S.C. Code Ann. § 31-9-90

The bonds authorized by this chapter and the income therefrom and all trust indentures and mortgages executed as security therefor, all loan agreements made pursuant to the provisions hereof (including lease agreements) and the revenues derived from any loan agreement, shall be exempt from all taxation in the State except for inheritance, estate or transfer taxes and all trust indentures, mortgages and loan agreements made pursuant to the provisions of this chapter shall be exempt from South Carolina stamp and transfer taxes.