Hazard-Based Safety Engineering: How IS/IEC 62368-1 Thinks Differently from IS 13252 and IS 616

Hazard-Based Safety Engineering: How IS/IEC 62368-1 Thinks Differently from IS 13252 and IS 616

Hazard-Based Safety Engineering: How IS/IEC 62368-1:2023 Thinks Differently from IS 13252 and IS 616

When engineers first encounter IS/IEC 62368-1:2023 after years of working with IS 13252 or IS 616, the most common reaction is: "This is structured completely differently." That is because it is. IS/IEC 62368-1 is not merely a revised version of the old standards — it represents a fundamental philosophical shift in how product safety is evaluated and designed.

Understanding this shift is essential for anyone responsible for product design, compliance, or testing for the Indian market.

The Old Approach: Prescriptive Safety

IS 13252 (aligned with IEC 60950-1) and IS 616 (aligned with IEC 60065) used a prescriptive approach to safety. This means:

  • The standard told designers exactly what to do — specific insulation requirements, specific creepage distances, specific temperature limits
  • Compliance was essentially a checklist — you did what the standard said, and if you checked all the boxes, the product passed
  • The approach was developed for specific product categories — computers on one hand, televisions on the other — and it worked when these were clearly distinct products

The problem emerged as technology converged. A modern smart TV is simultaneously a television (IS 616), a computer (IS 13252), and a streaming device. A laptop is a computer with AV capabilities. An IP-based CCTV camera is an IT device with embedded video processing. The old two-standard framework could not elegantly handle these hybrid products.

The New Approach: Hazard-Based Safety Engineering (HBSE)

IS/IEC 62368-1:2023 starts from a completely different premise: identify the energy sources in the equipment, classify them by hazard level, and apply safeguards proportional to the hazard.

The key insight is that all safety hazards in electronic equipment ultimately come from energy — electrical energy, thermal energy, mechanical energy, radiation energy, or chemical energy. By focusing on energy management rather than product category, the standard becomes technology-neutral and future-proof.

The Energy Classification System

IS/IEC 62368-1 classifies energy sources into three levels:

Electrical Energy Classes (PS = Power Source)

  • PS1 (Class 1 Power Source): Energy levels that cannot cause injury — typically <20VA and <120V peak. No safeguard required beyond basic insulation in many cases.
  • PS2 (Class 2 Power Source): Energy levels that could cause pain but not serious injury under ordinary conditions — typically <250VA. One safeguard required (basic protection).
  • PS3 (Class 3 Power Source): Energy levels that could cause serious injury or death — mains voltages and high-power circuits. Two independent safeguards required (double protection).

Thermal Energy Classes (TS = Thermal Source)

  • TS1: Temperature that cannot cause a burn — does not need guarding against tissue damage
  • TS2: Temperature that could cause a reversible burn — one safeguard required
  • TS3: Temperature that could cause an irreversible burn — two safeguards required

Safeguard Classes

Safeguards are also classified by reliability:

  • Safeguard 1 (Basic safeguard): Single-level protection — can fail
  • Safeguard 2 (Double/reinforced safeguard): Two independent protections — if one fails, the other provides protection

How This Changes Product Design Thinking

Under IS 13252 or IS 616, a designer would look up a table of requirements and implement them. Under IS/IEC 62368-1, a designer must:

  1. Identify all energy sources in the product (mains power input, internal SMPS output, battery, heat from components, motor/fan, LED/laser, chemicals in batteries)
  2. Classify each energy source into PS1/PS2/PS3 or TS1/TS2/TS3 based on measured or calculated parameters
  3. Determine what safeguards are required based on the classification — PS3 needs two safeguards, PS2 needs one, PS1 needs none (or minimal)
  4. Implement safeguards appropriate to the classification — and document why the chosen safeguard meets the standard's criteria

This approach gives designers more flexibility — you can choose how to implement the required protection level rather than following a single prescribed solution. But it also requires more engineering judgment and documentation — you must be able to explain and justify your safety design choices to the test lab and BIS.

Practical Impact: What Actually Changes for Most Products

For straightforward consumer electronics (laptops, phones, TVs), the practical testing differences from IS 13252 or IS 616 are often moderate — the underlying physical phenomena are the same, and the numerical limits are broadly similar. However, specific areas do change:

  • Component clause (Clause 4): Components previously certified under IEC 60950-1 (for IS 13252) or IEC 60065 (for IS 616) need to be evaluated for acceptability under IS/IEC 62368-1. Not all legacy certifications are automatically transferable.
  • Lithium battery requirements: Significantly expanded and more rigorous under IS/IEC 62368-1 — directly relevant for laptops, tablets, phones, power banks, and wireless speakers.
  • Interconnected equipment: Products that connect to other equipment (via USB, Ethernet, HDMI, etc.) need evaluation of the combined energy scenario — new territory not well-covered by IS 13252 or IS 616.
  • Instruction and marking requirements: Updated requirements for user safety instructions and product marking — review your existing documentation.

What This Means for Your Testing Strategy

When preparing for IS/IEC 62368-1:2023 testing, the most important pre-step is a gap analysis: systematically compare your product's existing design and documentation against the new standard's requirements. This identifies:

  • Which tests are essentially unchanged from IS 13252 / IS 616 (allowing reference to previous test data in some cases)
  • Which tests are new or significantly modified (requiring fresh testing)
  • Which design elements may need to be reviewed for compliance

House of Testing offers IS/IEC 62368-1:2023 gap analysis as a pre-testing service. This saves significant time and money by ensuring products are ready before formal type testing begins.