S.C. Code Ann. § 40-82-30

It is unlawful for a person to engage in the manufacture, distribution, sale, storage, or transportation by tank truck, tank trailer, or cylinder of liquefied petroleum gases or engage in the installation, servicing, repairing, adjusting, or connecting of appliances to liquefied petroleum gas systems and containers in this State without being licensed in accordance with this chapter. A retail establishment which sells prefilled liquefied petroleum gas cylinders of twenty-five pounds or less is exempt from the requirements of this chapter.