35 Miss. Code R. § 4-07-03-101
Mississippi sales tax law provides for a reduced rate and certain exemptions for manufacturers and custom processors. The reduced rate of 1 1/2% applies to the sale or rental of manufacturing machinery and machine parts which are used directly in the manufacturing process. Manufacturers and custom processors are also eligible for an exemption on purchases of electricity and natural gas used in the manufacturing process, as provided either by Miss. Code Ann. Section 27-65-107(f) or 27-65-111(n) used in an engine. Sales of raw materials, catalysts, processing chemicals, welding gases or other industrial gases to a manufacturer for use directly in manufacturing or processing a product for sale or rental are exempt.
35 Miss. Code. R. § 4-07-03-101