IEC 60601-1 Symbols and Temperatures: Clauses 7 and 11

Changes to IEC 60601-1 Symbols, Identification & Marking, and Excessive Temperature Clauses 

On December 17, 2023, IEC 60601-1 3.2, the general standards for medical electrical systems and equipment, will go into effect. The latest version was approved by the FDA in August 2020 and includes dozens of changes that were decided to be too urgent to wait for a Version 4 release. Some of the most major changes in Amendment 2 are in the following clauses: 

This blog will outline some of the major changes t o Clause 7 and Clause 11. 

Main Changes to Clause 7 – Identification and Marking

Consult Accompanying documents 

Documents that might accompany a ME device may be the primary way a manufacturer decides to control a specific risk associated with operating the device. If this is the case, and the usability engineering process also makes a determination that marking the equipment will help effectively control the risk, then the ME equipment needs to be marked with a mandatory safety sign designated in ISO 7010-M002 that indicates operators should refer to an instruction manual or booklet. This is SAFETY SIGN 10 in Table D.2 of that standard, which looks like a person reading instructions. 

The alternative to this, if consulting the manual is not mandatory but instead advised, is to have Table D.1 symbol 11 appear, which looks like a book with an “i” on one of the pages. 

IP Classification 

The revised standard provides clarification on marking based on IP classification. For ME equipment where IP classification of the enclosure is either not specified (IPXX) or is specified as either IPX0, IP0X, or IP00, the ME equipment or its parts don’t need to be marked. 

Safety Sign 

“Safety sign” was new terminology added in Clause 3, and it’s also been used as a specification across several parts of Clause 7. Clearly legible marking requirements were extended to include safety signs that appear on ME equipment. Several references to labeling were modified in Version 3.2 to specify requirements for safety signs. As previously mentioned, required safety signs were pointed out to indicate accompanying documents. 

Clause 7.5 about Safety Signs has also been modified to include more clarifying language and detail on how the term is defined and what different parts of equipment require safety signs based on potential risk and scenarios. 

Alarm indicator and indicator lights for ME equipment

Table 2 in Version 3.2 of Clause 7 outlines meanings that should be applied to different colors of indicator lights on ME equipment, as well as whether there should be sound or flashing accompanied with the lights. The table includes instructions for the following conditions:

  • Warning 
  • Caution 
  • Ready for use
  • Alarm conditions – high priority, medium priority, low priority 
  • Other (situations where you wouldn’t use red, yellow, cyan, or green lights) 


If replaced incorrectly, lithium batteries or fuel cells can create a hazardous situation, including explosions, fires, or excessive temperatures. If these are incorporated in the ME equipment, warnings need to be present regarding the potential hazardous situation, plus there needs to be a marking that refers to the accompanying documents. 

Power Switches 

Power switches on ME equipment should have symbols marking the “on” and off” positions as specified in Clause 7.4.1, in IEC 60417-5264 (2002-10), or IEC 60417-5265 (2002-10), Table D.1, Symbols 16 and 17. Otherwise, they could be indicated in other unambiguous ways or by an indicator light that’s adjacent to the switch. “Stand-by” can also be marked using IEC 60417-5009 (2015-03) Table D.1, Symbol 29. 

Changes in Clause 11 – Protection Against Excessive Temperatures and Other Hazards

Excessive temperatures can cause harm to patients or operators, and Clause 11 is concerned with protecting anyone who might be in contact with ME equipment from excessive temperatures and related hazards.

Accessible parts 

“Accessible parts” was terminology that was added in reference to allowable maximum temperatures for parts on Table 23. Other parts of Clause 11 also have “accessible parts” added. 

Fire enclosures

Fire enclosure requirements for ME equipment were also updated. This included the flammability identification requirement for insulated wire and connectors that are within the fire enclosure, plus printed circuit boards and insulating material that components are mounted on. 

For insulated wire and connectors that are within the fire enclosure, there should be a minimum of V-2 flammability classification. Clause 11 references IEC 60695-11-10 for this classification and appropriate testing. Otherwise, they need to be insulated with one of the following: 

  • TFE 
  • PVC
  • FEP
  • PTFE 
  • Polyimide 
  • Polychloroprene 

Printed circuit boards and insulating materials that components are mounted on also need the same flammability classification according to the same standard. 

The bottom of the fire enclosure either needs to have no openings, baffles, perforated metal, or mesh metal. Sides as indicated in the Figure 39 should either not have openings, be made of perforated metal, or be made of mesh metal. Further specifications can be found in the standard. There is also room for other design options as outlined in other standards as long as risk management is factored in. 

How can manufacturers prepare for the switch to IEC 60601-1 Version 3.2? 

Manufacturers who are currently working on ME equipment with planned development finishing after December 17, 2023 need to ensure they are meeting the standards outlined in IEC 60601-1 3.2 One piece of this is making sure the PSUs used are compliant with this standard. RAM Technologies PSUs have been certified under 60601-1 3.2 and can help you get one step closer to compliance. 

When you’re ready for that step in development, contact us.


RAM Technologies’ power supplies are 60601-1 3.2 certified and meet 60601-1-2 EMC standards. When you’re designing your medical device and need help with a PSU,  contact us for details.

More Resources:

What the FDA Moving to IEC 60601-1 3.2 Means for Manufacturers

Downloadable Guide to IEC 60601-1 

Differences Between 3.1 and 3.2 Certification for IEC 60601-1

Understanding IEC 60601-1-2

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