Type CF applied part (heart in a square)

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

“To identify a type CF applied part complying with IEC 60601-1.”

IEC 60417-5335 · IEC 60601-1, Table D.1, symbol 21

What it means for you

An applied part is the part of the equipment that touches the patient — an electrode, a sensor, a probe. The letter is its protection class against electric shock under IEC 60601-1. Type CF (C for cardiac) has the strictest leakage-current limits and is the class for parts that may have direct contact with the heart, such as some cardiac catheters and the electrodes of equipment used during heart procedures.

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

What it looks like: A filled heart inside a square.
Where you see it: On medical electrical equipment and its accessories — on the cable, the sensor, the connector socket or the rating plate — not on the sterile box. IEC 60601-1 Table D.1 lists it.
Other names: CF; heart in a box; cardiac floating applied part

What it does not tell you

It does not say the device is safe for you or suitable for a given procedure; it names the protection class only.

Often confused with

Type BF applied part (figure in a square)IEC 60417-5333

To identify a type BF applied part complying with IEC 60601-1.

More symbols in “A person or a heart”

Patient number (person with #)ISO 15223-1:2021, 5.7.1 Patient name (name card)ISO 15223-1:2021, 5.7.2 Patient identification (person with ?)ISO 15223-1:2021, 5.7.3 Health care centre or doctor (doctor with a cross)ISO 15223-1:2021, 5.7.5 Type B applied part (figure)IEC 60417-5840 Defibrillation-proof type B applied part (figure with side marks)IEC 60417-5841 Defibrillation-proof type BF applied part (figure in a square with side marks)IEC 60417-5334 Defibrillation-proof type CF applied part (heart in a square with side marks)IEC 60417-5336

Sources

IEC 60417 and IEC 60601-1 are paid standards, so the wording above is quoted as 4 publishers’ public documents reproduce it; our drawing is not the IEC artwork. Each was fetched and read on the date shown:

Boston Scientific: Symbols Glossary — IEC 60601-1 Table D.1, symbol 21 “Type CF applied part — To identify a type CF applied part complying with IEC 60601-1.” Checked 2026-09-28.
NE Scientific: Master Symbol Glossary (CTF-100011 Rev 01) — Shows the heart in a square for IEC 60417-5335, same description. Checked 2026-09-28.
Hillrom: Symbols Glossary (80022945 Ver. J) — Lists “Type CF applied part”, IEC 60417-5335, same description. Checked 2026-09-28.
Ethicon: Symbols glossary (100584677 Rev.8) — Lists “Type CF applied part”, IEC 60417 reference 5335. Checked 2026-09-28.

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