Lewisite is a chemical compound that was developed as a chemical warfare agent during World War I. It is classified as a blister agent, meaning it can cause severe skin and eye irritation, as well as damage to the respiratory system. Lewisite has a distinctive odor similar to geraniums, which can help in its detection. The compound is a member of the arsenic family, and its chemical formula is C2H2AsCl3. Although it was never used in combat during WWI, it has been stockpiled by various countries. Today, efforts are ongoing to safely dispose of any remaining stockpiles to prevent potential misuse.