Desiccant sachets sit inside food and drug packaging in enormous volumes, and the material itself is rarely the problem. Silica gel is inert and long-established. What goes wrong is documentation: the declaration covers the wrong food type, the sachet material has no paperwork of its own, or the supplier answers “FDA approved” to a question that has no single answer. This page sets out how the three main rule systems actually work, and what to demand before you order.
| Market | What governs it | What a buyer should receive |
|---|---|---|
| European Union | Framework Regulation (EC) 1935/2004 for all food contact materials; Regulation (EU) 10/2011 for plastic layers; mandatory GMP for food contact materials. | A written declaration of compliance naming the material, the food types it may contact and the conditions of use. A multi-layer sachet may need more than one. |
| United States | The FDA authorises food contact substances for specified intended uses rather than as a blanket category. Silica gel appears in the FDA inventory of food contact substances cited to 21 CFR 175.390. | A food contact letter from the supplier that cites the regulation and names your specific intended use. A generic “FDA approved” statement is not sufficient. |
| China | Mandatory national standards: GB 4806.1 for general safety requirements, GB 4806.8 for paper and paperboard, GB 4806.7 for plastics, GB 9685 for additives. | A test report against the specific GB 4806 part that applies to each material, plus a conformity declaration. Composite articles must satisfy the standard for every layer. |
| Pharmaceutical (US) | USP <670>, Auxiliary Packaging Components — the chapter covering articles that support or enhance a drug container-closure system. | Testing under USP <670>, including the inorganic impurities test the chapter sets for silica gel, plus DMF-free and animal-origin statements. |
This is the part worth reading twice. The FDA publishes an Inventory of Food Contact Substances Listed in 21 CFR. Look up silica gel and you find CAS 63231-67-4 cited to a single section: 21 CFR 175.390.
Read that section and the picture changes. 21 CFR 175.390 is titled Zinc-silicon dioxide matrix coatings. In it, silica gel appears as one optional substance in a coating that is applied to metal, cured and washed, and then used as the food-contact surface of bulk reusable containers. That is a specific, narrow authorisation.
The FDA makes the rule explicit on the same page: substances listed in 21 CFR parts 175–178 are authorised “for specified intended users and conditions of use as stated in the regulation”, and a substance may be cited in more than one section.
The GB 4806 series are mandatory national standards — a food contact product sold in China must comply, and the applicable part depends on the material rather than the product name.
| Standard | Applies to |
|---|---|
| GB 4806.1 | General safety requirements for food contact materials and articles. It defines composite and multi-material articles and requires each to satisfy the standard applying to its materials. |
| GB 4806.8 | Paper and paperboard in contact with food — the relevant standard for most desiccant sachet papers. |
| GB 4806.7 | Plastics in contact with food — relevant for plastic films and coated structures. |
| GB 9685 | The permitted additives list. Additives used in the material must be within it, with the prescribed restrictions. |
Composite structures face an additional requirement introduced with the standard: the layers must be declared in order, from the outer layer to the layer that directly contacts food, including adhesives. If you buy a multi-layer sachet, ask for that layer-by-layer declaration — it is a frequent gap.
Drug packaging does not follow food law. In the United States it follows the pharmacopoeia, and USP <670>, Auxiliary Packaging Components, is the chapter that matters for desiccants. It covers articles used to support or enhance a container-closure system, and it names the desiccant types in common commercial use: silica gel, molecular sieve, bentonite, calcium chloride and calcium oxide. For silica gel the chapter sets an inorganic impurities test.
Pharmaceutical buyers routinely ask for three things beyond the chapter itself: a DMF-free statement, a BSE/TSE-free statement, and confirmation that no animal-origin material enters the product. These are paperwork, not chemistry — and they are what stalls orders when they are missing.
It is almost never the desiccant. It is one of these five:
We supply silica gel and desiccant sachets for food, pharmaceutical and industrial packaging, direct from our own production, from one tonne with OEM and ODM available.
Silica gel itself is chemically inert and is widely used in food and pharmaceutical packaging. But "food safe" is not a property of the material alone — it depends on the sachet, the food it sits next to, the market you sell in and whether the chain of documentation supports the claim. A supplier should be able to name the regulation that covers your specific use.
Not in the way the question is usually meant. The FDA authorises food contact substances for specified intended uses, not as a blanket category. Silica gel appears in the FDA inventory of food contact substances cited to 21 CFR 175.390, which covers it as a component of zinc-silicon dioxide matrix coatings on bulk reusable containers. Whether your sachet is lawful depends on your intended use, and the evidence is a written food contact statement from the supplier naming that use.
At minimum a declaration of compliance or food contact letter that names the material, the food types and the conditions of use; a batch COA; an SDS; and food contact documentation for the sachet material itself, not only the desiccant. Pharmaceutical buyers additionally ask for USP <670> related testing, a DMF-free statement and a statement on animal-origin material.
Yes, and this is where most audits fail. The paper, non-woven, OPP or composite film that encloses the desiccant is itself a food contact material. It may need its own declaration, separate from the desiccant inside it. Printed inks and adhesives on that material are also in scope.
Yes. A desiccant sachet placed inside a food package is treated as a food contact material under the framework Regulation (EC) 1935/2004, and plastic layers in the structure are additionally covered by Regulation (EU) 10/2011, which requires a written declaration of compliance. In practice a multi-layer sachet may need more than one declaration.
USP <670>, Auxiliary Packaging Components, is the United States Pharmacopeia chapter covering articles that support or enhance a drug container-closure system. Desiccants are one of the two categories it covers, alongside pharmaceutical coil, and the chapter names silica gel, molecular sieve, bentonite, calcium chloride and calcium oxide. The chapter carries an inorganic impurities test for silica gel. It applies when your customer is a pharmaceutical packager, not to food packaging.
No. Publishing a compliance claim you cannot evidence is worse than making none — the moment a buyer asks for the declaration, the gap is exposed, and in some markets an unevidenced claim is itself a problem. Describe the requirements, state your position plainly, and issue documents when you hold them.
Our food-grade desiccant page covers sachet formats and materials, and the pharmaceutical packaging page covers drug-packaging applications in detail.
