Also known as: 1,1-Dichloroethene, 1,1-DCE, Vinylidene chloride
Chemical reference number (CAS): 75-35-4

1,1-Dichloroethylene (1,1-DCE) is a man-made substance used to make fire retardant fibers and polyethylene food wraps. It is a clear, colorless, flammable liquid with a mild, sweet smell. Dichloroethylene evaporates quickly at room temperature and can pollute the air.

When 1,1-DCE gets into water or on soil it evaporates quickly. However, in groundwater or soil, it breaks down very slowly. Most 1,1-DCE in the environment results from industrial use and improper disposal.

Exposure Information

Most people who are exposed to 1,1-DCE are exposed to it at work.

Most exposures happen when people breathe 1,1-DCE vapors. Low level exposures can occur in the home when people use products that contain 1,1-DCE. If the home water supply is contaminated, people can inhale the chemical when they use water for cooking, laundering, or bathing.

People may be exposed to 1,1-DCE when they drink contaminated water or when they eat food that was wrapped in polyethylene. People who work or play around contaminated soils may be exposed to 1,1-DCE if they touch their mouths or eat with dirty hands. 1,1-DCE can also pass through the skin.


The state and federal drinking water standards for 1,1-DCE are both set at 7 parts per billion (ppb). We recommend that you stop drinking water that contains more than 7 ppb of 1,1-DCE. If levels of 1,1-DCE are very high in your water, you may also need to avoid washing, bathing, or using the water for other purposes.

No standards exist for regulating the amount of 1,1-DCE allowed in the air of homes. However, the Wisconsin Department of Natural Resources (DNR) has set a residential indoor air action level for 1,1-DCE at 52 parts per billion by volume (ppbv). The action level is considered to be protective of public health. Breathing 1,1-DCE for a lifetime at 52 ppbv is very unlikely to be harmful to people. If 1,1-DCE concentrations in air are above the action level, we recommend taking an action to halt exposure.

Most people can't smell 1,1-DCE until levels exceed 36,000 ppbv. If you can smell 1,1-DCE, the level is too high to be safe.

The Wisconsin Department of Natural Resources regulates the amount of 1,1-DCE that can be released into outdoor ambient air by industries.

Health Effects

Everyone's Reaction is Different

A person's reaction to chemicals depends on several things, including individual health, heredity, previous exposure to chemicals including medicines, and personal habits such as smoking or drinking. It’s also important to consider the length of exposure to the chemical, the amount of chemical exposure, and whether the chemical was inhaled, touched, or eaten.

There is very little human health information available on the effects of exposure to 1,1-DCE. The following information is based on animal studies:

Short term exposure to high levels of 1,1-DCE can result in:

  • Irritation of the nose, throat and lungs;
  • Burning of eyes and skin; and
  • Damage to liver, kidneys, nervous system, and heart.

The following long-term effects were observed in animal studies:

  • 1,1-DCE is considered to be a possible cancer-causing substance. Laboratory animals developed kidney and adrenal gland tumors following exposure to high doses of 1,1-DCE.
  • Lung, liver, and kidney damage can occur.
  • Animal studies showed damage to the developing fetus when the mother also showed signs of illness from exposure.

1,1-DCE can be detected in the breath, urine, blood, and body tissues. Breath tests are now the most common way to tell whether a person has been recently exposed to 1,1-DCE. These tests require specialized equipment and are not available at all doctor's offices. Your physician can tell you where these tests can be done.

Tests of lung, liver, and kidney function are used to assess damage to these systems. However, they cannot pinpoint the cause of the damage.

Last Revised: February 28, 2018

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