Electrical safety compliance is one of the most consequential disciplines in product development, and one of the most frequently misunderstood. It is not a final checklist before certification. It is a set of engineering decisions, made continuously from concept through production, that determine whether a product can be safely placed in human hands. When those decisions are made well, certification follows naturally. When they are deferred or treated as formalities, the consequences range from failed test campaigns to product recalls and, in the worst cases, serious injury.

The regulatory landscape for electrical safety has undergone a significant shift in recent years. The adoption of IEC 62368-1 as the successor to IEC 60065 and IEC 60950-1 marked a move away from prescriptive, technology-specific rules toward an energy-based hazard model. Rather than dictating circuit topologies, the standard asks engineers to identify, classify, and control the energy sources in their products before they reach users. This approach demands more from designers upfront, but it also provides more flexibility and, when applied rigorously, produces safer products.

This guide brings together everything published on Regulatory Decoded about electrical safety compliance. It is structured around the four core technical areas that every product engineer working on mains-powered or battery-powered equipment needs to master: leakage current, dielectric strength testing, protective earth design, and thermal management.

Leakage current is present in every electrical product. It is not a defect ,it is a physical consequence of imperfect insulation, EMI filter components, and parasitic couplings inherent to any real circuit. The engineering task is not to eliminate it, which is impossible, but to understand where it comes from, how to measure it accurately, and how to keep it within the limits that protect users from harm.
At low levels, leakage current causes tingling sensations. As it rises, it triggers involuntary muscle contractions and eventually becomes lethal. The thresholds defined in IEC 60479-1 exist precisely because the relationship between current magnitude and physiological effect is well documented. Standards such as IEC 60990 and IEC 60601-1 translate those thresholds into measurement protocols and absolute limits that manufacturers must meet.

Our three-part series covers every stage of the subject. Part 1 on leakage current theory and risks establishes the physics and the human body’s response to different current types and frequencies. Part 2 on measurement methods and instrumentation covers the IEC 60990 measurement networks, test setup, and how to interpret results under both dry and wet conditions. Part 3 on design and mitigation strategies addresses how to control leakage at the source, insulation selection, creepage and clearance, PCB layout, and EMI filter optimisation

The HiPot test, or high potential dielectric strength test, is the primary method used to verify that the insulation barriers in a product will hold under stress conditions. It applies a voltage significantly higher than the product’s working voltage across insulation systems to confirm that no breakdown will occur during normal use or foreseeable fault conditions. Passing a HiPot test is a mandatory requirement under virtually every major electrical safety standard.

Understanding what the test actually measures, how to set it up correctly, and how to design insulation that will survive it are distinct competencies. Part 1 of our HiPot series explains the theory and why the test matters beyond its regulatory function. Part 2 covers test execution, instrument selection, and common sources of false failures. Part 3 addresses how to design insulation systems and creepage paths that pass consistently, by design.

Thermal management is the third dimension of electrical safety that engineers often underestimate until a product fails its temperature test. Standards including EN 563, EN ISO 13732-1, IEC 60335-1, and IEC 62368-1 define precise surface temperature limits based on material type and contact duration, limits that cannot be negotiated after the PCB is laid out. Understanding where those limits come from, how to measure accurately against them, and how to design a product that stays within them are three distinct problems, each covered in dedicated articles.

Temperature limits in product design explains how the limits are derived, what varies across standards and material classes, and where engineers most commonly miss a requirement. Temperature measurement for compliance and safety covers thermocouple types, their characteristics, and how to select the right one for your application. Thermocouple placement under IEC 60335-1 goes into the specific placement requirements of the standard, the decisions that determine whether your temperature readings are valid for certification or not. The third article in this group, on thermal design strategies for compliance, is forthcoming and will address how to control surface temperatures through component selection, layout, and enclosure design before you reach the test lab.

This resource is part of Compliance Handbooks, Regulatory Decoded’s in-depth technical series for product engineers.