Fill

Moisture Barrier Bags & Desiccants — Protecting Humidity-Sensitive Shipments

Moisture damage is an underappreciated shipping risk — electronics, food, printed goods, and leather products can all be damaged by humidity during transit. A sealed corrugated box doesn't protect against humidity; moisture permeates cardboard readily. For humidity-sensitive products, moisture barrier bags and desiccants are the solution.

Types of Moisture Barrier Bags & Desiccants

Foil moisture barrier bags (MBB)

Multi-layer foil-laminate bags with heat-seal closure — the strongest moisture barrier available for packaging.

Best for: Electronic components, PCBs, food products, moisture-sensitive pharmaceuticals

Vacuum seal bags

Polyethylene/nylon bags with airtight zipper or heat seal — removes air along with moisture.

Best for: Clothing storage shipments, food, leather goods, anything needing both moisture and oxygen exclusion

Silica gel desiccant packets

Silica gel absorbs moisture from inside a sealed package — does not require a foil bag to work.

Best for: Shoes, leather goods, electronics in standard bags, any sealed package with humidity risk

Molecular sieve desiccants

More aggressive moisture absorption than silica gel — maintains lower relative humidity.

Best for: Pharmaceutical components, precision optical equipment, sensitive electronics

Practical Tips

  • •Desiccants extend the time a sealed package stays dry but don't work forever — size desiccant quantity to the transit time and bag volume
  • •Standard silica gel unit: 1 gram of silica gel per 1 cubic foot of bag volume for standard transit (under 7 days)
  • •Moisture barrier bags must be heat-sealed or properly ziplock-sealed — an open top defeats the purpose entirely
  • •For electronics shipped internationally (longer transit, varied humidity climates), use both MBB and silica gel desiccant together
  • •Include humidity indicators (color-change cards) in high-value sensitive shipments so receivers can confirm moisture exposure during transit

Frequently asked questions

Do I need moisture barrier bags for shipping electronics?
For consumer electronics in finished products (phones, cameras), standard packaging is typically sufficient for domestic transit. For bare circuit boards, PCBs, and sensitive components, moisture barrier bags with desiccants are strongly recommended — moisture can cause corrosion and ESD issues.
How do desiccant packets work?
Silica gel desiccants absorb water vapor from the air inside a sealed package. They don't produce anything — they just capture moisture molecules. When saturated, they stop working. Size them for the expected transit duration — don't assume one small packet protects a large sealed bag for a month.
Can I reuse silica gel desiccant packets?
Yes — silica gel can be regenerated by heating in an oven at 250°F for 1–2 hours. The color-indicating type (blue/pink) makes it easy to see when they're saturated and need regeneration.

More Supply Guides

Mailer
Rigid Mailers & Stay-Flat Mailers
Fill
Gel Ice Packs & Refrigerants
Fill
Paper Void Fill & Honeycomb Wrap
Label
Label Printer Rolls & Thermal Paper

Create a Shipping Label

Free for USPS, UPS, FedEx, DHL.

Make a Label Free →