Felons, including sex offenders, are allowed to work as substance abuse counselors in California because of lax rules, according to a new report.

The state Senate Office of Oversight and Outcomes found California does not require criminal background checks for drug and alcohol counselors. Applicants are not required to report their criminal histories, the Los Angeles Times reports.

At least 23 sex offenders have been allowed to work as substance abuse counselors since 2005, the report found. “Almost all other large states want to know about serious convictions before credentialing drug and alcohol counselors, even if the disclosure doesn’t automatically disqualify them,” the report notes.

There are an estimated 36,000 registered or certified substance abuse counselors in California, and that number is expected to grow as more people gain health insurance under the Affordable Care Act. Although counselors must be registered with or certified by one of seven private organizations in the state, they can continue working even if they have their registration or certification revoked, by signing up with a different organization, the report found.

The report recommends the state be put in charge of credentialing counselors. An alternative would be to require certifying organizations to perform background checks.

David Peters, a spokesperson for the California Association of Addiction Recovery Resources, one of the certifying organizations, said his group supports background checks. He noted many people become counselors while in recovery from addiction, and cautioned against disqualifying someone simply because they have a criminal history that includes drug use.