In the food packaging industry, barrier performance is crucial for extending shelf life, maintaining freshness, and ensuring product safety. Two key metrics used to evaluate barrier packaging materials are:
- OTR (Oxygen Transmission Rate)
- MVTR (Moisture Vapor Transmission Rate)
Understanding and optimizing these specifications helps manufacturers select the right materials and comply with industry standards.
What Is OTR (Oxygen Transmission Rate)?
OTR measures the amount of oxygen gas that permeates through a packaging material over a given period. It is usually expressed as:
cc/m2·day (cubic centimeters per square meter per day)
Why OTR Matters in Food Packaging:
Prevents Oxidation: Low OTR materials protect oxygen-sensitive products like snacks, coffee, and dairy.
Improves Shelf Life: Reduces spoilage and rancidity in fats and oils.
Supports MAP Packaging: OTR is essential for Modified Atmosphere Packaging systems.
Typical OTR Specifications by Material (approximate):
| Material Type | OTR (cc/m2·day) | Barrier Rating |
|---|---|---|
| Polyethylene (PE) | >5000 | Poor |
| Oriented Nylon (ONy) | 50–200 | Moderate |
| EVOH Coextruded Films | <2 | High |
| Aluminum Foil Laminates | ~0 | Excellent |
What Is MVTR (Moisture Vapor Transmission Rate)?
MVTR, also called WVTR (Water Vapor Transmission Rate), measures how much water vapor passes through packaging material. It’s usually expressed as:
g/m2·day (grams per square meter per day)
?? Why MVTR Matters:
Controls Moisture Ingress: Crucial for dry foods, powders, and crisp snacks.
Prevents Texture Changes: Keeps products from becoming soggy or stale.
Protects Against Mold: Essential in humid environments or long distribution chains.
? Typical MVTR Specifications by Material:
| Material Type | MVTR (g/m2·day) | Moisture Barrier |
|---|---|---|
| Polyethylene (PE) | ~10 | Low |
| BOPP | 0.5–1.5 | Moderate |
| Metallized PET | 0.1–0.5 | High |
| Aluminum Foil Laminates | ~0 | Excellent |
How to Test OTR & MVTR Accurately?
To ensure barrier quality, many companies use standardized laboratory instruments that comply with ASTM or ISO methods:
OTR Test Methods: ASTM D3985, ISO 15105-2
MVTR Test Methods: ASTM F1249, ISO 15106
Recommended Testing Equipment:
Final Thoughts: Choose the Right Barrier, Backed by Data
Selecting the correct OTR and MVTR specifications is not one-size-fits-all. The right barrier depends on:
Product sensitivity to oxygen and moisture
Desired shelf life
Storage and transportation conditions
Packaging format (bag, pouch, tray, etc.)
If you manufacture or supply barrier food packaging, accurate OTR/MVTR data is a must for product performance and regulatory compliance.
Need Help Measuring OTR or MVTR?
At Labthink, we specialize in precision barrier testing solutions. Whether you're testing multilayer films, trays, or pouches, our instruments help ensure your packaging meets international standards.
Request a demo or quote today!