Correction: An earlier version of this story incorrectly stated that the D.C. schools have no plans for random drug tests. They will begin in the fall.

Nine years after a District law mandated that public employees who work with children or hold safety-sensitive positions submit to random drug testing, the D.C. public school system has yet to heed it.

The D.C. Office of the Inspector General condemned the lack of a testing program in a report issued last month that said the school system had not tested any of more than 8,200 employees subject to the law.

It was the inspector general’s second warning since April 2012. In response, the school system told teachers and other employees that, starting in 30 days, they will be subject to testing when drug or alcohol use is suspected; when substance abuse may have caused an on-the-job accident; or when an employee returns to work after treatment for drug or alcohol abuse.

The school system will begin random testing in the fall, according to an e-mail from spokeswoman Melissa Salmanowitz.

A 2010 policy drafted after the drug-testing law was adopted in 2004 makes clear that city agencies are expected to conduct random tests covering every employee who works with children.

“We are in compliance with the program,” Salmanowitz said.

Few school districts in the country mandate random drug testing for teachers. Linn Goldberg, a doctor at Oregon Health and Science University who has researched drug testing and drug-use prevention in educational settings, said random testing is rarely useful for school employees.

“What are the reasons for doing a program that’s going to cost a fair amount of money? Certainly . . . in a job where you’re dealing with children, you don’t want people who are on drugs,” Goldberg said. “But teachers are among the lowest users of drugs of any population.”

Godlberg said drug testing in schools poses numerous logistical challenges, such as whether to shut off the water in bathrooms so test subjects can’t dilute their specimens and whether to hire substitutes to step in when teachers are called out of class for random testing.

“If your idea is, we want an environment where drugs are not used, what are you getting at? If the teachers are not on drugs, the kids won’t be? Fat chance,” Goldberg said.

The inspector general’s report, released late last month, found fault with many other agencies among the 16 covered by the law on mandatory drug testing. But no other agency employs anywhere near as many safety-sensitive workers as the school system, and none of the others had completely failed to implement a testing program.

The report faulted the fire department for posting unclear regulations on whether employees will be dismissed if they test positive for alcohol on the job. And the Department of Youth Rehabilitation Services tested 79 percent of eligible employees for drug use in 2012, but it neglected to conduct any alcohol screenings.

The Child and Family Services Agency’s record was similar to the schools’: One of the agency’s 550 safety-sensitive employees was tested last year.

In total, the city employs more than 13,000 people in safety-sensitive jobs. Almost half of them were tested for drug use in 2012, and nearly 3 percent of the tests were positive.

Most of the tests were not random, including pre-employment and post-accident screenings, tests resulting from a supervisor’s suspicion, and tests of employees returning to work from drug or alcohol treatment. Of more than 2,200 random tests conducted last year, 1.7 percent were positive.

The agencies covered in the inspector general’s report are required to inform the inspector general’s office when they achieve compliance. Deputy Inspector General Blanche Bruce declined to say whether there is a deadline.