Chemical Migration Test Protocols for Modified Dispersion Coated Packaging
Chemical migration testing for dispersion coated board requires single-sided extraction cells and post-crease migration proofs to account for score-line breaks.
21 CFR 176.170
Regulatory Scope
Federal regulations establish safety criteria for paper and paperboard components intended to contact aqueous or fatty foods. Compliance with 21 CFR 176.170 requires paper manufacturers to select indirect food additives from an approved list of substances subjected to migration analysis. The regulation establishes boundaries based on food type, processing temperature and storage conditions.
Packaging for dry food falls outside this specific section and belongs under separate statutory requirements.
Extraction Limit
Migration testing under prescribed conditions measures the total extractable fraction transferring from paperboard into food simulants. The provisions of 21 CFR 176.170 specify exposure to distilled water or n-heptane solutions at defined temperatures representing retorting or room temperature storage. Laboratory protocols require continuous exposure inside liquid extraction cells for periods ranging from two hours to ten days.
Extraction values must not exceed 0.5 milligrams per square inch of food-contact surface area when calculated across triplicate determinations. Fatty food simulants like n-heptane employ a division factor of five to account for realistic lipid absorption rates during commercial shelf life. Non-volatile residues are weighed following solvent evaporation to determine total extractives.
The upper boundary limits the chemical transfer of functional additives and coating binders into packaged goods.
Compliance Audit
Verification of packaging materials relies on analytical certification documentation issued by accredited testing facilities. Under 21 CFR 176.170, convertors and paper mills maintain technical dossiers containing extraction test results and raw material declarations. Inadequate documentation or failure to meet extractable thresholds prevents legal distribution of packaging intended for wet food contact.
Regulatory enforcement operates through market sampling and facility inspections conducted by federal agents.