Ethylbenzene
[CAS# 100-41-4]

Identification

• Classification: Organic raw materials >> Hydrocarbon compounds and their derivatives >> Aromatic hydrocarbon
• Name: Ethylbenzene
• Synonyms: Phenylethane
• Molecular Formula: C₈H₁₀
• Molecular Weight: 106.17
• CAS Registry Number: 100-41-4
• EC Number: 202-849-4
• SMILES: CCC1=CC=CC=C1

Properties

• Density: 0.9±0.1 g/cm³, Calc.^*, 0.867 g/mL (Expl.)
• Melting point: -95 ºC (Expl.)
• Index of Refraction: 1.497, Calc.^*, 1.495 (Expl.)
• Boiling Point: 136.2±3.0 ºC (760 mmHg), Calc.^*, 136 ºC (Expl.)
• Flash Point: 22.2 ºC, Calc.^*, 15 ºC (Expl.)
• Water solubility: 0.0206 g/100 mL (Expl.)

Safety Data

• Hazard Symbols: GHS02;GHS07;GHS08 Danger
• Hazard Statements: H225-H332-H304-H373
• Precautionary Statements: P210-P233-P240-P241-P242-P243-P260-P261-P271-P280-P301+P316-P303+P361+P353-P304+P340-P317-P319-P331-P370+P378-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Acute toxicity	Acute Tox.	4	H332
Aspiration hazard	Asp. Tox.	1	H304
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	3	H336
Carcinogenicity	Carc.	2	H351
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Acute toxicity	Acute Tox.	4	H312
Specific target organ toxicity - single exposure	STOT SE	2	H371
Flammable liquids	Flam. Liq.	3	H226
Acute toxicity	Acute Tox.	4	H302
Reproductive toxicity	Repr.	1B	H360
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Carcinogenicity	Carc.	1A	H350
Serious eye damage	Eye Dam.	1	H318
Germ cell mutagenicity	Muta.	1B	H340
Aspiration hazard	Asp. Tox.	2	H304
Eye irritation	Eye Irrit.	2B	H320

• Transport Information: UN 1175

Discovory and Applicatios

Ethylbenzene is an aromatic hydrocarbon with the chemical formula C₈H₁₀, consisting of a benzene ring substituted with an ethyl group. It is a colorless liquid at room temperature with a characteristic sweet odor. Ethylbenzene is widely used in industry and plays a critical role as a precursor in the production of various chemicals.

Ethylbenzene was first synthesized in the 19th century. The synthesis typically involves the alkylation of benzene with ethylene in the presence of a catalyst, such as aluminum chloride (AlCl₃) or ferric chloride (FeCl₃). The process was developed to facilitate the introduction of the ethyl group into the benzene ring, which significantly enhances its chemical reactivity and applications.

The primary use of ethylbenzene is in the production of styrene, an important industrial chemical. Ethylbenzene is dehydrogenated to styrene, which is a key precursor for the production of polystyrene and other copolymers. Polystyrene is one of the most commonly used plastics, employed in the manufacture of products such as packaging materials, disposable cutlery, and insulation. Styrene is also used in the production of synthetic rubber and other polymers, making ethylbenzene an essential starting material in the plastics industry.

Aside from its role in the production of styrene, ethylbenzene is also used as a solvent in various industrial applications. Its solvency properties make it useful for dissolving resins, oils, and other organic compounds. It is commonly used in paints, coatings, varnishes, and adhesives, where it helps to improve the spreadability and performance of these materials.

Ethylbenzene is also used as an intermediate in the synthesis of a variety of other chemicals. For instance, it can be used to produce phenylethanol, which is used in the fragrance industry, and as a precursor to a variety of aromatic compounds used in the production of pharmaceuticals, agrochemicals, and other industrial chemicals.

In addition to its industrial uses, ethylbenzene is studied in the field of environmental chemistry. As it is a volatile organic compound (VOC), its presence in the atmosphere is a subject of research, particularly regarding its potential contribution to air pollution. Ethylbenzene is also a component of gasoline, and its emission during combustion processes is monitored for environmental and health concerns.

Ethylbenzene is primarily produced through the catalytic alkylation of benzene with ethylene, and the industrial-scale production is dominated by this method. This process typically occurs in the presence of a zeolite or aluminum chloride catalyst, allowing for the formation of ethylbenzene with high efficiency. The compound is produced in large quantities worldwide, reflecting its importance in the chemical industry.

In summary, ethylbenzene is an important industrial chemical with wide-ranging applications, most notably in the production of styrene and polystyrene. It is also used as a solvent and intermediate in the synthesis of various chemicals. Its discovery and continued use underscore its significance in the global chemical industry.

References

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DOI: 10.1016/j.envpol.2024.125149

2024. Fuel fumes and foliage: The fate of speciated gasoline VOCs during phytoremediation and their impact on the bacterial phenotype. Environmental pollution (Barking, Essex : 1987), 357.
DOI: 10.1016/j.envpol.2024.125199

2025. An assessment of atmospheric concentrations and spatiotemporal variation of BTEX and associated pollutants in India. Journal of environmental sciences (China), 142.
DOI: 10.1016/j.jes.2024.03.004