Ind. Code § 6-2.5-5-11
Transactions involving tangible personal property are exempt from the state gross retail tax, if:
(2) the person acquiring the property is a public utility that furnishes or sells natural or artificial gas in a retail transaction described in IC 6-2.5-4-5 .
As added by Acts 1980, P.L.52, SEC.1. Amended by P.L.23-1988, SEC.9; P.L.71-1993, SEC.7.