Ind. Code § 15-16-1.5-6
"Aqua ammonia" means an aqueous solution of anhydrous ammonia generally containing from eighteen percent (18%) to thirty percent (30%) of ammonia (NH3) by weight and having a vapor pressure usually varying from zero (0) to ten (10) pounds per square inch gauge (psig) at one hundred four (104) degrees Fahrenheit.
As added by P.L.98-2026, SEC.2.