British medical and security experts are evaluating the impact of the secret gas Russian security forces used to end the hostage crisis Saturday in Moscow. Based on reports of what the gas did, the experts think it may be a gas developed during the Vietnam War.
Russian authorities have refused to identify the gas used to end the Moscow hostage standoff with Chechen rebels.
But British experts think the intoxicant may have been a gas called BZ, or something very much like it. BZ gas was first produced by the U.S. Army during the Vietnam War.
"It is an agent, which disorientates," said Alastair Hays, professor of chemical pathology at the University of Leeds in England. He said the symptoms displayed by the freed hostages are similar to those caused by BZ gas.
"It has an effect on the brain to sedate people and later on to cause hallucinations," he said. "But it also affects them physically. It makes people restless. It affects their ability to walk, so they become uncoordinated. It can cause vomiting. And it will increase the heart rate very markedly."
Mr. Hays says the Russians may have felt they had no choice but to use a powerful, knockout gas, though he says they could have done more to save lives afterward.
"The Russian authorities were faced with a very difficult situation. Nobody denies that," he said. "The choice of BZ, some people may indeed question its use. But certainly what could have been done ... to have limited the number of deaths, would have been to get people out quickly, and [tell] what [gas] had been used. This is the treatment that these people need to receive, and that could have been done straight away."
Russian doctors have been appealing to security forces to know the nature of the gas used, and the antidote, if any. BZ gas has no antidote, but certain drugs can alleviate its effects.
Security experts say it would be illegal to use BZ or similar gas in combat under treaties Russia has signed to ban chemical and biological weapons. They say its use in a hostage situation falls into a gray area of international law.
The most recent reported use of BZ gas was by Serb forces against Bosnian and Kosovar fighters during the Balkans conflict in the 1990s.