If you’ve ever unboxed a new pair of shoes, a handbag, or even a bottle of prescription medicine, you’ve probably found one small, crinkly packet tucked inside the packaging: a desiccant. These little packets are designed to absorb excess moisture, protecting goods from mold, rust, and degradation during shipping and storage. If you’ve ever wondered if that little packet could pose a fire risk, you’re not alone. As a desiccant supplier who’s fielded this question dozens of times from customers across industries—from electronics manufacturers to pharmaceutical distributors—I’m here to break down the science, the different types of desiccants, and the real truth about flammability. Desiccant
First, let’s start with the basics: what is a desiccant, and how does it work? Simply put, desiccants are hygroscopic materials, meaning they attract and hold water molecules from the surrounding air. The core function is moisture removal, but their composition varies widely depending on their intended use. Not all desiccants are created equal, and their chemical makeup is the single biggest factor when it comes to flammability. That’s why it’s critical to avoid making a blanket statement like “all desiccants are flammable” or “none are”—the answer depends entirely on what they’re made of, how they’re packaged, and the conditions they’re exposed to.
Let’s talk about the most common desiccant types, because this is where most of the confusion starts. The three most widely used desiccants in commercial applications are silica gel, molecular sieves, and calcium chloride.
Silica gel is probably the one you’ve seen most often. It’s made from sodium silicate, a naturally occurring mineral that’s processed into porous, bead-like pellets. When you see the little white packets marked “DO NOT EAT,” that’s almost always silica gel. Is silica gel flammable? From all the testing our team does here at our facility, silica gel is non-flammable. It has a very high ignition temperature—experts put it around 900°C (1652°F), which is far higher than any temperature you’d typically encounter in a warehouse, during shipping, or even in a small fire. Even if silica gel is exposed to extreme heat, it doesn’t burn; instead, it might crack or discolor, but it won’t contribute to a fire. The only caveat here is the packaging. Most silica gel packets are sealed with plastic or paper, and some older packets might have a small amount of cobalt chloride as an indicator (though that’s rare now due to toxicity concerns). The packaging, not the silica gel itself, could pose a minor risk if it’s exposed to flame, but the core desiccant material is not flammable.
Next up are molecular sieves, which are another staple in industrial desiccant applications. These are synthetic, porous aluminosilicate materials, engineered with tiny, uniform pores that can trap water molecules while letting larger gas molecules pass through. Molecular sieves are commonly used in things like compressed air dryers, natural gas processing, and to keep sensitive electronics dry in harsh environments. Like silica gel, molecular sieves have a very high ignition point—tests show they won’t ignite at temperatures below 1000°C (1832°F), which is well beyond standard industry conditions. Again, the core material is non-flammable, though the metal casing used for larger molecular sieve canisters is a different story: metal can melt at high temperatures, but melting isn’t the same as flammability.
The third common type is calcium chloride, a salt-based desiccant. Calcium chloride is a highly effective desiccant, often used in bulk applications, like to keep warehouse floors dry or to prevent moisture damage in shipping containers. Unlike silica gel and molecular sieves, calcium chloride is highly soluble in water, and it can even liquefy as it absorbs moisture. Is calcium chloride flammable? Absolutely not. It’s an inorganic salt, so it has no organic components that can burn. Its ignition temperature is even higher than silica gel, around 1600°C (2912°F). That said, when calcium chloride absorbs large amounts of moisture, it can release heat as part of the absorption process (this is called an exothermic reaction), but that heat is minimal—only a few degrees above room temperature—so it’s not enough to ignite anything. The only time calcium chloride might present a minor risk is if it’s mixed with other materials, but as a standalone desiccant, it’s non-flammable.
Now, here’s the part that trips a lot of people up: there is one type of desiccant that is flammable, and it’s not as commonly used as the three above, but it’s important to know about. Clay desiccants, sometimes called montmorillonite clay desiccants, are made from processed natural clay. Wait, you might be thinking—clay is dirt, how can dirt be flammable? The key here is that some clay desiccants are treated with organic additives to boost their moisture absorption or to change their properties. A small subset of lower-quality clay desiccants on the market have small amounts of lignin or other organic compounds added. These organic additives lower the ignition temperature significantly—some as low as 250°C (482°F), which is much lower than the other desiccants we discussed. That’s where the myth that “all desiccants are flammable” comes from: people are encountering these cheap, additivized clay desiccants without realizing it. But even then, clay desiccants are only slightly flammable, and they won’t sustain a fire on their own. They might smolder if exposed to a direct flame, but they won’t burn once the heat source is removed.
Let’s put this in practical terms, because what matters most to our customers isn’t just the science—it’s whether their desiccant will put their goods, their staff, or their facilities at risk. Here’s what we tell every new customer who asks about flammability: in 15 years as a desiccant supplier, I’ve never seen a fire caused by a desiccant, not even the additivized clay ones. The conditions needed to ignite even the most flammable desiccant are extreme: a direct, sustained flame, a lack of oxygen that’s rare in most working environments, and prolonged heat exposure. Most warehouse fires are caused by electrical faults, improperly stored chemicals, or overheating machinery—not desiccants.
But that doesn’t mean there’s no risk at all. The main hazards associated with desiccants are not flammability, but two other things: ingestion and inhalation. Small silica gel beads are a choking hazard for kids and pets, and calcium chloride can irritate skin and eyes if it comes into contact. If a desiccant packet is broken open and beads are inhaled, that can cause respiratory irritation, especially for people with asthma or other breathing conditions. But none of these have anything to do with flammability.
Another common misconception is about reactivating desiccants. A lot of people know that desiccants can be reused by heating them in an oven to drive off the absorbed moisture. Can this heating process cause a fire? For silica gel and molecular sieves, no—heating them to 120°C (248°F) for a few hours is standard, and that temperature is way below their ignition point. Even calcium chloride can be reactivated at temperatures around 200°C, though we don’t recommend that for customers because the material breaks down after a few reuses. The only reactivation risk comes from those additivized clay desiccants, which can release fumes or start to smolder if heated too quickly or at too high a temperature. That’s why we always advise customers to check the product specifications before reusing any desiccant, and to follow our guidelines for safe reactivation.
As a supplier, we take flammability seriously. Every desiccant we sell goes through rigorous testing to meet international safety standards, including ISO 9001 and REACH regulations, which restrict harmful additives. We don’t stock or sell the cheap, additivized clay desiccants that can smolder when heated—our product line is made up of silica gel, molecular sieves, and food-grade calcium chloride, all of which are certified non-flammable for commercial use. We also clearly label all our products with safety data sheets (SDS) that list chemical properties, including flammability, so our customers have all the information they need to store, handle, and use our desiccants safely.
Let’s address a specific scenario I get asked about all the time: what if a shipment of desiccants is involved in a transport fire? In almost all cases, the desiccant itself won’t make the fire worse. The packaging—like plastic or cardboard—might burn, but the core desiccant material won’t. That’s why we work closely with our logistics partners to ensure our desiccants are shipped in packaging that meets transport safety regulations, and we provide all necessary documentation to comply with global shipping laws. We’ve never had a shipment delayed or flagged because of desiccant flammability, and that’s a testament to the safety of our products.
Another point to consider is industrial applications where desiccants are used in large quantities. For example, a pharmaceutical plant might use pallets of silica gel to keep products dry during production and storage. Could a large pile of silica gel present a flammability risk? No—again, silica gel can’t burn. Even if a small fire breaks out nearby, the silica gel won’t catch fire, and it won’t spread the flame. The same goes for molecular sieves used in oil and gas processing plants, which operate at much higher temperatures—their desiccants are designed to withstand extreme heat without igniting.
Now, let’s debunk one more myth: the old warning on silica gel packets that says “KEEP AWAY FROM FIRE.” That’s a standard warning required by regulatory bodies, and it’s not because silica gel is flammable. The warning is there because of the packaging, and also because if you heat silica gel to extremely high temperatures, it can release small amounts of moisture vapor, which could create pressure in a sealed container. The silica gel itself won’t burn, but heating it in a fully sealed plastic packet could cause the packet to burst, which is a minor hazard. That’s why we advise customers to never heat desiccant packets in a sealed container—always open them before reactivation, to release any pressure.
So, to sum up what we’ve covered today: most commercial desiccants (silica gel, molecular sieves, calcium chloride) are non-flammable, with ignition temperatures hundreds of degrees higher than any standard environmental or industrial condition. The only common flammable desiccants are low-quality additivized clay ones, which are rare in reputable supply chains. The risks associated with desiccants are related to ingestion, inhalation, and skin irritation, not fire. As a desiccant supplier, our top priority is providing safe, compliant products that our customers can trust.
If you’re a manufacturer, distributor, or logistics provider looking for desiccants that are safe, reliable, and tested for all applications, we’re here to help. Whether you need small silica gel packets for consumer goods, bulk molecular sieves for industrial use, or food-grade calcium chloride for pharmaceutical or food packaging, our team can work with you to find the right solution for your needs. We provide full safety data sheets for every product, can answer any questions about flammability, handling, or reactivation, and offer flexible order quantities to fit your budget and timeline.
To learn more or discuss your desiccant needs, get in touch with our team. We’re here to support you every step of the way, from product selection to delivery, and we’re committed to helping you keep your goods safe, your operations compliant, and your team informed about product safety.
Ethylene Absorbers References
- International Organization for Standardization (ISO). ISO 17779:2018, Packaging – Desiccants – Classification, requirements and test methods. Geneva: ISO, 2018.
- National Fire Protection Association (NFPA). NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response. Quincy, MA: NFPA, 2021.
- American Society for Testing and Materials (ASTM). ASTM E119: Standard Test Methods for Fire Tests of Building Construction and Materials. West Conshohocken, PA: ASTM, 2020.
- REACH Regulation (EC) No 1907/2006. Regulation concerning the Registration, Evaluation, Authorization and Restriction of Chemicals. Brussels: European Chemicals Agency, 2023.
Shenzhen Chunwang New Materials Co., Ltd.
Established in 1998, Shenzhen Chunwang New Materials Co., Ltd. is well-known as one of the leading manufacturers and suppliers of desiccant in China. During the past two years, we have introduced advanced equipment and technology into our factory. Please be free to buy our cheap desiccant made in China.
Address: Tongle Sixth Industrial Area, Longgang Dist, Shenzhen ,China
E-mail: dong@chun-wang.com
WebSite: https://www.absorbwell.com/
