Moisture control is a critical factor in preserving the quality and longevity of various products. Whether it’s electronic devices, foods, pharmaceuticals, or sensitive materials like artwork and optics assemblies, excess moisture can lead to damage and deterioration. That’s where indicating silica gel comes into play.
What is Silica Gel Desiccant?
Silica gel is a desiccant known for its great moisture-adsorbing capabilities. Silica gel consists of silicon dioxide and is shaped as small, porous beads. Silica gel is available in different types and sizes, making it a versatile desiccant capable of application across a wide range of industries. Its primary role is to adsorb moisture, preventing it from damaging the surrounding environment or products.
For more information about desiccants, AGM has you covered!
Indicating Silica Gel Desiccant: What Makes It Different?
Unlike regular silica gel (known as bulk, or non-indicating silica gel), indicating silica gel is enhanced with color-changing indicators. These indicators, typically either cobalt chloride or methyl violet, change color as the silica gel saturates with moisture. This visible change serves as an effective moisture detection mechanism, providing a clear visual indication of when the silica gel needs to be replaced or recharged.
Conversely, non-indicating desiccant forms do not provide a way to determine saturation level, resulting in added difficulty when evaluating the amount of moisture adsorbed by the desiccant.
Two types of indicating silica gel: Orange and blue
Orange indicating silica gel desiccant
Orange indicating silica gel appears orange or yellow in color when dry and transitions to green as the desiccant progressively saturates with moisture (to about 15% by weight).
In addition, orange silica gel is a non-toxic, pollution-free desiccant that will meet the needs of environmentally conscious companies. This orange silica gel can be used in many applications where visual control of moisture is required, such as in compressed air dryers, breathers, and for protection of non‐consumable packaged goods, as well as drying and storing flowers and seeds. That said, orange silica gel should not be used in direct contact with products that are intended for consumption, such as food and pharmaceuticals.
BLUE INDICATING SILICA GEL
Blue indicating silica gel is a bead or granule that has been washed with a concentration of cobalt chloride (a heavy metal salt). The cobalt chloride is a deep-blue color when dry and transitions from blue to pink as the desiccant saturates.
Blue silica gel can be used in many of the same applications as orange silica gel; however, due to the addition of the moisture indicator (cobalt chloride), blue silica gel should not be used in direct contact with products intended for consumption, such as food or pharmaceuticals.
Applications of Indicating Silica Gel
Indicating silica gel finds its application in various industries. One of its prominent uses is in the protection of electronic devices and equipment, and especially when desiccators or tank vent dryers are used. Moisture is a common enemy of electronics, causing corrosion and malfunction. By placing indicating silica gel packets in electronic enclosures or packaging, moisture can be effectively controlled, prolonging the lifespan and performance of devices.
Moreover, indicating silica gel is widely used in the preservation of food and pharmaceuticals. It helps maintain the freshness and quality of consumable goods by preventing moisture-related spoilage. In addition, industries dealing with sensitive materials such as artwork and documents rely on indicating silica gel to create optimal storage conditions, preventing mold, degradation, and other forms of damage.
How Much Desiccant Do You Need?
Knowing how much desiccant is enough to protect you is tricky. That’s why we made a Desiccant Unit Calculator! Free and easy to use, just input your enclosure volume and find out how much desiccant you need.
WHY USE ORANGE INDICATING SILICA GEL?
In 1998, the European Union prohibited Blue Indicating Silica Gel (which contains cobalt chloride, a known human toxin) from being sold within European markets. Alternatively, orange indicating silica gel, which is used in a variety of the same industries and applications, such as transformer breathers and compressed air dryers, conforms to the European Union requirements for moisture indicating desiccants.
In addition to conforming to EU requirements, AGM’s orange indicating silica gel also has a high adsorption capacity, and will remove moisture at temperatures as high as 150° F (65°C). However, it is best used at room temperature (70‐90° F /21-32°C).
WHY USE BLUE INDICATING SILICA GEL?
Blue Indicating Silica Gel tends to be less expensive than orange indicating silica gel, while still maintaining the same performance standards. However, the use of blue indicating silica gel has been limited due to its ban in the European Union. Despite this fact, blue indicating silica gel is still available for use in the United States.
Blue or Orange indicating silica gel: Which to use
The use of blue over orange or orange over blue is largely a matter of use case and expense. Blue indicating silica gel is not legal in the European Union and may be similarly prohibited elsewhere due to the toxicity of the cobalt chloride used to facilitate its color indicator. This limits its regional usability while also prohibiting its use in certain applications, such as with foods or pharmaceuticals.
Alternatively, orange indicating silica gel is usable across larger stretches of the globe and may be used in more sensitive applications.
POPULAR AGM PRODUCTS FEATURING INDICATING SILICA GEL
Desi View® is the trade name of a bagged indicating silica gel mixture sold by AGM. The Desi View mixture consists of either 90% clay or 90% silica gel; the remaining 10% is always indicating.
Desi View bags are only 10% indicating for two reasons:
- A 10% indicating silica gel content is enough of a color change indicator to be easily viewed through the bag’s polyethylene side; and
- Indicating is more expensive than non-indicating silica gel.
Indicating silica gel is also available in special packet sizes for use in electronics, pharmaceutical, or food packaging.
Benefits of Indicating Silica Gel
The use of indicating silica gel offers several advantages. First and foremost, it provides quick and visible moisture detection. When the color-changing indicators activate, it’s a clear signal that the silica gel has reached its moisture absorption capacity and needs attention.
Additionally, indicating silica gel is a cost-effective solution for moisture control. By accurately indicating when it needs to be replaced or recharged, it minimizes wastage and allows for efficient use of resources. Many types of indicating silica gel can also be regenerated and reused, further enhancing its economic value.
How to Use Indicating Silica Gel
To use indicating silica gel effectively, proper placement is crucial. It’s recommended to place silica gel packets near the items or areas that require moisture control. The quantity of indicating silica gel required varies depending on the application, and guidelines provided by the manufacturer should be followed. Regular monitoring and interpretation of color changes will ensure timely replacement or regeneration.
Safety Considerations
While indicating silica gel is generally safe to handle, it’s essential to take some precautions. Avoid direct contact with eyes or ingestion, and wash hands thoroughly after handling. Furthermore, proper disposal methods should be followed to minimize environmental impact. Check with local regulations or recycling centers for guidelines on disposing of used silica gel.
Need help finding desiccant?
For more information about indicating desiccants, please call us at (520) 881-2130 or send us an email.
