Some key federal computer people are getting ready to take on the General Services Administration in a fire extinguisher fight.

Your next check from Uncle Sam is part of their ammunition.

Last year the GSA reaffirmed its long-standing mandate that sprinkler systems be used almost exclusively to protect federal computers from fire.

And recently GSA's accident and fire protection director, Or Miasch, said, "We are sold 100 percent on sprinklers."

The wisdom of that policy is being called into question increasingly by major federal computer users, particularly after the sprinklers at the Census Bureau's computer center in Suitland went off accidentally on Aug. 8. That incident cost the Census Bureau more than $200,000, and two of its major computers still are incapacitated. It has caused some federal computer officials to wonder if the answer to fire protection is a gas, Du Pont's Halon 1301.

The latest flooding of the Census facility, however, has not been water but an onslaught of computer operators from nearly every major federal agency who are interested in getting information to support the installation of Halon in their own data rooms, according to Census computer chief Thomas DiNenna.

The agency that writes nearly all government checks, the disbursements division of the Treasury Department, began its inquiry earlier this year into whether to use Halon.

Officials from the eight federal disbursement centers across the nation saw a demonstration of the Halon system in May at a meeting in St. Louis.

Since then, disbursements has begun a study -- due Dec. 15 -- on its entire computer security operations, including fire safety. One official said he expects the report will recommend Halon for any new buildings the agency might move into, but he doubts if the report would call for adding the system to present facilities.

Disbursements chief Robert Burrill said he's worried about sprinklers because they could "damage the equipment, damage the tape and the whole works."

Just the operation of the sprinklers alone could delay checks, although there are backup systems and duplicate files in most instances.

Census computer chief DiNenna said the problems caused by water in his computers are similar to what would happen if you used water to put out a fire in your television: rust, corrosion and shorts and, because water is a good conductor, electricity would be going places it shouldn't.

Because the sprinklers most often are activated when temperatures at the ceiling reaches 160 degrees Fahrenheit, damage may occur even before the sprinkler system reacts.

"By the time the sprinklers go off, we know that piece of equipment is gone," said Jack Barritt, a fire engineer of the National Fire Protection Association committee that writes computer fire safety standards for the national fire code.

Halon systems react faster than water because they usually are activated by smoke detectors, and Halon proponents say the substance doesn't damage the equipment.

But they remain in the minority of the leadership of the National Fire Prevention and Control Administration which wrote the GSA's bible on computer safety, the standard practice for the fire protection of essential electronic equipment operations, commonly known as RP-1.

In two pages giving the rationale for the preferred use of water, the report states water is the best protection against "major catastrophe."

Edwin West Jr., a NASA aerospace engineer and chairman of the NFPCA committee that wrote the report, said water prevents the rekindling of a fire by staying in place and removing heat, which Halon doesn't do. He also characterized Halon as potentially toxic, but a quick survey of major federal health agencies didn't reveal any instances where Halon gas had injured someone during a fire.

Ed Murphy, a spokesman at the Center for Disease Control in Atlanta, said the Navy had some studies showing that Halon could cause respiratory irritation, but he characterized the problem as slight.

West said the Census accident doesn't diminish the value of sprinkler systems because it was caused by human error. He said he has heard from investigators that the accident was caused by someone accidentally turning on a water valve and because sprinkler heads that should have stopped the flow of water in the absence of heat hadn't been installed properly.

Most computer fires have started outside of the central unit. There are documented cases of arson where a fire has started in an adjacent room.

The GSA's major objection of Halon appears to be cost. Halon systems usually cost nearly double water sprinkler systems. Halon also has to be recharged after every use, and one official said there is no way to test the system without depleting the gas.

Those who promote Halon contend, however, that the extra cost -- amounting in the low tens of thousands -- is worth it to protect a million-dollar computer.