Food-grade silicone compliance is more than just "passing the test".
For purchasing and brand customers, it is even more critical that migration tests match real-world usage scenarios, that the production process is stable, and that the data is fully traceable.
1. Clarification: food grade/contact grade/maternal and child grade is not a concept.
- "Food contact" emphasizes migration and safety limits; "mother and baby" often includes odor, skin feel and more stringent supply chain controls.
- Compliance conclusions may be completely different for the same silicone material due to different formulations, additives, and colorants.
2. What regulatory and customer audits look for
- Migration test (total migration/specific migration): by exposure medium (oil/water/acid/alcohol simulant) in combination with temperature and time.
- Prohibited substances: Heavy metals, PAHs, etc. (depending on regional and industry requirements).
- Traceability: Closed-loop record from raw material lot number to finished product batch.
- Change management: Re-verification rules after recipe/supplier/process parameter changes.
3. What makes a migration test "effective"?
3.1 Using the right simulants and conditions
- The real medium is prioritized, followed by the selection of analogs according to the criteria.
- The conditions should cover the most demanding use scenarios: maximum temperature, maximum contact time, maximum contact area.
3.2 Sample Morphology and Surface Area Calculations
- Differences between the specimen and the actual part can affect the results: surface finish, degree of vulcanization, and thickness can all alter migration performance.
- It is recommended to include at least the "real part" version of the migration validation.
4. Production process control: a key point in determining consistency
- Raw material entry: batch number, COA, statement of prohibited and restricted substances
- Mixing and vulcanization: recording of key parameters (temperature, time, pressure)
- Secondary vulcanization: significant impact on volatiles and odor control
- Cleanliness and pollution prevention: workshop partitioning, tool specialization, packaging material compliance
5. Information checklist (can be used for supplier reviews/customer audits)
- Materials: formulation statement (confidential version available), COA, declaration of prohibited or restricted substances
- Testing: Migration report, odors/volatiles (if any), RoHS/REACH (if requested by customer)
- Process: process flow diagrams, key control points (KCP), inspection specifications
- Traceability: batch coding rules, sample production record forms, retention and shelf life rules
FAQ
1. Do I have to redo the migration for the same material to change colors?
Recommended to do. Color masterbatches/pigments are a common source of risk for migration and banned substances.
2. Is it sufficient to provide only third-party reports?
Not necessarily. Customers are more interested in whether "your batch" is equivalent to a reportable sample, requiring proof of lot traceability and process control.
