SAN FRANCISCO, MAY 31 -- In a severe blow to drug-testing in the workplace, the California Supreme Court today rejected attempts by employers to force workers to submit to random tests to detect the use of illicit substances.

The justices, in a brief order, let stand two appeals court rulings that declared employees, both public and private, are protected by the state constitutional right to privacy from being dismissed solely for refusing to submit to random drug tests.

In both instances, the lower court held that the state privacy guarantee applies not only to governmental actions but to those of private employers as well.

In one case, a state Court of Appeal in San Francisco held that a worker in a job that was not safety-related could not be required to take such a test and upheld a $485,042 damage award to a computer programmer who refused to provide a urine sample.

In the other case, a state Court of Appeal in San Bernardino allowed a chemical firm employee to sue for wrongful dismissal after he declined to submit to an eye-pupil reaction test to determine whether he was under the influence of drugs. Neither ruling applied to job applicants.

The court action, taken without dissent, makes both appellate rulings binding on trial courts statewide. Specialists in employment law said that as a result, employers, in order to have a legally valid program, will have to provide more specific reasons for testing, such as an employee's involvement in an accident or work in a safety- or security-related job. One attorney said the action sounded the "death knell" for random drug tests.

The justices' refusal to hear employer challenges to the appellate rulings came as something of a surprise. The court, now led by a moderately conservative majority, has proved much more receptive to business concerns than its liberal-dominated predecessor under former Chief Justice Rose Elizabeth Bird.

In a recent study, 12.1 percent of a sampling of employees in California tested positive for drug use. Only 3.5 percent of the workers in the 49 other states tested positive.