Lewisite (L)

Other Names

L, EA 1034, Ruisato


The arsenical vesicants are a group of blister agents in which arsenic is the central atom, as opposed to sulfur (H, HS, HD) or nitrogen (HN).

Lewisite is a liquid with an odor similar to geraniums and very little odor when pure. L warns of its presence by irritating the eyes and skin and has a rapid rate of action. Liquid L causes immediate burning sensation in the eyes and permanent loss of sight if not decontaminated within one minute with large amounts of water. It has about the same blistering action on the skin as does mustard (HD), even though the lethal dosage for L is much higher. Skin exposure to L produces an immediate and strong stinging sensation; reddening of the skin starts within 30 minutes. Blistering does not appear until after about 13 hours.


Chemical Agent Identification Sets (CAIS) Information Package (1995)

TM 9-1904, Ammunition Inspection Guide (1944)