Fire suppression and explosion protection have used halons in many applications because they are electrically nonconductive, dissipate rapidly without residue, are safe for limited human exposure, and are extremely efficient in extinguishing most types of fires. However, they have a very strong Ozone Depletion Potential (ODP). The Montreal Protocol on Substances that Deplete the Ozone Layer was designed to reduce the production and consumption of ozone depleting substances in order to reduce their abundance in the atmosphere, and thereby protect the earth’s fragile ozone Layer. Many international organisations like the United Nations Environment Programme (UNEP) have mandated earliest production and import phase-out of halons. Substitutes are reviewed on the basis of ozone depletion potential, global warming potential, toxicity, flammability, and exposure potential.