1, 2-Dichloroethene, also called 1, 2-dichloroethylene, is a highly flammable, colorless liquid with a sharp, harsh odor. It is used to produce solvents and in chemical mixtures. You can smell very small amounts of 1, 2-dichloroethene in air (about 17 parts of 1, 2-dichloroethene per million parts of air [17 ppm]).