semiatic
STERILEEO

Sterilized using ethylene oxide (STERILE EO)

The standard’s wording, as the sources below reproduce it:

“Indicates a medical device that has been sterilized using ethylene oxide.”

ISO 15223-1:2021, 5.2.3 · ISO 7000-2501

What it means for you

The device was sterilised with ethylene oxide gas, a low-temperature method used for plastics and electronics that heat would damage.

Whether a device is right for you is a question for your pharmacist, nurse or doctor.

What it looks like
A STERILE box with an extra cell holding the letters EO.
Where you see it
Catheters, tubing sets, many plastic single-use devices and procedure kits.
Other names
STERILE EO; EtO sterilised; ethylene oxide

What it does not tell you

It does not say anything about residues or suitability for you; it names the method only. It also does not mean you can sterilise the item again.

Often confused with

Indicates a medical device that has been sterilized using irradiation.

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 5.2.3 “Sterilized using ethylene oxide — Indicates a medical device that has been sterilized using ethylene oxide.” Image labelled ISO 7000-2501. Checked 2026-09-25.
  • NE Scientific: Master Symbol Glossary (CTF-100011 Rev 01) — Shows the STERILE | EO box for reference no. 5.2.3 (ISO 7000-2501). Checked 2026-09-25.
  • Cook Medical: Glossary of standard symbols — ISO 15223-1 5.2.3 “Sterilized using ethylene oxide — Indicates a medical device that has been sterilized using ethylene oxide.” Checked 2026-09-25.

Plain-language parts are in our own words; quotations are the sources’ wording.