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How to Determine the Net Weight and Purge of Packaged Chitterlings Using NIST Handbook 133, “Checking the Net Contents of Packaged Goods”



Kenneth S. Butcher


Weights and Measures Inspector tests frozen chitterlingsto determine if the package contains the labeled net weight and if the purge is 20 % or less. Inspectors typically use Section 2.3. “Basic Test Procedure” and other portions of National Institute of Standards and Technology (NIST) Handbook 133, “Checking the Net Contents of Packaged Goods” to conduct these tests. To determine the amount of purge, inspectors modify the procedures in Section 2.6. “Determining the Net Weight of Encased-In-Ice and Ice Glazed Products.” The modifications include thawing the product while it is still in the package, then draining it and applying the 20 % purge limit established by the Food Safety and Inspection Service (FSIS) of the U.S. Department of Agriculture (USDA). Inspectors defer to the USDA purge value because a specific limiting value for the purge for chitterlings has not been adopted by the National Conference on Weights and Measures (NCWM), and, therefore, a value is not in NIST Handbook 133. The USDA recommends that whenever possible purge determinations should be conducted at the plant immediately after packing but before the chitterlings are frozen. However, continued state and local inspections of chitterlings are needed outside packing plants because inspections are usually only carried out in response to consumer complaints about short weight or excessive purge in the packages they purchase at retail or over the Internet. In the past few years, most of the inspection results shared with the Office of Weights and Measures (OWM) at NIST indicated that inspectors have found the purge from chitterlings was often much greater than 20 %.
NIST Office of Weights and Measures


purge, weights and measures, packaging and labeling, chitterlings, net weight, inspections


Butcher, K. (2014), How to Determine the Net Weight and Purge of Packaged Chitterlings Using NIST Handbook 133, “Checking the Net Contents of Packaged Goods”, NIST Office of Weights and Measures, [online],, (Accessed May 29, 2024)


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Created August 13, 2014, Updated February 19, 2017