Recently, the Southern Common Market (Mercosur) adopted Resolution No. 34/2025, enacting the "Technical regulations on silicones used in the manufacturing of materials, containers, coatings, and equipment that come into contact with food." This resolution systematically revises three existing regulations related to adhesives, elastomers, and plastic products, establishing for the first time a dedicated regulatory framework for silicone-based materials.
Core Requirements
1. Positive List System
Only substances listed in the regulation are permitted (divided into five categories):
- Part I: Silicone oils and emulsions (viscosity ≥100 mm²/s)
- Part II: Silicone resins
- Part III: Silicone rubbers (elastomers), with specific provisions: Products for infants and young children (e.g., pacifiers) must additionally comply with nitrosamine limits (≤0.01 mg/kg).
- Part IV: Additives and fillers (including silica, alumina, carbon black, etc.)
- Part V: Monomers
2. Permitted Salts
Explicitly authorizes the use of certain salts (e.g., aluminum, barium, cobalt, copper, iron) and sets specific migration limits (SML):
- Cobalt: 0.05 mg/kg
- Nickel: 0.02 mg/kg
- Aluminum/Barium: 1 mg/kg
- Copper/Zinc: 5 mg/kg
3. Migration Limits
- Volatile organic compounds: ≤0.5% (m/m)
- Extractables: ≤0.5% (m/m) (tested using water, 3% acetic acid, and 10% ethanol as simulants)
- Peroxide residues: Not detectable (by titration, with blank difference ≤2.0 mL)
- Aromatic amines: Not detectable (limit 0.01 mg/kg)
4. Colorants
Must comply with Mercosur’s technical regulations on colorants for plastics.
5. Food Additives
Food additives not listed in this regulation but authorized by Mercosur may also be used, provided that the combined migration level and pre-existing amount in the food do not exceed specified limits.
