Oxygen Absorber vs Silica Gel

Effective packaging preservation techniques are essential in maintaining the quality and extending the shelf life of products across various industries. As manufacturers strive to deliver their goods in the best possible condition, controlling environmental factors like moisture and oxygen becomes a critical aspect of packaging. Silica gel and oxygen absorbers are the solutions to tackle these challenges.

Moisture can lead to the proliferation of mould and mildew, tarnish and corrode metals, and compromise the structural integrity of packaging materials. Oxygen, a catalyst for oxidation, can cause discolouration, rancidity, and spoilage in a wide range of products. Together, these elements can significantly diminish packaged goods’ quality, safety, and shelf life, leading to increased waste, higher costs, and reduced brand reputation. Using silica gel and oxygen absorbers in packaging addresses these challenges, safeguarding products against the detrimental effects of moisture and oxygen and ensuring they remain in optimal condition throughout their lifecycle.

Understanding Silica Gel

Silica gel is a granular, porous form of silicon dioxide (SiO2), a naturally occurring mineral. Despite its name, silica gel is solid and dry to the touch. It’s manufactured by processing silicon dioxide into a highly adsorbent material with a vast network of microscopic pores. This unique structure allows silica gel to absorb up to 40% of its weight in moisture, making it an exceptionally efficient desiccant. This substance induces or sustains a state of dryness in its vicinity.

Silica gel absorbs moisture through physical adsorption, a process where water molecules adhere to the surface of the silica gel’s pores. The large surface area provided by the porous structure of silica gel facilitates the adsorption of water vapour from the air, effectively reducing humidity and protecting products from moisture-related damage. This capacity to control environmental moisture without any chemical reaction or byproduct makes silica gel a preferred choice for safeguarding sensitive items.

Types of Silica Gel

• Indicating Silica Gel: This type contains a colour-changing indicator visually demonstrating the gel’s moisture saturation level. Commonly, silica gel will transition from blue to pink or orange to green as it absorbs moisture, signalling when it’s time for replacement or regeneration. Indicating silica gel is particularly useful in applications where monitoring moisture levels is critical.
• Non-Indicating Silica Gel: Non-indicating silica gel does not change colour when it absorbs moisture. It’s typically used when visual moisture indicators are unnecessary or in products that might be compromised by the dye used in silica gel. Non-indicating silica gel is often found in food, pharmaceuticals, and electronics packaging.
• Packet Sizes and Forms: Silica gel comes in various packet sizes to accommodate different packaging needs, ranging from small sachets for pharmaceuticals to large bags for industrial applications. Beyond packets, silica gel can also be incorporated into other forms, such as silica gel beads and boards or even directly into packaging materials.

Benefits of Using Silica Gel in Packaging

• Moisture Control: By effectively reducing the humidity within packaging, silica gel protects products from the harmful effects of moisture, such as condensation and spoilage.
• Prevention of Mold, Mildew, and Corrosion: Silica gel’s moisture-absorbing properties help prevent the growth of mould and mildew, as well as the corrosion of metal components, ensuring the integrity and longevity of packaged goods.
• Product Longevity: The use of silica gel in packaging significantly extends the shelf life of products by maintaining an optimal moisture level, thereby preserving their quality, effectiveness, and aesthetic appeal over time.

Understanding Oxygen Absorbers

Oxygen absorbers are small packets that contain iron powder and are used to remove oxygen from a sealed environment, creating an atmosphere almost devoid of oxygen. They work through a chemical reaction where the iron powder oxidises, turning it into iron oxide. This process removes oxygen from the air around the packet, reducing the oxygen level to 0.01% or less. The absence of oxygen significantly slows the rate of oxidation and other processes that can lead to spoilage or degradation of products.

The primary active ingredient in oxygen absorbers is iron powder. Other components may include natural zeolites (which absorb moisture to activate the iron powder), salt (to speed up the reaction), and charcoal (to disperse the oxygen absorption more evenly). Oxygen absorbers are typically encased in a breathable material that allows oxygen to enter the packet but prevents the iron powder from leaking.

Benefits of Using Oxygen Absorbers

• Prevention of Oxidation: By removing oxygen from the packaging, oxygen absorbers prevent the oxidation process, which can lead to spoilage, discolouration, and off-flavours in food products. In non-food items, oxidation can cause corrosion and degradation of materials.
• Extending Shelf Life of Food Products: Oxygen absorbers can significantly extend food products’ shelf life by preventing the growth of aerobic bacteria and fungi. These microorganisms require oxygen to survive, so removing oxygen creates an inhospitable environment.
• Inhibiting the Growth of Aerobic Pathogens and Spoilage Organisms: The absence of oxygen inhibits the growth of aerobic pathogens, which are responsible for food spoilage and can pose health risks. This makes oxygen absorbers a critical component in ensuring the safety and longevity of packaged food products.

Applications of Silica Gel and Oxygen Absorbers in Packaging

The use of silica gel and oxygen absorbers spans various industries, safeguarding products from the detrimental effects of moisture, oxygen, and other environmental factors. The strategic use of packaging across these industries enhances product integrity and longevity and aligns with regulatory requirements and safety standards.

Below, we explore their applications in the food industry, pharmaceutical and nutraceutical packaging, and the packaging of electronics and metal parts, highlighting specific examples, regulatory considerations, and the benefits they bring to each sector.

Industry	Applications	Examples	Regulatory and Safety Considerations
Food Industry	Silica Gel: Controls moisture to prevent spoilage and clumping. Oxygen Absorbers: Extends shelf life by preventing oxidation and inhibiting the growth of aerobic pathogens.	Silica Gel: Jerky, spices, nuts. Oxygen Absorbers: Packaged snacks, cakes, grains, flour, milk powder.	Must comply with food safety regulations such as those by the FDA, ensuring non-toxicity and no direct food contact.
Pharmaceutical and Nutraceutical Packaging	Silica Gel: Protects against moisture to maintain the efficacy of products. Oxygen Absorbers: Preserve the potency of pharmaceuticals by preventing oxidation.	Silica Gel: Vitamins, medications, dietary supplements. Oxygen Absorbers: Sensitive pharmaceutical formulations.	Packaging materials must meet regulatory standards (e.g., FDA) for pharmaceutical use, ensuring they do not compromise product safety or quality.
Electronics and Metal Parts	Silica Gel: Prevents moisture-induced corrosion and damage. Oxygen Absorbers: Used less commonly but can protect metal parts from oxidation during storage and shipping.	Silica Gel: Electronic components and devices. Oxygen Absorbers: Metal parts and components.	Focuses on preventing corrosion and oxidation to maintain condition over long-term storage, ensuring electronic and metal components remain in optimal condition.

Best Practices for Using Silica Gel and Oxygen Absorbers

Using silica gel and oxygen absorbers effectively in packaging requires careful consideration of several factors to ensure optimal protection of products from moisture and oxygen. Adhering to these best practices maximises the protective benefits of silica gel and oxygen absorbers, extending the shelf life and maintaining the quality of packaged products. Proper calculation, strategic placement, and adherence to safety guidelines are essential to effectively leveraging these desiccants and absorbers in various packaging applications.

Determining the Right Amount

Using too little can result in ineffective moisture or oxygen control, while too much can be wasteful and cost-efficient. Manufacturers often provide tables or calculators to help determine the appropriate amount for specific applications.

• Silica Gel: The amount needed depends on the package volume and the product’s specific moisture sensitivity. A general guideline is to use 5 grams of silica gel per cubic foot of volume.
• Oxygen Absorbers: The required quantity varies based on the package’s volume and the product’s oxygen sensitivity. For food packaging, a typical rate is 100 to 300 cc of oxygen absorption capacity per gallon of product volume.

Placement and Distribution

• Place silica gel and oxygen absorbers in direct contact with the product or as close as possible, ensuring they are evenly distributed throughout the package for uniform protection.
• For larger packages or containers, consider using multiple smaller packets rather than one large one to facilitate better coverage and effectiveness.
• Ensure that the packaging is well-sealed and that the materials used are compatible with silica gel and oxygen absorbers to prevent any potential reaction or compromise in efficacy.

Safety Considerations

Handling and Disposal: Wear gloves when handling silica gel and oxygen absorbers to avoid moisture absorption from your hands or any potential irritation. Dispose of used silica gel and oxygen absorbers according to local regulations. While silica gel can often be regenerated by heating, oxygen absorbers contain iron powder and should be disposed of in the trash.

Ensuring Product Safety for Consumer Products: Clearly label packets of silica gel and oxygen absorbers with “Do Not Eat” warnings to prevent accidental ingestion by consumers, especially in food packaging. Choose food-grade silica gel and oxygen absorbers for applications involving direct or indirect contact with consumables to ensure they are free from toxic substances.

Conclusion

Silica gel and oxygen absorbers are often used in the packaging of products, offering a reliable means to extend shelf life, preserve freshness, and ensure the safety of products. Their use not only meets the practical needs of preservation but also aligns with regulatory standards and consumer expectations for quality and longevity.

At Stream Peak Vietnam, we offer both silica gel and oxygen absorbers as part of our protective packaging solutions. We manufacture silica gel bags in compliance with ISO 9001 and ISO 14001 standards, ensuring quality and environmental responsibility. Our oxygen absorbers are manufactured using advanced Japanese technology, reflecting our commitment to delivering effective preservation methods. For more details on our products and how they can meet your packaging needs, please feel free to contact us.