Custom Chinese Food-contact Plastic Parts: Key Compliance Points for FDA and GB 4806

For food-contact plastic custom parts sold to domestic and overseas markets, it is necessary to clarify the differences between China’s GB 4806 series standards and the US FDA 21 CFR regulations. Full-process control should be implemented from raw material selection, formula management, mold development, production process, finished product testing to traceability records to avoid non-conformity, product recall or cargo detention. Both standards focus on the migration of substances, but there are clear differences in permitted material lists, test simulants, limit values and application scenarios. For export orders, the regulatory version corresponding to the target market must be confirmed in advance.

Raw material and formula control with positive lists

Under GB 4806 system, plastic resins shall comply with GB 4806.6, and finished plastic products follow GB 4806.7-2023. All additives must be selected from the permitted list in GB 9685. Additives, color masterbatches and fillers outside the list cannot be used directly. Recycled materials are subject to strict restrictions, and recycled materials are generally not recommended for food-contact parts for infants. FDA compliance mainly refers to 21 CFR Part 177. All resins, additives and colorants must be included in FDA food contact substance inventories. New materials need FCN notification before application. A formula that meets both standards needs to check two lists separately. Many additives approved in China are not accepted by FDA, and sharing the same formula blindly will lead to disqualification of export batches. Suppliers must provide material certificates matching the corresponding standards instead of simple grade descriptions.

Differences in migration test, limit values and test conditions

Migration test is the core judgment basis. Test simulants, temperature, duration and limits cannot be mixed. GB 4806 adopts four types of food simulants: aqueous, acidic, alcoholic and oily. The general total migration limit is 10 mg/dm², with special relaxed limits for oil contact scenarios. It also controls the migration of specific substances such as bisphenol A, phthalates and heavy metals. FDA divides application conditions by food type, contact temperature and duration, including high-temperature repeated contact, normal-temperature short-term contact and long-term storage. Its extraction solvents, calculation units and judgment methods are different from GB 4806. GB test reports cannot replace FDA compliance certificates. Test samples must cover all molding areas including gates and parting lines. Excessive molding temperature will cause resin degradation and raise migration results.

Mold design and mold material control requirements

For food-contact products, cavity surfaces prefer corrosion-resistant stainless steel such as 420, S136 and 17-4PH. Ordinary pre-hardened steel is prone to rust in humid and acidic cleaning environments, and precipitated metal contaminants will cause heavy metal overrun. Demolding agents should be avoided as much as possible. Mold polishing and low-friction PVD coating are preferred for smooth demolding. If demolding agent is necessary, only food-contact grade products compliant with both GB 4806 and FDA can be used, with pre-production mold cleaning procedures. Runners, dead corners and vent slots should be easy to clean to prevent accumulated carbon and residue. Deep etched textures require additional cleaning validation. Complete mold cleaning must be performed before switching from non-food-grade products to avoid cross-contamination.

Workshop and process management for injection molding

Domestic production shall meet GB 31603 hygiene specifications. Production lines for food-grade plastic parts are separated from ordinary industrial plastic lines to prevent cross-contamination of raw materials and debris. Drying parameters, barrel temperature, back pressure and material residence time shall be fixed in work instructions. Overlong residence of plastic in the barrel causes thermal degradation and small molecular precipitates that increase migration risk. Food-grade purging compounds are used for material and color change. Operators wear clean work clothes, and cleaning agents and lubricants used on site also need compliance certificates. FDA does not mandate cleanroom levels, but auditors will check cross-contamination control and purging records.

Marking, documentation and traceability system

GB 4806.1 requires mandatory marking of “Food Contact Use”, together with spoon symbol, material grade, service temperature, applicable food types and manufacturer information. Usage limits shall be marked for high-risk products. FDA has no unified marking template, but a Declaration of Conformity (DoC) must be retained, recording raw material grades, service conditions, test reports and supply chain documents. The traceability chain covers resin, color masterbatch, mold batches, production shifts and inspection records. Missing data of upstream additives will cause failure in compliance proof.

Common risks and implementation suggestions for dual-standard customization

Common pitfalls include using one test report for both domestic and export sales, using uncertified colorants, skipping high-temperature migration tests and mixing industrial release agents. For dual-market orders, formula review for both standards shall be carried out in advance, and two separate migration tests shall be arranged. Compliance evaluation shall be included in DFM review at the early stage, rather than after mold machining and trial molding.