2-метоксиэтанол

Описание

2-Methoxyethanol (2-ME), also known as methoxyethanol or ethylene glycol monomethyl ether, is a glycol ether that has been known since the 1920s, but its use significantly increased in the 1970s. Cellosolve was a solvent product containing glycol ethers and registered in the 1920s by Carbide and Carbon Chemicals Corp. Glycol ethers are derived from either ethylene oxide (E-series) or propylene oxide (p-series) combined with an alcohol. Methoxyethanol is an E-series glycol ether derived from methanol and ethylene oxide. Other commonly used glycol ethers include ethoxyethanol, butoxyethanol, and methoxypropanol. Use of methoxyethanol has declined in recent years due to risk management procedures and replacement by other substances.

Химические свойства

2-Methoxyethanol is a colorless liquid with a slight ethereal odor. The Odor Threshold is 0.9
2.3 ppm. It is miscible with water and with aliphatic and aromatic hydrocarbons. It is a solvent for essential oils, lignin, dammar, Elemi Essential Oil, ester gum, kauri, mastic, rosin, sandarac resin, shellac, Zanzibar, nitrocellulose, cellulose acetate, alcohol-soluble dyes and many synthetic resins. Its solvency far cellulose esters is augmented when a ketone or a halogenated hydrocarbon i s added. The uses for 2-Methoxyethanol are as a solvent in quick-drying varnishes and enamels, in conjunction with aliphatic, aromatic and halogenated hydrocarbons, alcohols and ketones; in solvent mixtures and thinners for lacquers and dopes; in the manufacture of synthetic resin plasticizers and as a penetrating and leveling agent in dyeing processes, especially in the dyeing of leather, animal and vegetable fibers. Other uses are as o fixative in perfumes and as a solvent in odorless nail-polish lacquers. 2-Methoxyethanol should not be added to nitrocellulose lacquers containing coumarone resins or ester gum because it will cause incompatibility between these substances.

Физические свойства

Colorless liquid with a mild, ether-like odor. Experimentally determined detection and recognition odor threshold concentrations were <300 μg/m³ (<96 ppb_v) and 700 μg/m³ (220 ppb_v), respectively (Hellman and Small, 1974).

Использование

2-Methoxyethanol is considered a non-comedogenic raw material. It is used as a solvent in nail products and as a stabilizer in cosmetic emulsions. It is able to penetrate the skin and may cause skin irritation.

Определение

ChEBI: 2-methoxyethanol is a hydroxyether that is ethanol substituted by a methoxy group at position 2. It has a role as a protic solvent and a solvent.

Подготовка

From Methanol Plus Ethylene glycol, by heating under pressure.

Общее описание

A clear colorless liquid. Flash point of 110°F. Less dense than water. Vapors are heavier than air.

Реакции воздуха и воды

Flammable. Water soluble.

Профиль реактивности

2-Methoxyethanol is incompatible with oxygen and strong oxidizing agents. Contact with bases may result in decomposition. Incompatible with acid chlorides and acid anhydrides. . 2-Methoxyethanol forms explosive peroxides.

Опасность

Toxic by ingestion and inhalation. Moderate fire risk. Toxic by skin absorption. Questionable carcinogen.

Угроза здоровью

2-Methoxyethanol is a teratogen and a chronic inhalation toxicant. The target organs are blood, kidney,and the central nervous system. In addi tion to inhalation, the other routes of expo sure are absorption through the skin, and ingestion. Animal studies indicated that over-exposure to this compound produced anemia, hematuria, and damage to the testes.In humans, inhalation of EGME vapors cancause headache, drowsiness, weakness, irrita tion of the eyes, ataxia, and tremor. The acuteinhalation toxicity, however, is low and anytoxic effect may be felt at a concentration ofabout 25–30 ppm in air
The oral and dermal toxicities of thiscompound in test animals were found to belower than the inhalation toxicity. Ingestioncan produce an anesthetic effect and in alarge dosage can be fatal. An oral intake ofabout 200 mL may cause death to humans.
LC50 value (mice): 1480 ppm/7 h,
LD50 value (rabbits): 890 mg/kg
EGME is a teratogen exhibiting fetotoxi city, affecting the fertility and the litter size,and causing developmental abnormalities inthe urogenital and musculoskeletal systemsin test animals.

Пожароопасность

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. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.

Профиль безопасности

Moderately toxic to humans by ingestion. Moderately toxic experimentally by ingestion, inhalation, shin contact, intraperitoneal, and intravenous routes. Human systemic effects by inhalation: change in motor activity, tremors, and convulsions. Experimental teratogenic and reproductive effects. A skin and eye irritant. Mutation data reported. When used under conditions that do not require the application of heat, thts material probably presents little hazard to health. However, in the manufacture of fused collars which require pressing with a hot iron, cases have been reported showing disturbance of the hemopoietic system with or without neurologcal signs and symptoms. The blood picture may resemble that produced by exposure to benzene. Two cases reported had severe aplastic anemia with tremors and marked mental dullness. The persons affected had been exposed to vapors of methyl "Cellosolve," ethanol, methanol, ethyl acetate, and petroleum naphtha. flame. A moderate explosion hazard. Can react with oxidizing materials to form explosive peroxides. To fight fire, use alcohol foam, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes. See also GLYCOL ETHERS. Flammable liquid when exposed to heat or

Возможный контакт

2-Methoxyethanol is used as a jet fuel additive; solvent for protective coating; and in chemical synthesis. Ethylene glycol ethers are used as solvents for resins used in the electronics industry, lacquers, paints, varnishes, gum, perfume; dyes and inks; and as a constituent of painting pastes, cleaning compounds; liquid soaps; cosmetics, nitrocellulose, and hydraulic fluids.

Канцерогенность

There are no experimental carcinogenicity or cancer epidemiology data relating to this chemical , but some short-term test data are available and are summarized in the section on genetic and related cellular effects.

Экологическая судьба

Photolytic. Grosjean (1997) reported an atmospheric rate constant of 1.25 x 10^-11 cm³/molecule?sec at 298 K for the reaction of methyl cellosolve and OH radicals. Based on an atmospheric OH concentration of 1.0 x 106 molecule/cm³, the reported half-life of methyl cellosolve is 0.64 d (Grosjean, 1997).
Chemical/Physical. At an influent concentration of 1,000 mg/L, treatment with GAC resulted in an effluent concentration of 342 mg/L. The adsorbability of the carbon used was 132 mg/g carbon (Guisti et al., 1974).

Перевозки

UN1188 Ethylene glycol monomethyl ether, Hazard Class: 3; Labels: 3-Flammable liquid

Методы очистки

Peroxides can be removed by refluxing with stannous chloride or by filtration under slight pressure through a column of activated alumina. 2-Methoxyethanol can be dried with K2CO3, CaSO4, MgSO4 or silica gel, then distilled from sodium. Aliphatic ketones (and water) can be removed by making the solvent 0.1% in 2,4-dinitrophenylhydrazine and allowing to stand overnight with silica gel before fractionally distilling. [Beilstein 1 IV 2375.]

Несовместимости

Vapors may form explosive mixture with air. Heat or oxidizers may cause the formation of unstable peroxides. Attacks many metals. Strong oxidizers may cause fire and explosions. Strong bases cause decomposition and the formation of toxic gas. Attacks some plastics, rubber and coatings. May accumulate static electrical charges, and may cause ignition of its vapors.

Утилизация отходов

Concentrated waste containing no peroxides: discharge liquid at a controlled rate near a pilot flame. Concentrated waste containing peroxides: perforation of a container of the waste from a safe distance followed by open burning.