According to Article 415 of the NAFTA, fungible goods are goods that are interchangeable for commercial purposes, and have essentially identical properties. When a producer mixes originating and non-originating fungible goods, so that physical identification of originating goods is impossible, the producer may determine origin of those goods based on any of the standard inventory accounting methods (e.g., FIFO, LIFO) specified in the Uniform Regulations. These provisions apply equally to fungible materials that are used in the production of a good.
|Company Y of Mexico supplies clips to airplane manufacturers throughout North America. Some of the clips Y supplies originate in Mexico and others are made in China. All of the clips are of identical construction and are intermingled at Y's warehouse so that they are indistinguishable. On January 1, Company Y buys 3000 clips of Mexican origin; on January 3 it buys 1000 clips of Chinese origin. If Company Y elects FIFO inventory procedures, the first 3000 clips it uses to fill an order are considered Mexican, regardless of their actual origin.|