Made Infamous in FBI Waco Raid, CS Tear Gas Hovers at Legal Fringe

CS tear gas is outlawed on the battlefield. It can also be lethal, especially when used against children. Yet federal agents fired 400 football-sized canisters of the gas into the Branch Davidian compound near Waco, Texas, in an effort to end the 51-day standoff with the religious group.

The 1993 Chemical Weapons Treaty, which banned CS gas ''during wartime,'' was signed by the United States in January 1993. That was four months before the FBI's final raid on the Branch Davidians. Today, experts say the reasons for banning CS gas are compelling.

Robert Cortese of Cortese Armaments Consulting in Philadelphia, who worked for the Federal Labs in Strasborough, Pa., relating to riot-control agents, says: ''If it is used as recommended, there will be no problems.''

But he adds: ''Complications arise depending on the health of the individual and mixing the CS gas canisters with other compounds, or using it in enclosed areas like it was done in Waco.''

Developed by the British in the 1950s and used liberally by the US during the Vietnam War, CS gas is usually nonlethal but temporarily incapacitates the effected individual. In 1966, the New England Journal of Medicine detailed the effects of CS gas, while warning that high concentrations of the gas could prove lethal, especially, ''with the very young, the very old, and the very sick.''

Field manuals from the US armed forces warn that CS gas should not be used indoors, except in ''extreme emergencies.''

''Using the gas indoors aggravates the effects, because incapacitation lasts until the individual is removed to fresh air,'' explains Cortese. According to a Federal Labs study, for instance, ''A hazardous overdose could be created by the release of ... even one full-sized grenade in a closed room.'' At Waco, the FBI used 400 canisters.

House hearings will also try to discover the cause of the fire that consumed the Waco compound. In Cortese's view, ''The fire at Waco was not set from outside or by the inmates from the inside. It was a result of the explosions of the CS gas canisters around highly inflammable materials that were stockpiled and the wooden structure was like fuel to the fire.''

Attorney General Janet Reno testified that she was unaware of the existing international ban on CS gas when she approved the FBI's April 17, 1993 request to use it in Waco. She said the FBI gave her a British study that found that CS gas had made babies cry, but had no lasting effects. The joint House subcommittee on Waco has since learned that federal agencies deliberately withheld part of the information relating to the effects and status of the CS gas.

The Waco experience points to the difficulties of universally applying the 1993 Chemical Weapons Treaty resolutions.

Amy Smithson, a chemical weapons expert at the Stimson Center in Washington, says, ''The treaty bans the use of CS gas as a method of warfare. But its use in riot control has been very effective, if you go by the experience of the '60s and '70s. In a situation where a riot is developing, the police would not want to use lethal force, like batons,'' which might cause injury, she says. CS gas ''is only dangerous when it is used indoors and the canisters come with warnings against such usage.''