Collateral Medical Standards in the CB Scheme
The basic standard for all electrical medical equipment is IEC 60601-1. In addition, there are also multiple collateral standards, but it is not always clear which collateral standards apply and what testing and certification needs to be done. This article discusses the role of collateral standards in CB scheme.
About IECEE and the CB Scheme
The CB Scheme is a multilateral global certification system, operated by the IEC System for Conformity Testing and Certification of Electrical Equipment (IECEE). Their objective is to create one global certification system in order to promote free trade and assist manufacturers to create safe and efficient equipment.
The CB Scheme should not be confused with the CE mark or other national regulatory approvals. For example, in Europe devices must meet the Essential Requirements. Some product classes require more extensive testing than CB Certification, others may require less testing. However, in many cases the Scheme is a useful starting point.
The basic idea behind the CB Scheme is to use the principle of mutual recognition for its national members. When a member of the Scheme in country A has certified electrotechnical equipment and components to meet requirements, there is no need to perform additional testing for the same equipment in country B. Member body of country B will issue a national certification mark for the equipment, based on the original testing. The purpose of the Scheme is to unify requirements and simplify trade to participating countries.
Standards operated by IECEE are divided in 17 categories. We are going to discuss in more detail one of them: electrical equipment for medical use (MED).
IEC 60601-1: the basic standard and collaterals
The basic standard for all MED equipment is IEC 60601-1. There are two editions of it in common use: 2nd edition (1988-12) ‘Medical Electrical Equipment – Part 1: General Requirements for Safety’; and more recent is the 3rd edition (2005-12) ‘Medical Electrical Equipment – Part 1: General Requirements for Basic Safety and Essential Performance’. The 3rd edition has been strongly restructured and the basic concept has moved from ‘safety by type testing’ to ‘safety by risk management and testing’. Both editions have been amended since the original publication.
In Europe, USA and Canada the transition from 2nd edition to 3rd edition has already been accepted by the regulatory authorities, or is in the process of changing, but in other parts of the world, for example in China and Japan, the 2nd edition is still in current use.
The basic standard has later been expanded with collateral standards, which apply to some subcategory or functionality of equipment. For example, IEC 60601-1-3 applies to radiation protection in diagnostic X-ray equipment. Just as the basic standard exists in two major editions, the collateral standards have editions that are specific to either 2nd edition or 3rd edition of the basic standard.
Which collaterals are compulsory to be tested along with the basic standard?
For the CB Scheme there are practical considerations, which determine the applicable standards that need to be taken into account. For instance, ‘Is there added value for the manufacturer and customer?’ or ‘Are the test laboratories capable of addressing all the needs?’ In the IECEE CB Scheme, the Certification Management Committee (CMC) makes these decisions and in June 2012, they held a meeting to determine the ‘compulsory’ collaterals.
In the table below the status of collaterals have been consolidated:
Table 1: Status of collateral standards in reference to basic standard testing and certification.
- A separate test report and certificate possible
- Included in basic standard, requires additionally IEC 62304 ed1.0 (2006-05) SW life cycle process
- Requires additionally IEC 62366 ed1.0 (2007-1) Usability process.
Some countries may require IEC 60601-1-6 ed2.0 (2006-12) instead
- Original conditional Yes proposal of CMC was reversed, based on email feedback
- Actually referenced in clause 48 Biocompatibility of the basic standard
- Actually referenced in sub-clause 11.7 Biocompatibility of ME Equipment and ME Systems of the basic standard
It is interesting that standard IEC 60601-1-6 ‘Usability’ was originally proposed to be a compulsory inclusion for the test report and certificate. However, the CMC meeting decided to take a two month timeout for the final decision. Based on the feedback received from members, it was later decided to be excluded from the list.
Table 1 contains consolidated information of what collaterals need to be included in a CB Scheme test report and certificate. However, local regulatory authorities may have different requirements. For example, while the evaluation of usability is not compulsory in the CB Scheme, both Medical Device Directive in EU and FDA in USA require that the manufacturer has addressed risk of use errors (or human factors engineering) in the safe design of the equipment. It should also be noted that while exclusion is possible, inclusion may benefit the manufacturer more.
Full table for ‘Use of Standards’ in the IECEE system standards for edition 2 and 3 of the basic standard IEC 60601-1 can be found at:
Please note that as of January 18, 2013, the referenced tables have not yet been updated for the IEC 60601-1-6 standard.