📌 Key Takeaways
A “pass” on one migration test report may be irrelevant—or misleading—in another jurisdiction because Specific Migration Limits (SML) compliance depends on matching test conditions to actual use.
- Test Conditions Define Validity: A migration result means nothing without documented simulant type, contact time, and temperature that correspond to the actual food contact scenario.
- EU and US Frameworks Differ Fundamentally: EU regulations set numeric substance limits while US FDA clearance focuses on permitted uses—treating them as interchangeable creates compliance gaps.
- Material Boundary Determines Risk: Compliance evidence must cover the actual structure—coatings, inks, adhesives—not just the paper substrate, since that’s where migration risk typically resides.
- Scope Statements Prevent Audit Failures: Declarations lacking defined product grades, production sites, and use conditions create ambiguity that auditors will challenge.
- Change Notification Protects Qualification: Supplier agreements must require re-evaluation when formulations change, or compliance documentation becomes outdated without warning.
Market logic, conditions of use, and material structure must align—when that triangle is explicit, audits stay focused.
QA managers and compliance leads expanding food-grade paper packaging into new markets will find a defensible verification workflow here, preparing them for the supplier questions and checklists that follow.
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For QA managers and compliance leads expanding into new markets, understanding SMLs matters because a test report showing “pass” in one jurisdiction may be irrelevant—or even misleading—in another.
This workflow addresses mid-market packaging operations teams who need to verify food-grade paper compliance across borders without becoming regulatory specialists. This guide establishes a technical framework for aligning legal limits into supplier specifications and audit-ready documentation—critical knowledge when evaluating food packaging paper suppliers or food-grade kraft paper mills.
What an SML Is (and What It Is Not)
A specific migration limit defines how much of a particular substance can transfer from a food contact material into food under standardized conditions. In the EU regulatory context, Regulation (EU) 10/2011 establishes SMLs for plastics, expressed as milligrams per kilogram of food (mg/kg food).
The critical distinction for paper packaging: EU 10/2011 applies to plastics, not paper directly. SML concepts become relevant for paper when the material structure includes functional coatings, barrier laminates, printing inks, or adhesives—components that may contain substances with established migration thresholds. Uncoated virgin paper presents different compliance considerations than a coated paperboard with a polymer barrier layer.
Key Terms That Create Cross-Functional Confusion
- Overall Migration Limit (OML): Total quantity of all non-volatile substances transferring from packaging to food, regardless of chemical identity. EU plastics regulation sets this at 10 mg/dm² (equivalent to 60 mg/kg of food using the standard 6:1 surface-to-volume ratio) under specified conditions.
- Specific Migration Limit (SML): The toxicologically derived threshold for the transfer of a discrete chemical constituent (e.g., monomers or additives) into a food simulant.
- Residual Quantity Limit (QM/QMA): Maximum amount of a substance permitted within the material itself, distinct from what migrates out of it.
Units That Require Attention
EU regulations typically express SMLs as mg/kg food. Some test reports use mg/dm² (milligrams per square decimeter of contact surface). Converting between these requires knowing the geometric exposure ratio of the specific packaging format—a detail frequently absent from generic supplier documentation.
Why SML Confusion Explodes in Global Paper Packaging
Three failure modes account for most compliance gaps when sourcing food-grade packaging paper across jurisdictions:
Wrong Regime Mapping
Teams treat EU-style SML tables as interchangeable with US FDA clearance logic. The frameworks operate differently. The EU system under Regulation (EC) 1935/2004 establishes positive lists of permitted substances with numeric migration limits. The US FDA approach under 21 CFR Part 176 focuses on clearance status and conditions of use—a fundamentally different verification structure. A substance “cleared” under FDA logic is not the same as a substance “tested to SML” under EU logic.
Wrong Test Conditions
Migration testing is only meaningful when the simulant (the substance representing food), contact time, and temperature match actual use conditions. A test using water at 40°C for 10 days provides no evidence about safety for fatty foods at 70°C for 30 minutes. Results can appear compliant while being entirely irrelevant to the intended application.
Wrong Material Boundary
Assuming “paper” is the compliance subject when actual risk resides in functional coatings, printing inks, or adhesive layers. The base paper substrate—whether sourced from kraft paper manufacturers or packaging paper manufacturers—may present minimal migration concern. Add a moisture barrier coating or solvent-based ink system, and the compliance profile shifts substantially. Evidence covering only the paper substrate—when the actual structure includes coated, laminated, or printed layers—represents a boundary mismatch that auditors will identify.
What Auditors Typically Request: Supplier declarations of compliance with clear scope statements, batch traceability linking raw materials to finished goods, evidence of Good Manufacturing Practice per EU GMP Regulation 2023/2006, and test reports with documented justification for how test conditions align with declared end use.
The Practical Workflow: How to Use SMLs to Qualify Food-Grade Packaging Paper
This sequence audits supplier claims through seven discrete verification gates. Each phase builds the documentation needed to defend sourcing decisions during audits or market-entry reviews.
Phase 1: Application Parameter Documentation
Document the actual application parameters: food type (aqueous, acidic, fatty, dry, alcoholic), expected contact duration and temperature range, whether contact is direct or separated by a functional barrier, and the surface-area-to-volume ratio of the package format. These parameters determine which test conditions are relevant.
Phase 2: Jurisdictional Mapping
List every jurisdiction where the packaged product will be sold. EU and UK markets invoke one regulatory framework. The US invokes another. Other markets may reference EU requirements, FDA clearances, or maintain independent national standards. Each market requires separate verification.
Phase 3: Material Component Profiling
Identify every component layer: base paper or paperboard (such as kraft paper or kraft linerboard), any functional coatings (moisture barriers, heat-seal layers, primers), printing inks and their location (food-contact side versus outer surface), adhesives, and any plastic film laminates. Each layer may carry distinct compliance requirements.
Phase 4: Substance Disclosure Protocols
Request from suppliers: composition boundaries describing what substance families are present, intentionally added substances with CAS registry numbers where applicable, their documented position on non-intentionally added substances (NIAS), and separate declarations for ink and adhesive systems if these are sourced independently.
Phase 5: Migration Testing Configuration
Specify which food simulants (e.g., 10% ethanol, 3% acetic acid, vegetable oil, or Poly(2,6-diphenyl-p-phenylene oxide) [Tenax] for dry foods) and which time/temperature combinations reflect actual use. For EU markets, Regulation (EU) 10/2011 Annex III defines standardized simulants, while Annex V outlines the test conditions for plastics; similar logic applies when evaluating coated paper structures.
Phase 6: Data Validation and Gap Analysis
Confirm that test results demonstrate compliance against relevant SMLs or clearance conditions for each target market. Flag any mismatch between tested conditions and actual intended use. Verify that declarations explicitly state what they cover and what they exclude.
Phase 7: Specification Finalization and Change Control
Determine what becomes a standing specification requirement (verified with each production lot or at defined intervals) versus a one-time qualification artifact. Build change-notification requirements into supplier agreements so formulation modifications trigger re-evaluation.
Supplier Qualification Mini-Checklist
Copy into RFQ or specification documents:
- Complete material structure documented (all layers)
- Intentionally added substances listed with identifiers
- NIAS position statement provided
- Ink/adhesive compliance documented separately
- Test conditions specified (simulant, time, temperature)
- Test conditions match intended use case
- Laboratory accreditation confirmed (ISO 17025)
- Declaration scope statement present
- Change notification clause included
The Cross-Jurisdiction Comparison Table
| Dimension | EU Approach | US FDA Approach | What QA Must Verify | Common Misread |
| Regulatory Anchor | Framework Regulation (EC) 1935/2004 establishes general FCM requirements; specific measures like EU 10/2011 set detailed limits for plastics | 21 CFR 176.170 and 21 CFR 176.180 define permitted substances and use conditions for paper and paperboard components | Confirm which regulation applies to each material layer in the structure | Assuming EU plastics regulation directly governs uncoated paper |
| How Limits Are Expressed | SMLs stated as mg/kg food or mg/dm²; explicit numeric thresholds per regulated substance | Clearance language describing permitted substances under specified conditions; less reliance on numeric SML values | Match test report units and format to the regulatory requirement being claimed | Treating FDA “cleared” status as equivalent to “tested against SML” |
| Testing Logic | Defined simulants (Simulants A through E) with standardized time and temperature protocols | Extraction conditions specified per substance category or intended use | Verify that simulant type and test conditions match actual food contact scenario | Accepting a generic test report without confirming condition relevance |
| Documentation Expectation | Declaration of Compliance (DoC) required; must reference applicable regulations and supporting evidence | No mandatory DoC format; compliance demonstrated through substance clearance and use-condition alignment | Request explicit DoC with scope statement for EU; request clearance evidence and condition verification for US | Accepting DoC without verifying it covers the specific material structure and use case |
| Paper-Specific Guidance | No harmonized EU regulation specific to paper; BfR Recommendation XXXVI widely referenced as industry benchmark for paper and board | 21 CFR 176.170 and 176.180 address paper and paperboard components directly | Confirm whether BfR or equivalent guidance is referenced; verify scope covers actual materials | Treating BfR recommendation as legally binding regulation rather than industry guidance |
Supplier Verification Questions: The “Don’t Waste a Week” Set
These questions are grouped to enable efficient supplier screening before committing procurement resources to extended qualification processes.
Material Structure and Coatings
- What is the complete material structure from food-contact surface to outer surface?
- Are functional coatings applied? If yes, what substance categories do they contain?
- For multi-layer structures, which specific layer is intended for direct food contact?
Ink and Adhesive Scope
- Are printing inks applied to the food-contact side, the outer surface, or between layers?
- For printed structures, what set-off risk controls are in place to prevent ink migration from non-contact surfaces?
- What adhesive systems are used, and are they covered under separate compliance documentation?
- Do your ink and adhesive suppliers provide independent declarations of compliance?
Test Conditions and Laboratory Accreditation
- What simulants, contact times, and temperatures were used in migration testing?
- Is the testing laboratory accredited to ISO 17025 for food contact material analysis?
- Do the tested conditions correspond to our intended use case (food type, duration, temperature)?
Version Control
- What is the issue date and revision number of the current declaration of compliance?
- Which specific product grades and production facilities does this documentation cover?
- What is explicitly excluded from the declaration scope (alternate coatings, print systems, basis-weight ranges, market claims)?
Change Notification and Formulation Drift
- What is your change-notification policy when formulation or raw material sources change?
- Can you provide batch traceability linking incoming raw materials to finished packaging products?
Common Pitfalls and Red Flags
These indicators signal documentation that may not support compliance claims under audit scrutiny.
“Pass” Report Without Test Condition Details. A migration test result showing compliance means nothing without explicit documentation of simulant type, contact time, and temperature. Absent these details, the report cannot be evaluated against any specific use case.
Wrong Boundary Evidence. A declaration citing only EU 10/2011 for a product described as paper or paperboard suggests incomplete understanding of the material boundary. Paper substrates require separate compliance consideration, often referencing industry guidance such as BfR Recommendation XXXVI rather than plastics-specific regulation. The inverse also applies: paper-only evidence used to support a coated, laminated, or printed structure leaves the compliance-driving layers unaddressed.
Missing Scope Statement. Declarations should specify exactly what they cover: which product grades, which production sites, which material layers, and which use conditions. A blanket claim without defined scope creates ambiguity that auditors will question.
“Food Safe” Without Jurisdiction or Conditions. The phrase “food safe” carries no standalone regulatory meaning. Compliance is always jurisdiction-specific and condition-specific. Request clarification identifying which regulatory framework and which use parameters the claim addresses.
No GMP or Traceability Documentation. For EU market access, GMP compliance under Regulation (EC) 2023/2006 is mandatory for food contact material manufacturers. Absence of GMP evidence indicates a gap in the supplier’s compliance infrastructure that affects the entire documentation chain.
Building Your Compliance Workflow
SML compliance is a technical alignment process: mapping regulatory thresholds to empirical test parameters, supplier specifications, and audit-defensible documentation. The workflow presented here—define use cases, map markets, identify material layers, request substance data, align test conditions, evaluate evidence, lock specifications—provides a standardized protocol for scaling oversight and product lines.
Every defensible compliance file rests on a triangle: the market’s regulatory logic, the actual conditions of use, and the specific material structure. When that triangle is explicit and aligned, approvals move faster and audit conversations stay focused.
Copy the supplier verification questions and mini-checklist into your next RFQ or specification document. Buyers ready to source compliant materials can submit an RFQ and receive quotes free from verified suppliers.
Share this framework with QA and procurement teams to establish consistent evaluation criteria across your organization. For additional guidance on defining enforceable specifications, verifying supplier documentation, and structuring compliance audit checklists, explore related resources in the PaperIndex Academy.
Disclaimer:
This article is for educational purposes and does not constitute legal advice. Regulatory requirements vary by jurisdiction and change over time. Consult qualified regulatory and legal professionals for compliance determinations specific to your products, materials, and target markets.
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