S.C. Code § 13-17-90
It is found and declared that the project authorized by this chapter is in all respects for the benefit of all the people of the State, for the improvement of their welfare and material prosperity, and is a public purpose and a corporation owned completely by the people of the State. The authority shall pay no taxes or assessments including, but not limited to, income tax, sales and use tax, and property tax upon any of the property acquired by it or upon any of its activities; except that the authority is entitled to the above-referenced sales and use tax exemption only in (1) transactions to obtain tangible personal property for the authority's own use or consumption, (2) transactions related to authority contracts with governmental entities and nonprofit entities, and (3) transactions related to authority contracts with private, for-profit entities doing business in South Carolina, where these contracts do not place these entities in competition with other private, for-profit entities doing business in South Carolina. The securities and other obligations issued by the authority, their transfer, and the income is free from taxation. After payment of necessary operating expenses and all annual debt requirements, the authority shall reinvest net earnings furthering the purposes of this chapter.
S.C. Code § 13-17-90