Workplace testing has become increasingly popular, as employers screen their workers in an effort to figure out who would be the best candidate for promotion or who is responsible for a workplace problem. As long as a test is designed to predict a worker's actual ability to do the job (and is relatively non-invasive), it is probably legal. For example, an employer can generally require typing tests for clerical jobs or agility/strength tests for positions requiring certain physical skills. (This article is about testing existing employees. For information on testing prospective employees, see Testing Job Applicants.)

Privacy Violations

Employers who require their employees to take more comprehensive or intrusive tests can get into trouble for violating their workers' privacy rights, particularly if the tests aren't closely related to the job in question. Generally, an employer should have a sound, work-related reason to require a current employee to submit to testing. But that might not be enough: if the test is too intrusive or delves too deeply into personal issues, it might invade the employee's right to privacy (and result in a lawsuit).

For example, one California employer asked applicants to take a comprehensive psychological exam -- including agreeing or disagreeing with such statements as "I am very strongly attracted by members of my own sex" or "I believe in the second coming of Christ" -- before considering them for the position of store security guard. The company eventually paid more than $2 million to settle the dispute.

There are few hard and fast rules about whether a particular test is legal -- courts generally decide these issues on a case-by-case basis, looking at all the facts and circumstances. For the most part, employers can stay out of trouble by using simple common sense. An employer who inquires into an employee's sex life or personal beliefs probably crosses the line, while an employer who tests only for necessary job skills is probably on safe ground.

In addition to these general considerations, specific rules apply to particular types of tests.

Medical Examinations

The Americans With Disabilities Act (ADA) limits an employer's ability to administer medical tests that might unfairly screen out workers with disabilities. Employers can require a medical examination only after a job offer has been made, for example.

In addition, the ADA cloaks the results of a medical examination with certain privacy protections. Data gathered in medical examinations must be kept in a separate file available only to those with a demonstrable "need to know." (See Keeping Personnel Files and Medical Records Confidential for more information on record-keeping requirements.)

Once an employee is already on the job, an employer's right to conduct a medical examination is usually limited to so-called "fitness for duty" situations. Where an employee has exhibited objective indications that he or she is physically or mentally unfit to perform the essential functions of the job, an employer may ask about the employee's condition or request that the employee take a medical examination.

Drug Tests

Although an employer can generally require job applicants to submit to drug testing, state laws place more restrictions on an employer's right to drug test current employees. (For more on drug testing of applicants, see Testing Job Applicants.)  For example, many states allow testing only for certain occupations or in certain circumstances (for instance, if an employee has recently completed a rehabilitation program or has been involved in a workplace accident). To find out more about your state's rules, contact your state labor department.

Psychological Screening

Some employers use pencil and paper psychological tests to attempt to predict whether an employee will steal, fight, or engage in other misconduct in the workplace. There are two problems with using such tests. First, it is heavily disputed whether these tests can accurately predict an employee's future conduct. Second, many of the test questions are highly intrusive and invade the employee's privacy. For the most part, employers would be well-advised to steer clear of psychological tests unless there is a compelling justification -- and a consultation with a lawyer.

Lie Detector Tests

The Federal Employee Polygraph Protection Act (29 U.S.C. § 2001) prohibits most private employers from requiring their workers to submit to lie detector tests, with one exception: An employer may require a worker it reasonably suspects of theft or embezzlement to take a polygraph test, if certain requirements are met. Aside from this limited exception, however, an employer may not require a current employee to take a lie detector test, use the results of any such test, or discipline or discharge any employee who refuses to take one. Many states ban polygraph testing outright, in any circumstances.