What is the scope of IEC 62368-1?

IEC 62368-1 is the horizontal safety standard covering audio video equipment, information technology (IT) equipment and communications equipment. It applies to laptops and desktop computers, servers, networking equipment, televisions, audio amplifiers, set-top boxes, monitors, phones and telecommunication terminals, plus their mains-powered or battery-powered accessories. The 4th edition published in 2023 is the current version in the IEC catalogue. The standard is transposed as EN 62368-1 under the Low Voltage Directive (LVD) in the European Union, as UL 62368-1 in the United States and as CSA C22.2 No. 62368-1 in Canada.

What is the HBSE principle introduced by 62368-1?

HBSE, hazard-based safety engineering, structures the analysis in three stages. First, identify every energy source present in the equipment: electrical energy, thermal energy, mechanical energy, chemical energy, radiation. Second, classify each source according to its hazard level (class 1, class 2 or class 3) using numerical thresholds defined in the standard. Third, place between the source and the exposed person one or more safeguards whose severity matches the energy class and the user type (ordinary, instructed, skilled). This logic replaces the prescriptive approach inherited from IEC 60950-1 and IEC 60065 with a documented justification approach.

When did IEC 62368-1 replace IEC 60950-1 and IEC 60065?

The transition was decided by the IEC in 2014 with a long horizon to give manufacturers time to adjust their portfolios. The effective withdrawal date of both legacy standards is 20 December 2020. From that date, IEC 60950-1 (IT equipment) and IEC 60065 (audio video equipment) are no longer recognised for CE marking under the LVD, nor listed by the FDA or US NRTLs. Any legacy test report based on these two standards after 20 December 2020 no longer grants presumption of conformity, save for residual national transitional provisions.

What is the difference between ordinary, instructed and skilled persons?

The standard recognises three user categories with different protection rules. An ordinary person is the end user without electrotechnical training: the general public, an office worker, a retail customer. An instructed person has been trained by a skilled person to avoid the hazards of a given source: a network operations technician, a first-level maintenance agent, staff trained on a specific procedure. A skilled person has the training, experience or technical knowledge to identify and avoid electrical, thermal and mechanical hazards: a qualified maintenance technician, a field engineer, a certified electrician. The narrower the authorised category, the higher the energy class the standard permits to remain accessible, but under stricter access and warning conditions (keys, tools, signage).

What do ES1, ES2 and ES3 mean for electrical energy?

The ES (electrical energy source) classes categorise electrical energy according to the thresholds defined in clause 5. ES1 covers levels not hazardous under normal and single-fault conditions (typically below 30 V RMS AC or 60 V DC for voltage). ES2 covers painful but not life-threatening levels for an ordinary person on brief contact. ES3 covers levels capable of severe shock or death. The exact thresholds (voltage, current, capacitance, stored energy) are tabulated in the standard and must be verified directly in the IEC text, since the values may be adjusted between editions.

What are the PS1, PS2 and PS3 power source classes?

The PS (power source) classes categorise the steady-state available power that a source can deliver. PS1 covers up to 15 W (low power, low risk of electrically initiated fire), PS2 covers up to 100 W (medium power, fire risk contained by construction), PS3 covers above 100 W (high power, increased containment requirements, flame-resistant materials, larger separation distances). These thresholds drive the requirements for the enclosure, the internal wiring, fire-containment design and the material choices under UL 94. A typical server power supply is PS3, an ordinary USB charger PS1 or PS2 depending on its rated power.

How does EN 62368-1 interact with the Low Voltage Directive?

Directive 2014/35/EU (Low Voltage Directive, LVD) covers the placement on the European market of electrical equipment operating between 50 and 1000 V AC or 75 and 1500 V DC. EN 62368-1, the European transposition of IEC 62368-1, is published as a harmonised standard under the LVD through notices in the Official Journal of the European Union. Its application grants presumption of conformity with the safety objectives of the directive for the equipment categories covered. The harmonised reference (edition, amendment, cessation date) must be checked on the official European Commission page for the LVD, since the list evolves at each communication.

Why is a medical device certified to 62368-1 not 60601-1 compliant?

62368-1 and 60601-1 address different purposes. 62368-1 covers audio video, IT and communications equipment intended for the general public or the professional user without direct patient contact. 60601-1 covers medical electrical equipment, which includes an applied part (electrode, sensor, probe) in patient contact and requires a higher protection level through MOPP (Means of Patient Protection). A medical monitor certified only to 62368-1 does not cover the requirements for patient leakage current, reinforced dielectric strength or MOPP insulation. For the medical component, see the [IEC 60601-1 guide](/en/guides/iec-60601-1-medical-electrical-safety/).

What are the most common pitfalls when applying 62368-1?

Four pitfalls recur in notified-body and NRTL reports. First, keeping a 60950-1 or 60065 report beyond 20 December 2020 without redoing the full HBSE analysis. Second, mis-classifying an energy source: a reservoir capacitor in a switching power supply can be ES2 or ES3 depending on its stored energy, which changes the safeguard requirement. Third, failing to distinguish between zones accessible to an ordinary person and zones accessible only to a skilled person, which can expose an ES3 source without sufficient interlocks. Fourth, overlooking battery and lithium-ion requirements when the equipment includes a battery (cross-references to IEC 62133-2 for the cell and UN 38.3 for transport).

IEC 62368-1: safety of AV, IT and communications gear

Author Hugues Orgitello Last updated 27 May 2026 ~14 min read

Guide - IEC 62368-1

IEC 62368-1 is the horizontal safety standard for audio video equipment, information technology and communications equipment. Published by the International Electrotechnical Commission and maintained by Technical Committee TC 108, it has replaced since 20 December 2020 two long-standing prescriptive standards: IEC 60950-1 for IT equipment and IEC 60065 for audio video equipment. The 4th edition, published in 2023, is the current version in the IEC catalogue. This page lays out the principle of hazard-based safety engineering (HBSE), the electrical, thermal, mechanical and power-source energy classes, the distinction between ordinary, instructed and skilled persons, the safeguard hierarchy, the articulation of EN 62368-1 under the LVD and UL 62368-1 under the US NRTL regime, and the pitfalls observed in practice.

History and trajectory

IEC 62368-1 followed a long, planned trajectory of more than a decade between the pilot first edition and the withdrawal of the legacy standards.

Stage	Year	Content
Edition 1	2010	First formal publication, voluntary status, coexistence with 60950-1 and 60065 without enforced transition
Edition 2	2014	Maturation of the HBSE principle, second edition published alongside the IEC decision to engage the transition of the two legacy standards
Transition decision	2014	The IEC sets the schedule for replacing 60950-1 and 60065 with 62368-1, with a target withdrawal date for the two earlier standards
Edition 3	2018	Consolidation of the HBSE rules, alignment with UL and CSA, first firm regulatory adoptions
Withdrawal of 60950-1 and 60065	20 December 2020	The two legacy standards cease to be recognised for new certifications
Edition 4	2023	Current version, battery clarifications, USB-C Power Delivery, integration of recent industry feedback

The IEC choice to merge the requirements of 60950-1 and 60065 into a single text has two justifications. First, the physical convergence of products: a modern smart television is both an audio video device and an IT terminal, a laptop embeds an audio amplifier and a video decoder. The 60950 / 60065 split no longer matched functional reality. Second, moving from a prescriptive to a risk-based approach allows the standard to cover hybrid architectures without multiplying vertical references.

The 2014 to 2020 transition window was generous. Six years for an industrial vendor to migrate its portfolio of test reports from 60950-1 or 60065 to 62368-1 is a reasonable horizon against the typical certificate renewal cycle (five years in most NRTL and European regimes). 20 December 2020 marks the cut-off beyond which a legacy report no longer carries presumption-of-conformity value for a new placement on the market.

Hazard-based safety engineering (HBSE)

The HBSE principle structures the entire body of the standard. It breaks with the prescriptive logic of the two legacy standards (such insulation for such application class) in favour of a causal logic: identify the energy source, classify its hazard level, place between the source and the person a proportionate safeguard.

The formal analysis sequence has three steps.

Identify the energy sources present in the equipment: electrical energy (voltages, currents, capacitances), thermal energy (hot surfaces, fluids), mechanical energy (moving parts, springs, batteries under compression), chemical energy (electrolytes, gases), radiation (laser, UV, microwave, X-ray).
Classify each source against the numerical thresholds tabulated in the standard. For electricity, three classes (ES1, ES2, ES3). For thermal energy, three classes (TS1, TS2, TS3). For mechanical energy, three classes (MS1, MS2, MS3). For available power, three classes (PS1, PS2, PS3).
Place safeguards whose number and severity are determined by the class of the source and the type of person (ordinary, instructed, skilled) who can access the exposed zone.

The table below summarises the energy families and their naming inside the standard.

Energy family	Code	Coverage
Electrical energy	ES1 / ES2 / ES3	Voltage, current, capacitance, stored energy: electric shock and its physiological consequences
Thermal energy	TS1 / TS2 / TS3	Accessible hot surfaces, burns on contact, combinations of duration and temperature
Mechanical energy	MS1 / MS2 / MS3	Moving parts, suspended masses, springs, injuries by contact, crushing, perforation
Power source	PS1 / PS2 / PS3	Available steady-state power, electrically initiated fire risk, containment sizing
Chemical energy	(specific categories)	Fluids, electrolytes, batteries, leaks
Radiated energy	(specific categories)	Laser, UV, microwave, ionising

The exact numerical thresholds appear in the normative text and must be read directly in the IEC publication to avoid approximation. For electrical energy, the historical order of magnitude commonly cited is around 30 V RMS AC or 60 V DC for the ES1 / ES2 boundary, with an ES3 threshold markedly higher, corresponding to voltages capable of severe electric shock. The thresholds are conditioned by contact duration, frequency, contact impedance and stored capacitive energy, which makes the extraction of a single value misleading.

Ordinary, instructed and skilled persons

The standard modulates protection requirements according to the profile of the person exposed to the energy source. The distinction is fundamental because it governs which energy classes may remain accessible and under what conditions.

Profile	Definition	Examples
Ordinary person	End user without electrotechnical training, who may be unaware of normal precautions	General public, office worker, retail customer, student, child
Instructed person	Person who has received training from a skilled person to avoid the hazards of a given source	Network operations technician, first-level maintenance agent, staff trained on a precise procedure
Skilled person	Person with the training, experience or technical knowledge to identify and avoid electrical, thermal and mechanical hazards	Qualified maintenance technician, field engineer, certified electrician

The narrower the category authorised to access a zone, the higher the energy class the standard tolerates, but under strict access and signage conditions. An ES3 source behind a tool-operated cover marked with a regulatory pictogram remains acceptable if access is restricted to a skilled person. The same ES3 source behind a hand-openable cover accessible to an ordinary person is a direct non-conformity.

Accessibility rules are detailed in the annexes of the standard: shape of the test finger, depth of access, opening force, requirements for tool or key locking, prevention signage. Several recurring non-conformities arise from a wrong assumption about the profile of the person actually exposed: a piece of equipment in a factory technical cabinet is not necessarily restricted to skilled persons, the audit must verify it case by case.

Safeguard hierarchy

HBSE defines a hierarchy of safeguards whose robustness rises with the severity of the residual hazard.

Level	Definition	Typical application
Basic safeguard	Primary protection between the energy source and the person under normal conditions	Basic insulation, structural separation, non-locked cover
Supplementary safeguard	Redundant protection in case the basic safeguard fails	Supplementary insulation, protective earth, second insulating layer
Reinforced safeguard	Single protection equivalent to the combination basic plus supplementary, dimensioned more severely	Reinforced insulation in a class II power module, qualified isolation transformer
Double safeguard	Combination of two independent safeguards (typically basic plus supplementary)	Classical architecture of a switched-mode power supply with protective earth and basic insulation

The insulation system associated with these safeguards reuses the classical electrotechnical categories: functional insulation (necessary for operation, not counted as protection), basic insulation, supplementary insulation, reinforced insulation, double insulation. Clearances, creepage distances and dielectric-strength requirements are tabulated against the working voltage, the overvoltage category (OVC I to IV), the pollution degree (PD1 to PD3) and the energy class of the source.

A structuring rule: a reinforced safeguard fulfils the role of two independent safeguards for the purpose of the standard, provided its characteristics (thickness, creepage, clearance, test voltage) are dimensioned to the combined level. This correspondence is what permits a class II power module (double insulation, no protective earth) facing an ES3 source on the mains side.

Power sources PS1 / PS2 / PS3

The power source classes govern the requirements for containment against the risk of electrically initiated fire and the sizing of the enclosure materials.

Class	Available power	Construction implication
PS1	Up to 15 W	Limited fire risk, relaxed requirements on flame-resistant materials for the enclosure
PS2	Up to 100 W	Fire risk present, V-1 or V-2 materials per UL 94 acceptable for the enclosure
PS3	Above 100 W	Significant fire risk, V-0 or metallic materials required, reinforced containment, larger distances

Available power is measured after limitation by protection devices (fuse, limiter, switched-mode regulation). A 200 W switching power supply whose output is electronically limited to 50 W presents a PS2 class on the limited output, even if the mains input remains PS3. This gradation lets requirements differ between the primary and secondary parts of a single piece of equipment, which simplifies the enclosure of low-voltage secondary modules.

In practice, a 5 V / 1 A USB charger is PS1, a typical 65 W laptop charger is PS2, a server power supply or a large television is PS3. Enclosure design (materials, walls, ventilation, distances) is sized to the highest PS class accessible in the zone considered.

The PS classification interacts with the fire-enclosure rules of clause 6 of the standard. A PS3 zone must be contained in a fire enclosure whose materials and openings meet the V-0 or metallic criteria, with bottom openings sized to prevent the projection of burning material onto surrounding combustibles. A PS2 zone may use a V-1 enclosure subject to the same opening rules with slightly relaxed thresholds. A PS1 zone, by contrast, does not require a dedicated fire enclosure, the residual fire risk being too low to justify the cost of containment. The classification has therefore a direct mechanical and material consequence on the bill of materials.

Equipment covered by the standard

The scope of IEC 62368-1 is broad but defined by implicit exclusion: anything historically covered by 60950-1 or 60065. A non-exhaustive list helps to position a product.

laptops, desktops, ultrabooks, tablets
servers, workstations, data-centre equipment (excluding data-centre-specific extensions)
routers, switches, Wi-Fi access points, wired and wireless networking equipment
televisions, set-top boxes, soundbars, media players
audio amplifiers, amplified musical instruments, non-professional mixing desks
monitors, displays, projectors, videoconferencing equipment
fixed and mobile telephone terminals, IP-PBX
printers, scanners, office peripherals
chargers and mains adapters shipped with these devices
integrated and removable batteries (with cross-reference to IEC 62133-2 for the lithium cell)

Classical exclusions: medical electrical equipment (see the IEC 60601-1 guide), heavy industrial machinery, ATEX equipment in explosive atmospheres, aeronautical equipment under DO-160, automotive equipment under the ISO 16750 and IEC 60068 families. For these categories, dedicated vertical standards apply in place of 62368-1, even though the embedded electronics may share common subassemblies.

Typical test sequence

A 62368-1 test campaign takes place in an accredited laboratory (ISO/IEC 17025 on the electrical safety scope) and combines documentary checks with physical tests on a prototype.

upstream documentary review: HBSE analysis, identification of energy sources, classification, safeguard plan, electrical schematics, mechanical exploded views, datasheets of critical components (transformers, optocouplers, fuses), bill of materials with the UL 94 classification of enclosure materials,
dielectric strength tests (HiPot): application of AC or DC test voltages on each declared insulation interface, in line with the working voltage and overvoltage category,
earth continuity tests: verification of the impedance between accessible metallic parts and the earth pin of the mains cord, under high test current, for the prescribed duration,
insulation resistance tests: steady-state insulation-resistance measurement under DC voltage, comparison against thresholds,
leakage current tests: measurement of earth leakage and touch-current leakage, under normal and single-fault conditions,
abnormal operation tests: short-circuit of components, blocked fan, simulated overheating, verification that the fault does not produce a violation of the HBSE rules,
thermal tests: steady-state surface-temperature measurement, application of the TS thresholds, evaluation of thermal single-fault conditions,
mechanical tests: enclosure robustness, stability, drops for portable equipment, suspension robustness,
battery review: IEC 62133-2 cell conformity, UN 38.3 transport tests, verification of the electronic management (BMS),
downstream documentary review: drafting of the test report in the CB scheme format of IECEE for multi-country certifications.

For the test-sequence detail in a CE context, see the CE tests page and the list of harmonised standards on the CE standards page.

EN 62368-1 and the Low Voltage Directive

In the European Union, the electrical safety of products falling within the IT, audio video and communications scope is governed by Directive 2014/35/EU on Low Voltage equipment (LVD). EN 62368-1 is the European transposition of IEC 62368-1, published by CENELEC. It appears in the list of harmonised standards under the LVD through communications published in the Official Journal of the European Union.

Application of EN 62368-1 in its harmonised version grants presumption of conformity with the safety objectives of the LVD for the equipment categories covered. A manufacturer who relies on this presumption:

declares conformity with EN 62368-1 in the EU Declaration of Conformity,
attaches the test report and supporting documents to the technical file made available to market surveillance authorities,
carries the normative reference in the marking and the user documentation in line with the directive.

The exact reference of the harmonised edition (year, amendment, cessation date if any) appears on the official European Commission page dedicated to the LVD. The list evolves with successive communications, and the pinned edition must be checked before committing to a test campaign whose report must retain its value over the commercial cycle in view.

UL 62368-1 in the United States and CSA C22.2 No. 62368-1 in Canada

In the United States, the electrical safety of IT, audio video and communications equipment is administered by Nationally Recognized Testing Laboratories (NRTLs) recognised by OSHA. UL 62368-1, published by UL Standards & Engagement, is the US transposition of IEC 62368-1 with minor national deviations (earthing, cords, plugs, fuses per the National Electrical Code).

Certification is materialised by an NRTL mark on the product (UL, Intertek ETL, TUV Rheinland, CSA and other recognised bodies). The mark is the outcome of a dossier comprising a UL 62368-1 conformant test report, an Initial Production Inspection on the manufacturing sites, and a Follow-Up Service for periodic surveillance.

In Canada, the transposition is CSA C22.2 No. 62368-1, published by the CSA Group. The CSA mark (or an equivalent Canadian NRTL mark recognised by the Provinces) is required for placement on the Canadian market. Since UL 62368-1 and CSA C22.2 No. 62368-1 are aligned with IEC 62368-1, a single test report in the IECEE CB scheme can cover the three jurisdictions subject to application of the national deviations.

The FCC does not address electrical safety: its scope is limited to electromagnetic compatibility (Part 15 and Part 18) and to use of the radio spectrum. Electrical safety in the United States lies solely with the NRTL route.

IEC 62368-2: the explanatory document

The IEC publishes alongside the normative text an explanatory standard referenced IEC 62368-2. This document provides the technical and physiological justifications of the chosen thresholds, references to research on the effects of electric current on the human body, examples of application of the HBSE rules, and the genealogy of the engineering choices.

IEC 62368-2 carries no normative force. No certification rests on its sole reference. Its utility is pedagogical and legal: a vendor who must defend an interpretation in front of a certification body or a market surveillance authority can rely on it to make explicit the HBSE reasoning behind a design decision. For a comprehensive reading of 62368-1, the 62368-2 is an almost indispensable companion, particularly during the first migration projects from 60950-1 or 60065.

Transition between editions

The move from edition 3 (2018) to edition 4 (2023) does not present the rupture that the replacement of 60950-1 and 60065 represented. The changes cover clarifications, alignment with UL and CSA, and the integration of industry feedback on batteries, USB-C Power Delivery and architectures without protective earth.

For the project schedule, two practical rules:

the EN 62368-1 harmonised cessation date for a given edition appears on the European Commission LVD page and conditions presumption of conformity,
US NRTLs typically accept edition-3 reports during a grace period after the publication of edition 4, under a transition policy published by each body.

A test report initiated under an edition that is withdrawn during the targeted commercial-validity window is a frequent source of surprise at renewal. The prudent rule is to engage a test campaign on the latest edition harmonised and NRTL-recognised, even if the lead time is slightly longer.

Pitfalls observed in practice

Without claiming exhaustiveness, several recurring pitfalls appear in feedback from certification bodies and industrial vendors.

Keeping a 60950-1 or 60065 report after 20 December 2020 without redoing the full HBSE analysis. Both standards being withdrawn, their reports no longer carry presumption-of-conformity value for new market placements. Any product change or certificate renewal forces the migration to 62368-1.
Mis-classification of an energy source. A reservoir capacitor in a switching power supply stores an energy that, when released, can be ES2 or ES3 depending on its capacitance and voltage. A wrong classification leads to undersized safeguards. Verification must be done on the schematic by computing the stored energy, not by extrapolation from the upstream supply class.
Wrong accessibility assumption. A piece of equipment assumed to be installed in a technical room reserved for skilled persons may in practice be installed by a reseller in an office accessible to an ordinary person. The installation environment must be documented in the technical file, and the marking must be consistent with that definition.
Omission of battery requirements. Equipment containing a lithium-ion battery must demonstrate IEC 62133-2 conformity on the cell and UN 38.3 conformity for transport. These two references apply on top of 62368-1, not in its place. Several technical files miss one or the other.
Confusion with IEC 60601-1. A device with a sensor in direct patient contact (probe, electrode, ECG sensor) does not fall under 62368-1 but under 60601-1. A medical monitor certified to 62368-1 alone is not medical compliant. See the IEC 60601-1 guide for the functional boundary.
Confusion between electrical safety and EMC. EN 62368-1 and the LVD cover electrical safety. Electromagnetic compatibility falls under a separate directive (2014/30/EU) and separate standards (EN 55032, EN 55035 for the IT and audio video scope). A product certified under the LVD will not be CE-markable without a separate EMC demonstration.
Subcontracting a laboratory without checking NRTL scope. A laboratory accredited ISO/IEC 17025 on 62368-1 is not necessarily entitled to grant a US NRTL mark. The commercial mark requires a specific NRTL certification body. Verification must be made on the OSHA-recognised scope before placing the test order.