Analytical Differentiation of Recycled Content Claims and Physical Furnish in Food Contact Packaging
Analytical testing verifies physical furnish markers and migration safety, while administrative chain records prove legal recycled content claims.
Migration Limit
Threshold Metric
Statutory packaging regulations define maximum permissible quantities of chemical substances capable of transferring from contact materials into foodstuffs or food simulants. A migration limit establishes an enforceable concentration ceiling designed to protect consumer health and prevent unacceptable alterations in food composition, taste or odour. Regulatory authorities establish these thresholds based on comprehensive toxicological assessments, deriving specific values from acceptable daily intake levels and calculated exposure models.
Testing laboratories verify compliance by exposing paper and paperboard specimens to standard chemical simulants under defined temperature and duration conditions matching real-world distribution and shelf storage.
Measurement Distinction
Analytical frameworks differentiate between overall transfer of all non-volatile substances and the specific movement of individual identifiable chemical compounds. Overall migration limits measure the total mass of non-volatile substances transferring into fatty or aqueous simulants, expressed in milligrams per square decimetre of packaging surface. Specific migration limits apply to individual chemical species, including monomer residues, plasticizers, printing photoinitiators, primary aromatic amines and mineral oil hydrocarbons.
For paper and board packaging lacking dedicated universal European regulations, specific limits derive from national recommendations, the European Plastics Regulation positive lists or Council of Europe policy guidelines. Gas chromatography and liquid chromatography quantify target analytes against parts-per-billion calibration standards.
Packaging Verification
Compliance testing evaluates either direct physical contact or vapour-phase transfer across barrier layers. Thick board materials intended for dry dry food packaging undergo testing with modified polyphenylene oxide simulant, commercially known as Tenax, to capture volatile and semi-volatile chemical transport. When packaging uses a functional barrier, such as a continuous aluminium foil or EVOH extrusion layer, the barrier must prevent specific migration of unlisted substances above 0.01 milligrams per kilogram of food.
Converters and carton suppliers document compliance by issuing declarations of compliance that reference verified migration limit data, allowing brand owners to match packaging substrates safely with food contact requirements.