This is the drill if you are a visitor to the industrial-looking plant that sits in the high desert, between low mountain ranges, in northern Utah, about 30 miles south-east of Salt Lake City. As a welcoming ritual, it is a little frightening. But then so is almost everything about this place, properly known as the TOCDF, or the Tooele Chemical Agent Disposal Facility.
Within minutes we are ushered into a complex that is a monument to one of two things, depending on your point of view. It is either a monument to the American government's determination to help rid the planet of one of the most lethal legacies of warfare in the 20th century, or one to its arrogance in rushing hell-bent into using a new technology, which, if it proves flawed, could visit silent death on hundreds of thousands of Utah residents.
Eerily reminiscent of a James Bond set, the TOCDF is Washington's response to the Chemical Weapons Convention, signed in Paris two years ago. It is a series of high-temperature incinerators into which the Army is preparing to toss an array of weapons - rockets, bombs and missiles - containing nerve agents and mustard gas.
Last week, the last layers of secrecy surrounding the plant were lifted when the Pentagon declassified the extent of its stockpile of chemical munitions. It has 30,000 tons of chemical agents and is undertaking to destroy all of it by 2004, at a cost of $12bn. Forty-four per cent of that stockpile is at Tooele - 1.1 million chemical weapons, mostly stored in concrete bunkers across 19,000 acres adjacent to the plant. The remainder is kept at nine other sites across the United States.
Simply leaving the weapons stored here is not an option. Even in this desiccated climate, they are deteriorating and, occasionally, spilling open. Only a week ago, five M55 rockets were discovered leaking their loads of deadly VX liquid, an oily form of the sarin agent. Two years ago, 80 gallons of mustard gas poured from a tank stored above ground and out in the open.
But the US Army, which is responsible for the plant, is engaged in a furious public relations struggle to convince doubters that incineration is the best method for disposal. The controversy has contributed to several delays in the start-up of the facility. The Army hopes now to fire up the plant on 15 April, but even that target is in doubt. Only when it has done so, and begun to prove the new plant's viability, can the Army hope to gain public support to begin construction of similar ones at the other stockpile sites.
The project's greatest foe is Steve Jones, who was hired to monitor safety and security at Tooele until he was sacked in September 1994 because of "irreconcilable differences" with the management of EG&G, the civil contractor hired by the Army to set up and run the facility. Mr Jones has turned whistle-blower against the government, alleging that the Tooele incincerators are riddled with design flaws and could emit plumes of toxic gases. He contended last week that, in a worst-case scenario, such a plume could be blown 40 miles. That could mean as far as Salt Lake City, a city of 160,000 people.
Representing Mr Jones in a lawsuit against EG&G is Joanne Royce, of the Government Accountability Project, a support group for government whistle- blowers. "There is a lot at stake, because this will be the first plant to go 'hot' in the continental US," she said. "The other plants are dependent on their operating this one." Also campaigning against the Army is Craig Williams of the Chemical Weapons Working Group, which advocates developing alternative methods of dismantling the munitions and neutralising the agents inside them. "There is clear scientific evidence that the incineration facilities will emit toxic materials that will impact on the environment and on public health," Mr Williams said. "It clearly indicates the high potential for the release of some of the most toxic chemicals on the planet into civilian communities."
Toxic emissions have been recorded both at a prototype research incinerator already running on the Tooele site and at anoperational facility on the Johnston Atoll, a US territory in the Pacific where 292,000 chemical weapons are stored. But according to Dave Jackson, second-in-command at Tooele, none of the leaks posed a threat to civilian populations. He also contends that medical treatment has never been sought, even for those operating the two plants.
An earthquake is probably the most serious threat to the Tooele facility. Even then, Jackson ridicules Mr Jones's suggestion of a 40-mile plume stretching to Salt Lake City, arguing that any emission even spreading beyond the depot's boundaries is most unlikely. "That is highly ridiculous," he retorted. "Could a freak tornado whip through the facility, pick up a missile and drop it on the city? I suppose you could argue that that is a credible scenario."
On a grand tour, we are taken to the central control room, a emporium of computer monitors that reminds one of Nasa's Mission Control in Houston. A test run is being conducted with surrogate agents. Still nervy, we jump when a siren suddenly goes off at one of the monitors. The operator reassures us that it is nothing serious; something to do with pressure rising too fast. He taps in an instruction to rectify the problem and inadvertantly strikes a wrong key. The monitor flashes up something unexpected. He looks at it and, bewildered for a moment, exclaims: "Ooops!"