Importance of Water and Oxygen Permeability Tests in the Plastic Industry

13 September 2025

Plastic films, widely used in daily life, play a crucial role in packaging products such as food, pharmaceuticals, and cosmetics that directly affect human health. These plastic packages are not only used to protect the product from external factors, but also to extend shelf life, ensure food safety, and protect consumer health. However, in order to determine whether the protective properties of packaging films are truly of high quality, they must undergo certain quality control tests. Among the most important of these are liquid and gas permeability tests.

What is Permeability and Why is it Important?

Packaging films are never 100% impermeable. At the molecular level, gases, water, and moisture can pass through the film and interact with the product.

Gas permeability: the rate at which gases such as oxygen and carbon dioxide pass through the packaging.
Water vapor permeability: the rate at which moisture in the environment penetrates the film and reaches the product.
Water permeability: the rate at which liquid water passes through the film under pressure or contact.

Conducting these tests is critical to prevent product spoilage, maintain quality, and ensure compliance with international standards.

Gas Permeability: The Oxygen and Carbon Dioxide Barrier

Oxygen permeability is particularly important in packaging films. Oxygen causes the spoilage of many foods and pharmaceuticals.

For example, foods deteriorate and lose taste and aroma upon contact with oxygen. The active ingredients in medicines degrade when exposed to oxygen, reducing their shelf life.

Water Vapor Permeability: The Moisture Barrier

Moisture is the biggest enemy of food and pharmaceutical packaging:

Hygroscopic foods (e.g., milk powder, coffee, biscuits) soften or spoil when exposed to moisture.
Medicines (tablets and capsules) dissolve with moisture and lose effectiveness.
Mechanical and electronic parts corrode due to humidity.

For this reason, the WVTR (Water Vapor Transmission Rate) is measured in packaging films to determine their permeability rate.

Water Permeability

Water permeability is especially important in plastic packaging where direct liquid contact occurs (e.g., liquid food containers, shampoo bottles, liquid medicine packaging).

Leakage tests measure how well the packaging retains liquid.
Permeability tests under pressure analyze long-term durability of the packaging.

Standards: ASTM and ISO Explained

For permeability tests to be reliable, they must be carried out according to international standards.

🔹 ASTM Test Standards

ASTM D3985: The most widely used method for measuring oxygen permeability.
ASTM F1249: Developed for measuring water vapor permeability.
ASTM F1307: Defines various test methods for gas and vapor permeability.

These standards allow manufacturers to compare different materials and gain international recognition.

🔹 ISO Test Standards

ISO 15105-1: Defines the differential pressure method for measuring gas permeability.
ISO 15105-2: Explains the coulometric sensor method for gas permeability.
ISO 2528: Regulates water vapor permeability test methods.

ISO standards ensure that packaging films are valid particularly in European and Asian markets.

Test Instruments for Measuring Liquid and Gas Permeability

Oxygen Transmission Rate (OTR) Tester: Complies with ASTM D3985 and ISO 15105.
Water Vapor Transmission Rate (WVTR) Tester: Measures according to ASTM F1249 and ISO 2528.
Water Permeability Tester: Tests packaging resistance against direct liquid contact.
Multi-station systems: Test multiple samples simultaneously, saving time.

Quality Control Process in Packaging Films

Quality control in packaging films should be conducted at every stage of production:

Raw material control: Testing the barrier properties of the polymer used.
Post-production film control: Samples taken from extruded films are tested.
Compatibility testing: Packaging is tested with the actual product to measure real-world performance.
Routine laboratory testing: Ongoing quality monitoring throughout production.

Alarge’s Solutions

Alarge offers the following solutions for packaging film manufacturers and related sectors:

ASTM and ISO-compliant OTR (oxygen permeability), WVTR (water vapor permeability), and water permeability testing systems.
Complete water resistance testing systems.
Laboratory setup and consulting services.

This way, manufacturers ensure compliance with international standards while enhancing customer trust.

Conclusion

Gas, water, and water vapor permeability tests in packaging films are critical to extend product shelf life, ensure food safety, and demonstrate compliance with international standards. With devices that meet ASTM and ISO requirements, manufacturers can guarantee global acceptance of their products.

With the high-precision devices and consulting services provided by Alarge, companies can develop safer, more durable, and standards-compliant packaging solutions.