187. A covered facility manufactures specialty glass products. The starting materials are primarily metal silicates which are ground into a powder, mixed, and heated. The resulting mixture, the specialty glass, has all the metal silicates melted together in a non-crystalline structure. Since the metal silicates do not exist by themselves in the mixture, how should a threshold determination be made?
The metal silicates are processed since they become incorporated into a product (the specialty glass) that is distributed in commerce. If the metal silicates still exist as the original metal silicates but just mixed together then each metal silicate that belongs to a particular metal compound category is included in the processing threshold calculations for that category. If the metal silicates have been reacted to produce another compound (i.e., if the specialty glass is not just a mixture of individual metal silicates but is another new metal compound) then the metal silicates have still been processed, but a new metal compound has also been manufactured and its weight (i.e., the whole weight of the glass) must be included in the manufacturing threshold calculations.