Food packaging has a tough job: it must keep products fresh, safe, and appealing, all while meeting sustainability and regulatory requirements. Oxygen and moisture are two of the biggest threats to quality, and that’s where barrier testing comes in.

Barrier testing measures how well your packaging keeps oxygen (OTR: Oxygen Transmission Rate) and moisture (WVTR: Water Vapor Transmission Rate) out of the packaging. Think of it as a stress test that shows whether your packaging will actually perform once it leaves the factory.

For packaging engineers, R&D teams, and brand managers, barrier testing is about more than hitting a specification. It is about protecting your products, avoiding costly waste, and proving that your design can handle real-world conditions.

 

Why Barrier Testing Matters

Without testing, packaging choices are often made on assumptions. That can lead to recalls, wasted inventory, and disappointed consumers.

With OTR and WVTR testing, you gain the data to:

  • Prevent failures by spotting weaknesses before they reach store shelves
  • Accelerate development by avoiding costly redesigns later in the process
  • Back up shelf-life claims with reliable, defensible data
  • Reduce supply chain risk by qualifying suppliers and holding materials to measurable standards
  • Prove sustainability wins by showing that recyclable or lightweight materials still protect products
  • Stay compliant with FDA, EU, and evolving state-level EPR regulations

Barrier testing delivers the insights needed to make smarter, faster, and safer packaging decisions.

 

Building a Reliable Testing Program

The most effective testing programs are proactive, built into the packaging lifecycle rather than added as an afterthought.

Best practices include:

  • Define your goals by identifying whether oxygen, moisture, or both are the biggest risks
  • Select the right method based on product sensitivity, storage and distribution conditions, and regulatory requirements
  • Standardize sample preparation so results are reliable and reproducible, including conditioning protocols, sample orientation, and contamination prevention
  • Integrate results into quality systems with statistical process control, trending, and supplier scorecards
  • Test routinely through a trusted third-party lab to validate consistency across product lines and launches

 

OTR vs. WVTR: Choosing the Right Test

Oxygen Transmission Rate (OTR) Testing (ASTM D3985) measures how much oxygen passes through packaging. It is critical for oxygen-sensitive products such as fresh produce, coffee, snacks, and beverages.

Key parameters include:

    • Temperature control (typically 23°C ± 2°C)
    • Relative humidity conditions (0%, 50%, or 75% RH depending on application)
    • Oxygen concentration gradients
    • Consistent sample conditioning protocols

Water Vapor Transmission Rate (WVTR) Testing (ASTM F1249) measures how much moisture moves through packaging. It is essential for dry goods, frozen foods, confectionery, pet food, and supplements.

Optimal conditions include:

  • Temperature ranges from 5°C to 60°C
  • Humidity gradients from 0% to 100% RH
  • Extended test durations to ensure equilibrium
  • Multiple specimens for statistical reliability

Both tests simulate real-world storage and shipping environments, ensuring that packaging will perform where it matters most.

 

The Takeaway

Barrier testing is not just a technical requirement; it is a strategic tool for innovation, sustainability, and brand protection. With dependable OTR and WVTR data, you can optimize shelf life, reduce waste, and make packaging choices with confidence.

At Clear Packaging, we help food brands, packaging manufacturers, and material suppliers turn testing data into stronger, smarter packaging solutions.

Ready to see how your packaging performs? Contact our team today.