Hexachloroethane (HC) screening smoke grenades have been in use since World War II and while highly effective, Army scientists and engineers are looking for new compositions from which to form obscurants that balance performance, manufacturing cost, environmental impact, the availability of materials, and importantly, toxicity. HC toxicity is a result of the production of zinc chloride which is corrosive and astringent; and known to cause burning in the respiratory and gastrointestinal tract. It can damage nerve endings in the nasal passages and cause eye burns.
To address the above, Army researchers have identified lithium perchlorate (LiClO4) and boron as fundamental chemicals in a new smoke grenade. This composition has reduced toxicity that is produced without the use of organic liquids which add to air pollution. The composition produces boron oxide (B2O3) and lithium chloride (LiCl). A virtually undetectable amount of boron trichloride (BCl3) and chlorine gas may be by-products of the composition.
The grenades may be used by the military in battlefield situations or for training; and by the civilian sector for fire fighter training and crowd dispersal situations.
- Composition has a long shelf-life
- The ratios of the components in the composition can be varied in such a manner as to adjust the overall rate of the chemical reaction and create smoke beyond 120 seconds
- Additional coolants may be added to the composition to affect its burning rate as well as provide an added quantity of smoke by using the heat drawn from the main chemical reactions to vaporize and recondense the coolant materials
- The composition is suitable for pressing into canisters
- US patent 9,650,308 available for license
- Potential for collaboration with Army researchers