In daily communication within the liquid adhesive industry, we frequently encounter downstream customers asking the same question: "They're all silicone, so why is the price difference so big?" Behind this question lies a key fact that is easily obscured by the word "silicone": the existence of a material grading system determines that the safety boundaries between different "silicones" are worlds apart.

Industrial Grade: Performance First, Looser Safety Control

Industrial-grade liquid silicone is the foundational tier in the grading system. Its formulation design focuses on hardness, tensile strength, tear resistance, and weather resistance, with typical applications including automotive parts, industrial seals, conductive buttons, and general mold-making. Such materials typically comply with the basic requirements of environmental directives such as ROHS and REACH, but have not undergone rigorous biocompatibility testing, nor have they been subject to harmful substance migration control for food-contact or long-term human contact scenarios.

From the raw material end, industrial-grade silicone may contain trace volatiles or non-food-grade catalyst residues. Industry technical documentation explicitly states that industrial silicone "absolutely must not be used to produce children's silicone toys," as long-term skin contact may cause discomfort. The basis for this judgment is not that industrial silicone is "toxic," but that its quality control system has never taken human contact safety as a design objective.

Food Grade: Migration Control Is the Core

The safety logic of food-grade liquid silicone is completely different from industrial grade. Its core requirement is that the migration of harmful substances into food must be controlled within safe limits, while not causing food to develop off-odors or color changes.

In China, food-contact silicone rubber materials and articles must comply with the National Food Safety Standard for Food-Contact Silicone Rubber Materials and Articles (GB 4806.16-2025). This standard officially took effect on September 2, 2026, replacing the previous standard that mixed silicone and rubber together. An important change in the new national standard is the addition of a "volatile matter" limit indicator and its supporting testing methods, along with stricter testing conditions for potassium permanganate consumption and heavy metals. This means that the mere words "food grade" are no longer sufficient to prove compliance—suppliers need to be able to provide volatile matter testing data specific to the new national standard.

Food-grade silicone typically uses platinum catalysts rather than peroxide catalysts at the raw material end, reducing the risk of toxic residues from the source. This process choice is directly reflected in cost, and is one of the main sources of the price difference between food grade and industrial grade.

Toy Grade: The Gray Zone Between Safety and Cost

The toy-grade situation is far more complex than the previous two. Strictly speaking, "toy-grade silicone" is not an independent material certification grade, but an application scenario label. Silicone toys need to face two sets of safety logic simultaneously: if the product may be placed in a child's mouth (such as teethers or pacifiers), it needs to meet food-contact grade requirements; if the product is used only as an ordinary toy, it is primarily governed by toy safety standards.

Of notable concern, a testing report by Guangming Online in July 2025 showed that all 11 "squishy" toys submitted for testing were found to contain total volatile organic compounds, including formaldehyde, toluene, and xylene. The material composition of such products is far more complex than the word "silicone" suggests, covering polyurethane, thermoplastic rubber, polyvinyl chloride, and other systems. The problem lies precisely in this: when a product is labeled "silicone," consumers and some buyers assume it possesses food-grade or toy-grade safety attributes, while what is actually used may be lower-cost industrial-grade base material, or blended with other inexpensive polymers.

How to Avoid Pitfalls in Material Selection: Three Actionable Criteria

First, look at the standard number, not the marketing words. "Food grade," "mother-and-baby grade," and "safe silicone" are all marketing language; the real compliance basis is the standard number. For food-contact scenarios, confirm that the supplier can provide test reports compliant with GB 4806.16-2025, with focus on volatile matter indicators. For toy scenarios, distinguish whether the product is mouthable: mouthable products should also meet food-contact requirements, while non-mouthable products must comply with the GB 6675 series of toy safety standards.

Second, ask about the catalyst system. The platinum vulcanization system is the industry consensus for food-grade and medical-grade silicone, while peroxide vulcanization systems are more cost-advantageous but carry higher residue risks. Ask suppliers directly: "Is your curing system platinum-catalyzed or peroxide-based?" A qualified food-grade supplier should be able to answer clearly and provide corresponding evidence.

Third, be wary of "universal adhesive" rhetoric. No single silicone raw material can simultaneously meet all requirements for industrial sealing, food contact, and infant mouthing. If a supplier claims their product "can do everything," this itself is a signal that warrants careful scrutiny. The existence of material grading is precisely because the safety boundaries of different scenarios cannot be covered by a single formulation.

For liquid adhesive enterprises, clarifying the differences among these three is not only a technical service to help customers make correct choices, but also a baseline requirement for avoiding their own compliance risks. When "silicone" transforms from a material name into a marketing label, the true professional value lies precisely in this: restoring the label to verifiable standards and data.

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