Food-grade PP plastic sealing boxes do not have a clearly defined shelf life mandated by national regulations, but their safety and performance gradually decline over time depending on usage duration, environmental conditions, and how they are used. Therefore, although there is no fixed "expiration" date, it is recommended to replace them regularly based on actual conditions for the sake of health and safety.

Key factors affecting service life

The actual lifespan of PP plastic sealing boxes is influenced by various factors, and it’s generally recommended to replace them within 3 to 5 years. Here are the key factors that affect their durability:

Material type: PP (polypropylene) has excellent heat resistance and can last up to 5 years; however, materials like PC (polycarbonate) are prone to aging, so it’s recommended to replace them within 3 years.
Usage frequency: Daily-use lunch boxes wear out faster and are recommended to be replaced every 2–3 years; occasional users may extend their lifespan up to 4 years.
Cleaning method: Avoid scrubbing with steel wool or using strong acid or alkaline cleaners, as these can accelerate plastic oxidation.
High-temperature contact: Prolonged microwave heating or contact with high-temperature foods (such as oily dishes) can accelerate material degradation. If deformation, discoloration to white, or other abnormalities occur, discontinue use immediately.
Appearance damage: If cracks appear at the lid opening, scratches on the inner wall, or deformation at the bottom, replace the item promptly—even if it hasn’t reached its recommended lifespan.
How to determine whether replacement is needed?
Check the label: Ensure that the bottom bears food-grade markings such as "PP5" or "BPA Free."
Observe the condition: If the plastic becomes brittle, discolored, develops scratches, or loses its sealing performance, it should be replaced immediately.
Avoid long-term storage of acidic or alcoholic foods: these substances can accelerate plastic degradation.