S.C. Code Ann. § 41-1-15
(A) Notwithstanding any other provision of the law, an employer may establish a drug prevention program in the workplace pursuant to Section 38-73-500(B) which shall include:
(C) Employers, laboratories, medical review officers, insurers, drug or alcohol rehabilitation programs, and employer drug prevention programs, and their agents who receive or have access to information concerning test results shall keep all information confidential. Release of such information under any other circumstance shall be solely pursuant to a written consent form signed voluntarily by the employee tested or his designee unless the release is completed through disclosure by an agency of the State in a civil or administrative proceeding, order of a court of competent jurisdiction, or determination of a professional or occupational licensing board in a related disciplinary proceeding. The consent form must contain at a minimum:
(D) Information on test results shall not be released for or used or admissible in any criminal proceeding against the employee.
Liability for discharge of at-will employee for refusal to submit to drug testing. 79 ALR4th 105.
Employee's action in tort against party administering polygraph, drug, or similar test at request of actual or prospective employer. 89 ALR4th 527.