100 Ethylbenzene Ethylbenzene is an organic compound with the formula C6H5CH2CH3. This aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, which in turn is used for making polystyrene, a commonly used plastic material. Although often present in small amounts in crude oil, ethylbenzene is produced in bulk quantities by combining benzene and ethylene in an acid-catalyzed chemical reaction. It is one ingredient of cigarette. The acute toxicity of ethylbenzene is low, with an LD50 of about 4 grams per kilogram of body weight. The longer term toxicity and carcinogenicity is ambiguous. Eye and throat sensitivity can occur when high level exposure to ethylbenzene in the air occurs. At higher level exposure, ethylbenzene can cause dizziness. 100-41-4 7500 C8H10 106.078250 -94.9°C 0.169 mg/mL at 25 °C [SANEMASA,I et al. (1982)] Oral (L311); inhalation (L311) ; dermal (L311). Changes in the integrity of the cell membrane after partitioning of ethylbenzene into the lipid bilayer may subsequently affect the function of membrane, particularly as a barrier and in energy transduction, and in the formation of a matrix for proteins and enzymes. Ethybenzene inhibits the activity of the astrocytic membrane ATPases, which helps regulate adequate intercellular levels of ions, nutrients, metabolic intermediates and precursors in the central nervous system. Thus, this may disturb the ability of the cells to maintain homeostasis. (L311, A186) Ethylbenzene is metabolized mainly through hydroxylation and then through conjugation reactions from which numerous metabolites have been isolated. Hydroxylation of ethylbenzene to 1-phenylethanol is catalyzed by cytochrome P-450 isoforms CYP2E1 and CYP2B6. 1-Phenylethanol is conjugated to glucuronide, which then is either excreted or converted to subsequent metabolites. Oxidation of 1-phenylethanol yields acetophenone, which is both excreted in the urine as a minor metabolite and further transformed. Continued oxidation of the side chain leads to the sequential formation of 2-hydroxyacetophenone, 1-phenyl-1,2-ethanediol, mandelic acid, and phenylglyoxylic acid. Minor pathways (e.g., ring hydroxylation) include glucuronide and sulfate conjugation with hydroxylated derivatives to form glucuronides and sulfates that are excreted in the urine. In humans exposed via inhalation, the major metabolites of ethylbenzene in the urine are mandelic acid (70%) and phenylglyoxylic acid (25%). Following dermal exposure of humans, however, excretion of mandelic acid was shown to be only 4.6% of the absorbed dose, which may indicate differences in the metabolic fate between inhalation and dermal exposure routes. (L311) LD50: 3.5 g/kg (Oral, Rat) (L324) LD50: 77.4 g/kg (Dermal, Rabbit)(L324) LC50: 17.2 g/m3 (4000 ppm) (Inhalation, Rat) (L324) 2B, possibly carcinogenic to humans. (L135) Ethylbenzene is used in the petrochemical industry as an intermediate in the production of styrene, which in turn is used for making polystyrene, a commonly used plastic material. Exposure may occur from breathing contaminated air, drinking or eating food prepared with ethylbenzene-contaminated water, and through skin contact with products containing ethylbenzene, such as gasoline. (L311) Acute Inhalation: 10 ppm (L134) Intermediate Inhalation: 0.7 ppm (L134) Chronic Inhalation: 0.3 ppm (L134) Intermediate Oral: 0.5 mg/kg/day (L134) Chronic exposure to etylbenzene can lead to an increase in the mean number of lymphocytes and a decrease in hemoglobin levels. Acute duration and intermediate duration studies suggest that the auditory system is a sensitive target of ethylbenzene toxicity. Exposure ethylbenzene can lead to functional and organic disturbances (nervous system disturbances, toxic hepatitis and upper respiratory tract complaints). Metabolites of ethylbenzene have been shown to produce oxidative damage to DNA. (L311, T52) Cough, sore throat, dizziness, drowsiness, and headache follow inhalation or ingestion exposure to ethylbenzene. Ingestion exposure can also lead to burning sensation in the throat and chest. Skin or eyes contact to ethylbenzene can lead to redness and pain of the exposed surface. (L316) Following oral exposure, a gastric lavage is recommended. Protect airway by placement in Trendelenburg and left lateral decubitus position or by endotracheal intubation. Control any seizures first. Following inhalation, move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Following eye exposure, irrigate exposed eyes with copious amounts of room temperature water for at least 15 minutes. In case of dermal exposure, remove contaminated clothing and wash exposed area thoroughly with soap and water. Treat dermal irritation or burns with standard topical therapy. Patients developing dermal hypersensitivity reactions may require treatment with systemic or topical corticosteroids or antihistamines. Some chemicals can produce systemic poisoning by absorption through intact skin. Carefully observe patients with dermal exposure for the development of any systemic signs or symptoms and administer symptomatic treatment as necessary. (T36) 2009-03-06T18:58:04Z 2026-03-31T17:33:31Z Cytochrome P450 2B6 (P20813) Cytochrome P450 2E1 (P05181) (L311, A187) http://en.wikipedia.org/wiki/Ethylbenzene C07111 16101 CPD-9502 C004912 Ethylbenzene DB01722 606 true Cytochrome P450 2B6 (P20813) Cytochrome P450 2E1 (P05181) (L311, A187) CCC1=CC=CC=C1 C8H10 InChI=1S/C8H10/c1-2-8-6-4-3-5-7-8/h3-7H,2H2,1H3 YNQLUTRBYVCPMQ-UHFFFAOYSA-N 106.165 106.07825032 Exogenous Liquid HMDB59905 CHEMBL371561 7219 <p>Guenther Heimlich, Gregor Tremmel, Manfred Lieb, &#8220;Continuous preparation of ethylbenzene in a heterogeneous-phase reaction.&#8221; U.S. Patent US4431854, issued July, 1950.</p> CHEM000090 DTXSID3020596 NS00009164 ethylbenzene