Why raw-material compliance alone is insufficient, and how to review volatiles, migration and the finished formulation.
A compliant base polymer and a supplier document do not establish compliance of the finished article. GB 4806.16-2025 covers food-contact silicone rubber materials and articles, including raw-material requirements, sensory properties, physicochemical criteria and migration testing. It took effect on 2 September 2026.
For manufacturers already in production, the review needs to cover the whole sequence: raw materials, formulation, processing, finished article, testing and conditions of use. Approval of one stage cannot stand in for the others.
1 Permitted raw materials and compliant articles are different questions
Raw material evidence is only part of the assessment
Silicone rubber formulations commonly contain polysiloxanes, silica, crosslinkers, catalysts and other components. GB 4806.16-2025 sets requirements for base materials, their use and additives.
Asking whether a material has an FDA or GB document is only a starting point. Also establish its identity; whether the document concerns raw material or a cured article; its proportion in the final formulation; any added auxiliaries; actual food-contact conditions; and whether the article has been validated under the applicable standard.
FDA compliance does not mean FDA certification
Customers may search for “FDA silicone rubber” or “FDA compliant silicone rubber”. For purchasing and export, the useful questions are which provisions apply, what the material contains, how it is used and what the finished article must meet. Raw-material literature should not be presented as “FDA certification” of the final product. Keep supplier evidence and finished-article validation as separate records.
2 What to check under the standard
Compliance depends on several checks, rather than a single yes-or-no statement.
|
Review area |
What to check |
Why it matters |
|
Base materials |
Whether they fall within the permitted scope |
Establishes the formulation starting point |
|
Additives |
Permitted uses and restrictions |
Identifies problems with formulation components |
|
Sensory properties |
Color, odor and behavior of the migration solution |
Assesses sensory risk after food contact |
|
Physicochemical criteria |
Applicable physical and chemical indicators |
Confirms article requirements |
|
Volatile substances |
Requirements and testing under the new standard |
Controls residual volatile components |
|
Overall migration |
Testing under applicable conditions |
Assesses migration from the article during contact |
|
Use conditions |
Temperature, time, food type |
Determines test conditions |
GB 4806.16-2025 changes some test conditions and adds requirements for volatile substances. When rubber, silica or another component changes, hardness, tensile strength and processability are not enough for comparison.
3 Why volatiles need their own review
A material can pass mechanical tests while low-molecular-weight or volatile components remain insufficiently controlled. The new standard includes volatile-substance criteria and a corresponding test method. Research published in 2026 also examined migration of multiple siloxanes from food-contact silicone materials in China and assessed exposure.
If raw-material documents appear satisfactory and ordinary physical properties pass, but the finished article fails on volatiles or migration, do not immediately dismiss the result as measurement error. Check the base polymer and composition; silica and other fillers; crosslinking and catalyst systems; formulation ratios; mixing and curing; post-treatment and devolatilization; and actual service temperature and duration.
4 Replacing fumed or precipitated silica
Both are silicon dioxide, but that does not make them direct substitutes. Silica affects reinforcement efficiency, hardness, tensile strength, elongation, mixing, thixotropy, processing, appearance and interactions with other components, as well as the compliance review.
If cost or supply pressures prompt a replacement, treat it as a formulation change, not just a purchasing change. For food contact, establish the replacement grade's suitability and its effect on validation of the finished article.
5 Review a new supplier in four stages
Define the final application
Record direct food contact or otherwise, food type, contact temperature and duration, repeated use, and the finished article's form.
Review the composition
A single declaration is not enough. Confirm the base polymer, silica type, crosslinking system, catalyst system, other additives and formulation-change controls.
Establish the testing framework
Choose it according to the actual market and application.
|
Market or use |
Priority checks |
|
Food contact in China |
GB 4806.16-2025 and supporting standards |
|
Food contact in the US |
Applicable FDA provisions and use conditions |
|
EU market |
Specific food-contact legislation and customer requirements |
|
Global customers |
Customer Restricted Substance List, test specifications and compliance documents |
Confirm the finished article
This stage is often missed. Even when all raw materials have been reviewed, define the article's test plan using its actual formulation and intended use.
6 Changes that may require revalidation
Do more than update supplier paperwork when any of the following changes occurs. Assess the need for new validation:
1. Replacement of the silicone rubber base material.
2. Replacement of silica.
3. A different crosslinking system.
4. A different catalyst.
5. A substantial change in formulation ratios.
6. A change in curing.
7. A change in post-treatment.
8. A change in food-contact temperature or duration.
9. Entry into a new food-contact market.
10. Changes to customer regulatory requirements or the company's RSL.
Compliance records should be linked to formulation change control, rather than treated as one-time paperwork.
7 A six-step selection process
1. Establish the regulatory market. Identify where the product will be sold before choosing materials.
2. Define use conditions. Record food type, temperature, duration and repeated use.
3. Screen base materials. Check the permitted scope of rubber, silica and other components.
4. Validate the formulation. Evaluate the actual combination, not isolated raw materials alone.
5. Test the article. Match the plan to market and real use conditions.
6. Control changes. Reassess risk when suppliers, grades or key materials change.
This gives industrial buyers a workable approval process beyond labels such as “Food Grade” or “FDA”.
8 How IOTA can support selection
IOTA Silicone Oil (Anhui) Co., Ltd. provides solutions across the silicone industry chain, including oils, rubber, resins, silanes, polysilazanes, silica and silicone additives. Food-contact material selection must follow the final application.
IOTA can help identify the rubber direction for the application; assess silica against formulation needs; match silicone raw materials to processing; identify market-specific regulatory and testing questions requiring confirmation; and compare replacements across raw materials, processing and final performance.
IOTA supplies materials and selection support. It does not equate a raw-material compliance document with conformity of the finished rubber article. The final conclusion must account for the formulation, production, article tests and destination-market requirements.
9 Common misunderstandings
An FDA document guarantees a compliant article
It does not. Confirm the material, provisions and conditions covered before applying the document to the article.
GB-compliant raw materials automatically satisfy GB 4806.16-2025
They do not. The final formulation and use conditions still require validation.
Food-grade silica suits every food-contact rubber
Not necessarily. Validate the specific grade, surface properties, loading, process and article.
Silica changes affect only cost
They can also affect formulation, processing and final tests. Reassess the risk.
A passed test remains valid after a supplier change
Do not assume this. Reassess technical and compliance implications according to changes in suppliers, key materials or formulation.
10 What procurement and development teams need to retain
Since 2 September 2026, selection under GB 4806.16-2025 requires more than evidence of a food-grade raw material. Maintain traceable validation of materials, formulation, process, article and use conditions.
Changes to silica, crosslinkers, catalysts and other components require assessment of their effects on volatiles, migration and final properties. A supplier's ability to support that assessment matters beyond price and basic physical data.
FAQ
Q1 When did GB 4806.16-2025 take effect?
It was published in 2025 and took effect on 2 September 2026.
Q2 Does raw-material compliance guarantee the article?
No. Assess the actual formulation, processing, use conditions and article tests as well.
Q3 Why check volatiles?
Silicones may contain low-molecular-weight or volatile components. The new requirements make their control part of material and process validation.
Q4 Can fumed silica directly replace precipitated silica?
The name or silicon dioxide content is insufficient. Validate reinforcement, processing, compatibility and article tests.
Q5 Must a supplier change trigger full retesting?
That depends on the material, formulation and process changes. At least assess change risk; existing results cannot automatically be transferred.
Q6 Are FDA and GB compliance interchangeable?
No. Check each system against the sales market and actual use conditions.
Q7 What should buyers request first?
Specifications, composition information, applicable declarations, tests, batch consistency and change-control information. The final use determines further validation.
Related products
1. Food-contact silicone rubber: material selection for seals, articles and silicone elastomer applications. Confirm scope and compliance evidence for the intended use.
2. Silica: reinforcement and processing adjustment in silicone rubber. Validate the grade against formulation and final-article requirements.
Use current valid documentation on the following IOTA sites for grades and parameters.
