With exceptions discussed in this manual, the EPPA prohibits the use of all mechanical lie detector tests in the workplace, including polygraphs, psychological stress evaluators, deceptographs, and voice stress analyzers. EPPA allows for one type of lie detector test -- the polygraph -- to be used by private employers for certain types of pre-employment screening and as an aid in investigating incidents involving economic loss or injury to the employer's business. These uses are subject to several restrictions and procedures. Government employers may use any lie detector test without complying with any of EPPA's procedures or restrictions. The Federal Government may administer lie detector tests to employees of government contractors or consultants engaged in work involving national defense or national security. The checklists presented pertain to polygraph use in ongoing investigations, pre-employment screening, and drug company performance of such activities. Legal and constitutional challenges to the EPPA are also reviewed. Appended supplementary information.