Packaging barrier properties guide
Specify the protection the product needs and the test conditions before comparing a bottle or pouch material.
Barrier is a measured product-protection requirement, not a generic “high barrier” label.
Packaging barrier describes how the complete pack limits transfer of gases, vapour, light, aromas, oils or other substances under defined conditions. The required level depends on the product, intended shelf life, fill process, pack size, storage and distribution.
A supplier data sheet may describe a material or film under laboratory conditions. The finished pack also includes seals, closures, liners, fitments, labels and manufacturing variation, so shelf-life or compatibility validation is still required.
Translate product risks into evidence requests
| Oxygen | Relevant where oxidation, flavour change, colour change or ingredient degradation is a concern. Define headspace, closure and seal effects as well as wall or web performance. |
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| Moisture vapour | Relevant where a dry product can absorb moisture, a wet product can lose water or pack dimensions can change. Temperature and humidity affect the result. |
| Light and UV | Relevant for light-sensitive products. Bottle colour, opacity, label/sleeve coverage and secondary packaging can contribute; verify with the real exposure and product. |
| Aroma and flavour | Consider both loss from the product and ingress from the environment or packaging. Use representative contents and storage time. |
| Grease, oils and chemicals | Check swelling, softening, stress, permeation, seal/liner interaction, adhesive failure and print effects using the exact formulation. |
| Seal and closure integrity | A high-barrier wall or web cannot compensate for a leaking closure, contaminated seal, channel leak or poorly attached fitment. |
Ask for conditions, not isolated numbers
- Exact material or structure and nominal thickness.
- Test method, temperature, relative humidity and sample orientation.
- Whether the value covers a flat material sample or the finished package.
- Units, test variability and whether a maximum, typical or target value is stated.
- Effects of printing, folding, forming, sealing, sterilisation, filling or transport.
- Shelf-life protocol using representative product and finished packs.
Do not compare figures measured under different conditions as though they are equivalent. Where a precise barrier target is not known, start with the product failure mode and intended shelf life, then involve a packaging technologist or laboratory to define the test.
Use barrier only where it adds proven value
Additional layers or coatings can improve protection but may add cost, weight, process complexity or end-of-life challenges. The correct specification is the least complex structure that meets the validated product, production and distribution requirements—not the highest barrier available.
For flexible packaging, compare mono-material and laminated pouch structures. For bottles, compare PET and HDPE. Use the compatibility test plan to control filled-pack trials.