1,1-Dichloroethene (Ethene, 1,1-dichloro-)

CAS Registry Number 75-35-4

What is it?

• 1,1-Dichloroethene, also known as Ethene, 1,1-dichloro, is an industrial chemical.

How is it used?

• Globally, 1,1-dichloroethene is used primarily in the manufacture of polyvinylidene chloride polymers and copolymers which may in turn be used in a variety of end products such as food wrap, carpet latex backing, fire and ignition resistant clothing, vapour barriers for insulation, paper and board coatings and photographic film.
• 1,1-Dichloroethene may persist as an unintended manufacturing residue in some of these items that may be present in Canadian commerce.
• 1,1-Dichloroethene may also be used in the production of hydrochlorofluorocarbons, hydrofluorocarbons and latex and resins, as an aid in ore flotation, as a solvent in paint and varnish remover, and as a vapour degreaser and industrial cleaning agent.
• 1,1-dichloroethene was both manufactured in and imported into Canada in 2000 but it is no longer manufactured nor imported into Canada.

Why did the Government of Canada assess it?

• Prior to the assessment, 1,1-dichloroethene was identified as a potential concern to human health.  Furthermore, it is classified by international organizations as a substance that may cause cancer in laboratory animals.
• 1,1-Dichloroethene was not considered to be a priority for assessment of potential risks to the environment; however, potential environmental effects were also evaluated in this screening assessment.

How is it released to the environment?

• 1,1-Dichloroethene may be released into the environment during its manufacture and use.
• 1,1-Dichloroethene may also be released during the breakdown of polyvinylidene chloride (PVDC) products and during the decomposition of solvents containing this substance.

How are Canadians exposed to it?

• Exposure of the general population of Canada to 1,1-DCE is expected to be from indoor air and possibly food; however these exposures are expected to be low.

What are the results of the assessment?

• The Government of Canada has conducted a science-based evaluation of 1,1-dichloroethene, called a screening assessment.
• Screening assessments address potential for harm to the general population in Canada (not including workplace exposures) and the environment.
• Results of the final screening assessment indicate that 1,1-dichloroethene is not expected to remain in the environment for a long time or accumulate in organisms.
• Furthermore, the quantity of 1,1-dichloroethene that may be released to the environment is below the level expected to cause harm to organisms.
• The Government of Canada has therefore concluded that 1,1-dichloroethene is not entering the environment at levels that constitute a danger to the environment.
• The Government of Canada has also concluded that 1,1-dichloroethene is not harmful to human health at current levels of exposure.

What is the Government of Canada doing?

• Based on the conclusion of the final screening assessment, no further action will be taken on 1,1-dichloroethene.
• The final screening assessment report on 1,1-dichloroethene was published on June 1, 2013.

What can Canadians do?

• The health risks associated with a chemical depend on the hazard (its potential to cause health effects) and the dose (the amount of chemical to which you are exposed). 1,1-dichloroethene is not a concern for the environment or human health at current levels of exposure.
• As a general precaution, Canadians are reminded when using any product to carefully follow safety warnings and directions.
• Canadians who handle 1,1-dichloroethene in the workplace should consult with their occupational health and safety representative about safe handling practices, applicable laws and requirements under the Workplace Hazardous Materials Information System (WHMIS).