Shelf life is how long the device is known to be safe for use, between its manufacture date and its first use. Typically, it is applicable to devices with some characteristic that may degrade while awaiting first use. This could be something within the device itself (e.g., liquid) or the packaging (e.g., sterile pouch).

Shelf life is generally determined by the manufacturer through testing, e.g., accelerated/real-time testing which replicate the expected conditions for transport, storage and handling. Factors for determining shelf-life include the materials used to manufacture the device (including if they expire), packaging materials, and shipping/storage conditions.

If a manufacturer states that the shelf-life of the device is two years, it is expected they can empirically validate that the device does not degrade within that timeframe.

Shelf life can and may be extended by the manufacturer, as long as evidence is generated to support the longer shelf-life.

Examples of why a device may be considered unusable include deterioration of sterility of the product packaging or a decrease in the effectiveness of substance-based devices, such as the drying out of the gel on defibrillator pads.

The expiration date is the date the product loses stability and no longer functions as intended. And therefore, can no longer be safely used.

Generally, expiration dates are given to products that have some characteristic that will degrade within a certain timeframe, e.g., the acidity level in contact lens solutions.

Expected Lifetime / Useful Life

The terms expected lifetime and useful life are generally synonymous.  

The expected lifetime is how long the device is anticipated to safely meet its intended purpose. It is generally the time between the first use of the device and the timeframe when it is 1) used to its intended purpose (e.g., single-use consumable), 2) the device expires (e.g., a liquid based product), or 3) the failure intensity becomes unacceptable or when the device has an unrepairable failure (e.g., electromedical equipment).  

The expected lifetime is determined by the manufacturer, taking into consideration risk assessment, product testing, usability testing, post-market data, shelf-life (if applicable), expiration dates (if applicable), and other similar factors.

A device’s lifetime may range from 10+ years (with proper maintenance and servicing) for some hospital equipment, to less than 60 minutes for consumables. For reusable devices, it may include a maximum number of uses, with criteria established regarding when the device may no longer be safely reused.

Further Reading

Team Notified Body released a position paper on Medical Device Lifetime. It provides a common understanding of the term under the MDR, ways to determine lifetime, and recommendations to manufacturers: Team NB Position Paper – Medical Device Lifetime

Examples: Shelf Life, Expiration Date, Lifetime

A medical device’s shelf life, expiration date, and expected lifetime can be different.  

For example:

End of life is generally interpreted to mean when the device will no longer be manufactured and supported.

This may consist of the following phases:

Manufacturers should create quality plans to document a product’s end of life, including steps, timing, and internal/external communication.

Service Life

The service/support life is generally the length of time that the manufacturer will service devices still in the field, including cybersecurity, if applicable.

This timeframe is determined by the manufacturer. In addition to factors such as expected lifetime and environmental conditions, they may also consider the cost and availability of spare parts.

IEC 60601-1 states the expected service life is the:

“…time period specified by the manufacturer during which the ME equipment or ME system is expected to remain safe for use (e.g., maintain basic safety and essential performance);

(Note: Maintenance may be necessary during the Expected Service Life.)”

Further, IEC 60601-1 states that the Instructions for Use (IFU) should include:

• “the EXPECTED SERVICE LIFE of the ME EQUIPMENT;
• the EXPECTED SERVICE LIFE of parts or ACCESSORIES shipped with the ME EQUIPMENT; and
• where the SHELF LIFE is less than the EXPECTED SERVICE LIFE, the SHELF LIFE of parts or ACCESSORIES shipped with the ME EQUIPMENT.”

For products that require servicing, the manufacturer should have a plan for notifying users that the device is being retired and when the device will no longer be eligible for support.

Of course, manufacturers may still receive inquiries after a device’s service life has passed. As best practice, manufacturers should document how to handle service inquiries for discontinued products, or products past their service life. This may be as simple as a script for customer service, explaining the situation and advising of alternative devices currently being manufactured and eligible for servicing.

Life Cycle

A medical device’s life cycle is generally the combination of shelf life, expected lifetime, and service life.

That said, the device lifecycle may also be considered from the point of R&D and manufacturing, to the point there are no devices left on the market. For example, even if the device is no longer being manufactured or serviced, the manufacturer should still document reactive data as part of its Post-market Surveillance, e.g., complaints and vigilance received for products still in the field. This data may then warrant updates to the Clinical Evaluation Report.

NOTE: this page does not consider refurbished or re-manufactured devices beyond the manufacturer’s intended lifetime. Doing such would generally create a ‘new’ device, with a new expected lifetime.