2-Methoxyethanol

Description

Methoxyethanol 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.

Chemical properties

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.

Physical properties

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).

The Uses of 2-Methoxyethanol

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.

The Uses of 2-Methoxyethanol

Solvent for low-viscosity cellulose acetate, natural resins, some synthetic resins and some alcohol-soluble dyes; in dyeing leather, sealing moistureproof cellophane; in nail polishes, quick-drying varnishes and enamels, wood stains. In modified Karl Fischer reagent: Peters, Jungnickel, Anal. Chem. 27, 450 (1955).

The Uses of 2-Methoxyethanol

The primary use of 2-methoxyethanol is as asolvent for cellulose acetate, certain syntheticand natural resins, and dyes. Other applications are in jet fuel deicing, sealing moisture-proof cellophane, dyeing leather, and use innail polishes, varnishes, and enamels.

Definition

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.

Preparation

From Methanol Plus Ethylene glycol, by heating under pressure.

General Description

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

Air & Water Reactions

Flammable. Water soluble.

Reactivity Profile

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.

Hazard

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

Health Hazard

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.

Fire Hazard

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.

Flammability and Explosibility

Flammable

Safety Profile

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

Potential Exposure

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.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.Medical observation is recommended for 24- 48 h afterbreathing overexposure, as pulmonary edema may bedelayed. As first aid for pulmonary edema, a doctor orauthorized paramedic may consider administering a corticosteroid spray.

Carcinogenicity

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.

Environmental Fate

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).

storage

Color Code—Red: Flammability Hazard: Store ina flammable liquid storage area or approved cabinet awayfrom ignition sources and corrosive and reactive materials.Prior to working with this chemical you should be trainedon its proper handling and storage. Before entering confinedspace where this chemical may be present, check to makesure that an explosive concentration does not exist. 2-Methoxyethanol must be stored to avoid contact with oxidizers (such as perchlorates, peroxides, permanganates, chlorates, and nitrates) and strong caustics since violentreactions occur. Sources of ignition, such as smoking andopen flames, are prohibited where 2-methoxyethanol isused, handled, or stored in a manner that could create apotential fire or explosion hazard. Wherever 2-methoxyethanol is used, handled, manufactured, or stored, useexplosion-proof electrical equipment and fittings.Shipping: This compound requires a shipping label of“FLAMMABLE LIQUID.” It falls in Hazard Class 3 andPacking Group II.

Shipping

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

Purification Methods

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.]

Toxicity evaluation

High acute doses of methoxyethanol have a sedative and hypnotic effect. Kidney and lung damages, accompanied by hemoglobinuria, follow exposures to high doses. Toxicity is attributed to the active metabolites: methoxyacetaldehyde and methoxyacetate. In vitro studies with radiolabeled methoxyethanol indicate that formation of methoxyacetyl-coenzyme A may lead to the formation of methoxyacetyl derivatives of Krebs cycle intermediates. Methoxyacetate produces the same testicular lesions in rodents as does the parent compound, although the immunosuppression elicited by methoxyethanol exposure may depend on the putative metabolite, methoxyacetaldehyde. In both the testicular lesion and the immune suppression, some data suggest that the pattern of cell death termed ‘apoptosis’ may be stimulated. Methoxyacetate stimulates synthesis of progesterone by luteal cells in culture. This disturbance of luteal function may be related to the prolongation of gestation in rodents. Teratogenicity appears to be related to interference by methoxyethanol, or its metabolites, with one carbon metabolism in the synthesis of nucleotide precursors, and can be relieved by administration of other substrates, such as serine and glycine, which also provide substrates for nucleotide synthesis. It has also been suggested that toxicity is mediated through inhibition of flavoprotein dehydrogenase-catalyzed reactions.

Incompatibilities

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.

Waste Disposal

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.