1,1-Dichloroethylene
[CAS# 75-35-4]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Cyanopyridine
• Name: 1,1-Dichloroethylene
• Synonyms: Vinylidene chloride
• Molecular Formula: C₂H₂Cl₂
• Molecular Weight: 96.94
• CAS Registry Number: 75-35-4
• EC Number: 200-864-0
• SMILES: C=C(Cl)Cl

Properties

• Solubility: 0.04 g/100g
• Density: 1.213 g/mL
• Melting point: -122 °C
• Boiling point: 30-32 °C
• Flash point: -25 °C

Safety Data

• Hazard Symbols: GHS02;GHS08;GHS07 Danger
• Risk Statements: H224-H351-H332
• Safety Statements: P203-P210-P233-P240-P241-P242-P243-P260-P261-P264-P264+P265-P270-P271-P273-P280-P301+P317-P303+P361+P353-P304+P340-P305+P351+P338-P317-P318-P319-P330-P337+P317-P370+P378-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H332
Flammable liquids	Flam. Liq.	1	H224
Carcinogenicity	Carc.	2	H351
Eye irritation	Eye Irrit.	2	H319
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Acute toxicity	Acute Tox.	3	H301
Skin irritation	Skin Irrit.	2	H315
Carcinogenicity	Carc.	1B	H350
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Eye irritation	Eye Irrit.	2A	H319
Flammable gases	Flam. Gas	1	H220

• Transport Information: UN 1303

Discovery and Applications

1,1-Dichloroethylene, also known as vinylidene chloride, is a chemical compound with the formula C2H2Cl2. This colorless, flammable liquid has a sweet odor and is classified as a chlorinated hydrocarbon. It was first synthesized in the early 19th century, with the discovery attributed to the work of chemists investigating the properties of chlorinated alkenes. Its commercial production began in the mid-20th century, primarily due to the increasing demand for versatile and effective industrial solvents.

1,1-Dichloroethylene has found numerous applications across various industries. One of its primary uses is as a solvent in the formulation of adhesives, coatings, and paint removers. Its ability to dissolve a wide range of organic materials makes it valuable in these formulations, where it enhances the effectiveness of the products. In addition to serving as a solvent, 1,1-dichloroethylene is utilized in the production of fluoropolymers and other chemicals, functioning as an intermediate in the synthesis of more complex compounds.

Another significant application of 1,1-dichloroethylene lies in the field of plastics manufacturing. It is employed in the production of polyvinylidene chloride (PVDC), a polymer known for its excellent barrier properties against moisture, oxygen, and other gases. This characteristic makes PVDC widely used in food packaging and preservation, providing an effective means to extend the shelf life of perishable goods. The use of 1,1-dichloroethylene in creating PVDC has revolutionized packaging technologies, enhancing food safety and reducing waste.

In addition to industrial applications, 1,1-dichloroethylene has also been utilized in laboratory settings as a reagent in organic synthesis. Its reactivity allows for various chemical transformations, including polymerization and cross-linking reactions, contributing to the development of new materials and compounds. Furthermore, it has been investigated for its potential applications in the synthesis of agrochemicals and pharmaceuticals.

Despite its usefulness, 1,1-dichloroethylene is subject to regulatory scrutiny due to its environmental and health impacts. It is classified as a hazardous air pollutant by the United States Environmental Protection Agency (EPA) and is associated with potential risks, including carcinogenicity and reproductive toxicity. Consequently, industries utilizing this compound must adhere to strict guidelines and regulations to mitigate its release into the environment and minimize exposure to workers.

Efforts to find safer alternatives to 1,1-dichloroethylene have led to research into green chemistry solutions and the development of less toxic solvents. As industries evolve and seek to reduce their environmental footprint, the demand for safer and more sustainable alternatives continues to grow.

In summary, 1,1-dichloroethylene is a significant chemical compound with a rich history of discovery and diverse applications in various industrial and research contexts. While it has played a vital role in the development of new materials and products, ongoing concerns regarding its environmental and health impacts underscore the need for responsible use and the exploration of safer alternatives.

References

1984. 1,1-Dichloroethylene: An Apoptotic Hepatotoxin?. Environmental Health Perspectives, 57.
DOI: 10.1289/ehp.8457313

2017. Cometabolic degradation of dichloroethenes by Comamonas testosteroni RF2. Chemosphere, 187.
DOI: 10.1016/j.chemosphere.2017.07.156

2009. Large-scale production of bacterial consortia for remediation of chlorinated solvent-contaminated groundwater. Journal of Industrial Microbiology & Biotechnology, 36(9).
DOI: 10.1007/s10295-009-0600-5