29 CFR § 779.333 - Goods sold for use as raw materials in other products.
Goods are sold for resale where they are sold for use as a raw material in the production of a specific product to be sold, such as sales of coal for the production of coke, coal gas, or electricity, or sales of liquefied-petroleum-gas for the production of chemicals or synthetic rubber. However, the goods are not considered sold for resale if sold for general industrial or commercial uses, such as coal for use in laundries, bakeries, nurseries, canneries, or for space heating, or ice for use by grocery stores or meat markets in cooling and preserving groceries and meat to be sold. Similarly, ice used for cooling soft drinks while in storage will not be considered sold for resale. On the other hand, ice or ice cubes sold for serving soft drinks or other beverages will be considered as sales for resale.