Silica gel packets are small but essential — the difference between a product that arrives dry and one ruined by mould, rust or clumping. This buyer's guide focuses on the two questions that matter most when specifying them: what size and quantity do you need, and how are packets used across different industries. (If you're deciding between blue, white and orange gel, start with our dedicated guide to silica gel colour differences.)
What are silica gel packets?
Silica gel packets are breathable non-woven sachets filled with silica gel beads or crystals. The gel adsorbs water vapour from the sealed space around it, keeping relative humidity low. Packets are made in a huge range of sizes — from tiny 0.5 g and 1 g sachets for bottles and blisters, up to 500 g and 1 kg bags for cartons and shipping containers.
How to choose the right packet size
As a practical starting point, use roughly 1 gram of silica gel per 30–40 cm³ of sealed air volume, then adjust for how humid the environment is, how long the product will be stored or in transit, and how moisture-sensitive it is. Typical choices look like this:
| Packet size | Typical use |
|---|---|
| 0.5 g – 2 g | Medicine bottles, blister cartons, diagnostic kits, jewellery |
| 5 g – 10 g | Electronics, small boxes, leather goods, camera gear |
| 25 g – 50 g | Shipping cartons, footwear, machine parts |
| 100 g – 1 kg | Pallets, drums and full container-load shipments |
When in doubt, it is better to slightly over-dose than under-dose — an under-sized packet saturates early and stops protecting the product. Share your packaging dimensions with us and we'll calculate the exact grammage.
Silica gel packets by industry
- Electronics: Prevents corrosion, condensation and tin-whisker issues during storage and ocean freight.
- Pharmaceuticals: Protects tablet and capsule stability; cobalt-free gel is used in bottles and blisters.
- Food & beverage: Keeps snacks, spices and powders crisp and free of clumping.
- Packaging & logistics: Prevents container rain and mould on long export routes.
- Automotive & aerospace: Stops rust on machined parts and fogging in sealed instruments.
Usage tips
- Place packets where moisture is most likely to enter or collect.
- Seal the packaging as well as possible — desiccants work best in a closed space.
- Replace indicating packets once the colour changes.
- Store spare packets in an airtight container so they don't saturate before use.
Conclusion
Choosing the right silica gel packet is mostly about matching the quantity to your sealed volume and the type to your product's safety needs. At Aharnish Desiccant we manufacture the full range — from 0.5 g sachets to 1 kg bags, with custom sizes and private labelling. Request a quote and we'll recommend the right packet for your packaging.