chloropicrin

Chloropicrin, or trichloronitromethane, is a volatile chemical compound with the formula CCl3NO2. It is a colorless to pale yellow liquid at room temperature with a pungent, irritating odor. It belongs to nitro compounds and is primarily recognized for its strong lachrymatory properties.

Historically, chloropicrin was developed and deployed as a chemical irritant in World War I and was later used in some riot-control contexts. In modern times, its principal use is as a soil fumigant and pesticide, where it is employed to control a range of soil-borne pests, nematodes, fungi, and weed seeds. It is often applied as a volatile component in combination fumigants, sometimes alongside other gases.

Safety and regulation: Chloropicrin is highly toxic to humans in sufficient concentrations, causing tearing, coughing, sneezing, chest tightness, and, with higher exposures, severe pulmonary irritation and edema. It is corrosive to mucous membranes and skin. Handling requires strict safety measures, including protective equipment, controlled ventilation, and compatible storage. Its production and use are subject to international and national regulations, including restrictions under the Chemical Weapons Convention, and it is controlled as a hazardous fumigant with requirements for labeling, containment, and environmental protection.