ETHYLENE GLYCOL

Ethylene glycol is a clear, colorless syrupy liquid. 
Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula (CH2OH)2. 
Ethylene glycol is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. 

CAS:    107-21-1
MF:    C2H6O2
MW:    62.07
EINECS:    203-473-3

Ethylene glycol is an odorless, colorless, flammable, viscous liquid. 
Ethylene glycol has a sweet taste, but it is toxic in high concentrations.
Ethylene glycol also is used as a raw material in the production of a wide range of products including polyester fibers for clothes, upholstery, carpet and pillows; fiberglass used in products such as jet skis, bathtubs, and bowling balls; and polyethylene terephthalate resin used in packaging film and bottles. 
Many of these products are energy saving and cost efficient as well as recyclable.
Since Ethylene glycol is a liquid Ethylene glycol can easily penetrate the soil and contaminate groundwater and nearby streams.

Ethylene glycol is the simplest aliphatic dihydric alcohol with chemical properties of alcohols such as being capable of generating ether, ester, or being oxidized into acid or aldehyde as well as being condensed to form ether or being substituted by halogen. 
Ethylene glycol's reaction with acyl chloride or acid anhydride generally forms di-esters. 
Under heating in the presence of catalyst (manganese dioxide, aluminum oxide, zinc oxide or sulfuric acid), Ethylene glycol can be subject to intermolecular or intramolecular dehydration to form the cyclic ethylene acetals, which can react with nitric acid to generate glycol dinitrate (an explosive). 
Ethylene glycol is the raw material for production of polyester resins, alkyd resins and polyester fiber. 
Ethylene glycol can also be used as the refrigerant agent for automobile and aircraft engines refrigerant. 
In 1980, the Ethylene glycol amount used as refrigerant agent is equal to the amount consumption for producing polyester. 

In addition, Ethylene glycol can also be used for synthesizing polymers such as polyester fibers. 
Ethylene glycol dinitrate, when used in combination with nitroglycerine can reduce the freezing point of explosives. 
Ethylene glycol can also be used as the raw material of pharmaceuticals and plastics and high-boiling solvents. 
Industry applied ethylene as a raw material with first converting Ethylene glycol to ethylene oxide and then hydrolyzing to produce ethylene glycol.
Ethylene glycol is of fire and explosion hazards. 
Ethylene glycol is irritating to skin and mucous membrane with inhalation of vapors or skin absorption producing a narcotic effect on the central nervous as well as causing kidney damage. 

The plasma concentration of Ethylene glycol is 2.4g/L and can cause acute renal failure. 
Ethylene glycol can be absorbed through the digestive tract, respiratory tract and skin. 
Ethylene glycol can be discharged from the kidney in the form of prototype or ethanedioic acid (oxalate) from through oxidation. 
Ethylene glycol, after being oxidized into carbon dioxide, can be discharged from the respiratory tract.
Although Ethylene glycol has a high toxicity but its volatility is small. 
Therefore, Ethylene glycol is unlikely that the inhalation of it during production can cause severe poisoning. 
Inhalation poisoning is manifested as blurred consciousness, nystagmus and urine containing protein, calcium oxalate crystals and red blood cells. 
Oral toxicity in clinical practice can be divided into three stages: the first stage is mainly the central nervous system symptoms, such as the performance of ethanol poisoning; the second phase of the main symptoms mainly include shortness of breath, cyanosis, and various manifestations of pulmonary edema or bronchopneumonia; at the third stage, there may be significant renal disease, low back pain, kidney area percussion pain, renal dysfunction, proteinuria, hematuria, urine containing calcium oxalate crystals, as well as oliguria, anuria and even acute renal failure.

Patients mistakenly take Ethylene glycol should be subject to the treatment based on the general principles of first aid for oral poisoning and can be given 600 mL of 1/6 mol of sodium lactate solution and 10 mL of 10% calcium gluconate through intravenous infusion. 
Patients of severe poisoning can subject to treatment of artificial kidney dialysis.
Container of Ethylene glycol should have "toxic agents" mark. 
Ethylene glycol, upon heating, should be sealed, vented to prevent inhalation of the vapor or aerosol. 
Avoid long-term direct skin contact with the product.

Ethylene glycol was first synthesized in 1859; however, Ethylene glycol did not become a public health concern until after World War II. 
In fact, the first published series of deaths from Ethylene glycol consumption involved 18 soldiers who drank antifreeze as a substitute for ethanol. 
Despite the early recognition that patients who drank ethanol in addition to Ethylene glycol had prolonged survival when compared to those drinking ethylene glycol alone, antidotal treatment of Ethylene glycol toxicity with ethanol was not evaluated until the 1960s. 
Today, Ethylene glycol poisoning continues to be a public health problem, particularly in the southeastern United States. 
In 2009, US poison control centers received 5282 calls about possible ethylene glycol exposures, and the toxicology community believes these exposures are underreported.

Ethylene glycol is a useful industrial compound found in many consumer products. 
Examples include antifreeze, hydraulic brake fluids, some stamp pad inks, ballpoint pens, solvents, paints, plastics, films, and cosmetics. 
Ethylene glycol can also be a pharmaceutical vehicle. 
Ethylene glycol has a sweet taste and is often ingested by accident or on purpose. 
Ethylene glycol breaks down into toxic compounds in the body. 
Ethylene glycol and its toxic byproducts first affect the central nervous system (CNS), then the heart, and finally the kidneys. 
Ingesting enough can cause death. 
Ethylene glycol is odorless.

Ethylene glycol Chemical Properties
Melting point: -13 °C (lit.)
Boiling point: 195-198 °C
Density: 1.113 g/mL at 25 °C (lit.)
Vapor density: 2.1 (vs air)
Vapor pressure: 0.08 mm Hg ( 20 °C)
Refractive index: n20/D 1.431(lit.)
Fp: 230 °F
Storage temp.: 2-8°C
Solubility water: miscible
Form: Viscous Liquid
pka: 14.22(at 25℃)
Color: blue
Relative polarity: 0.79
PH: 6-7.5 (100g/l, H2O, 20℃)
Odor: Odorless
Explosive limit: 3.2%(V)
Water Solubility: miscible
FreezingPoint: -11.5℃
Sensitive: Hygroscopic
λmax λ: 260 nm Amax: ≤0.03
λ: 280 nm Amax: ≤0.01
Merck: 14,3798
BRN: 505945
Exposure limits: Ceiling limit in air for vapor and mist 50 ppm (~125 mg/m3) (ACGIH); TWA 10 mg/m3 (particulates) (MSHA).
LogP: -1.36 at 25℃
CAS DataBase Reference: 107-21-1(CAS DataBase Reference)
NIST Chemistry Reference: Ethylene glycol (107-21-1)
EPA Substance Registry System: Ethylene glycol (107-21-1)

Ethylene glycol is colorless transparent viscous liquid with sweet taste and moisture absorption capability. 
Ethylene glycol is also miscible with water, low-grade aliphatic alcohols, glycerol, acetic acid, acetone, ketones, aldehydes, pyridine and similar coal tar bases. 
Ethylene glycol is slightly soluble in ether but almost insoluble in benzene and its homologues, chlorinated hydrocarbons, petroleum ether and oils.
Ethylene glycol, CH20HCH20H, also known as glycol,ethylene alcohol, glycol alcohol, and dihydric alcohol, is a colorless liquid. 
Ethylene glycol is soluble in water and in alcohol. 
Ethylene glycol has a low freezing point,-25°C (-13 OF), and is widely used as an antifreeze in automobiles and in hydraulic fluids. 
Ethylene glycol is used as a solvent for nitrocellulose and in the manufacture of acrylonitrile, dynamites, and resins.
Ethylene glycol is a colorless, viscous, hydroscopic liquid with a sweetish taste. 
Often colored fluorescent yellow-green when used in automotive antifreeze. 
Ethylene glycol is odorless and does not provide any warning of inhalation exposure to hazardous concentrations. 

Chemical reactions
Ethylene glycol is used as a protecting group for carbonyl groups in organic synthesis. 
Treating a ketone or aldehyde with Ethylene glycol in the presence of an acid catalyst (e.g., p-toluenesulfonic acid; BF3·Et2O) gives the corresponding a 1,3-dioxolane, which is resistant to bases and other nucleophiles. 
The 1,3-dioxolane protecting group can thereafter be removed by further acid hydrolysis.
In this example, isophorone was protected using Ethylene glycol with p-toluenesulfonic acid in moderate yield.
Water was removed by azeotropic distillation to shift the equilibrium to the right.

Uses    
Ethylene glycol is mainly used as the antifreeze agent for preparation of the automobile cooling systems and the raw material for the production of polyethylene terephthalate (the raw material of polyester fibers and plastics material). 
Ethylene glycol can also be used for the production of synthetic resins, solvents, lubricants, surfactants, emollients, moisturizers, explosives and so on. 
Ethylene glycol can often used as alternative of glycerol and can often be used as hydration agent and solvent in the tanning industry and pharmaceutical industry. 
Ethylene glycol has a strong dissolving capability but Ethylene glycol is easily to be oxidized to toxic metabolic oxalic acid and therefore can’t be widely used as a solvent. 

The Ethylene glycol can be supplemented to the hydraulic fluid and can be used for preventing the erosion of oil-based hydraulic fluid on the rubber of the system; the water-based hydraulic fluid with Ethylene glycol as a main component is an inflammable hydraumatic fluid and can be applied to the molding machine in aircraft, automobiles and high-temperature operation. 
There are many important derivatives of ethylene glycol. 
Low molecular weight polyethylene glycol (mono-uret ethylene glycol, bi-uret ethylene glycol, tri-uret ethylene glycol or respectively called as diethylene glycol, triethylene glycol, tetraethylene glycol) is actually the byproduct during the hydration of ethylene oxide B for preparation of Ethylene glycol.

Ethylene glycol is used as an antifreeze inheating and cooling systems (e.g.,automobileradiators and coolant for airplane motors).
Ethylene glycol is also used in the hydraulic brake fluids;as a solvent for paints, plastics, and inks; as a softening agent for cellophane; and in themanufacture of plasticizers, elastomers, alkydresins, and synthetic fibers and waxes.

Antifreeze in cooling and heating systems. 
In hydraulic brake fluids and de-icing solutions. 
Industrial humectant. 
Ingredient of electrolytic condensers (where Ethylene glycol serves as solvent for boric acid and borates). 
Solvent in the paint and plastics industries. 
In the formulation of printers' inks, stamp pad inks, ball-point pen ink. 
Softening agent for cellophane. 
Stabilizer for soybean foam used to extinguish oil and gasoline fires. 
In the synthesis of safety explosives, glyoxal, unsatd ester type alkyd resins, plasticizers, elastomers, synthetic fibers (Terylene, Dacron), and synthetic waxes. 
To create artificial smoke and mist for theatrical uses.

Ethylene glycol is used in the following products: textile treatment products and dyes, washing & cleaning products, adhesives and sealants, coating products, non-metal-surface treatment products, anti-freeze products, inks and toners, leather treatment products, polishes and waxes, polymers, heat transfer fluids, biocides (e.g. disinfectants, pest control products) and hydraulic fluids.
Other release to the environment of Ethylene glycol is likely to occur from: outdoor use, indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners), indoor use in close systems with minimal release (e.g. cooling liquids in refrigerators, oil-based electric heaters) and outdoor use in close systems with minimal release (e.g. hydraulic liquids in automotive suspension, lubricants in motor oil and break fluids).

Ethylene glycol is used in the following products: laboratory chemicals, polymers, heat transfer fluids, anti-freeze products and adhesives and sealants.
This substance is used in the following areas: mining.
Release to the environment of Ethylene glycol can occur from industrial use: in processing aids at industrial sites, of substances in closed systems with minimal release, for thermoplastic manufacture, as an intermediate step in further manufacturing of another substance (use of intermediates), formulation in materials and in the production of articles.

The major use of Ethylene glycol is as an antifreeze agent in the coolant in for example, automobiles and air-conditioning systems that either place the chiller or air handlers outside or must cool below the freezing temperature of water. 
In geothermal heating/cooling systems, Ethylene glycol is the fluid that transports heat through the use of a geothermal heat pump. 
The Ethylene glycol either gains energy from the source (lake, ocean, water well) or dissipates heat to the sink, depending on whether the system is being used for heating or cooling.

Pure Ethylene glycol has a specific heat capacity about one half that of water.
So, while providing freeze protection and an increased boiling point, Ethylene glycol lowers the specific heat capacity of water mixtures relative to pure water. 
A 1:1 mix by mass has a specific heat capacity of about 3140 J/(kg·°C) (0.75 BTU/(lb·°F)), three quarters that of pure water, thus requiring increased flow rates in same-system comparisons with water.

The mixture of Ethylene glycol with water provides additional benefits to coolant and antifreeze solutions, such as preventing corrosion and acid degradation, as well as inhibiting the growth of most microbes and fungi.
Mixtures of Ethylene glycol and water are sometimes informally referred to in industry as glycol concentrates, compounds, mixtures, or solutions.

Production Method    
1. Direct hydration of ethylene oxide is currently the only way for industrial-scale production of Ethylene glycol. 
Ethylene oxide and water, under pressure (2.23MPa) and 190-200 ℃ conditions, and can directly have liquid-phase hydration reaction in a tubular reactor to generate ethylene glycol while being with byproducts diethylene glycol, tripropylene ethylene gl]ycol and multi-uret poly ethylene glycol. 
The dilute ethylene glycol solution obtained from the reaction further undergoes thin film evaporator condensation, and then dehydration, refinement to obtain qualified products and by-products. 

2. Sulfuric acid catalyzed hydration of ethylene oxide; ethylene oxide can react with water, in the presence of sulfuric acid as the catalyst, at 60-80 ℃ and pressure of 9.806-19.61kPa for hydration to generate ethylene glycol. 
The reaction mixture can be neutralized by liquid alkaline and evaporated of the water to obtain 80% ethylene glycol, and then distilled and concentrated in distillation column to obtain over 98% of the finished product. 
This method is developed in early time.
Owing to the presence of corrosion, pollution and product quality problems, together with complex refining process, countries have gradually discontinued and instead change to direct hydration. 

3. Direct ethylene hydration; directly synthesize ethylene glycol from ethylene instead of being via ethylene oxide. 

4. Dichloroethane hydrolysis. 

5. Formaldehyde Method.
Industrial preparation of ethylene glycol adopts chlorine ethanol method, ethylene oxide hydration and direct ethylene hydration with various methods having their characteristics, as described below.
Chlorohydrin method
Take chloroethanol as raw materials for hydrolysis in alkaline medium to obtain Ethylene glycol. 
The reaction is carried out at 100 ℃. First generate ethylene oxide. 
Then pressurize at 1.01 MPa pressure to obtain ethylene glycol.

Ethylene Oxide Hydration
Hydration of ethylene oxide contains catalytic hydration and direct hydration. 
The hydration process can be carried out under either normal pressure or under compression. Normal pressure method generally take a small amount of inorganic acid as catalyst for reaction at 50~70 ℃.
Pressurized hydration had a high demand for the molar ratio of ethylene oxide over water which is higher than 1:6, to reduce the side reaction of producing the ether with the reaction temperature being at 150 °C and the pressure being 147kPa with hydration generating ethylene glycol.
There are currently gas phase catalytic hydration with silver oxide being the catalyst and the alumina oxide being the carrier for reaction at 150~240 ℃ to generate ethylene glycol.
Direct hydration of ethylene
Ethylene, in the presence of catalyst (e.g., antimony oxide TeO2 with palladium catalyst) can be oxidized in acetic acid solution to generate monoacetate ester or diacetate ester with further hydrolysis obtaining the ethylene glycol.
The above several methods takes ethylene oxide hydration as good with simple process and is suitable for industrialization.

Health Hazard    
The acute inhalation toxicity of 1,2-ethanediolis low. 
Ethylene glycol is due to its low vaporpressure, 0.06 torr at 20°C (68°F). 
Ethylene glycol's saturationconcentration in air at 20°C (68°F)is 79 ppm and at 25°C (77°F) is 131 ppm(ACGIH 1986). 
Both concentrations exceedthe ACGIH ceiling limit in air, which is50 ppm. 
In humans, exposure to its mist orvapor may cause lacrimation, irritation ofthroat, and upper respiratory tract, headache,and a burning cough. 
These symptoms maybe manifested from chronic exposure toabout 100 ppm for 8 hours per day for severalweeks.
The acute oral toxicity of 1,2-ethanediol islow to moderate. 
The poisoning effect, however,is much more severe from ingestionthan from inhalation. 
Accidental ingestion of80–120 mL of this sweet-tasting liquid canbe fatal to humans. 
The toxic symptoms inhumans may be excitement or stimulation,followed by depression of the central nervoussystem, nausea, vomiting, and drowsiness,which may, in the case of severe poisoning,progress to coma, respiratory failure, anddeath. 
When rats were administered sublethaldoses over a long period, there was depositionof calcium oxalate in tubules, causinguremic poisoning.

LD50 value, oral (rats): 4700 mg/kg
Ingestion of 1,2-ethanediol produced reproductiveeffects in animals, causing fetotoxicity, postimplantation mortality, andspecific developmental abnormalities. 
Mutagenictests proved negative. 
Ethylene glycol tested negativeto the histidine reversion–Ames test.

Biochem/physiol Actions    
Ethylene glycol is a low toxicity molecule and is used for embryo cryopreservation in many domestic animals.
Ethylene glycol is an additive screening solution of Additive Screening Kit. 
Additive Screen kit is designed to allow rapid and convenient evaluation of additives and their ability to influence the crystallization of the sample. 
The Additive Kit provides a tool for refining crystallization conditions.

Toxicity evaluation    
Ethylene glycol has low toxicity but it is metabolized to a variety of toxic metabolites. Ethylene glycol and glycolaldehyde have an intoxicating effect on the central nervous system that can lead to ataxia, sedation, coma, and respiratory arrest similar to ethanol intoxication. However, the profound metabolic acidosis reported in toxicity is secondary to accumulation of acid metabolites, especially glycolic acid. 
The oxalic acid metabolite complexes with calcium and precipitates as calcium oxalate crystals in the renal tubules, leading to acute renal injury. 
Further, oxalate’s ability to chelate calcium may cause clinically relevant serum hypocalcemia.

Synonyms
ETHYLENE GLYCOL
Ethane-1,2-diol
1,2-ethanediol
107-21-1
glycol
monoethylene glycol
1,2-Dihydroxyethane
2-hydroxyethanol
Glycol alcohol
Ethylene alcohol
Macrogol
Fridex
Tescol
Ethylene dihydrate
Norkool
Macrogol 400 BPC
Dowtherm SR 1
ethanediol
Zerex
Ucar 17
Lutrol-9
ethyleneglycol
Aethylenglykol
Ethylenglycol
1,2-Ethandiol
1,2-ethylene glycol
ethylen glycol
ethylene-glycol
146AR
Lutrol 9
MFCD00002885
NSC 93876
DTXSID8020597
PEG
1,2-dihydroxy ethane
HOCH2CH2OH
PEG 1000
M.e.g.
FC72KVT52F
CHEBI:30742
1, 2-Ethanediol
NSC-93876
Glycol, ethylene-
DTXCID40597
Caswell No. 441
Aethylenglykol [German]
CAS-107-21-1
CCRIS 3744
Dowtherm 4000
HSDB 5012
NCI-C00920
PEG 3350
EINECS 203-473-3
UNII-FC72KVT52F
EPA Pesticide Chemical Code 042203
WLN: Q2Q
ethyleneglycole
Athylenglykol
ehtylene glycol
etylene glycol
AI3-03050
2-ethanediol
Ilexan E
4-vinyl cathecol
MEG 100
Solbanon (TN)
1,2-ethane diol
1,2-ethane-diol
ethane-1.2-diol
GXT
PEG 4000
1,2-ethyleneglycol
ethan-1,2-diol
mono-ethylene glycol
Macrogol 400
1,2-ethylene-glycol
Lutrol E (TN)
NANOSILVER+EG
YLENE GLYCOL
DuPont Zonyl FSO Fluorinated Surfactants
Ethylene glycol-[d6]
GLYCOL [INCI]
Macrogol 400 (TN)
Ethyleneglycol, ReagentPlus
Macrogol 1500 (TN)
Macrogol 4000 (TN)
Macrogol 6000 (TN)
EC 203-473-3
LOWENOL T-163A
Macrogol ointment (JP17)
HO(CH2)2OH
NCIOpen2_001979
NCIOpen2_002019
NCIOpen2_002100
Macrogol 400 (JP17)
ETHYLENE GLYCOL [II]
ETHYLENE GLYCOL [MI]
MLS002454404
BIDD:ER0283
Macrogol 1500 (JP17)
Macrogol 4000 (JP17)
Macrogol 6000 (JP17)
ETHYLENE GLYCOL [HSDB]
CHEMBL457299
ETHYLENE GLYCOL [MART.]
Ethylene glycol, AR, >=99%
Ethylene glycol, LR, >=99%
Macrogol 20000 (JP17)
CHEBI:46793
ETHYLENE GLYCOL [USP-RS]
ETHYLENE GLYCOL [WHO-DD]
PEG1000
HMS2267F07
Ethylene glycol, p.a., 99.5%
1,2-ETHANEDIOL (GLYCOL)
AMY22336
NSC32853
NSC32854
NSC57859
NSC93876
PEG 3600
PEG-1000
STR01171
ZINC5224354
Ethylene glycol, analytical standard
Tox21_202038
Tox21_300637
Ethane-1,2-diol (Ethylene Glycol)
Ethylene glycol, anhydrous, 99.8%
NSC-32853
NSC-32854
NSC-57859
NSC152324
NSC152325
NSC155081
STL264188
AKOS000119039
NSC-152324
NSC-152325
NSC-155081
Ethylene glycol, Spectrophotometric grade
NCGC00091510-01
NCGC00091510-02
NCGC00091510-03
NCGC00254292-01
NCGC00259587-01
BP-13454
BP-31056
GLYCEROL IMPURITY B [EP IMPURITY]
SMR001262244
ETHYLENE GLYCOL HIGH PURITY GRD 1L
Ethylene glycol, ReagentPlus(R), >=99%
DuPont Zonyl FSE Fluorinated Surfactants
Residual Solvent Class 2 - Ethylene Glycol
E0105
Ethylene glycol 1000 microg/mL in Methanol
Ethylene glycol, puriss., >=99.5% (GC)
FT-0626292
FT-0692978
1,2-Ethane-1,1,2,2-d4-diol-d2(9ci)
EN300-19312
Ethylene glycol, BioUltra, >=99.5% (GC)
Ethylene glycol, SAJ first grade, >=99.0%
C01380
D03370
D06418
D06419
D06420
D06421
D06422
D06423
Ethylene glycol, JIS special grade, >=99.5%
Ethylene glycol, anhydrous, ZerO2(TM), 99.8%
Ethylene glycol, Vetec(TM) reagent grade, 98%
A851234
Ethylene glycol, spectrophotometric grade, >=99%
Q194207
J-001731
F0001-0142
004143F9-240E-472F-9D5A-B1B13BBA2A18
Ethylene glycol, United States Pharmacopeia (USP) Reference Standard
Ethylene glycol, Pharmaceutical Secondary Standard; Certified Reference Material
ethylene glycol;1,2-ethanediol;ethane-1,2-diol;glycolethylene glycol;ethanediol;ethylene glycol 1,2-ethanediol ethane-1,2-diol glycolethylene glycol ethanediol
Residual Solvent Class 2 - Ethylene Glycol, United States Pharmacopeia (USP) Reference Standard