On September 2, 2026, GB 4806.16-2025, the National Food Safety Standard for Food-Contact Silicone Rubber Materials and Articles, officially took effect, fully replacing the silicone rubber-related provisions in the previous GB 4806.11-2016. The most core change in the new standard is the addition of a mandatory "volatile matter" testing item, with a limit of ≤0.5 g/100 g (i.e., 0.5%), which imposes higher requirements on the production and application of silicone rubber materials.

Where Do Volatile Substances Come From?

During production, silicone rubber may retain unreacted monomers (such as octamethylcyclotetrasiloxane D4, D5, etc.), processing aids (vulcanizing agents, catalysts), and other low-molecular-weight polysiloxanes. Among these, D4 has reproductive toxicity and is listed by the EU as a Substance of Very High Concern (SVHC). When silicone products are heated at high temperatures, exposed to oils and fats for extended periods, or repeatedly sterilized, these volatile substances readily migrate into food, posing potential safety risks.

Testing Methods Under the New Standard

The new standard adopts headspace gas chromatography (HS-GC) or the dry weight loss method: samples are cut into pieces and baked at 200°C ± 3°C for 240 minutes, with volatile matter content calculated by mass difference. This indicator and sensory requirements are parallel, independent items—failure to meet either one results in a non-compliant determination.

Material Selection: LSR vs. Conventional Solid Silicone

In terms of material selection, there are significant differences between liquid silicone rubber (LSR) and conventional solid silicone. LSR uses addition-cure vulcanization and injection molding processes, with a dense molecular structure, and D4 residue can be achieved at non-detectable levels; conventional silicone requires the introduction of sulfur-containing vulcanizing agents and may have D4 residue, making it more prone to releasing harmful substances at high temperatures. Therefore, food-grade applications should prioritize addition-cure LSR materials, with suppliers required to provide test reports compliant with the new national standard.

Improved Raw Material Control Requirements

The new standard also refines raw material control requirements: silicone rubber raw materials (such as silicone oil and silica) must comply with GB 4806.6-2016 or relevant announcements, with suppliers required to provide test reports; food simulant selection remains consistent with GB 31604.1, with vegetable oil preferred as the simulant for oily foods, no longer following the old rule of "50% ethanol substitution."

Compliance Recommendations for Manufacturers

For enterprises engaged in the production of food-contact silicone rubber products, it is recommended to address compliance from three aspects: first, strengthen raw material traceability management, requiring suppliers to provide compliance test reports; second, upgrade testing capabilities by equipping volatile matter testing equipment or commissioning qualified third-party institutions; third, optimize material selection by prioritizing addition-cure LSR systems for food-grade applications, reducing volatile matter residue risks from the source.

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