Description
2-Methoxyethanol (2-ME, 109-86-4), 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.
Chemical Properties
2-Methoxyethanol is a colorless liquid with a slight ethereal odor. The Odor Threshold is 0.92.3 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 ppbv) and 700 μg/m3 (220 ppbv), respectively
(Hellman and Small, 1974).
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
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.