Chemical Properties
cetone cyanohydrin is a colorless, fl
ammable liquid with a faint odor of bitter almond.
It is an organic compound used in the production of methyl methacrylate, the monomer
of the transparent plastic polymethyl methacrylate (PMMA), also known as acrylic. It is
incompatible with sulfuric acid and caustics. Acetone cyanohydrin readily undergoes
decomposition by water to form hydrogen cyanide and acetone.
General Description
A colorless liquid. Flash point 165°F. Lethal by inhalation and highly toxic or lethal by skin absorption. Density 7.8 lb/gal (less dense than water). Vapors heavier than air. Produces toxic oxides of nitrogen during combustion.
Reactivity Profile
ACETONE CYANOHYDRIN readily decomposes to acetone and poisonous hydrogen cyanide gas on contact with water, acids (sulfuric acid) or when exposed to heat. Should be kept cool and slightly acidic (pH 4-5) [Sax, 2nd ed., 1965, p. 388]. Slowly dissociates to acetone, a flammable liquid, and hydrogen cyanide, a flammable poisonous gas, under normal storage and transportation conditions. Rate of dissociation increased by contact with alkalis and/or heat.
Health Hazard
Acetone cyanohydrin is extremely toxic. Exposures to acetone cyanohydrin cause adverse
health effects. The symptoms of toxicity include, but are not limited to, irritation to the
eyes, skin, respiratory system, dizziness, lassitude (weakness, exhaustion), headache, con-
fusion, pulmonary edema, asphyxia convulsions, liver, kidney injury, pulmonary edema,
and asphyxia. The target organs include the eyes, skin, respiratory system, central nervous
system (CNS), cardiovascular system, liver, kidneys, and the gastrointestinal tract.
Health Hazard
This material is considered very hazardous and should only be handled under conditions that prevent any inhalation of vapor or skin contact. May be slightly irritating to skin and mucous membranes.
Potential Exposure
Used in the manufacture of insecticides and making other chemicals, such as methyl methacrylate.
Fire Hazard
Too dangerous to health to expose fire fighters; a few whiffs of vapor could cause death; vapor or liquid could be fatal on penetrating normal protective clothing. Vapor forms explosive mixture with air. Decomposes when heated to 248F or at lower temperature under alkaline conditions, emitting highly toxic hydrogen cyanide. May react violently with water. Contact with sulfuric acid may cause ACETONE CYANOHYDRIN, STABILIZED to explode.
First aid
Move victim to fresh air; call emergency medical care. If this chemical gets into the eyes, remove any contact lenses at once and irrigate immediately for at least 15 minutes, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts the skin, quickly remove contaminated clothing and wash with large amounts of water. Speed in removing material from skin is of extreme importance. Seek medical attention immediately. When this chemical has been swallowed, get medical attention immediately. If this chemical has been inhaled, remove from exposure, and transfer promptly to a medical facility. If not breathing, give artificial respiration (avoid mouth to mouth resuscitation). If breathing is difficult, give oxygen. If heart has stopped begin CPR. Keep victim quiet and maintain normal body temperature. Effects may be delayed; keep victim under observation. Avoid contact with contaminated skin. A cyanide antidote kit should be kept in the immediate work area and must be rapidly available. Kit ingredients should be replaced every 1 2 years to ensure freshness. Persons trained in the use of this kit; oxygen use, and CPR must be available within 1 2 minutes of exposure
Shipping
UN1541 Acetone cyanohydrin, stabilized, Hazard Class: 6.1; Labels: 6.1-Poison Inhalation Hazard, Inhalation Hazard Zone B.
Incompatibilities
May form explosive mixture with air. Not compatible with strong reducers, strong bases; strong oxidizers, and strong acids, such as hydrochloric, sulfuric (explosive), and nitric. Contact with strong acid and strong bases may cause explosions. Slowly decomposes to acetone and hydrogen cyanide gas at room temperatures; rate is accelerated by an increase in pH, contact with water, or temperature.
Waste Disposal
Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform with EPA regulations governing storage, transportation, treatment, and waste disposal. Add with stirring to strong alkaline calcium hypochlorite solution. Alternatively dissolve in flammable solvent and burn in incinerator with afterburner and scrubber.
Uses
Acetone cyanohydrin is used as a raw material for insecticides manufacture and also to produce ethyl α-hydroxyisobutryate, a pharmaceutical intermediate. It has been used as a complexing agent for metals refining and separation.
Uses
Acetone cyanohydrin is used to make methyl methacrylate; in the production of pharmaceuticals, foaming agents, and insecticides; and to produce polymerization initiators.
Uses
In preparative organic chemistry for transcyanohydrination, such as preparing the 17-monocyanohydrin of a 3,17-diketo steroid by hydrogen cyanide exchange with the reagent, e.g. Ercoli, de Ruggieri, J. Am. Chem. Soc. 75, 650 (1953).
Definition
ChEBI: 2-hydroxy-2-methylpropanenitrile is a cyanohydrin.
Production Methods
Acetone cyanohydrin is formed by adding acetone to sodium or potassium cyanide in water and treating with H2S04 or by reaction of acetone with hydrogen cyanide
(HSDB 1988; Windholz et al 1983). Technical acetone cyanohydrin may contain
as much as 0.2% free hydrogen cyanide. U.S. production in 1984 is estimated at
546,000 tons (HSDB 1988).
Production Methods
Acetone cyanohydrin is manufactured by the direct reaction of hydrogen cyanide with acetone, catalyzed by base, generally in a continuous process.
Industrial uses
Actone cyanohydrin is used primarily in the preparation of methyl methacrylate,
which is polymerized to form various plastics, including plexiglas, and as intermediate
for resins (Hawley 1981). It also is employed for the manufacture of
insecticides; to produce oc-hydroxy-isobutyrate, a pharmaceutical intermediate; as
a complexing agent for metals; and as a reagent for chemical synthesis.
Metabolism
Acetone cyanohydrin is readily absorbed by all routes (Hartung 1981). Shkodich
(1966) found no evidence of cumulative effects of acetone cyanohydrin in white
mice or albino rats over a period of 20 d in which daily doses of one-fifth of the
LD50s were given. Rapid detoxication and excretion were presumed to occur.
Acetone cyanohydrin may be largely metabolized to yield free cyanide (H?rtung
1981).
Purification Methods
Dry the cyanohydrin with Na2SO4, and distil it as rapidly as possible under vacuum to avoid decomposition. Discard fractions boiling below 78-82o/15mm. Store it in the dark. USE AN EFFICIENT FUME HOOD as HCN (POISONOUS) is always present. [Cox & Stormont Org Synth Coll.Vol. II 7 1940, Beilstein 3 H 316, 3 IV 785.]
