Glycidol

Description

Glycidol is a chiral molecule with epoxide and primary alcohol functional groups. It is racemic mixture and exists in the dextrorotatory and the levorotatory enantiomeric forms. Several synthetic methods are available for preparation of glycidol. However, it is commercially prepared from the epoxidation of allyl alcohol with hydrogen peroxide and a catalyst (tungsten or vanadium), or from the reaction of epichlorohydrin with caustic. Glycidol has been used in the industrial synthesis of pharmaceutical products since the 1970s. However, its use for research purposes has been reported since 1956. Available information indicates that glycidol is manufactured by several companies in Japan, Germany, and the United States.

Description

Glycidol is an epoxide and an alcohol, and as such is a highly reactive compound. It is miscible with water but also reacts with it. It decomposes when distilled at atmospheric pressure.
In 1909, chemist Nikolai Prilezhaev at the Warsaw University of Technology prepared glycidol by epoxidizing allyl alcohol with peroxybenzoic acid. This reaction was a breakthrough at the time and became known as the Prilezhaev oxidation. Glycidol is still manufactured in much the same way; but in 2018, a group of companies built a pilot plant in Teesside, UK, to make it via a “green” process.
Glycidol has a chiral center, but it is generally produced and used as the racemic mixture. It is used as a chemical intermediate and in the production of detergents, healthcare products, and industrial paints and coatings.
As shown in the hazard information table, glycidol presents an unusually large number of health risks. These factors were recently acknowledged when the US Food and Drug administration identified 19 substances as potentially harmful constituents of nicotine delivery systems (“e-cigarettes” and “e-liquids”). Glycidol, along with former Molecules of the Week diacetyl and ethylene glycol, is prominent in the FDA list. The agency now requires manufacturers and importers of the delivery systems to report the concentrations of each compound in its products.

Chemical properties

colourless liquid

Chemical properties

Glycidol is a colorless liquid.

The Uses of Glycidol

Glycidol is a Stabilizer in the manufacture of vinyl polymers; chemical intermediate in preparation of glycerol, glycidyl ethers, esters, and amines; in pharmaceuticals; in sanitary chemicals.

The Uses of Glycidol

Stabilizer in manufacturing of vinyl polymers; intermediate in synthesis of glycerol, glycidyl ethers, and amines; additive for oil and synthetic hydraulic fluids; epoxy resin diluent.

The Uses of Glycidol

Glycidol is used as a stabilizer for natural oilsand vinyl polymers, as a demulsifier, and asa leveling agent for dyes.

What are the applications of Application

(±)-Glycidol is an epoxide building block

definition

an epoxide

General Description

Odorless clear colorless liquid.

Air & Water Reactions

Sensitive to moisture.

Reactivity Profile

Glycidol is sensitive to moisture. Glycidol is also sensitive to light. Glycidol may polymerize if heated above room temperature. Glycidol may darken on storage. Stability studies of Glycidol stored for two week protected from light indicated definite decomposition at 140° F, and strongly indicated instability at 77° F. A solution of Glycidol in water was found to be unstable when stored at room temperature, even after one day in the dark. Glycidol is incompatible with strong oxidizers. Glycidol will undergo explosive decomposition in the presence of strong acids or bases, salts (such as aluminum chloride, iron(III)chloride or tin(IV) chloride) or metals (such as copper and zinc). Glycidol is also incompatible with nitrates. Glycidol will attack some forms of plastics, rubber and coatings.

Hazard

Toxic material. Probable carcinogen.

Health Hazard

Glycidol is an eye, lung, and skin irri-tant. The pure compound caused severebut reversible corneal injury in rabbit eyes(ACGIH 1986). Exposure to its vapor causedirritation of lung in mice, resulting in pneu-monitis. There is no evidence of any cumula-tive toxicity. From the limited toxicity data,it appears that the health hazard to humansfrom its exposure is, primarily, respiratoryirritation, stimulation of the central nervoussystem, and depression.
Glycidol is mutagenic, testing positive inthe histidine reversion–Ames test. There isno report of its carcinogenic action. Oraland intraperitoneal administration of gly-cidol in rats showed harmful effects onfertility.

Fire Hazard

Glycidol is combustible.

Flammability and Explosibility

Non flammable

Safety Profile

Confirmed carcinogen with carcinogenic data reported. Poison by intraperitoneal route. Moderately toxic by ingestion, inhalation, and sh contact. Experimental teratogenic and reproductive effects. A skin irritant. Human mutation data reported. Animal experiments suggest somewhat lower toxicity than for related epoxy compounds. Readdy absorbed through the skin. Causes nervous excitation followed by depression. Explodes when heated or in the presence of strong acids,bases, metals (e.g., copper, zinc), and metal salts (e.g., aluminum chloride, iron(II1) chloride, tin(Iy chloride). When heated to decomposition it emits acrid smoke and fumes. See also DIGLYCIDYL ETHER.

Potential Exposure

Glycidol is used as an intermediate in the synthesis of glycerol, glycidyl ethers, esters, and amines.

Carcinogenicity

Glycidol is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.

Environmental Fate

Chemical/Physical. May hydrolyze in water forming glycerin (Lyman et al., 1982).

Shipping

UN2810 Toxic liquids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required.

Purification Methods

[S(-)-isomer, § also available on polymer support, has b 49-50o/7mm, 66-67o/19mm, [ ] D -1 5o(neat)], [R(+)-isomer has b 56 -5 6 . 5o/11mm, d 4 1.117, n D 1.429, [ ] D +15o (neat)]. Purify glycidol by fractional distillation.

Toxicity evaluation

Glycidol is a small molecule possessing a chemically reactive epoxide group. Therefore, it acts as a direct alkylating agent. Nucleophilic bioactive compounds such as glutathione react readily with glycidol. Glycidol decreases glutathione content in rat liver by direct binding to the glutathione. In vitro experiments revealed that glycidol reacts with purified DNA to form the DNA adducts. This is likely to be responsible for the genotoxic activity of the compound without a requirement for metabolic activation.

Incompatibilities

May form explosive mixture with air. Violent reaction with strong oxidizers, nitrates. Decomposes on contact (especially in the presence of heat) with strong acids, strong bases, water, metal salts, e.g., alu minum chloride, ferric chloride, and tin chloride), or metals (copper and zinc), causing fire and explosion hazard. Contact with barium, lithium, sodium, magnesium, and tita nium may cause polymerization. Attacks some plastics, rubber, and coatings.

Waste Disposal

Concentrated waste contain ing 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.