Safety Inspection and Judgment Standards for Food-Grade Plastic Molds

Food-grade plastic molds are core tooling for forming food packaging and food containers. Material safety, structural compliance, and stable performance directly impact food quality and human health. High-temperature injection molding and repeated long-term use may trigger hidden risks including hazardous substance precipitation, material aging, and surface contamination. Therefore, standardized safety inspections must be conducted complying with national food safety standards, and qualified molds shall be screened via unified judgment standards to eliminate food safety hazards. This article follows GB4806 series national food safety standards and systematically elaborates core safety inspection judgment requirements for food-grade plastic molds, providing compliance basis for mold manufacturing, on-site use, and third-party testing institutions.

I. Visual and Physical Appearance Safety Judgment Standards

Visual and physical inspection is the most basic screening item for food-grade plastic molds, intuitively judging whether molds meet basic use requirements for food contact and eliminating obvious safety defects. Qualified food-grade mold molding surfaces must be smooth and flat, free of cracks, air holes, burrs, depressions, and impurity black spots. No breakage, peeling, or wear aging shall appear on food contact surfaces to prevent plastic debris shedding and pollutant adhesion contaminating food. The overall mold color is uniform without obvious yellowing or carbonization traces; colored molds shall not fade or bleed pigment.

After thorough cleaning and disinfection, molds shall have no peculiar, pungent, or rancid odor. Test liquid after immersion testing remains clear and transparent without turbidity, floating matter, or sediment. Physical performance indicators require stable structural rigidity with high temperature resistance and tolerance to repeated clamping and extrusion, without deformation or warpage during production. Any mold with obvious breakage, persistent peculiar odor, color bleeding, or severe aging is directly judged unqualified and prohibited from food production and processing.

II. Safety Judgment Standards for Chemical Migration Substances

Chemical migration testing is the core indicator of food-grade mold safety judgment, detecting precipitation of hazardous substances under contact with water, acidic food, oily food, alcohol-containing food media, and high-temperature molding working conditions. All testing complies with GB4806.7-2016 National Standard for Food Contact Plastic Materials and Products.

First is total migration volume judgment. Four food simulants (water, acetic acid, ethanol, vegetable oil) simulate all food contact scenarios, and total migration volume under normal temperature and high temperature working conditions must meet national standard limits to avoid organic residue mixing into food. Second is heavy metal migration control: migration volume of lead shall not exceed 0.01mg/kg, and cadmium shall not be detected, preventing heavy metal accumulation that endangers human health.

Strict limits are imposed on plasticizers, bisphenol A, volatile organic compounds, and other restricted substances. Phthalate plasticizers and bisphenol A are prohibited from detection, and migration volume of unintentionally added substances shall not exceed 0.01mg/kg. Potassium permanganate consumption must also meet standards, reflecting precipitation volume of small soluble organic molecules from molds. Excessive values indicate impure mold material and risk of organic pollutant precipitation, marking the mold unqualified.

III. Compliance Judgment Standards for Base Materials and Additives

Compliance of mold base materials and additives is the fundamental guarantee for safety from the source, implemented in accordance with GB9685 National Standard for Additives Used in Food Contact Materials and Products. Qualified food-grade molds must adopt compliant virgin plastic materials including food-grade PP, PE, PET, and silicone. Recycled plastic, industrial waste, and regrind materials are strictly forbidden for mold production to eliminate hidden risks of industrial impurities and residual contaminants.

All additives including plasticizers, stabilizers, and colorants added during mold manufacturing must be listed within national permitted usage catalogs with strictly controlled dosage below limit values. Toxic and high-migration-risk additives are prohibited entirely. Mold materials shall not alter natural color, flavor, or composition structure of food, and shall not undergo chemical reactions with food. For plastic molds with coatings or modified structures, additional special safety assessment is required to confirm no coating peeling or excessive substance precipitation before judging the mold compliant.

IV. Safety Judgment Standards for Working Condition Adaptability and Durability

Food-grade plastic molds must adapt to high-temperature, high-pressure, repeated-use working conditions in food production, and working condition adaptability and durability standards determine long-term safe service life. Molds must withstand regular food processing high-temperature environments without softening, decomposition, smoking, or hazardous substance precipitation at common injection molding temperatures. All chemical migration indicators remain within safety limits under high-temperature working conditions.

After hundreds of cycles of repeated clamping, molding, cleaning, and disinfection, molds shall not develop aging cracks, material deterioration, or accumulated residual contaminants, with all safety testing indicators staying within standard limits. In addition, mold cleanability must reach standards: no residue adsorption or dirt-trapping gaps exist on surfaces to allow complete cleaning and disinfection and prevent microbial breeding that triggers food contamination. Molds with performance attenuation, out-of-tolerance indicators, or incomplete cleaning under matching working conditions are judged unfit for safe use and shall be decommissioned or scrapped.

Conclusion

Safety inspection judgment of food-grade plastic molds follows the core principle of qualified appearance, compliant migration, source-compliant materials, and matched working conditions. Visual and physical inspections screen visible surface defects, chemical migration testing controls core safety risks, material and additive audits lock compliance at the production source, and working condition durability testing guarantees long-term stable safe use. The four sets of standards complement each other and are all indispensable.

Food manufacturers and testing institutions must conduct regular standardized inspections fully complying with GB4806 series and GB9685 national standards. Timely sorting and replacement of unqualified molds eliminate hidden risks of chemical pollution, physical impurity contamination, and microbial pollution originating from production tooling. This fully guarantees safety and standardization of food production and processing links.