Food contact migration testing verifies that your packaging film does not transfer harmful or unacceptable amounts of substances into the food it touches. In the EU the headline limit is 10 mg/dm² of total non-volatile matter under Regulation (EU) No 10/2011; in China the governing standard is GB 4806.7; in the US, FDA 21 CFR defines cleared components. If your supplier cannot produce current test reports against the right standard for your market, you do not have a compliant film — you have an assumption.

This article lays out what migration testing actually measures, which rules apply, and the minimum document set a food factory should demand with every film release.

What Migration Actually Means

Migration is the transfer of substances from the packaging material into food. It happens through three routes:

• Diffusion of additives, monomers or adhesives residues through the polymer layers.
• Set-off, where ink or coating on the outer web transfers to the food-contact layer while the roll is wound.
• Penetration through pinholes, cracks or poor seal areas.

Testing distinguishes overall migration (OM) — the total mass of everything that transfers — from specific migration (SM) of named substances such as monomers, heavy metals or primary aromatic amines.

Which Limits Apply?

European Union — Regulation (EU) No 10/2011. Overall migration limit: 10 mg/dm² of food contact surface. For small packaging (capacity below 500 ml or above 10 L) the limit is expressed as 60 mg/kg of food. Specific migration limits apply to listed substances — for example bisphenol A at 0.05 mg/kg. Testing uses food simulants (A: 10% ethanol; B: 3% acetic acid; C: 20% ethanol; D1: 50% ethanol; D2: vegetable oil) under time/temperature conditions matched to the real use, e.g. 10 days at 40°C for long-term room-temperature storage.

United States — FDA 21 CFR Parts 174–186. The US system is component-based: each film, adhesive and ink component must be cleared for its intended food type and use condition, either through 21 CFR listings, an effective Food Contact Notification, or Threshold of Regulation. There is no “10 mg/dm²” equivalent; compliance is demonstrated by formulation review against these lists plus supporting extraction data.

China — GB 4806 series. GB 4806.7 (food contact plastics) sets general requirements and permitted polymer lists, tested per GB 31604 methods. Overall migration and permitted substance limits follow the GB 9685 additions list. Exporters serving China should expect a GB-compliant report, not just an EU one.

Good manufacturing practice is legally separate from testing: in the EU, Regulation (EC) No 2023/2006 requires the whole chain — resin, film, converter — to run under documented GMP. A test report does not replace a GMP system; it samples the output of one.

What Documents to Require From Your Film Supplier

Ask for four items, every time, not just at first approval:

1. Declaration of Compliance (DoC) per (EU) 10/2011 Article 17 or equivalent, naming the structure, intended food types and use conditions. 2. Accredited lab test report — overall and specific migration — for the actual structure and thickness you buy, at conditions matching your process (retort, hot-fill, frozen, ambient). 3. CoA per release batch, covering at minimum residual solvents and appearance, plus migration data on an agreed frequency (typically annual or on change). 4. Change notification commitment in writing: any change of resin grade, adhesive, ink system or process triggers re-testing before your next shipment.

If a supplier quotes “food grade” without being able to name the standard, the simulant set and the test lab, treat it as unverified. The declaration chain matters because in the EU, the food business operator carries the legal burden of confirming materials were supplied with a valid DoC.

Common Failure Modes in Flexible Packaging

The same failures recur across audits:

• Primary aromatic amines (PAA) from polyurethane adhesives that are under-cured; fixing this is a curing-time issue, not a film redesign.
• Set-off contamination when printed rolls are wound too tight or stacked hot, transferring ink components onto the food-contact side.
• Excessive residual solvents from fast press speeds without adequate oven balance, which also produces off-odor complaints.
• Heavy metals from ink pigments, relevant when regulations like GB 9685 or European ink guidance are not followed.

All four are process controls at the converter. This is why your audit question should not be “do you test?” but “which structure, which simulant, which lab, and what triggers a retest?”

Retesting: When and Why

Re-run migration testing when:

• The structure changes (layer recipe, thickness, adhesive system).
• The ink or OPV system changes, or a new varnish is introduced.
• The intended use changes — moving from dry ambient to hot-fill or retort is a different test regime.
• Regulatory updates revise a specific migration limit for a substance in your structure.

For stable structures, annual confirmation is a common and defensible cycle. Keep reports version-linked to purchase orders so traceability survives personnel changes.

Practical Cost and Lead Time

Full migration screening for a three-layer laminate typically runs one to three weeks at an accredited lab, with cost scaling by the number of simulants and targeted substances. Compared with the cost of a customs detention or a retailer delisting, it is the cheapest insurance in the packaging budget. For background on how film composition drives performance, see our guides on packaging downgauging and zipper selection, and on our sister brand’s site the process notes on dry lamination and extrusion lamination, where most contamination risks originate and are controlled.

FAQ

What is food contact migration testing? It is laboratory analysis that measures how many substances transfer from packaging material into food or a food simulant, expressed as overall migration in mg/dm² and, for named substances, as specific migration in mg/kg.

What is the overall migration limit in the EU? Regulation (EU) No 10/2011 sets 10 mg/dm² of contact surface, or 60 mg/kg of food for small-capacity packaging below 500 ml or above 10 litres.

Does the US have a 10 mg/dm² limit? No. The US system under FDA 21 CFR Parts 174–186 clears individual components for defined uses, so compliance is a formulation-and-notification review rather than a single overall number.

Which standard applies for packaging sold in China? GB 4806.7 for food contact plastics, tested with GB 31604 methods, with permitted substances controlled through the GB 9685 positive list.

How long does migration testing take? Typically one to three weeks for a full screen at an accredited laboratory, depending on how many simulants and target substances are included.

When must migration testing be repeated? Whenever the structure, adhesive, ink system or intended use changes, and periodically — annual reconfirmation is a common cycle for stable structures.

Who is legally responsible for compliance? In the EU the food business operator must ensure materials come with a valid Declaration of Compliance; the converter and resin suppliers are responsible for the supporting data under GMP Regulation (EC) No 2023/2006.