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Ruling 90-49


You have inquired as to whether the clean room air purification system machinery purchased by your client (Corporation X) is exempt from the sales and use tax.


Corporation X is constructing a manufacturing plant for the "growing" of gallium arsenide wafers to be used in a laser diode line of business. A two inch diameter wafer can potentially yield 1,500 finished diodes. The "growing" of wafers involves an extremely sensitive production process which requires a very high level of cleanliness and purity of materials.

A clean room is required to achieve and maintain the cleanliness required for the "growing" of the wafers. This clean room will include an air purification system designed to trap airborne particles and pollutants in order to protect the "growing" of the wafers. The clean room is essential in this manufacturing process.


Based on the facts recited herein, the air purification machinery is used directly in the manufacturing production process of "growing" gallium arsenide wafers. Corporation X may purchase the air purification machinery tax exempt by issuing its supplier a certificate of exemption for purchases of machinery, materials, tools and fuel.


May 17, 1990