shelflife

Shelf life is the length of time a product remains safe to use and retains its intended quality under specified storage conditions. It varies by product type and handling, and is distinguished from related terms such as use-by, best-before, and expiry dates. Perishable items spoil quickly, while durable goods can remain usable for longer when stored properly.

Several factors influence shelf life, including moisture content, water activity, pH, fat content, microbial load, enzymatic activity, and chemical changes such as oxidation. Packaging reduces exposure to oxygen, light, and moisture; technologies such as vacuum sealing, canning, and modified-atmosphere packaging extend longevity. Temperature and humidity control are also critical.

Labeling varies by region. Use-by or expiry dates indicate safety limits for foods and medicines, while best-before dates refer to quality and may allow extended use if stored correctly and inspected. Shelf life also differs between foods (perishable, semi-perishable, shelf-stable) and non-food items (cosmetics, pharmaceuticals, chemicals).

Measures to extend shelf life include proper storage, sanitation, and handling; refrigeration or freezing when appropriate; protection from light and oxygen; moisture control; and the use of permissible preservatives or antioxidants. Consumers should inspect products for signs of spoilage, such as off odors, color changes, texture shifts, or mold, and discard items that show indicators of degradation.