IEC 62368-1 certification is now the market access baseline for audio/video, ICT, and communication equipment in the EU, North America, and most other major markets.
CENELEC withdrew EN 60950-1 and EN 60065 from the LVD harmonised list in December 2020, ending the transition and closing the route to compliance via those legacy standards.
Products still documented under the withdrawn standards have no valid presumption of conformity under the Low Voltage Directive or the Radio Equipment Directive. Re-certification is not optional.
This article explains how hazard-based safety engineering works in practice. It covers the energy classification framework, what a certification test programme under IEC 62368-1:2018 requires, and how the approach differs from IEC 60950-1.
What products does IEC 62368-1 apply to?
The IEC 62368-1 scope, defined in Clause 1 and Annex A, covers audio/video equipment, information and communication technology equipment, and communication equipment. Coverage extends up to a rated voltage of 600 V.
IEC 62368-1 replaced two separate standards. Previously, IEC 60950-1 governed ICT equipment. Audio and video equipment fell under IEC 60065.
Both standards had been overtaken by product reality before the replacement was drafted. A networked streaming device, for example, could not be cleanly assigned to either category.
Multiple national bodies publish IEC 62368-1 under their own designations. EN IEC 62368-1 is the European adoption under the Low Voltage Directive (2014/35/EU) and the Radio Equipment Directive (2014/53/EU). UL 62368-1 is the North American counterpart.
Both adoptions carry the same HBSE technical framework, with national deviations addressed through dedicated annexes. Find the base standard at IEC 62368-1:2018 on the IEC website.
Note: EN 62368-1:2014 (2nd edition) is the edition currently cited in the Official Journal of the European Union under both directives.
EN IEC 62368-1:2020 (3rd edition) and EN IEC 62368-1:2024 (4th edition) did not achieve OJEU harmonisation. Confirm the applicable edition with your certification body before opening a new submission.
Medical devices, industrial machinery, and automotive electronics fall outside the IEC 62368-1 scope. Those categories fall under separate frameworks. Combination products that also integrate wireless communications may require additional standards alongside IEC 62368-1.
How does hazard-based safety engineering work?
HBSE replaces the prescriptive tables and component specifications of IEC 60950-1 with a structured analytical process. The engineer identifies hazard sources, classifies their severity, and justifies the safeguards chosen.
That shift places design responsibility with the engineering team rather than with a standards lookup table. A prescriptive standard tells you which insulation grade to use. HBSE requires you to demonstrate why your choice provides the required protection level.
The framework rests on three core questions, applied to every energy source present in the product:
- What energy sources does the product contain?
- Who can be exposed to those energy sources?
- What safeguards exist to prevent exposure from causing harm?
These three questions define the structure of IEC 62368-1. Each clause of the standard addresses one or more of them for a specific energy domain.
IEC 62368-1 recognises four energy source categories that engineers must evaluate during the HBSE analysis. Each category has its own clause and three-level severity hierarchy.
- Electrical energy (Clause 5)
- Thermal energy (Clause 9)
- Mechanical energy (Clause 8)
- Radiation and sonic energy (Clause 10)
For each category, severity level determines the safeguard tier required. Higher severity demands a more protective architectural response.
User classifications add a second dimension. IEC 62368-1 distinguishes ordinary persons, instructed persons, and skilled persons. A safeguard adequate for a skilled technician may not satisfy the requirement for consumer-facing equipment accessible to ordinary persons.
The combination of energy classification and user classification determines the safeguard architecture. An engineer cannot satisfy IEC 62368-1 without working through both dimensions for every identifiable energy source.
What are the IEC 62368-1 energy classes and safeguard requirements?
Clause 5 defines three electrical energy source (ES) classifications. Each classification of an accessible circuit determines the safeguard requirements for that circuit.
Below is a summary of the electrical energy source boundaries for frequencies below 1 kHz, from IEC 62368-1:2018 Clause 5.
| Energy source | Voltage limits | Accessible to | Safeguard requirement |
|---|---|---|---|
| ES1 | ≤ 30 Vrms / ≤ 42.4 Vpeak / ≤ 60 Vdc | Ordinary persons | None required for accessible parts |
| ES2 | ≤ 50 Vrms / ≤ 70.7 Vpeak / ≤ 120 Vdc | Instructed persons | Safeguard against ordinary person access |
| ES3 | Exceeds ES2 limits | Skilled persons only | Safeguards required against ordinary and instructed person access |
Engineers declare mains conductors ES3 without measurement. Voltage levels place them above the ES2 boundary by definition.
Clause 4 categorises safeguards by type. Physical safeguards prevent contact with hazardous energy through barriers and enclosures. Functional safeguards limit energy levels through circuit design. Instructional safeguards communicate hazards through markings and documentation.
Clause 9 applies the same classification logic to thermal energy. IEC 62368-1 classifies thermal sources as TS1, TS2, or TS3 based on contact temperature limits.
For the specific TS1 surface temperature limits by material category, see IEC 62368-1 Table 38 touch temperature limits.
When evaluating ES1 accessible parts, leakage current limits become a key boundary condition alongside voltage thresholds. For measurement methods and instrumentation, see leakage current limits for Class 1 accessible parts.
How does IEC 62368-1 certification differ from IEC 60950-1?
The essential difference is that IEC 60950-1 prescribed solutions. IEC 62368-1 requires engineers to derive and justify solutions based on energy classification.
Under IEC 60950-1, insulation requirements followed from a clearance and creepage table keyed to working voltage and pollution degree. Designers selected from prescribed options with defined equivalences.
IEC 62368-1 changes that process completely. The engineer must classify the electrical energy source, identify the accessible user group, and justify that the insulation provides a sufficient safeguard for that energy class and user combination.
Documentation requirements
No equivalent to the HBSE documentation package existed under IEC 60950-1. Certification labs now expect an energy source identification analysis before formal testing begins.
That analysis maps each circuit and accessible part to an energy source classification. It identifies safeguards in place and the clause references that justify each one. Labs use this document to structure the test programme scope.
Note: This analysis is a practice formalised by certification bodies rather than a deliverable mandated by a single named clause. The standard’s HBSE methodology implies it throughout; labs require it as a pre-test submission.
Consider a power supply output at 30 Vdc. With IEC 60950-1, that output received a SELV classification and specific constructional rules followed from it.
IEC 62368-1 treats 30 Vdc as sitting at the ES1 boundary, requiring an analysis of the user group who can access the circuit and what safeguards apply.
That analysis may confirm no safeguard is required, or it may identify a gap the prescriptive evaluation would have missed. The outcome depends on the actual hazard profile, not a product-type category.
UL 62368-1 for North America
UL 62368-1 applies the same HBSE approach as the IEC base standard. Annex NB contains national deviations specific to the North American market. Products targeting both markets require attention to both the IEC and the UL annexes during engineering and testing.
What does IEC 62368-1 require from the certification test programme?
A standard IEC 62368-1 certification scope covers six evaluation areas. Labs adjust the scope based on the product’s energy classification and target markets.
The following areas apply to most ICT and AV product certifications:
- Clause 5: electrically-caused injury, including dielectric strength and leakage current measurement
- Clause 6: electrically-caused fire, including component ratings and fire enclosure evaluation
- Clause 9: thermal injury, covering surface temperature under normal and abnormal conditions
- Clause 8: mechanical injury, including force, energy, and stability assessments
- Abnormal operating conditions: single-fault analysis across all energy domains
- HBSE documentation package: energy source analysis and safeguard rationale
Each area requires both test evidence and an engineering justification tied to the energy source classification. Documentation packages serve as the structural link between test results and clause requirements.
Dielectric strength testing under the HBSE framework
Engineers familiar with IEC 60950-1 often expect the hipot test voltage to follow the same fixed lookup logic. Under IEC 62368-1, the test voltage derives from the energy source classification and the safeguard function under evaluation.
A circuit classified ES2 must demonstrate that a safeguard prevents ordinary person access. Hipot testing confirms the insulation integrity of that safeguard. For the full test methodology, see IEC 62368-1 hipot testing requirements.
Conducting a pre-compliance thermal assessment before the formal test programme can reveal thermal margin violations early.
That step is not a clause requirement, but experienced certification teams treat it as standard practice to avoid test failures that delay schedules.
IEC 62368-1 also requires formal evaluation of abnormal operating conditions as a distinct test phase. Engineers must show that the safeguard architecture holds under component failure and overload scenarios, a more explicit requirement than existed under IEC 60950-1.
Frequently Asked Questions
What products does IEC 62368-1 apply to?
IEC 62368-1 covers audio/video equipment, ICT equipment, and communication equipment with rated voltages up to 600 V. Annex A of the standard lists the specific product categories within scope.
What replaced IEC 60950-1 and IEC 60065?
IEC 62368-1 replaced both standards. IEC 60950-1 governed ICT equipment and IEC 60065 governed audio/video equipment; CENELEC withdrew both in December 2020.
What is the difference between IEC 62368-1 and IEC 60950-1?
IEC 62368-1 uses a hazard-based framework requiring engineers to justify safeguard choices through an energy source analysis. IEC 60950-1 used a prescriptive approach, deriving requirements from lookup tables.
Is IEC 62368-1 mandatory in the EU?
Yes. Products in scope must demonstrate compliance with the Low Voltage Directive (2014/35/EU) and, where wireless functions are present, the Radio Equipment Directive (2014/53/EU). EN 62368-1:2014 remains the OJEU-harmonised edition under both directives.
What is hazard-based safety engineering?
HBSE is an engineering methodology that identifies energy sources, classifies their severity, and requires safeguards proportional to that severity. It replaces prescriptive construction rules with engineering analysis and justified design decisions.
Conclusion
The HBSE framework treats IEC 62368-1 certification as an engineering analysis, not a prescriptive checklist: safeguard justification belongs with the design team.
HBSE documentation is as important as the test report itself; labs use the energy source analysis to structure the entire certification scope.
EN IEC 62368-1 and UL 62368-1 carry the same HBSE technical framework, making aligned global certification achievable from a single test programme.
IEC 62368-1 Edition 4 (IEC 62368-1:2023) is now published, but EN IEC 62368-1:2024 has not achieved OJEU harmonisation; engineers should confirm the operative edition with their certification body before opening new submissions.
