The Employee Polygraph Protection Act (EPPA) is applicable to most private employers, and prohibits employers from using polygraph tests as a pre-employment screening tool, or in connection with discipline, termination or other employment-related decisions.  The U.S. Department of Labor has an information sheet concerning the EPPA available at www.dol.gov/compliance/guide/eppa.htm#who.

Under the federal act, polygraph tests may be used by employers, subject to strict standards outlined by the EPPA, in certain hiring situations involving security service firms and certain pharmaceutical-related positions.  Also, polygraph testing may be available for certain employees who are "reasonably suspected" of activity that resulted in economic loss or injury to the employer from theft or embezzlement. 

If a state or contract provides more restrictive requirements concerning the use of polygraphs, the more restrictive provisions apply.   For example, pursuant to Minn. Stat. § 181.75, Minnesota employers may not request or require a polygraph test to test honesty of employees or job applicants.  If an employee requests a polygraph test, the employer is required to advise the employee that taking the test is voluntary.  Wisconsin similarly restricts use of polygraph tests, requiring an employer to advise of the voluntary nature of any such testing, and also prohibiting hiring decisions based solely on polygraph results, without taking into account other relevant information.  Wisconsin also outlines other restrictions and standards applicable to any polygraph testing performed.