Ethyldichloroarsine, sometimes abbreviated "ED" and also known as ethyl Dick, is an

organoarsenic compound Organoarsenic chemistry is the chemistry of compounds containing a chemical bond between arsenic and carbon. A few organoarsenic compounds, also called "organoarsenicals," are produced industrially with uses as insecticides, herbicides, and fu ...

with the formula CH₃CH₂AsCl₂. This colourless volatile liquid is a highly toxic obsolete

vesicant A blister agent (or vesicant), is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affe ...

blister agent A blister agent (or vesicant), is a chemical compound that causes severe skin, eye and mucosal pain and irritation. They are named for their ability to cause severe chemical burns, resulting in painful water blisters on the bodies of those affe ...

that was used during World War I in chemical warfare. The molecule is pyramidal with the Cl-As-Cl and C-As-Cl angles approaching 90° (see image). Ethyldichloroarsine has high chronic toxicity, similar to lewisite.

References

{{Chemical warfare Arsenical vesicants Organoarsenic chlorides