Riot control grenades take two primary forms, chemical and kinetic. Chemical riot control grenades are designed to emit fumes that irritate or disable to the extent that they prevent persons from carrying out a chosen course of action, i.e., they quell rioters. The primary requirement demanded of such agents is that they irritate or disable and do no permanent damage.
For many years, the chosen irritant agent in riot control was tear gas. This relatively harmless substance does little more than bring tears to the eyes and impart a general feeling of choking and helplessness. Tear gas is now generally known as CN, but its proper chemical name is alpha chloroacetophenone.
Easily dispersed riot control grenades
The most significant failure of tear gas soon discovered once it had entered service as a riot-control agent was found to be that in the open area, its vapor cloud generally dispersed so readily and so quickly that the tear gas mist easily lost its disabling properties. Tear gas was also relatively easy to tolerate, especially after some experience of the substance, and many fit young people could, therefore, carry on their disorderly activities after exposure to CN with only a minimum of inconvenience.
Inside a building, it was often another matter entirely as the wall, roof, and floor of the building helped to contain the tear gas mist at a concentration that was still incapacitating, but in the open tear gas east soon seen to be relatively inefficient in its primary task as an anti-riot weapon.
During the early 1950s, therefore, a new and more effective, and persistent agent was demanded as a successor to tear gas. This led to the suggestion that e new chemical, rejoicing in the chemical name of orthocklorobenzalmalononltrile, be employed as an alternative to tearing gas with superior disabling capabilities.
It was not long before this new substance was given the handier appellation CS. CS usually is a solid substance, but on contact with air forms a white or light grey vapor cloud with a general odor of pepper, and, for this reason, CS is sometimes known as pepper gas. He vapor can induce the usual tears, but with the addition of a general choking sensation and a difficulty in breathing. The effect is distinctly unpleasant, and experience has revealed that high concentrations of CS can cause nausea and vomiting.
To add to its effects, CS can be persistent, especially if vapor droplets adhere to clothing. CS is not disabling, however, and there are no long-term physical effects. CS was first used during the late 1950s and was soon a remarkably efficient method of breaking up mobs. At first, the prime way of delivering the agent was the hand grenade, in precisely the same fashion used previously for tear gas and smoke.
While these riot control grenades were easy to manufacture and use, they suffered from the same drawbacks as the earlier grenades: it took time for the vapor cloud to build up, the range was limited by the strength of the thrower (who thereby came well into missile range of the offending crowd), and the grenades could readily be picked up by an adventurous rioter and thrown back. A redesign of the primary CS grenade has therefore taken place.
New grenade design
Modern CS grenades nearly all contain small multiple containers or pellets to emit the CS fumes. As it lands, the grenade body scatters these small containers or pellets (the British L11A1 grenade releases 23 pellets, for example) over a wide area, and the emission period is usually short so that any container or pellet is thrown back by a rioter has little or no effect.
The other design point is that it is now infrequent for CS grenades to be thrown, for they are generally projected using a small propellant charge from a launcher to a range of 100 m (110 yards) or more launcher, usually being some riot gun.
When riot guns are used, the usual diameter of the grenade is 37-mm (1.456-in), but this is now generally regarded as being too small, and the British army has opted for a grenade diameter of 66-mm (2.6-in) and uses a specialized launcher, the Grenade Discharger L1A1, rather than a riot gun to fire the grenade. CS is not the only modern form of irritant agent, but it is certainly the type that is most widely used.
Other irritant agents include mild hallucinogenic agents that impart a temporary feeling of panic or fear. Still, the use of such agents is disapproved by many on humanitarian grounds, and such weapons may thus be of the double-edged type, generating adverse publicity of more significance than any real advantage gained on basic riot-control terms.
Moreover, some of these ‘mind’ agents have a nasty habit of being just as effective on their users as on their intended targets, even when a respirator is being used. Most police and para-military respirators are limited in their effectiveness, providing protection only against CS and CN. Some powerful modern agents could overcome the protective properties of such equipment.
Kinetic riot control grenades
Humanitarian considerations also come to the fore when kinetic riot control grenades are considered. These are usually the baton rounds or the infamous rubber bullets that are used to disable by stunning.
Kinetic projectiles of this type were first mooted during the 1950s when it started to become clear to authorities in several countries that the last-ditch but yet effective control of riots demanded not conventional firearms, whose use would lead to severe wounds and deaths, and therefore to a mass of adverse publicity, but rather something more powerful than the standard irritant agents in use at that time.
At first disabling missiles of several types were considered, these ranging from a lead shot in thick bags to heavy rubber rings. Such munitions were usually fired from ordinary riot guns, but it was not long before the baton round in its present form appeared. At first wooden projectiles were used, but these were soon discarded as they were prone to splintering and causing the type of nasty wounds that drew adverse publicity.
Then for some time, rubber was used before it was discovered that under certain circumstances, rubber was also likely to cause injuries that were too severe. The current baton rounds are flat-ended PVC slugs that are not as heavy as rubber but are nonetheless expected to impart a decisive blow on the recipient.
It cannot be denied that baton rounds can cause severe injuries if used at very close ranges and have also caused many deaths. They are also wildly inaccurate and often have to be used as area weapons rather than point target weapons. But around this type can prove effective in breaking up hostile crowds, and when used with extreme care, they can even disable ringleaders of a riot or other troublesome individuals.
They can undoubtedly keep crowds out of hand-thrown missile range. Despite this, the use of baton rounds has often resulted in a tremendous public outcry against their employment. But in the absence of anything better, the baton round is an established anti-riot munition.