Shelf life

Shelf life is the period during which a product, stored as directed, stays safe and keeps its expected quality. The best before or use by date on the label is based on it.

How packaging affects shelf life

• Oxygen causes rancidity and aroma loss; controlled with low OTR materials.
• Moisture softens dry foods or dries moist ones; controlled with low WVTR.
• Light fades colours and degrades vitamins and fats; foil, metallised or opaque layers help.
• Physical damage such as punctures or leaking seals cancels all other protection.

Tools to extend it

Suitable barrier laminates, vacuum or modified atmosphere packing, one-way degassing valves for coffee, resealable zippers, and heat treatments such as hot fill or retort where the product allows.

How it is set

Shelf life is established by testing the product in its final pack under expected storage conditions, sometimes with accelerated trials. The food business placing the product on the market is responsible for setting it. Any packaging change, for example a move to a recyclable mono-material structure, should be followed by a new shelf life check. Give your converter a concrete target rather than "as long as possible" to avoid over-engineered, costly packs.