Terrorists could deliberately release chemicals that poison people, animals, plants, or the environment. Chemical “agents” can be delivered in various forms—vapors, aerosols, liquids, and solids—and by a wide variety of methods, including sprays and bombs.
Chemical agents can produce effects quickly (within a few seconds) or slowly (as much as two days after exposure), and some are odorless and tasteless. It is difficult to deliver chemical agents in lethal concentrations, and—outdoors—agents often dissipate rapidly.
150314-M-XX123-417 Photo by: Lance Cpl. William Hester