Pork casing falls within the food category and is used for stuffing sausages for human consumption. Therefore, enterprises involved in processing casings for export must comply with the regulations stipulated in the "Hygienic Standards for the Registration of Export Casing Processing Enterprises" issued by the National Bureau of Commodity Inspection. This ensures their processing hygiene conditions meet the required standards. The raw materials used in processing should originate from safe, non-epizootic areas and come from livestock that have passed veterinary inspections both ante-mortem and post-mortem, confirming they are healthy and disease-free. When procuring casings, it is essential to focus on the following four key points:

1. The raw pork intestines must be sourced from pigs that have passed veterinary inspection and are confirmed to be healthy and disease-free. The small intestines should appear bright and fresh, with no off-odors.

2. The casings must be intact at both ends, complete with both the larger and smaller ends present. They should be free from breaks or damage, uncontaminated by mud, sand, or debris, and each should measure over 14 meters in length.

3. Do not procure small intestines from sick or dead pigs, "worm intestines" (referring to intestines affected by proliferative enteropathy, where the pathogen damages the ileal mucosa, causing thickening of the inner mucosal layer), or "fen chang" (a term referring to a specific part of the colon near the junction of the small and large intestines in pigs, which is thicker than other sections of the small intestine).

4. Upon procurement, the pork small intestines must not be stored in metal containers nor piled together dry. They should be soaked and rinsed in clean water.