Epichlorohydrin

Description

Epoxy resins of the bisphenol A type are synthesized from epichlorhydrin and bisphenol A. This leads to bisphenol-A diglycidyl ether, which is the monomer of bisphenol-A-based epoxy resins. Sensitization to epichlorhydrin occurs mainly in workers in the epoxy-resin industry. Sensitization in individuals not working at epoxy resin plants is rare. It has however been described to occur after contact with a soil fumigant, due to solvent cement and in a worker in a pharmaceutical plant, in a division for drug synthesis. Epichlorhydrin was used for the production of both drugs propranolol and oxprenolol.

Description

Epichlorohydrin, aka 2-(chloromethyl)oxirane, is a hazardous bifunctional liquid with a chloroform-like odor. The article of commerce is normally a racemic mixture of its two enantiomers; the 3-D image shown here is the (+)-isomer1.
In 1848, the pioneering French chemist Marcellin Berthelot—at the age of 21—was the first to describe epichlorohydrin. He prepared it by treating glycerol with hydrogen chloride gas. Berthelot’s synthesis has since been refined and is the basis of the modern manufacturing process. An alternative method is the epoxidation of allyl chloride. Current worldwide production is estimated to be >2 million tonnes.
By far the largest use of epichlorohydrin is in the production of epoxy resins. It is most often combined with bisphenol A in a base-catalyzed condensation reaction to produce the resin bisphenol A diglycidyl ether2. It is also used as a reagent for chemical and polymer synthesis and as a solvent for resins and coatings.
The health hazards associated with epichlorohydrin, bisphenol A, and epoxy resins require the use of protective equipment and adequate ventilation.
1. CAS Reg. No. 67843-74-7. 2. CAS Reg. No. 1675-54-3.

The Uses of Epichlorohydrin

Epichlorohydrin is used to make glycerol,epoxy resins, adhesive, and castings; asderivatives for producing dyes, pharmaceu-ticals, surfactants, and plasticizers; and asa solvent for resins, gums, paints, andvarnishes.