Does Corrugated Affect Corrosion & What Can You Do About It?

After opening a corrugated box to retrieve a spare part, you discover unexpected rust on the metal surface. The component was dry when packaged, and the box appears intact. Naturally, you begin to wonder: Does Corrugated Affect Corrosion?

Corrugated boxes are one of the most common packaging materials used in industrial shipping and storage. They are lightweight, economical, and easy to handle.

But when it comes to protecting metal parts, corrugated packaging can contribute to corrosion if not properly designed.

If you’ve ever opened a box to find unexpected rust, staining, or oxidation, corrugated may have been the culprit.

In this article, we’ll explain:

• How corrugate can affect corrosion
• Why moisture and chemistry matter
• When corrugated becomes a risk
• What you can do to protect metal parts effectively

How Corrugated Affects Corrosion in Metal Packaging

Corrugated fiberboard is made from paper pulp. Paper products naturally contain:

• Residual moisture
• Organic acids
• Sulfur compounds
• Chlorides (depending on source materials)

Under certain environmental conditions, these components can accelerate corrosion.

1. Moisture Absorption and Release

2. Acidic Residues in Paper Fibers

3. Condensation from Temperature Fluctuations

4. Direct Contact Corrosion

When bare metal parts are placed directly against corrugated without protective wrapping:

• The paper can trap localized moisture.
• Acidic residues can concentrate at contact points.
• Imprint corrosion or staining can occur.

This is particularly common with:

• Sheet metal panels
• Cast components
• Machined flat surfaces
• Automotive parts stacked in cartons

Why Moisture and Metal Are a Problem Together

Corrosion requires three basic elements:

1. Metal
2. Oxygen
3. Electrolyte (water)

Corrugated can introduce or trap the electrolyte component.

Once moisture is present, corrosion can initiate before traditional packaging barriers are able to stop it.

Chemical Interaction Between Corrugated and Metal

Some corrugated materials may contain acidic residues from the pulping or recycling process. These acidic components can:

• Lower pH inside the enclosure
• Promote flash rust
• Cause staining on sensitive surfaces
• Increase corrosion rates in humid conditions

This is especially problematic for:

• Precision-machined components
• Bearings
• Electrical enclosures
• Automotive parts
• Aerospace components

When Does Corrugated Not Affect Corrosion?

Corrugated itself is not inherently harmful. Problems occur when:

• Parts are not surface dry
• Humidity is high
• Temperature fluctuations cause condensation
• Long-term storage is required
• Export shipments face uncontrolled environments

If your supply chain includes ocean freight, seasonal climate changes, or extended storage, corrugated alone is not enough.

How to Prevent Corrosion If Corrugated Affects Your Packaging

The solution is not to eliminate corrugated. It is to use it correctly within a corrosion protection system.

1. Add Vapor Corrosion Inhibitor (VCI) Protection

Using VCI packaging inside corrugated dramatically reduces corrosion risk.

ZERUST® VCI films and papers release protective vapor molecules that:

• Form an invisible corrosion-inhibiting layer
• Protect multimetal components
• Guard against humidity-driven corrosion
• Provide clean, dry protection without residue

Recommended solutions include:

• ZERUST® VCI Film
• ZERUST® VCI Paper
• ZERUST® VCI Bags
• ZERUST® ActivDri™ PWA Moisture Control Packets

2. Ensure Parts Are Clean and Dry Before Packaging

Even the best VCI system cannot compensate for standing water.

Before placing metal parts into corrugated:

• Remove machining fluids
• Eliminate visible water droplets
• Allow parts to cool to ambient temperature
• Verify no trapped condensation exists

If moisture exposure is unavoidable, consider pairing VCI packaging with:

• ZERUST® Axxanol™ rust preventative oils
• ZERUST® Axxatec™ water-based corrosion inhibitors

3. Control Moisture Inside the Box

In high-humidity or export environments, additional moisture control may be required.

ZERUST® ActivDri™ PWA Packets combine:

• Moisture absorption
• VCI vapor protection
• Fast and slow-release corrosion inhibitors

This dual-action approach protects sensitive electronics, electrical enclosures, and multimetal assemblies.

4. Consider Long-Term Storage and Export Conditions

If your corrugated packaging will face:

• Ocean container shipment
• High-humidity warehouses
• Seasonal temperature swings
• Layup or spare parts storage

Then your packaging design should include:

• Proper sealing
• Correct VCI placement
• Adequate volume calculation
• Testing validation

Testing and Validation Matter

Corrosion protection should not rely on assumptions.

ZERUST® offers laboratory and field validation testing to evaluate:

• Corrosion risk in corrugated packaging
• Environmental simulation performance
• Long-term storage protection
• Export container conditions

Proper testing ensures your packaging system works before shipment, not after failure.

Does Corrugated Affect Corrosion? Understanding and Managing the Risk

Corrugated boxes are economical and practical. However, they can:

• Absorb moisture
• Introduce corrosive compounds
• Create condensation conditions
• Accelerate corrosion without proper controls

The key is to design a complete corrosion protection system that includes:

✔ Surface preparation
✔ VCI protection
✔ Moisture control
✔ Proper sealing
✔ Environmental validation

Protect Your Metal Parts with Confidence

Whichever corrosion protection strategy you choose, ZERUST® is ready to support your corrosion prevention goals.

We begin by analyzing the current state of your corrosion management program and identifying potential risk points within your process. Our team works alongside you to implement the most effective and cost-efficient solution tailored to your environment, storage conditions, and shipment requirements.

ZERUST® can come directly to your facility to perform a detailed, step-by-step evaluation of your current corrosion control practices, including:

• Fluid audits
• VCI packaging and process audits
• Packaging design reviews
• Environmental monitoring and data logger analysis
• Root cause investigation of corrosion failures

Our mission is to provide the right combination of products, processes, and procedures so you can confidently achieve consistent, corrosion-free results.