Protect from heat and radioactive sources
The standard’s wording, as the sources below reproduce it:
“Indicates a medical device that needs protection from heat and radioactive sources.”
ISO 15223-1:2021, 5.3.3
What it means for you
Store the device away from heat and from sources of ionising radiation, such as X-ray rooms or radioactive materials. The plain sun-over-roof mark without the trefoil asks only for protection from light.
Whether a device is right for you is a question for your pharmacist, nurse or doctor.
- What it looks like
- The keep-away-from-sunlight mark (a sun with rays over a roof sheltering a small box) with a radiation trefoil added beside the sun.
- Where you see it
- Radiation-sensitive products such as some dosimeters, films, diagnostic kits and devices with electronics or radiation-sensitive materials.
- Other names
- keep away from heat and radiation; radiation trefoil and sun over a box
What it does not tell you
It gives no temperature or dose limit; a temperature-limit mark or the instructions for use give figures where they matter.
Often confused with
Indicates a medical device that needs protection from light sources.
More symbols in “Umbrella, sun or glass”
Sources
ISO 15223-1 is a paid standard, so the wording above is quoted as 2 publishers’ public documents reproduce it. Each was fetched and read on the date shown:
- Boston Scientific: Symbols Glossary — ISO 15223-1 5.3.3 “Protect from heat and radioactive sources — Indicates a medical device that needs protection from heat and radioactive sources.” Checked 2026-09-28.
- STERIS: STERIS Product Labeling, SCS-145, Exhibit A: Symbol Glossary — Shows the sun, trefoil and roof drawing for I.S. EN ISO 15223-1:2021 5.3.3 with the same explanatory text. Checked 2026-09-28.
Plain-language parts are in our own words; quotations are the sources’ wording.