The Employee Polygraph Protection Act (EPPA), which became law in 1988, establishes polygraph guidelines and restrictions for commercial businesses. It does not affect government agencies, public agencies, or businesses which are exempt due to certain services provided or contracts established with the federal government. The EPPA states that employers cannot mandate polygraph examinations of employees at any time and that polygraph examinations can only be requested of current employees when certain criteria are met (e.g. the employer must be able to show that economic loss was incurred by the incident under investigation). If an employee examination is requested, the employee has a right to decline examination without reprimand or discharge.
More detailed information about the EPPA is available at the American Polygraph Association Website.
Source: American Polygraph Association (www.polygraph.org)