S.C. Code Ann. § 2-5-30

Each member of the General Assembly (hereinafter referred to as legislator) shall designate not fewer than three nor more than seven emergency interim successors to his powers and duties and specify their order of succession. Each legislator shall review and, as necessary, promptly revise the designations of emergency interim successors to his powers and duties to insure that at all times there are at least three such qualified emergency interim successors.