Editor’s note: I am pleased to bring you this blog authored by Jeff Schnabel, VP Marketing, CUI Inc.

Following the expected update to the EU Official Journal on June 15, and UL’s immediate response, the date for the new 62368-1 hazard-based safety standards to supersede the outgoing 60950-1 and 60065 standards is now harmonized in both the US and EU. The “Effective Date” associated with UL 62368-1 in the US, and the EU’s date have both now moved from June 20, 2019 to December 20, 2020. This coincides with the EU’s declared Date of Withdrawal for EN 60950-1 and EN 60065.

This harmonization and solidification of dates should help OEMs coordinate measures to ensure that products destined for either market are compliant with the new regulations. It also gives companies an extra 18 months to comply. Other territories including China, Japan, Australia, and New Zealand are also in the process of changing to their own regional versions of IEC 62368-1.

Although the IEC began developing 62368-1 to cover both ICT and AV equipment, because the distinctions between the two types have become increasingly blurred, it has stressed that the new unified standard is not a simple merger of the old standards. It takes a fundamentally different approach, founded on hazard-based safety engineering (HBSE) principles, and its scope – although initially the same as the two older standards – will be further extended in successive editions of the documentation.

So, what is HBSE, how is the new approach better and what do OEMs need to do to ensure their products comply?

Understanding HBSE

HBSE contrasts with the prescriptive approach that defines 60950-1 for ICT equipment and 60065 for AV equipment. Whereas these are focused on specifications, such as safety extra low voltage (SELV) limits for accessible assemblies, or minimum isolation voltages, HBSE seeks to ensure user safety by requiring design teams to demonstrate that potential hazards have been considered and suitable safeguards have been put in place.

HBSE essentially consists of: (a) identifying energy sources in the product; (b) classifying the energy according to the potential for causing injury or damage; (c) identifying needed safeguards for protection from potentially dangerous energy sources; and (d) qualifying the safeguards as effective.

This approach is intended to be less prescriptive and, as a result, more flexible to handle changes in technology and product-design practices without calling for frequent and expensive updating of applicable safety documentation.

Comparing the structure of the two standards can give a feel for the differences in approach:


Table 1 Structures of prescriptive (60950-1) and hazard-based (62368-1) standards.

HBSE covers the considerations in sections 5 to 10 by taking a 3-block approach that analyzes each potentially hazardous energy source and how energy may be transferred to the user, as outlined by this diagram:


Three-block model for hazard assessment.

A similar approach is taken for assessing the suitability of safeguards:


Assessing safeguards under 62368-1.

Energy sources are classified according to both magnitude and duration, which are categorized into three classes as shown in table 2. As table 1 suggests, 62368-1 considers all sources of energy that may be present in an item of ICT or AV equipment, including electrical energy, thermal energy such as hot accessible parts, chemical energy such as electrolytic reactions or poisons, kinetic energy such as moving parts and radiated energy including optical or acoustic energy.


Table 2
Classification of energy sources.

The documentation for 62368-1 describes each type of energy source and the appropriate thresholds for classes 1, 2 and 3 in each case. The treatment of electrical energy under 62368-1 contrasts with that of 60950-1, by taking into account both current and voltage. Accordingly, SELV limits are not defined in 62368-1, which reflects the fundamental differences in approach of these two standards. Managing such differences in the interim period – during which components and sub-systems such as power supplies have been tested under the outgoing standards and admitted for use in equipment tested according to 62368-1, and vice versa – has called for pragmatism on the part of standards bodies. For example, recognizing that both SELV and ES1 circuits are intended to be safe to touch has permitted components certified to the old 60950-1/60065 standards to be used in equipment certified to 62368-1.

Act now on Edition 2

With the updating of the EU Official Journal in June of this year, manufacturers marketing products in the EU now know they must transition from EN 60065 or EN 60950-1 by December 20, 2020. Most likely, they will need to ensure compliance with 62368-1 Edition 2, which is the currently published version of the standard. This makes it imperative to start working with test houses as soon as possible, to avoid being caught out closer to the deadline when workloads are sure to be heavy.

It is worth pointing out that the next iteration of 62368-1, Edition 3, is already planned but has not yet been published. Publication had been expected around Q3 2018, but the latest announcements suggest publication could now happen in late 2019 with adoption likely sometime in 2022.

What we do know is that Edition 3 will extend the scope of 62368-1 to include equipment such as tablets, smartphones, 3D printers and wearable technology, as well as IEC 60950-21 rules on remote power feeding, which will affect Power Over Ethernet equipment. Rules on stored energy, outdoor enclosures, backfeeds and associated safeguards, requirements for insulating liquids and coin cells, and new demands on interconnected ES3, ES2 and ES1 circuits in SMPS secondaries will also be added.

For now, it seems smart to commit to Edition 2 and work towards establishing compliance, while keeping abreast of developments with Edition 3. Clearly this will become the reference standard in the EU and US/Canada eventually, and other territories will likely adopt it too.

Overall, the 62368-1 standards should make life safer for end users, and in the longer term simplify compliance for product manufacturers, while reducing the need for updates that demand frequent attention by compliance teams. On the other hand, there is a lot to understand to make a successful transition by the 2020 deadline. At CUI, many of our power supplies are already compliant to the new standard and we are working toward 100% compliance well before 62368-1 is set to take effect.

Learn more about 62368-1 from CUI.