SAN JOSE, Calif. -- Playing on concerns about workplace injuries, a growing number of office equipment manufacturers are using inflated and sometimes inaccurate claims to sell products, experts say.

The latest buzzword is "ergonomics," the science of making equipment fit people safely. Many manufacturers say their products are ergonomically correct without any research behind the claim, specialists in the field say.

There aren't any legal standards for what can be called ergonomic. And many people who call themselves experts don't have any formal training in ergonomics, an interdisciplinary field that includes engineering, biomechanics, medicine and industrial psychology. Scientifically trained consultants are only now establishing a national certification program for people who want to call themselves ergonomists. In the meantime, anyone with a business card can claim expertise.

"There are a lot of snake oil salesmen," said David A. Thompson, an ergonomics consultant and professor emeritus at Stanford in industrial engineering. "There is no authorized label, no holy water you can sprinkle on chairs and say it's ergonomic."

The proliferation of new devices with an ergonomic label comes in response to a giant increase in repetitive motion injuries nationally -- from 18 percent of all workplace illnesses in 1980 to nearly 60 percent in 1990.

Such injuries are often caused by computer work or other repetitive tasks in the office or manufacturing areas.

Employees have begun suing their companies and manufacturers for poor equipment design. And there's been an increase in government regulation, including a new San Francisco VDT ordinance that requires adjustable work stations, regular breaks and training on safe use of video display terminals.

"Employers have a lot of pressure on them to go out and purchase all this new equipment," said Tami Carver, program director at the Repetitive Motion Institute at Santa Clara Valley Medical Center in San Jose. "There is good and bad. Often the consumer doesn't have the knowledge to sort it out."

Some equipment manufacturers agree with the criticism. The term ergonomic "is being abused greatly," said Drew Congleton, an owner of the Chair Works, a Texas firm that sells chairs for people with back problems. "Most chairs are made by architects or interior designers concerned about appearance with no ergonomic background," he said.

But others said they are being criticized for experimenting in a new field.

Repetitive strain injury "is such a new problem and getting worse by the day, they [the experts] don't know what the answer is," said John Lechman of Nova Office Furniture Inc., designer of a work station that has been criticized by ergonomic experts.

Not everyone selling ergonomic equipment is a charlatan. Some excellent equipment has been developed by firms that have invested in ergonomic research -- in some cases because they want to sell computer products in Europe, where some countries have developed strict legal ergonomics standards. Other companies have had more mixed results in adopting the latest ergonomic research.

But a sizable group has simply slapped a new label on their products as a marketing tool in the United States, where only general voluntary industry design standards exist, experts said.

False or exaggerated claims are common:

* In an attempt to profit from fears about computer radiation, some companies are touting computer screens to shield workers from electromagnetic fields. Such devices can block electronic charges that cause static electric shocks but not the electromagnetic radiation that has caused public concern, experts said.

One company that advertises such screens, Curtis Manufacturing Co. Inc. of Illinois, admitted that its promotional material was misleading and said it would change it after being contacted by the San Jose Mercury News.

Curtis Creative Director Greg Snarski said the company had tried to be "upfront and straightforward" in its claims but had not realized it had been provided incorrect information by a subcontractor that manufactured the screens.

* A number of supposed ergonomic solutions could actually injure workers, said Ms. Carver of Valley Medical Center. Wrist-rests are designed to cushion and support while the employee is typing on a computer keyboard. One wrist-rest now on the market is made of a thin plastic with a sharp seam on the end. It flips up when placed under the keyboard, and the sharp edge hits the user at the vulnerable median nerve, she said.

* And one European computer monitor manufacturer claimed the amber characters on its screens were much less fatiguing for the eye than green characters. But when Wanda Smith, a Palo Alto, Calif., ergonomics consultant, asked about the basis for the claim, the firm's marketing director confided he had merely called some general medical doctors and asked which color they liked best.

"More often than not, the ergonomic label is applied to a device without any backing for it," said Dr. David Rempel, director of the University of California's Ergonomics Laboratory in Richmond. "There is almost no testing of devices to see if they will be effective."

Mr. Thompson, the Stanford engineering professor, is discouraged by the uninformed efforts of manufacturers to meet the demand for better-designed equipment.

"It's not even bad science. There is no science at all," he said. "When I pin them down, they usually have a letter from some consultant who said he tried it out himself and found that of all chairs, this one was the most comfortable."

But if equipment and furniture manufacturers are coming out with poor designs, it isn't necessarily because they are unscrupulous. The science of ergonomics is so new that often the supposed experts disagree widely, and some solutions touted five years ago have been abandoned today.

For years, ergonomic design for such basic office equipment as desks and chairs was based on measure ments of white males in the military. As a result, many women and smaller people from varied ethnic backgrounds don't properly fit into equipment that is viewed as standard, like a 29-inch-high desk.

That lesson was brought home to Amdahl Corp. of Sunnyvale, Calif., when it decided to measure all manufacturing employees after receiving complaints of musculoskeletal strain.

The company found the equipment was much too large for its employees, who came from a variety of ethnic backgrounds. On average, they fell below the 2 percentile level of the physical range of sizes for which the equipment was designed.

Because everything from work tables to hand tools was too big, Amdahl has redesigned all of its equipment.

The results were dramatic. In one area where ergonomic equipment was first installed in late 1989, the incidence of new injuries decreased by 66 percent.