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IEC 60601-1, 3rd ed. related standards changes & new Interpretation Sheet 3

IEC 60601-1, 3rd ed. has been out for about 7 years now and there have been lots of changes within the IEC 60601 series of standards to align with 3rd edition. 

Last summer Amendment 1 (A1) came out and if you haven’t yet you should start learning about those changes as they will be impacting you sooner rather than later (sign-up for an FX Conferences recording of my recent presentation on A1 of IEC 60601-1 and its’ impact on users, follow the instructions to get a $50.00 discount, and sign up for the presentation titled “IEC 60601–1, 3rd Edition, Amendment 1 and its Impact on Users”) and also A1 can help you as it will reduce the amount of Risk Management File work you need to do for a product safety certification or approval. There are about 25 less Risk Management File requirements when using A1 vs using 3rd ed.  To understand the differences and changes of A1 it is highly recommended that you get the IEC 60601-1 edition 3.1 (consolidated) edition as that shows you where all the changes are to the text vs 3rd ed.  Note, when you submit for testing thru a test lab you will either want to use either edition 3.1 or 3rd ed. but you can’t mix and match as that would not work well and any CB scheme certified lab, among most other labs, will not mix and match requirements as it gets messy quickly.

So, what are the current changes to the standards related to alignment with 3rd ed. & the new Interpretation Sheet?  Let’s start with the standards.

The updates are actually withdrawal of two standards that have been embedded into 3rd ed. when it was released (i.e. IEC 60601-1-1, 2nd edition – Medical Electrical Systems & IEC 60601-1-4 Programmable Electrical Medical Systems) and so the 2nd ed. aligned standards needed to be withdrawn as 2nd edition of IEC 60601-1 has been withdrawn since the publication of 3rd edition back at the end of 2005.  The withdrawal report to IEC for IEC 60601-1-1, Edition 2.0 (now in IEC 60601-1, 3rd ed. in clause 16) covered the following 3 points, and it is the same circumstances for IEC 60601-1-4, edition 1.1 (1st ed. + A1) (now in IEC 60601-1, 3rd ed. in clause 14):

  • IEC 60601-1 Ed. 2.2 (IEC 60601-1:1988+A1:1991+A2:1995) was withdrawn in 2005, yet those who want to use it have been able to do so for the past seven years.
  • IEC 60601-1 Ed. 2.2 makes normative reference to a number of supporting standards that have been revised or superseded, yet users have been able to find the versions they need to implement Edition 2.2.
  • With the changes made in Amendment 1 to IEC 60601-1:2005, there are substantive technical differences between this collateral standard and its respective clause in IEC 60601-1 Ed. 3.1. Therefore, this document can no longer be considered to represent the generally accepted state of the art.

Let’s move onto the Interpretation Sheet 3 (or IS3) for IEC 60601-1 3rd edition and also for edition 3.1 or 3rd edition + A1.  It is the 3rd interpretation sheet issued since IEC 60601-1, 3rd edition has been issued.  IS3 is a clarification of the requirement for sub-clause 13.1.2, 4th dashed line which the sub-clause is titled “Emissions, deformation of ENCLOSURE or exceeding maximum Temperature”.  The requirement of concern is:

“The following HAZARDOUS SITUATIONS shall not occur;”

“- ….”
“-     temperatures of ME EQUIPMENT parts that are not APPLIED PARTS but are likely to be touched, exceeding the allowable values in Table 23 when measured and adjusted as described in 11.1.3;”  (This is the fourth dashed line of 13.1.2)

So, this requirement is saying that this situation should not occur (following HAZARDOUS SITUATIONS) if there is a part that isn’t an APPLIED PART (An APPLIED PART is a part of the device that in NORMAL USE necessarily comes into physical contact with the PATIENT for the device to perform its function.  So, a part other than an APPLIED PART) that is likely to be touched that exceeds the temperature limits of Table 23 (Allowable max temperatures for ME EQUIPMENT parts that are likely to be touched) in the temperature test method described in sub-clause 11.3.

The IS3 gives an alternative route to meeting the above requirement by stating the following:

“This is clarified by the following:

The above requirement is regarded as fulfilled in accordance with Subclause 4.5 for temperatures at the surfaces of the enclosure, if the following conditions are fulfilled:

− The maximum allowed temperature on OPERATOR accessible surfaces in SINGLE FAULT CONDITION is 105 °C; and

− the instructions for use contain a warning that, under some SINGLE FAULT CONDITIONS, the temperature of: (indicate the surface of concern) could get hot and there is a possible RISK of a burn if touched, and

− if the RISK ANALYSIS demonstrates a need for a warning symbol on the ENCLOSURE, safety sign ISO 7010-W018 ( ) shall be used on or adjacent to the hot spot on the ENCLOSURE; and

− the RISK ASSESSMENT demonstrates that the temperature attained in the SINGLE FAULT CONDITION is acceptable, and

− the RISK ASSESSMENT demonstrates that applying the alternative RISK CONTROL measures in this Interpretation Sheet results in a RESIDUAL RISK that is comparable to the RESIDUAL RISK resulting from applying the requirement of the standard.

NOTE 1 This Interpretation Sheet is intended to be used with both Edition 3.0 and Edition 3.1 of IEC 60601-1.

NOTE 2 An example of an analysis that demonstrates an adequately low probability of occurrence of HARM is shown below.”

To access this IS3 for free please go to the IEC website link.

If you need assistance with this or other issues, please contact us at Leo at EisnerSafety dot com.