Is drug testing legal?

Drug testing is allowed under the following circumstances: All employees of the same position are tested, and the applicant is given advanced notice before the test is given. Further, drug tests can only be given after the applicant has been offered the job, conditioned upon passing the drug test. Also, if an applicant fails a drug test, a second must be given for verification purposes. In addition to federal laws, many states have their own drug and alcohol testing laws as they pertain to employment screening.