Food contact material migration testing is one of the most important quality checks for food packaging, yet it is also one of the least understood. When a lab report arrives with terms like “overall migration” and “specific migration”, most buyers ask the same question: what does migration testing actually measure? This guide explains the principles, test items and pass criteria of migration testing in plain language, so you can read a compliance report with confidence.
What Is Migration and Why It Matters
Migration is the transfer of substances from packaging into food during contact. Plastic films contain additives, inks and adhesives that, under certain temperature, time and contact conditions, may be released into the food. Migration testing simulates real contact scenarios and verifies that the amount released stays within legal safety limits. It answers one core question: will this package transfer anything unwanted into the food? Understanding the basics of food contact materials is a good starting point.
Overall Migration: The Screening Indicator
Overall migration measures the total amount of non-volatile substances released from packaging into food simulants. Tests use aqueous, acidic, alcoholic and fatty simulants at set temperatures for set durations. Standards such as China’s GB 4806 series and the EU Regulation 10/2011 set clear limits for overall migration. Exceeding the limit signals that the material formulation or process needs review. Overall migration is a screening indicator: failing it does not prove a specific substance is toxic, but it does mean the material must be improved.
Specific Migration: Tracking Key Substances
Specific migration targets listed substances such as plasticizers, heavy metals, bisphenol A and primary aromatic amines. Each substance has its own specific migration limit (SML), and testing is performed substance by substance. Specific migration is the decisive factor for compliance: for example, the plasticizer DEHP has an extremely strict limit in food contact materials, and any exceedance means the material fails. Most compliance problems are actually found in specific migration tests.
Food Simulants and Test Conditions
Migration tests do not soak packaging in real food. Instead, standardized food simulants are used: water, 3% acetic acid for acidic foods, 10% or 50% ethanol for alcoholic foods, and vegetable oil for fatty foods. Temperature and duration follow the real use scenario — ambient storage typically uses 40°C for 10 days, while hot-fill applications use higher temperatures for shorter periods. The choice of simulant directly affects the result, and exporters must follow the simulant system of the destination market. Regulatory requirements differ sharply between regions, as our US vs EU packaging requirements guide explains.
How to Read a Migration Test Report
When reviewing a test report, check three things. First, the standard the test is based on — GB 4806, EU 10/2011 or US FDA 21 CFR. Second, whether the simulants and conditions cover your product’s real usage. Third, the margin between each result and its limit. A report that only covers overall migration without specific migration is incomplete. For exporters, remember that European rules are tightening across the board, as detailed in our EU PPWR regulation guide.
How Factories Keep Migration Compliant
Compliance is not achieved by testing alone; it is built into formulation, process and quality control. Reliable suppliers use compliant raw materials with certificates of analysis, control ink and adhesive residues, keep workshops clean, and maintain batch retention and regular third-party testing. At OMOpack, we select food-grade materials at the source and send finished products for testing according to the applicable standards, reducing migration risk from the very beginning.
Summary and Recommendations
Migration testing is essentially a mock exam for packaging safety: overall migration looks at the big picture, specific migration tracks the critical substances, and simulants and conditions reflect real usage. When sourcing packaging, always request the complete test report and confirm that the test conditions match your product’s actual use. OMOpack offers food-grade flexible packaging customized to national and export standards — contact us for material compliance advice, and visit OMOpack.com for more packaging knowledge.
