A glass manufacturer was entitled to a refund of Illinois sales tax under the machinery and equipment exemption because nitrogen and hydrogen purchased by the manufacturer caused a direct and immediate physical change on the glass being produced. The chemicals – which were added to a float bath containing the glass – resulted in the glass undergoing an observable direct and immediate physical change. Under the manufacturing and assembly exemption, “Equipment” includes … chemicals or chemicals acting as catalysts but only if the chemicals or chemicals acting as catalysts effect a direct and immediate change upon a product being manufactured or assembled for wholesale or retail sale or lease. Chemicals are not required to chemically react with the glass to effect a direct and immediate change. As a result, the chemicals qualify for the machinery and equipment exemption. (PPG Industries, Inc. v. Illinois Department of Revenue, Circuit Court, Cook County Judicial Circuit (Illinois), 13 L 050140, September 9, 2014)