What EDC Is
EDC stands for ethylene dichloride, also called 1,2-dichloroethane, registered under CAS 107-06-2. It is a clear, colourless to pale yellow oily liquid with a chloroform-like odour, produced industrially by the chlorination of ethylene or by oxychlorination of ethylene with hydrogen chloride and air. Almost all of the tonnage is consumed inside integrated chemical complexes rather than sold into open distribution, because it is both a hazardous material and a convenient intermediate.
| Property | Value |
|---|---|
| Chemical name | 1,2-dichloroethane |
| CAS number | 107-06-2 |
| Molecular formula | C2H4Cl2 |
| Molar mass | 98.96 g/mol |
| Boiling point | 83.6 C |
| Melting point | about minus 36 C |
| Flash point | 13 C |
| Vapour pressure at 25 C | about 102 hPa |
| Relative density at 20 C | about 1.24 |
Use One: Vinyl Chloride Monomer and PVC
The dominant use, accounting for the large majority of world production, is the manufacture of vinyl chloride monomer. EDC is thermally cracked in a high-temperature furnace to give vinyl chloride and hydrogen chloride; the hydrogen chloride is returned to the oxychlorination step, which converts it back into more EDC and closes the chlorine loop of the plant. Vinyl chloride is then polymerised into polyvinyl chloride, the raw material of pipes, window profiles, floor coverings, cable insulation and medical tubing. Because of the scale of the PVC industry, the economics of EDC are tied directly to construction and infrastructure demand.
Use Two: Solvent Applications
EDC dissolves fats, oils, waxes, resins and rubbers, and this solvent power has been used in extraction processes, in textile scouring, in the degreasing of metal parts and as a carrier in some formulations. These applications have declined sharply in regulated markets because of the carcinogenicity classification, and many users have reformulated around less hazardous solvents. Where solvent use continues, it is normally in closed equipment with full vapour recovery, not in open cleaning operations.
Use Three: Intermediate for Other Chemicals
Beyond vinyl chloride, EDC is a building block for other chlorinated and amine products. It is used to make ethyleneamines and related polyamines through reaction with ammonia, and it is a precursor in the production of trichloroethylene and perchloroethylene. Smaller dedicated volumes are used in the synthesis of pharmaceutical and agrochemical intermediates where a two-carbon chlorinated unit is required. In each case the chemistry exploits the reactivity of the carbon-chlorine bonds, and the reaction is carried out in a closed system.
Health, Safety and Regulatory Status
1,2-Dichloroethane is classified in the European Union as a category 1B carcinogen, with the hazard statement H350, may cause cancer, and as harmful if inhaled, H332. It is also a skin and eye irritant. Occupational exposure is controlled through closed handling, local exhaust ventilation, monitoring of workplace air against the applicable national limit, and protective clothing with suitable gloves, since the liquid is absorbed through the skin. The vapour is heavier than air and, although the flash point of 13 C makes the liquid flammable, the more serious long-term risk is the inhalation of vapour and the chronic carcinogenic hazard. For transport, the substance is a toxic and flammable liquid and is shipped only in dedicated equipment with the corresponding documentation.
Frequently Asked Questions
Q: What is EDC mainly used for?
A: About the whole of world production goes to vinyl chloride monomer, which is polymerised into PVC. Smaller amounts are used as a solvent and as an intermediate for ethyleneamines and chlorinated solvents.
Q: Which CAS number should be quoted on a purchase order?
A: 1,2-Dichloroethane is registered as CAS 107-06-2, and that is the number shown on certificates of analysis for the commodity. It is good practice to write the full chemical name as well, so the identity is unambiguous.
Q: Is EDC a carcinogen?
A: Yes. It is classified as a category 1B carcinogen in the European Union with hazard statement H350, and exposure is controlled through closed systems and workplace air monitoring.
Q: Can EDC be replaced as a solvent?
A: In most cleaning and extraction duties it can, and many industries have already substituted less hazardous solvents. Its role in the vinyl chloride chain, where it is a chemical intermediate rather than a solvent, has no simple substitute.
Q: How is EDC shipped?
A: In dedicated tankers, tank containers and drums designed for toxic and flammable liquids, with vapour recovery during loading, correct transport classification and full documentation.
Q: What should a buyer check in the specification?
A: Purity, water content, acidity and colour, plus evidence that the shipment was produced and transferred under closed handling with a batch certificate of analysis and a current safety data sheet.