S.C. Code Ann. § 22-2-100
The names drawn pursuant to either Section 22-2-80 or Section 22-2-90 shall be placed in a box or hat and individual names randomly drawn out one at a time until six jurors and four alternates are selected. Each party shall have a maximum of six peremptory challenges as to primary jurors and four peremptory challenges as to alternate jurors and such other challenges for cause as the court may permit. If for any reason it is impossible to select sufficient jurors and alternates from the names drawn, names shall be randomly drawn from Compartment A until sufficient jurors and alternates are selected.