Employees who use drugs and alcohol pose a considerable risk to safety and productivity on the job. It's critical for employers to be proactive in their approach to substance abuse by establishing and enforcing a written policy that addresses the issue. Remedial action for policy violators may range from mandatory substance abuse counseling to suspension or termination. Employers should exercise caution and tact in approaching an employee who is suspected of using drugs or alcohol. Acting on hearsay alone isn't advisable. Visible signs of substance abuse may include impaired performance, erratic behavior, violent outbursts, slurred speech and an unusually haggard appearance. These characteristics also may signal certain medical and mental problems. Unless an employer or co­worker sees an employee using drugs or alcohol, the only way of knowing whether a person is under the influence is to administer a substance abuse test. This is usually done during pre­employment screening, but some employers conduct random drug tests without prior notice to ensure the accuracy of the results. The employee's identity and test results should remain confidential.