The Employee Polygraph Protection Act of 1988 (EPPA) prohibits most private employers from using lie detector tests for pre-employment screening or during employment. Employers cannot ask about the results of a lie detector test or fire or discriminate against an employee or job applicant based on the results of a test.
A polygraph test may be used on certain job applicants of security service firms and pharmaceutical manufacturers, distributers and dispensers. They also may be used, in limited circumstances, on certain employees of private firms who are suspected of involvement in a workplace incident that resulted in economic loss to the employer. When allowed, specific standards for conducting the test, pre-test and post-test must be followed.
Employers must post a notice explaining the EPPA as part of its general posting requirements. The poster is available here.