What is the shelf life of an O-ring?

• A. 5 years
• B. 3 years
• C. 20 years
• D. 10 years

Answer: (A)

O-rings age over time, and their ability to seal depends on the material’s properties staying within spec. Shelf life is the period during which an O-ring stored under proper conditions is expected to remain usable and able to seal reliably. Aging factors include changes in elasticity, hardening, compression set, cracking, and surface degradation from heat, ozone, light, or humidity. With proper storage—original packaging, cool, dry environment, away from heat and ozone sources—the typical guideline for this program is a five-year shelf life. This duration balances keeping seals effective with practical inventory management. Using them beyond that window increases the risk that aging has degraded performance, even if they appear unopened. Shorter shelf lives would drive unnecessary replacements, while longer ones raise the chance of undetected degradation prior to use.