Burning-type grenades are usually fitted with igniting fuzes which function with a 1.2 to 2-second delay. Functioning of the fuze ignites the first-fire (starting) mixture which ignites the filler. The burning filler creates sufficient pressure to blow tape covering the emission holes (gas ports) free and allow the chemical agent (riot control gas, smoke) to escape.
WARNING: Burning-type grenades burn oxygen. Standard protective masks filter particles but will not supply oxygen. Therefore, burning grenades will not be used in enclosed or confined spaces.
Bursting-type grenades are fuzed with delay fuzes which contain high-explosive detonators. The detonators rupture the grenade body and disperse the filler (tear gas, white phosphorus). Although this type of grenade functions by bursting, it creates the same effect as burning grenades.
The current U.S. policy governing the use of CS and other riot-control munitions is found in Executive Order 11850, 8 April 1975. CS irritant gas (tear gas) may be employed in a combat zone with the approval of a higher authority. U.S. forces will employ CS in wartime defensively only to save lives as approved by the President. The Secretary of Defense may authorize the use of CS to protect and recover nuclear weapons. CS may be used on military installations (domestic and overseas), embassy grounds, and so forth, in war and in peace.
The U.S. and many other countries do not consider CS or other control agents to be chemical warfare weapons; however, some other countries do not draw a distinction.