What is event-related sterility?

The practice of treating a sterile package as sterile until an event compromises it, such as a tear, moisture or a broken seal, instead of discarding it on a fixed expiration date. CDC notes that contamination is event-related and that the chance of contamination increases with handling.

Is a package still sterile if it was dropped but looks intact?

Treat it as compromised and send it back for reprocessing. The impact can damage the barrier or force air and contaminants through the packaging without a visible tear. Follow your facility’s policy.

How far from the floor should sterile items be stored?

CDC’s guideline says 8 to 10 inches from the floor, 5 inches from the ceiling (18 inches from a sprinkler head) and 2 inches from outside walls.

Free tool · CRCST exam topic

Is it still sterile?

Sterility is event-related: a package stays sterile until something happens to it. Tick anything that applies to the package in your hand.

Torn, punctured or abraded wrap or pouchWet, damp or water-stainedSeal broken, lid lock or tamper-evident tag missingDropped on the floor or crushedExternal indicator did not change, or is missingVisibly soiled or dusty

Verdict

No event found

Nothing you ticked compromises the package. Before use, still inspect it, check the indicator and confirm it was stored at the right clearances.

Floor: 8 to 10 inches
Ceiling: 5 inches (18 inches from a sprinkler head)
Outside walls: 2 inches

Event-related sterility

CDC’s guideline notes that many hospitals have moved to an event-related shelf-life practice: a product stays sterile until an event contaminates it, such as a tear in the packaging, the packaging getting wet or a broken seal. The chance of contamination rises with handling, so sterile packages should be handled as little as possible.

Factors CDC lists as contributing to contamination include bioburden, air movement, traffic, location, humidity, insects, vermin, flooding, storage space, open or closed shelving, temperature and the properties of the wrap.

How sterile items should be stored

Floor: 8 to 10 inches.
Ceiling: 5 inches (18 inches from a sprinkler head).
Outside walls: 2 inches.
Closed or covered cabinets are ideal, but open shelving may be used.

Sterile storage on the CRCST exam

Sterile Storage, Transport and Inventory Management is 9% of the CRCST exam. Expect questions on event-related sterility, storage conditions, handling and transport, and inventory practices such as stock rotation and par levels. Packaging that fails before storage is covered under Preparation and Packaging; see the sterilization indicators guide.

Test yourself: a CRCST-style question

A sterile pack is found on a shelf with a water stain on the wrap, but the wrap is not torn. What should the technician do?

Use it, because the wrap is intact
Let it dry and return it to the shelf
Consider it contaminated and send it for reprocessing
Use it only for noncritical procedures

Show answer

C. Consider it contaminated and send it for reprocessing

Moisture is one of the events that compromise sterility: liquid can carry microorganisms through the packaging. A wet or water-stained package is considered contaminated and goes back for reprocessing.

Questions like this come up in the Sterile Storage, Transport and Inventory Management section of the CRCST exam. The 901 questions in the app each come with a written explanation.

FAQ

What is event-related sterility?: The practice of treating a sterile package as sterile until an event compromises it, such as a tear, moisture or a broken seal, instead of discarding it on a fixed expiration date. CDC notes that contamination is event-related and that the chance of contamination increases with handling.
Is a package still sterile if it was dropped but looks intact?: Treat it as compromised and send it back for reprocessing. The impact can damage the barrier or force air and contaminants through the packaging without a visible tear. Follow your facility’s policy.
How far from the floor should sterile items be stored?: CDC’s guideline says 8 to 10 inches from the floor, 5 inches from the ceiling (18 inches from a sprinkler head) and 2 inches from outside walls.

Sources

Checked against CDC on November 13, 2026. For CRCST exam study only. Your facility’s policy, the packaging manufacturer’s instructions for use and ANSI/AAMI ST79 decide what happens to a package in practice.