WASHINGTON (AP) _ Lie detector tests are administered to 2 million American workers in private business every year, but bipartisan support is building in Congress for legislation that would end their use in the workplace.

Businesses ranging from banks, retailers, computer companies and hotels to drug manufacturers and jewelers use the tests in an attempt to screen out dishonest workers and to apprehend employees who have committed crimes.

Company executives say polygraphs are one tool in efforts to reduce employee theft costing billions of dollars annually. By one estimate, employee theft raises the cost of goods to consumers by as much as 15 percent.

Even proponents concede, however, that polygraphs are not totally reliable. The Congressional Office of Technology Assessment says error rates range up to 50 percent when the devices are used in hiring workers.

Pre-employment screening accounts for 75 percent of the use of lie detectors, according to the American Polygraph Association. Some critics estimate that at least 50,000 workers a year are wrongfully denied employment, either because they refuse to take the exams or because of inaccuracies in the testing.

Abuse of the devices is rampant, says the 13.2 million-member AFL-CIO.

''Polygraphs have become vehicles for employee intimidation, and for screening out employees of political or union beliefs different from those of a particular manager,'' adds Rep. Pat Williams, D-Mont., who predicts the House will vote this year on his bill to prohibit use of the tests in the private sector.

One reason for growing interest in the issue of lie detector tests is that polygraph use in private business has increased four-fold in the 1980s.

Williams' legislation got an important boost in the Senate last month when Sen. Orrin Hatch, R-Utah, declared his support for it. Hatch and Sen. Edward Kennedy, D-Mass., introduced their own version of the Williams bill.

The House bill has 164 co-sponsors, including 26 Republicans.

Courts almost uniformly refuse to admit lie detector test results as evidence of guilt or innocence and ''it is time we extend the same basic protection to workers which we offer hardened criminals,'' says Rep. Jack Kemp, R-N.Y., one of the bill's Republican supporters.

Hatch, chairman of the Senate Labor and Human Resources Committee, ''believes there is far too much polygraph abuse for Congress not to move to protect working men and women in this country,'' says Irene Forde-Howard, a committee spokeswoman.

''There's no question that in some situations the polygraph is used to weed out key organizers in our campaigns and to ferret out people who would be inclined to join a union,'' said Mike Tiner, a lobbyist for the 1 million- member United Food and Commercial Workers union, one of the AFL-CIO's largest affiliates.

More than 20 states and the District of Columbia prohibit or limit the use of polygraphs in private employment under most conditions. However, workers in states that prohibit use of polygraphs frequently are shuttled across state lines to an adjoining jurisdiction that allows them, say critics, who add that states prohibiting the tests often are lax in enforcing the law.

The U.S. Chamber of Commerce is launching a counter-attack to the legislative effort.

Chamber officials say polygraphs are vital in a number of places, including the pharmaceutical industry. The Drug Enforcement Administration estimates that 1 million doses of legally produced drugs are stolen and illegally distributed each year, killing and injuring more than twice as many Americans as illicit drugs.

One hotel chain, Days Inn of America, says using lie detector tests for the past decade has helped reduce annual internal losses from more than $1 million to $115,000 and that more than $1 million in restitutions have been made by employees since the company started using the devices.

''Given the severity and growth of problems of employee theft and crime, ... we don't see the logic of taking away one of the weapons that employers and security agencies have to prevent that,'' says Mark A. de Bernardo, manager of labor law at the chamber.

Polygraph machines identify honesty as well as dishonesty, says the chamber, arguing that lie detector tests are often used to shield innocent employees from false accusations of misconduct by colleagues.

Opponents of the bill say the states, not the federal government, should regulate their use.

Industries staunchly opposing the legislation include the American Trucking Association. The ATA says in a recent statement that prohibiting polygraphs would make it ''vastly more difficult for employers to verify safety records, drug and alcohol abuse records and criminal records of employees.''

Many of the largest corporations, however, don't use lie detector tests and are not involved in the fight against the legislation. Many of them are better able to afford costly, in-depth background checks. Many fast-food chains don't use polygraphs either, saying they want to promote a family atmosphere with their employees.

Congress voted overwhelmingly earlier this year, in the aftermath of the Walker spy case arrests, to permit the use of lie detector tests by firms that operate in the national security and defense area. Williams' bill would not apply to state and local governments and lie detectors still could be used in police work.

The critics, however, say the devices should be barred from the workplace.

''Many employers use polygraphs as a cheap $25 or $40 substitute for good personnel practices such as checking backgrounds, references and educational backgrounds,'' says Jay Harvey, a lobbyist for the AFL-CIO's Food and Allied Service Trades Department.