Generally speaking, state laws typically allow employers to test applicants for drugs. However, the employer must follow the state's rules about providing notice and following procedures intended to prevent discrimination and inaccurate samples. For example, a number of states allow applicant testing only if:

• The applicant knows that such testing will be part of the screening process for new employees (for example, because the job application said so or because the employer's online job posting stated that a drug test would be required).
• The employer has already offered the applicant the job, contingent on passing a drug test.
• All applicants for the same job are tested similarly.
• The tests are administered by a state-certified laboratory.

Today, most companies that intend to conduct drug testing on job candidates include in their job applications an agreement to submit to such testing. If, in the process of applying for a job, you are asked to agree to drug testing, you have little choice but to agree to the test or drop out as an applicant.

Testing Current Employees

There are some legal constraints on testing employees for drug usage in most private employment jobs. In some states, companies cannot conduct blanket drug tests of all employees or random drug tests; the testing must be focused on an individual, either because the employer has a good reason to believe that person is using drugs or because the person's job carries a high risk of injury or damage if performed by someone who is under the influence.

Courts have generally ruled that companies may test employees after an accident that could have been caused by drug use or an incident in which the employee appeared to be impaired. For example, a bulldozer operator who swerved the machine illogically through a field crowded with workers could be the legal target of drug testing. And a legal secretary found slumped at her desk, unable to respond cogently to questions asked of her, was also considered fair game for a drug test.

Challenging Drug Tests

As an employee, you can always refuse to take a workplace drug test. But, if you are fired because of your refusal, you may have little recourse. (In fact, in some states, you might be denied unemployment benefits if you are fired for refusing to take a drug test.) Your employer needs only to show that there was good reason to believe that you were a safety hazard on the job or that you seemed unable to perform the work required. You would be placed in the difficult position of proving that your employer knew no such thing. You may, however, be able to win your job back if you can show that you were treated differently from other employees in the same position.

If you have been given a drug test and unfairly suspended or demoted because of it, your best bet may be to argue that the testers did not meet with the strict requirements for form and procedure set out in your state law. And note that employers are free to add safeguards to protect against specimen tampering—requiring those taking the test to remove their own clothing and don hospital gowns, or providing a test monitor who checks the temperature of the urine and adds dye to toilet water, as examples. However, a modicum of discretion is required; while most courts have found it reasonable to have a monitor listen as a urine test is administered, a number have found it an unreasonable invasion of privacy for the monitor to watch.