Understanding Desiccants
Desiccants are used across industries such as food, pharmaceuticals, electronics, and manufacturing, where controlling moisture is key to preserving product quality and extending shelf life.
These hygroscopic materials work by absorbing moisture from their surroundings, creating a dry environment that protects sensitive products from humidity-related damage. In most cases, desiccants are enclosed in specialised food packaging materials to prevent direct contact with food or other items, ensuring effective moisture control without risk of contamination.
Desiccant Types Commonly Used
In food packaging, desiccants protect against humidity. By controlling moisture levels, they ensure product quality and integrity throughout storage and transport.
Here are some types of desiccants used in food packaging include:
Desiccant Type |
Composition |
Key Features |
Common Applications |
Silica Gel |
Composed of silicon dioxide |
Highly effective at absorbing moisture. |
Safe for food contact when properly packaged. |
Molecular Sieves |
Synthetic, highly porous materials |
Precise moisture control. Effective at very low humidity levels. |
Commonly used in moisture-sensitive pharmaceuticals, electronics, and some food packaging. |
Clay Desiccants |
Made from bentonite or montmorillonite clay |
Natural, eco-friendly option. Effective across various humidity levels. |
Often used in organic and natural food products. |
How Desiccants Work to Preserve Food Quality
Desiccants preserve food quality through a process of adsorption or absorption, effectively reducing moisture levels in packaging environments.
By attracting and holding water vapour, desiccants create a drier environment that hinders the growth of mould, bacteria, and other microorganisms that thrive in humid conditions. This moisture control not only helps maintain the texture and flavour of food products but also extends their shelf life significantly.
Additionally, by preventing clumping in powdered foods and preserving the crispness of snacks, desiccants contribute to an overall improved consumer experience. In essence, the strategic use of desiccants plays a key role in keeping food fresh, safe, and visually appealing from production through to consumption.
- Moisture Removal: Desiccants actively extract excess moisture from the air inside packaging, creating a dry environment that inhibits mould growth and bacterial proliferation.
- Equilibrium Relative Humidity (ERH) Control: These agents maintain consistent ERH within the package, preventing condensation and moisture migration, which can cause clumping, caking, or texture changes in dry foods.
- Oxidation Prevention: By lowering moisture levels, they indirectly slow down oxidation, helping to preserve the flavour, colour, and nutritional value of packaged foods.
- Extending Shelf Life: The overall effect of moisture control extends the shelf life of packaged foods, ranging from weeks to months, depending on the product and packaging conditions.
- Maintaining Product Integrity: These moisture-absorbing solutions continue to protect products from humidity fluctuations throughout the supply chain, ensuring stability during transport and storage.
Desiccant Safety Concerns
When considering desiccants for direct or indirect contact with food products, safety is a critical factor.
While desiccants effectively control moisture, certain risks must be carefully evaluated to ensure consumer protection. By addressing these safety considerations, manufacturers can responsibly incorporate desiccants into food packaging while ensuring compliance with health standards and consumer trust.
Toxicity of Desiccant Materials: Common desiccants such as silica gel, molecular sieves, and clay are generally considered non-toxic. However, ensure these substances are food-grade and meet regulatory standards for direct or indirect food contact. Non-food-grade desiccants may contain additives or chemicals that could pose health risks if they come into contact with food.
Risk of Ingestion: While many desiccants are labelled as non-toxic, accidental ingestion can still present a hazard, particularly with silica gel packets, which are often marked with “Do Not Eat” warnings. For products that might come into direct contact with food, packaging design plays a vital role in preventing accidental ingestion. Clear labelling and the use of sachets or canisters to separate from the food product help mitigate this risk.
Regulatory Compliance: Desiccants used in the food industry must adhere to stringent regulatory standards. In the EU, the European Food Safety Authority (EFSA) outlines specific guidelines for materials that come into contact with food. Similarly, in the United States, the Food and Drug Administration (FDA) regulates the use of desiccants in food packaging. Compliance with these standards ensures that the materials are safe and free from harmful contaminants.
Contamination Risk: Improperly packaged or damaged desiccant bags could leak into food, leading to contamination. This is particularly a concern with loose granular desiccants. Manufacturers must ensure that the desiccants are enclosed in secure, food-safe packaging that prevents any direct contact with the food product.
Consumer Perception: Even if desiccants are deemed safe, consumer perception is another factor to consider. If a desiccant packet or material is found loose in a food package, it may cause alarm, leading to product returns or negative brand associations. Transparent communication and the use of desiccants in clearly separated, sealed formats can help alleviate these concerns.
Desiccants Common Packaging Forms
Desiccants do not commonly come into direct contact with food because they are securely packaged in specialised packaging that prevents moisture absorption agents from contaminating food items.
To cater to diverse packaging needs, desiccants come in several forms, each designed to fit specific applications. Below are some of the most common packaging formats:
- Packets or Sachets: Desiccant packets are small, sealed sachets from porous materials such as paper or Tyvek. These packets allow moisture to pass through without letting the desiccant material escape.
- Continuous strip: These desiccants are attached in a continuous strip, allowing for easy integration into packaging processes without manual handling.
- Canisters: Desiccant canisters are small, rigid plastic or metal containers that house desiccant materials for applications that need stronger protection.
- Cards: Desiccant cards or moisture-absorbing boards incorporate desiccant material into flat, rigid forms, making them space-efficient and easy to integrate into packaging.
Desiccant Packaging Considerations
When selecting desiccants for packaging, several factors must be considered to ensure optimal performance and product safety.
These considerations help tailor moisture-control solutions to specific products and packaging environments, maintaining product quality and extending shelf life. Here are a few essential factors to consider:
Consideration |
Details |
Packaging Materials |
All components (silica gel, packaging material, inks) should comply with relevant food safety regulations. To prevent contamination, use non-toxic, odourless materials. |
Durability |
Packaging must withstand handling during manufacturing and throughout the product lifecycle. Resistance to tearing or puncturing is crucial to avoid contamination. |
Permeability |
The packaging material should allow moisture to pass through while containing the silica gel. Various permeability levels suit different product needs and environments. |
Warning Labels |
Clear, prominent warnings (e.g., “DO NOT EAT,” “THROW AWAY”) are essential. Icons or symbols should be considered for non-English speakers. |
Size and Format |
Designed to be clearly distinguishable from food products. Larger formats are suitable for bulk packaging, while smaller formats work for individual items. |
Absorption Capacity |
Tailored absorption capacity can meet specific product needs. Different silica gel grades or mixtures with other desiccants may be considered. |
Best Practices for Using Desiccants with Food
To ensure effective moisture control and maintain food safety, there are several best practices to follow when incorporating desiccants in food packaging:
- Use food-grade desiccants and quality substrates (material used in desiccant packaging) specifically approved for direct food contact.
- Implement strict quality control measures to prevent desiccant packet breakage or leakage.
- Clearly label all desiccant packets and include appropriate warnings.
- Educate the production team on the proper handling and placement of desiccants during packaging.
- Stay informed about the latest regulations and safety guidelines regarding desiccant use in food packaging.
- Periodically check desiccant packaging for any signs of wear or damage.
When to Avoid Using Desiccants
While desiccants are effective in controlling moisture and preserving product quality, there are certain situations where their use may not be appropriate or necessary for food packaging.
Desiccants are not suitable for foods with naturally high moisture content, such as fresh fruits, vegetables, or meats. In these cases, removing moisture could degrade the product’s quality, texture, or freshness.
Food Type |
Consideration |
Brown Sugar & Similar Products |
Brown sugar relies on specific moisture content for its soft texture. Desiccants can harden it, making it unusable. Other sugar-based items like marshmallows and gummy candies may experience texture changes if over-dried. |
Fresh Produce |
Many fruits and vegetables require some humidity to stay fresh. Desiccants may cause premature drying, leading to wilting or shrivelling. Consider using humidity-control sachets or eythlene absorbers instead of desiccants. |
Cheeses |
Certain cheeses need specific humidity levels for proper ageing and flavour. Desiccants can interfere with this, affecting texture and taste. |
Baked Goods |
Products like bread, cakes, and pastries can dry out or become stale if exposed to desiccants. These goods are better preserved with modified atmosphere packaging or oxygen absorbers. |
Spices and Herbs |
Desiccants can help preserve some spices, but if over-dried, others may lose essential oils and flavours. Whole spices generally store better with minimal moisture removal. |
Striking the Balance: Quality and Safety in Desiccants
While desiccants are essential for moisture control in food packaging, their direct contact with food requires careful consideration.
Most desiccants, such as food-grade silica gel, are safe when properly enclosed to prevent contamination. By following industry standards and understanding product-specific needs, manufacturers can effectively use desiccants to extend shelf life and maintain food integrity without compromising consumer safety.
At Humi Pak, we manufacture desiccant bags in Malaysia, with ISO 9001 and 14001 certified facilities. Our in-house QA lab rigorously tests our products to ensure they meet the highest quality standards. We help manufacturers use desiccants effectively to extend shelf life, maintain food integrity, and safeguard consumer safety. Feel free to contact our packaging engineers to learn more.