Sterile fluid path
The standard’s wording, as the sources below reproduce it:
“Indicates the presence of a sterile fluid path within the medical device in cases when other parts of the medical device, including the exterior, might not be supplied sterile.”
ISO 15223-1:2021, 5.2.9
What it means for you
Only the channel the fluid runs through is sterile — the inside of the tubing, the drip chamber, the needle path. The outside of the set and the box are not promised to be sterile, so handling the outside with clean hands is normal; the inside must stay closed until use.
Whether a device is right for you is a question for your pharmacist, nurse or doctor.
- What it looks like
- A STERILE box sitting inside a double-lined bracket shaped like a square C opening to the left (the fluid-path mark). A sterilisation method box, such as EO or R, can be added.
- Where you see it
- Infusion and giving sets, extension lines, blood-collection sets, dialysis lines and pump cassettes.
- Other names
- STERILE with a bracket; sterile fluid pathway; sterile inside only
What it does not tell you
It does not say the outside of the device is sterile, and on its own it does not name the sterilisation method; a separate method box (EO, R) does that.
Often confused with
Indicates a medical device that has been subjected to a sterilization process.
More symbols in “The word STERILE”
Sources
ISO 15223-1 is a paid standard, so the wording above is quoted as 3 publishers’ public documents reproduce it. Each was fetched and read on the date shown:
- Boston Scientific: Symbols Glossary — ISO 15223-1 5.2.9 “Sterile fluid path — Indicates the presence of a sterile fluid path within the medical device in cases when other parts of the medical device, including the exterior, might not be supplied sterile”, with Annex A.12 examples combined with EO and irradiation. Checked 2026-09-28.
- Cook Medical: Glossary of standard symbols — ISO 15223-1 5.2.9 “Sterile fluid path”, with the same description. Checked 2026-09-28.
- Ethicon: Symbols glossary (100584677 Rev.8) — Shows the STERILE box inside the fluid-path bracket for 5.2.9 with the same description. Checked 2026-09-28.
Plain-language parts are in our own words; quotations are the sources’ wording.