit for workplace exposure until the final rule (establishing a 50 ppm time weighted average (TWA) limit) becomes effective on December 31, 1992. Engineering controls should be used to maintain airborne levels of alpha-methyl styrene to at or below the permissible limit. In activities and situations where over-exposure may occur, wear chemical protective clothing and a self-contained breathing apparatus. If contact should occur, irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes, and wash exposed skin thoroughly with soap and water. Contaminatedclothing should be removed and left at the worksite for cleaning. Alpha-methyl styrene is easily ignited by heat, sparks, or flames. Its heavier-than-air vapor may travel considerable distances to a source of ignition and flash back, or form explosive concentrations in enclosed spaces such as sewers. Also, containers of alpha-methyl styrene may explode in the heat of a fire. For fires involving alpha-methyl styrene, extinguish with dry chemical, CO2, Halon, water spray or standard foam. Consider evacuation of one half mile radius, especially if a tank car or truck is involved. Alpha-methyl styrene should be stored away from heat, oxidizers, peroxides, halogens, catalysts for vinyl or ionic polymers, aluminum, and iron chloride. For small spills of alpha-methyl styrene, take up with sand or other noncombustible absorbent and place into containers for later disposal. Dike far ahead of large spills to prevent runoff. Before implementing land disposal of alpha-methyl styrene waste, consult with environmental regulatory agencies for guidance.
Source: Hazardous Substances Data Bank (HSDB)
2-phenylpropene carcinogenicity classification
Under the conditions of this 2-year inhalation study, there was some evidence of carcinogenic activity of α-methylstyrene in male F344/N rats based on increased incidences of renal tubule adenomas and carcinomas (combined). The increased incidence of mononuclear cell leukemia in 1,000 ppm male F344/N rats may have been related to α-methylstyrene exposure. There was no evidence of carcinogenic activity of α-methylstyrene in female F344/N rats exposed to 100, 300, or 1,000 ppm. There was equivocal evidence of carcinogenic activity of α-methylstyrene in male B6C3F1 mice based on marginally increased incidences of hepatocellular adenoma or carcinoma (combined). There was clear evidence of carcinogenic activity of α-methylstyrene in female B6C3F1 mice based on increased incidences of hepatocellular adenomas and carcinomas.
Source: US National Toxicology Program · TR-543: Toxicology and Carcinogenesis Studies of alpha-Methylstyrene (CASRN 98-83-9) in F344/N Rats and B6C3F1 Mice (Inhalation Studies) (2007 )
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
2-phenylpropene occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 100 ppm (480 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | C 100 ppm (480 mg/m3) See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 50 ppm | Occupational Safety and Health Administration (OSHA) |
| REL | 100 ppm | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 50 ppm (240 mg/m3) ST 100 ppm (485 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 700 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 700.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 700 ppm | Hazardous Substances Data Bank (HSDB) |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
2-phenylpropene properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
2-phenylpropene boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 165.4 °C (329.7 °F) | HSDB | |
| 165.56 °C (330 °F) | NIOSH | ||
| 165.39 °C (329.7 °F) | at 760 mmHg | CAMEO |
2-phenylpropene melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -23.2 °C (-9.8 °F) | HSDB | |
| -23.33 °C (-10 °F) | NIOSH | ||
| -22.78 °C (-9 °F) | CAMEO |
2-phenylpropene density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.9106 g/cm³ | HSDB | |
| 0.91 g/cm³ | NIOSH | ||
| 0.91 g/cm³ | at 20 °C | CAMEO |
2-phenylpropene solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | SOL IN ALC; SOL IN ALL PROPORTIONS IN ACETONE, CARBON TETRACHLORIDE | HSDB | |
| Sol in benzene, chloroform | HSDB | ||
| Sol in ether | HSDB |
2-phenylpropene vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 2 mmHg | NIOSH | |
| 1.9 mmHg | at 20 °C | CAMEO | |
| 1.9 mmHg | at 25 °C | HSDB |
2-phenylpropene flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 83.89 °C (183 °F) | CLOSED CUP | HSDB |
| 57.8 °C (136 °F) | Cleveland open-cup | HSDB | |
| 53.89 °C (129 °F) | NIOSH |
2-phenylpropene autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 574.44 °C (1066 °F) | HSDB | |
| 574 °C (1065.2 °F) | ICSC |
2-phenylpropene lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 6.1 % by volume | upper flammable limit | HSDB |
| 6.1 % by volume | upper | HSDB | |
| 3.4 % by volume | upper | HSDB |
2-phenylpropene upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 6.1 % by volume | NIOSH | |
| 6.6 % by volume | ICSC |
2-phenylpropene vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 4.08 (air = 1) | CAMEO |
2-phenylpropene odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Odor detection in air, 5.20X10-2 ppm (purity not specified) | HSDB | |
| Odor recognition in air, 1.60X10-1 ppm (purity not specified) | HSDB | ||
| Odor (low) 0.2496 mg/cu m; Odor (high) 960.0 mg/cu m; Irritating concn 960.0 mg/cu m. | HSDB |
2-phenylpropene critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 384 °C (723.2 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
2-phenylpropene fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
2-phenylpropene fire potential
Moderate fire risk.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
2-phenylpropene storage and handling
2-phenylpropene safe storage
Store only if stabilized. Store in an area without drain or sewer access. Fireproof. Well closed. Separated from strong oxidants.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
2-phenylpropene storage conditions
DURING STORAGE IT IS FREQUENTLY STABILIZED WITH TERT-BUTYL CATECHOL AS INHIBITOR.
Source: Hazardous Substances Data Bank (HSDB)
2-phenylpropene incompatible materials
Oxidizers, peroxides, halogens, catalysts for vinyl or ionic polymers; aluminum, iron chloride, copper [Note: Usually contains an inhibitor such as tert-butyl catechol].
Source: Hazardous Substances Data Bank (HSDB)
2-phenylpropene reactivity
ISOPROPENYLBENZENE is easily peroxidizable; the peroxide may initiate exothermic polymerization of the bulk material. Reacts violently with strong oxidizing agents [Handling Chemicals Safely, 1980 p. 866; Bretherick, 1979 p. 160].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 2-phenylpropene in the storage compatibility matrix →
11 · Questions
2-phenylpropene — frequently asked questions
What is the CAS number of 2-phenylpropene?
The CAS number of 2-phenylpropene is 98-83-9. Its EC number is 202-705-0.
What is the chemical formula of 2-phenylpropene?
The molecular formula of 2-phenylpropene is C9H10 and its molecular weight is 118.18 g/mol.
What does a 2-phenylpropene label have to show?
Under CLP Annex VI the label for 2-phenylpropene carries the pictograms Flame, Exclamation mark and Environment and the signal word is Warning.
Is 2-phenylpropene flammable?
Yes. CLP Annex VI assigns 2-phenylpropene H226 — flammable liquid and vapour. The flash point reported for it is 83.89 °C (183 °F), CLOSED CUP (HSDB).
Is 2-phenylpropene a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for 2-phenylpropene. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health. IARC places it in Group 2B: possibly carcinogenic to humans.
What is the exposure limit for 2-phenylpropene?
The US occupational exposure limit reported for 2-phenylpropene is 100 ppm (480 mg/m³) (Occupational Safety and Health Administration (OSHA)). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the boiling point of 2-phenylpropene?
The boiling point reported for 2-phenylpropene is 165.4 °C (329.7 °F) (HSDB).
What is the melting point of 2-phenylpropene?
The melting point reported for 2-phenylpropene is -23.2 °C (-9.8 °F) (HSDB).
How should 2-phenylpropene be stored?
CLP Annex VI assigns 2-phenylpropene the storage statement P403. DURING STORAGE IT IS FREQUENTLY STABILIZED WITH TERT-BUTYL CATECHOL AS INHIBITOR. (Hazardous Substances Data Bank (HSDB))
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