Direct Answer
Migration testing measures whether substances from molded pulp packaging transfer into food under defined conditions, using food simulants and controlled time and temperature to represent the intended use. It reports overall migration and, where required, specific migration of named substances against the limits in the target market's regulations. The requirement follows the end use, so dry, aqueous, fatty, and acidic foods trigger different simulants and conditions. The buyer should require per-SKU documentation covering the food-contact basis, the test method, the result against the limit, and any coatings or additives, because the importer or brand still owns the final compliance decision. A blanket company statement does not replace a per-SKU test result.
Opening Hook
A buyer sourced molded pulp trays for a fatty prepared-food line and accepted a supplier's assurance that the material was food-safe. At the destination market the trays were questioned for lack of migration documentation, and the shipment was held while the buyer scrambled for test results the supplier had never produced per SKU. The program was rebuilt around per-SKU food-contact documentation with the test method, conditions, and results on file. At yisenpulp, we provide per-SKU food-contact documentation and tell buyers to verify the basis for their own market, because the compliance decision always sits with the brand that puts the food in the tray.
What Migration Testing Measures
Migration testing answers one question: what moves from the packaging into the food, and how much.
| Test Type | What It Reports | When Required |
|---|---|---|
| Overall migration | Total mass transferred | General food contact |
| Specific migration | Named substance limits | Additives, monomers, metals |
| Simulant testing | Transfer into a food stand-in | By food type |
| Extractables screening | What could migrate | Early material review |
The conditions are set to represent real use: the simulant, temperature, and time are chosen for the food type and the intended service, not taken from a generic default.
Data: The U.S. FDA regulates food-contact packaging under its Food Contact Substances framework, which establishes the basis for determining that a material is suitable for its intended food-contact use.
Judgment: Require the food-contact basis and test documentation per SKU for the intended food type, because the brand that places food in the packaging carries the compliance obligation, not the supplier's marketing claim.
Source: U.S. FDA — Packaging Food Contact Substances (FCS) (2024)
Food Simulants and Test Conditions
The test is only as good as the simulant and conditions chosen for the real food.
| Food Type | Simulant Direction | Condition to Define |
|---|---|---|
| Dry food | Low-transfer condition | Contact time and temperature |
| Aqueous food | Water-based simulant | Acidity and temperature |
| Fatty food | Oil-based simulant | Fat content and temperature |
| Acidic food | Acidic simulant | pH and temperature |
A tray tested against the wrong simulant can pass while failing the real food it holds. The buyer should confirm the simulant and conditions match the intended use before accepting any result.
Documentation Per SKU
Food-contact compliance is a document set, not a company slogan.
| Document | What It Covers | Why Per SKU |
|---|---|---|
| Food-contact basis | Regulatory basis for the material | Basis differs by market |
| Test method and conditions | Simulant, time, temperature | Match the end use |
| Migration result | Value against the limit | Proof, not promise |
| Coatings and additives | Named substances present | Specific migration needs |
A blanket company statement does not cover a specific SKU in a specific market. The per-SKU file is what survives a regulatory question at the dock or on a retail shelf. How the food-contact path is built is set out in the FDA food contact packaging guide.
Data: ASTM International maintains migration and food-contact testing standards that define how overall and specific migration are measured under controlled conditions.
Judgment: Match the test method, simulant, and conditions to the intended food and market, because a migration result against the wrong conditions is not evidence for the real use.
Source: ASTM International — Migration and Food Contact Testing Standards (2024)
Verifying Food Safety Readiness
Verification turns a food-contact claim into a reviewable file.
| Step | Action | Output |
|---|---|---|
| 1 | Define the food type and market | End-use profile |
| 2 | Confirm the simulant and conditions | Matched test plan |
| 3 | Obtain per-SKU test documentation | Evidence file |
| 4 | Review coatings and additives | Named substances |
| 5 | Keep the file for audit | Traceable record |
The file is kept by the buyer, not just the supplier, because the brand carries the obligation if the packaging is questioned. The lab discipline that produces these results is covered in the quality control lab testing guide.
Common Food-Contact Failures
Three failures account for most food-contact findings.
| Failure | Cause | Fix |
|---|---|---|
| Blanket "food-safe" claim | No per-SKU evidence | Require per-SKU documentation |
| Wrong simulant or conditions | Generic test | Match to the food type |
| Undocumented coating or additive | No named substances | List and test them |
The fix is always the same: per-SKU documentation matched to the real food and market, kept on file. A verbal assurance is worth nothing when the shipment is held.
Data: BPI operates a certification program for compostable products that verifies materials against defined standards, illustrating the third-party verification path for packaging claims.
Judgment: Treat third-party verification as the model for food-contact claims — a claim backed by a reviewable certificate or test report, not by a supplier's description.
Source: BPI — Compostability Certification Program (2024)
The Bottom Line
Molded pulp food safety is a per-SKU documentation exercise: match the migration test to the food type and market, hold the method, conditions, and result on file, and keep the food-contact basis reviewable. The brand that puts food in the packaging owns the compliance decision. In one sentence: yisenpulp provides per-SKU food-contact documentation and tells buyers to verify the basis for their own market, because the compliance decision never transfers to the supplier.