They are stockpiling food and water at the State Department, handing out "escape hoods" at the Pentagon and learning how to "shelter in place" at the Environmental Protection Agency.

As war looms in Iraq, federal agencies are girding against possible retaliatory attacks in Washington by honing protective measures put in place after the Sept. 11, 2001, terrorist strikes and adding a few new ones as well.

Like Americans armed with government-recommended duct tape and plastic sheeting, the agencies are getting some guidance from the administration. The color-coded Homeland Security Advisory System, for example, directs officials to take certain steps as the risk of an attack rises, such as increasing surveillance at buildings, dispersing workers to alternate sites and, in an extreme case, closing government facilities.

For the most part, however, each federal agency is on its own in crafting safety plans, training employees for an emergency and deciding whether to buy gas masks and other protective equipment. Much of the planning has taken place in secret, with officials saying that disclosing security measures -- even, in some cases, to employees -- would assist terrorists.

"[I]t is very likely that numerous steps have already been taken to secure your building that are not subject to open discussion," Kay Coles James, director of the Office of Personnel Management, wrote in a new eight-page federal employee emergency guide posted on OPM's Web site last week. "Trust your manager -- this information may be held more 'tightly' to better protect you from individuals who may seek to cause harm."

Nowhere is such information more closely guarded than at the Justice Department and the "White House Complex," the sealed-off stretch of Pennsylvania Avenue that also includes the Treasury Department and the Eisenhower Executive Office Building.

"We can't discuss what we're doing other than to say we are preparing," said Mark Corallo, a Justice Department spokesman. "We wouldn't want to let the bad guys know what we're doing. Obviously, since September 11 we have been at a heightened alert level, and those contingencies are being reinforced."

Marc Connolly, a spokesman for the Secret Service, which is responsible for deterring terrorism around the White House, said most measures are not visible to the public. "We have been and continue to be operating at a heightened state of alert," he said, declining to provide specifics. Some security steps around Washington are obvious to everyone -- the metal fencing around Lafayette Park, the concrete barriers encircling the Capitol, the Washington Monument and many agencies, the extra guards at building entrances and the need to display photo identification to get into many federal buildings.

The new Department of Homeland Security recently drafted an emergency protocol for the capital area. The plans range from partially evacuating a single federal building, to a staggered evacuation and lockdown of surrounding areas, to a government shutdown like the one during the 2001 terrorist attacks. Last month, 80 chiefs of staff from the executive, legislative and judicial branches were briefed about phased evacuation plans for 350,000 federal workers.

John Irvine, a spokesman for the American Federation of Government Employees, said the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City crushed the feeling of workplace security that many federal employees had enjoyed. The Sept. 11 attacks compounded the sense of vulnerability, but both incidents spurred dramatic improvements in safeguarding federal offices, he said.

"With what's going on currently, security is good at these buildings," Irvine said. "At the same time, federal employees to some degree are targets just because of where they work."

With that danger in mind, agency officials and their employees are doing what they can to prepare for possible terror strikes.

At the Department of Agriculture, a new "pop-up" instant messaging system can warn employees of an emergency by overriding whatever is on their computer screens, said Alisa Harrison, a department spokeswoman. The USDA also has distributed a family emergency preparedness guide to all 8,000 of its employees in the Washington area. And it has conducted several fire drills in recent weeks -- and one real evacuation when a fire broke out in a machinery room.

Officials at the Department of Labor, the Department of Commerce and the Department of Health and Human Services said they, too, have practiced evacuating their buildings in recent weeks.

At the EPA, federal workers are learning how to hunker down in their offices, which is said to be the safest course if terrorists release chemical, biological or radiological agents into the air outside. During one such sheltering-in-place drill, however, an intentional power shutdown triggered a fire alarm that told everyone to get out of the building, leaving employees confused about whether to stay or go.

"This is exactly why you do these drills," said Joe Martyak, an EPA spokesman. "So that you can see what happens in these situations and you are able to pinpoint those issues that need to be changed. And then you take corrective action."

The Defense Department has purchased 80,000 "escape hoods," at $150 apiece, to protect employees and visitors against chemical and biological attacks. The hoods, which are packed in vacuum bags and can be used only once, are being distributed at the Pentagon and 46 leased buildings in the area. The Pentagon lost 125 service members, civilian employees and contractors in the Sept. 11 terrorist attack on the building.

At the State Department, officials have stockpiled food and water and devised response plans for fires, bomb threats, terrorist attacks and what are termed "white powder incidents," an official said. Gas masks are being provided to diplomatic posts overseas, and the department is considering whether to pass them out in Washington.

"There's been a heightened awareness for some time, probably since September 11," said the official, who spoke on condition of anonymity. "Obviously, possible conflict with Iraq raises concern, without question. But given the culture of the State Department -- we've had embassies bombed, and with the attack on the Pentagon having happened so close -- it's something that we're obviously very sensitive to."

Months before the current conflict, some federal workers said they had begun taking steps to prepare themselves, such as keeping a flashlight and bottled water at their desks, wearing comfortable shoes in case they had to walk home, exercising more and paying attention, for a change, to fire alarms.

One employee at the Securities and Exchange Commission said he keeps a cell phone in his pocket and a folding bike in his car, though he uses them "even on days without a terrorist attack."

A worker at the EPA, who said he has training in hazardous materials, said that at his office he keeps rubber boots, neoprene gloves, a full-face mask with breathing cartridges to last eight hours, two rolls of duct tape and full body covering.

"I'm only four blocks from the White House," said the employee, who asked not to be identified. "It just makes prudent sense to be protectively cautious. Now, did I go overboard? Maybe, maybe not. I just don't want to go out in a really nasty, bad way. . . . I just think it's a matter of time before someone does something stupidly crazy here."

At the Pentagon, trainer Tim Czysc instructs military and civilian employees in the use of escape hoods in case of chemical, biological or nuclear attack. A street by the Capitol is one of several District roads closed as a safety precaution. Still other defensive measures are being taken in secret.