Packaging material migration testing quantifies the transfer of substances from packaging materials into food, pharmaceuticals, and other contact media, verifying compliance with global safety regulations such as EU Regulation (EU) No 10/2011, the GB 4806 national food safety standards, and FDA 21 CFR requirements. This technical guide explains the principles of overall and specific migration testing, food simulant selection, analytical methods, and applicable international standards for manufacturers and quality professionals.
Technical Overview
Migration is defined as the mass transfer of substances from a packaging material into the packaged product or a food simulant under defined conditions of time and temperature. The migrating substances may include residual monomers, additives, plasticizers, antioxidants, oligomers, degradation products, and non-intentionally added substances (NIAS) originating from raw materials, manufacturing processes, printing inks, adhesives, or coatings.
Migration testing is a fundamental requirement for food contact materials and is generally divided into two categories: overall migration (also called total or global migration), which measures the total mass of all substances released, and specific migration, which quantifies individual target substances against specific migration limits (SML). Regulatory frameworks including EU Regulation (EC) No 1935/2004, EU Regulation (EU) No 10/2011, the GB 4806 series in China, and the US FDA 21 CFR framework establish the legal limits and test conditions that packaging must satisfy before market placement.
The extent of migration depends on multiple factors: the chemical composition and thickness of the material, the nature of the contacting medium (aqueous, acidic, alcoholic, or fatty), the contact temperature, and the contact duration. A scientifically designed migration test must therefore replicate the worst foreseeable conditions of actual use.
Testing Samples
Plastic Packaging Materials
Flexible films, rigid containers, bottles, closures, trays, sealing gaskets, and laminated structures made from polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), polycarbonate (PC), and multilayer coextruded or laminated composites. These are the most extensively regulated materials, subject to both overall and specific migration limits.
Paper and Paperboard
Food-contact paper, carton board, molded pulp trays, and coated paper products. Testing focuses on fluorescent whitening agents, heavy metals, formaldehyde, pentachlorophenol, and overall migration into aqueous simulants.
Metal Packaging
Tinplate and aluminum cans, can ends, lids, and metal drums with organic protective coatings. Testing evaluates migration from the internal lacquers, including bisphenol A, BADGE and its derivatives, primary aromatic amines, and overall migration from coatings.
Glass and Ceramic Packaging
Glass bottles and jars, ceramic tableware, and enamel-coated containers. Testing emphasizes the release of lead and cadmium from the surface in contact with food, determined using acetic acid extraction methods.
Rubber, Silicone, and Elastomeric Materials
Seals, gaskets, teats, tubing, and dispensing components made from natural or synthetic rubber and silicone elastomers, tested for overall migration, volatile N-nitrosamines, formaldehyde, and accelerating agents.
Coatings, Adhesives, and Inks
Functional barrier layers, heat-seal coatings, laminating adhesives, and printing ink systems are evaluated either as finished articles or as representative coated or printed specimens prepared under production conditions.
Testing Items
Migration testing programs are typically structured around the following categories of test items:
- Overall migration (total migration limit, OML): the total quantity of non-volatile substances transferred into food simulants, expressed in mg/dm² or mg/kg, with a general limit of 10 mg/dm² under EU requirements.
- Specific migration of regulated monomers: vinyl chloride monomer, acrylonitrile, styrene, 1,3-butadiene, vinylidene chloride, caprolactam, and bisphenol A.
- Specific migration of plasticizers and additives: phthalates such as DEHP, DBP, DINP, and DIDP; adipates; citrates; antioxidants such as BHT and hindered phenols; and slip agents.
- Heavy metal migration: lead, cadmium, arsenic, mercury, chromium (VI), barium, cobalt, copper, iron, lithium, manganese, and zinc determined by inorganic analytical techniques.
- Primary aromatic amines (PAAs): aniline, toluidine, 4,4'-methylenedianiline, and related species migrating from polyurethane adhesives and coatings.
- Epoxy derivative migration: BADGE, BADGE hydrochloride and hydrate derivatives, BFDGE, and NOGE from epoxy-based coatings.
- Other target substances: formaldehyde, melamine, acetaldehyde, antimony, organotin compounds, perfluoroalkyl substances, mineral oil saturated hydrocarbons (MOSH/MOAH) from recycled board, photoinitiators such as benzophenone and ITX, and non-intentionally added substances (NIAS).
- Ancillary indices for aqueous extracts: potassium permanganate consumption and heavy metals (expressed as lead) in water-based extraction media required by certain national standards.
Testing Methods
Food Simulant Selection
Because testing directly in food is analytically impractical, standardized food simulants are used to model different food types. Typical assignments include distilled water or 10% ethanol (v/v) for aqueous and neutral foods, 3% acetic acid (w/v) for acidic foods, 20% or 50% ethanol for alcoholic beverages, 95% ethanol or iso-octane as substitute fatty food simulants, and vegetable oils such as olive or corn oil for fatty foods, with substitute simulants applied where analytical interference from the oil is unavoidable.
Overall Migration Determination
Overall migration is determined by exposing the specimen to the selected simulant under defined time-temperature conditions using total immersion, the single-sided cell, or the pouch method. After exposure, the simulant is evaporated to dryness and the non-volatile residue is gravimetrically determined and reported in mg/dm². Principal method standards include the EN 1186 series, GB 31604.8, and the extraction procedures recognized under the FDA 21 CFR framework for coatings and polymers.
Specific Migration Determination
Specific migration testing follows the EN 13130 series and the GB 31604 series of national food safety standards. Specimens are exposed to simulants under the applicable conditions, after which target analytes in the simulant are quantified by instrumental analysis. Common techniques include gas chromatography-mass spectrometry (GC-MS) for volatile and semi-volatile organics, high-performance liquid chromatography (HPLC) and LC-MS/MS for thermally labuble or non-volatile compounds, inductively coupled plasma mass spectrometry (ICP-MS) or atomic absorption spectrometry (AAS) for elemental migrants, and ultraviolet-visible spectrophotometry for substances such as primary aromatic amines and formaldehyde.
Test Conditions
Time-temperature conditions are selected to represent the worst foreseeable use, covering all stages of processing, storage, and consumption. Standardized condition sets define combinations such as 10 days at 40 °C or 60 °C for long-term room-temperature storage, 2 hours at 70 °C or 100 °C for hot-fill applications, and conditions up to sterilization temperatures for retort packaging. Results are conventionally evaluated at a standard surface-to-volume ratio of 6 dm² per kilogram of food, and certified reference materials and fortified simulants are used to verify method accuracy and recovery.
Quality Assurance
Accredited third-party laboratories perform migration testing under ISO/IEC 17025-accredited management systems, applying method validation, blank correction for simulant background, replicate determination, and measurement uncertainty evaluation to ensure results are legally defensible for regulatory submission and market surveillance.
Applications
Migration test data support a wide range of regulatory, commercial, and research objectives:
- Compliance demonstration for food contact materials intended for the Chinese market under the GB 4806 and GB 31604 series, including new product registration and market surveillance response.
- Export conformity for packaging placed on the EU market under Regulation (EU) No 10/2011 and Regulation (EC) No 1935/2004, including Declaration of Compliance documentation.
- US market access support under the FDA 21 CFR food contact regulations and food contact notification (FCN) requirements.
- Pharmaceutical packaging qualification, including extractables and leachables studies aligned with USP and ICH Q3E guidance for drug product contact materials.
- Cosmetic and personal care packaging safety evaluation for primary packaging components.
- Supplier verification, incoming material quality control, comparative material selection during packaging development, and stability studies under accelerated storage conditions.
- Investigation of NIAS and safety assessment support for recycled materials and functional barrier structures.
FAQ
What is the difference between overall migration and specific migration? Overall migration measures the total mass of all non-volatile substances transferred into a food simulant and is compared against a single limit (typically 10 mg/dm²), while specific migration quantifies individual named substances and compares each result against its specific migration limit expressed in mg/kg food.
How are food simulants chosen? Simulants are assigned according to the food classification of the intended application: aqueous foods are represented by water or 10% ethanol, acidic foods by 3% acetic acid, alcoholic foods by ethanol-water mixtures, and fatty foods by vegetable oil or authorized substitute simulants. If a packaging is intended for multiple food types, testing must cover the most severe simulant for each category.
What test conditions should be applied? Conditions must reproduce the worst foreseeable contact scenario, including filling, sterilization, hot filling, and storage. Standardized condition tables in EU Regulation (EU) No 10/2011 and the GB 31604 framework pair contact times with temperatures such that long-term ambient storage is typically demonstrated with 10 days at 40 °C or 60 °C.
How are results reported and evaluated? Results are reported in mg/dm² of contact surface or converted to mg/kg food using the conventional ratio of 6 dm² per kg. Measured values are compared against the applicable overall migration limit, specific migration limits, and any group restrictions, taking analytical measurement uncertainty into account.
What is NIAS and why does it matter? Non-intentionally added substances include impurities, reaction intermediates, and degradation or reaction products that are not deliberately added to the material. Regulatory frameworks require that NIAS be assessed using a risk-based approach, often involving targeted and non-targeted screening by chromatographic and mass-spectrometric techniques.
How much sample is required for testing? Typical programs require finished packaging articles or flat sheet material sufficient to provide at least 2 to 3 dm² of contact surface per simulant per condition, with additional material for duplicate determination. Laboratories should always be consulted for exact quantities, as requirements vary with the test plan and the number of simulants and conditions selected.