Propargyl chloride, or 3-chloro-1-propyne, is a highly toxic and flammable clear brown liquid with chemical formula CHCCH2Cl. It is miscible with benzene or ethanol and insoluble in water. Its refractive index is 1.4350. Common uses for propargyl chloride include soil fumigation, corrosion prevention, and as an intermediate in organic synthesis. It reacts with alcohols to form propargyl ethers.