How to Meet Strict VOC, FDA and LFGB Food-Safe Silicone Valve Standards?

With increasingly stringent international safety requirements, the safety standards for daily consumer products are becoming increasingly important. For silicone rubber products, especially those in contact with humans, such as breast pumps, silicone sealing rings, and check valves - products that come into contact with food, beverages, and baby products - the most common problems include: excessive volatile organic compounds (VOCs)/(VOMs); residual silicone cyclic compounds (the EU has very strict requirements on this); silicone odor residue and release of oily substances; migration of heavy metals (lead, cadmium, mercury, hexavalent chromium, etc.) (testing standards include: FDA, 1935/2004/EC (EU) (food contact), REACH SVHC, RoHS); water extraction and total migration (tested according to FDA/LFGB/1935/2004/EC (EU)); polycyclic aromatic hydrocarbons (PAHs), etc.

As an integrated manufacturing and export company, we not only provide customers with high-quality, stable products, but also actively cooperate with their quality requirements, continuously improving production and services. When customers are faced with VOC exceeding standards, we test and optimize solutions and promptly procure equipment to help them test VOC content to ensure each batch meets the limits. When customers encounter heavy metal migration issues, we comprehensively examine every step, from raw materials and production processes (equipment, environment) to process parameters, to identify the root cause and resolve the problem. If customers have FDA certification requirements (FDA compliance requires adherence to 21 CFR 177.2600), we strictly control these products from raw material selection and production processes to inspection.

How To Solve the Problem of Excessive VOC / VOM of Silicone Rubber Products?

First, raw materials, added curing agent (often use platinum-cured agent), and pigment all need to conform to food contact.

Second, the production is sufficiently cured and the temperature and time are sufficient. Let the raw materials be sufficiently sullied in the mold to avoid incomplete cross-linking and the residual of unreacted small molecules and curing agent.

Finally, the post curing oven meets the requirements and operates at the correct temperature and time (generally 200 ° C / 4 hours). Place the product evenly and disperse it so that the product can be fully post cured, so that small molecules and residues volatilize and decompose from the product and discharge through the oven vent.

How Do Silicone Rubber Products Comply with FDA, LFGB, EU Requirements?

The core controls of these three standards are consistent (all focusing on food contact safety): FDA focuses on raw material and mobility compliance, LFGB strictly regulates odors/tastes and PAHs, and EU focuses on total mobility and heavy metal mobility.

Silicone rubber products comply with the requirements of FDA (US Food Exposure), LFGB (Germany Food Exposure) and EU. The core is to establish a full-process compliance control system, covering the three major components of raw materials, production, finished products.

Control of Raw Materials and Additives (Foundation of Compliance)

Silicone rubber raw materials: the selection of food grade, low volatile, low cyclic (D3 ~ D20) raw materials in line with the three standards, no heavy metals, PAHs, phthalate and other harmful substances.

Agent materials: pigment, curing agent and other additives need to choose no heavy metals, no nitrosamine, no PAHs food grade products, to eliminate non-environmental protection additives into the pollutants.

Raw material storage: moisture prevention, pollution prevention, partitioning.

Production Process Control (Key Aspects)

Equipment control: Specialized equipment for food grade silicone products production, and it is prohibited to share with non-environmental rubber products. Check equipment cleaning records before each batch to avoid cross contamination; Clean ovens, cured machines and other equipment on a regular basis to ensure that the equipment is free of residual contaminants.

Curing process: Strictly enforce standardized processes. The first compression molding needs to calibrate the temperature and pressure meters, monitor the parameters in real time, and ensure that the cross-link is completed. The post curing is carried out according to 200℃ ± 5℃ and 4 hours standard to ensure that the exhaust is unobstructed, the product is not stacked, and the small molecules and residues are completely discharged.

On-site control: The production workshop avoids mixing with products containing heavy metals, phthalates and other pollutants, regularly cleans the production environment, standardizes the use of production tools, and prevents the introduction of pollutants in the production process.

Product Control (Compliance Verification)

Key Detection: VOC / VOM sampling for each batch. According to customer demand each batch sent to the third-party laboratory such as SGS testing (customer responsible for testing costs).

Odor/Taste Control: internal visual inspection of the finished product odor/taste, eliminate peculiar smell, ensure to pass the LFGB odor test, avoid the impact of unqualified odor compliance.

Storage and packaging: The finished packaging uses non-odorless and non-polluting materials, and the storage environment is damp and ventilated.

How To Test if VOC/VOM Levels Exceed the Limits?

According to French testing standards: Arrêté du 25 novembre 1992 relatif aux matériaux et objets en élastomères de silicone mis ou destinés à être mis au contact des denrées, produits et boissons alimentaires - Annexe III

We have compiled the following steps for detecting VOCs/VOM. SGS an Bureau Veritas refer to French method:

Determination of Free Volatile Organic Compounds

Principle: The method consists in measuring the weight loss of a sample after heating, corresponding to the evaporation of free volatile organic compounds.

Procedure:

Sample Preparation:

        Take approximately 10 grams of the sample.

        Cut it into pieces of about 1 cm × 1 cm.

Initial Drying:

        Place the pieces in a desiccator containing calcium chloride.

Leave for 48 hours at room temperature.

    Weighing and Heating:

     After drying, weigh the sample accurately to ± 0.1 mg using a flat filter balance.

        Place the sample in an oven and heat for 4 hours at 200 °C.

Cooling and Final Weighing:

        Allow the sample to cool in the desiccator.

        Weigh again after cooling.

Calculation:

        The volatile content is obtained by the difference in weight before and after heating.

        Express the result as a percentage of the initial weight. (Limit 0.50%)