Deadly Surprise.

• Author: CHARMAN, KAREN
• Position: Possible chemical disasters

Will Y2K cause chemical disasters?

HERE'S A SOBERING THOUGHT: AT least 85 million Americans live within five miles of a facility that handles toxic chemicals. And there is no information on what steps a huge number of these companies have taken to ensure they won't have catastrophic accidents because of Year 2000 computer bugs lurking in their operations.

The 1984 Bhopal disaster demonstrates how bad an accident at a chemical plant can be. Forty metric tons of methyl isocynate, a highly toxic organic chemical used to produce pesticides, were released into the air at the Union Carbide plant in the densely populated city of Bhopal, India, after water got into the tank and reacted with the chemical. Two thousand people died and 100,000 were seriously injured. Ten years after the event, 50,000 remained partially or totally disabled, according to the International Medical Commission on Bhopal.

Could the Y2K bug cause similar disasters here? The answer appears to be yes. The larger multinational companies have made a serious effort to discover, test, and fix their Y2K bugs, according to Gerald V. Poje, a member of the U.S. Chemical Safety and Hazard Investigation Board. But there is little information about how--or whether--vast numbers of small and medium-sized companies that manufacture, process, handle, and/or dispose of toxic chemicals are dealing with the task. More disturbing yet, Poje, who sits on the government body charged with both investigating chemical disasters and working with industry and communities to prevent them, said nobody even knows exactly how many of these companies exist or where they all are.

As almost everyone knows by now, the Y2K bug itself is a simple mistake. Computer programmers abbreviated the date in their computer codes so that, say, 69 was understood to mean 1969. When the date rolls over to 00 at the end of this year, computers won't know it is 2000, not 1900, which could cause them to malfunction or crash. The glitch resides in billions of lines of mainframe computer code, numerous personal computers, and an unknown but substantial percentage of the world's 20 to 70 billion microchips, fingernail-sized stand-alone computers "embedded" into everything from nuclear missiles, cars, and traffic lights to pacemakers, coffee makers, chemical plants, and reservoirs.

How could Y2K cause a chemical disaster? Computers run the "distributive control systems" that keep vats of volatile chemicals swirling at the appropriate levels of flow, pressure, and temperature at most plants. At midnight on January 1, 2000, a chip that failed to recognize the date could freeze or "zero out," causing the whole computer to stop working. The chemicals would no longer be circulating safely, and if there were no backup systems (or if they too failed) an "uncontrolled reaction" might be the result. "That could generate its own heat and pressure," as one engineer puts it, which might soon be too much for the vessel containing the chemicals. They could spill out, and turn into vapor. If the chemicals were highly flammable, like natural gas, styrene, or toluene, they could ignite, causing deadly fires or explosions.

Engineers insist that this scenario is extremely unlikely, because someone would be on hand to help, and most spills would be funneled off by safety valves before they became a real danger. Still, they are possible, especially because the Y2K bug exists on so many chips and could cause multiple simultaneous failures. The only way to be sure they won't occur is to remove the bug--and that is far from easy.

Consider the task facing a medium-sized chemical company, which typically has 8,000 computer programs with 12 million lines of code, according to Dennis Grabow, who has written on the Y2K problem for Chemical Engineering magazine. Since one out of every 50 lines contains a date, that works out to about 240,000 lines of code that must be changed. For smaller...