When sourcing canned mushrooms, the most critical factor is food safety compliance. You must ensure the supplier holds HACCP (Hazard Analysis and Critical Control Points) and ISO 22000 certifications. For specific markets, look for FDA registration (USA), BRC (British Retail Consortium), or IFS (International Featured Standard). Additionally, verify that the product meets the Codex Alimentarius (CODEX STAN 55-1981) for canned mushrooms, which regulates drained weight, acidity, and sterilization levels.