A new approach to product safety
Modern technology is being used in new places and
as a result demands new safety requirements
The narrowing distinction between IT (information technology) at home and as professional entertainment products has created a need to harmonize related safety requirements.
The increasing proliferation of audio, video, information and communication technology equipment also means that safety needs of children, the elderly and the disabled must be taken into consideration.
In addition, the safety requirements must keep up with the rapid advancement in technology for these products. All of this has changed the way the IEC looks at safety standards for these products.
In the past, an IEC standard was typically prescriptive, describing specific constructions. For example, the traditional standard would indicate exactly the size for a ventilation opening in a product for it to comply with safety requirements. Today, such guidelines can prove limitative to new product designs and may become obsolete when technology evolves.
TC (Technical Committee) 108: Safety of electronic equipment within the field of audio/video, information technology and communication technology, addressed this challenge by moving from a product-driven safety analysis to a systemic identification and analysis of hazards using an approach commonly referred to as HBSE (Hazards Based Safety Engineering).
TC 108 developed a new standard, IEC 62368-1, Audio/video, information and communication technology equipment - Part 1: Safety requirements. It clearly states the risk being addressed and its principles for compliance. To the extent practicable, compliance statements are performance-based. However, to minimize testing, acceptable constructions are also provided for a designer’s use, if they so choose.
From reactive to proactive
Typically, the differences can be illustrated by comparing the approach in a standard such as IEC 60065, Audio, video and similar electronic apparatus - Safety requirements, which is incident-based and product-specific, with that of the new IEC 62368, which is technology-independent and based on performance as opposed to construction. The former takes a reactive approach while the latter is proactive in its direction.
No longer product-specific
Being technology-independent, the standard is based on sound engineering principles. It is destined to be used by engineers who designed the product and evaluated its safety requirements. It is also intended to be used by first, second or third parties assessing conformance of products.
Scope for innovation
Says Richard L. Pescatore, Global Product Safety Standards Development and Certification Manager at HP (Hewlett-Packard Company) and Convenor of TC 108/WG HBSDT: "From now on, the designer, when going through the engineering and safety analysis of a product, will,understand what is needed to make that product safe. He will no longer be bound by specific required constructions. Instead, he will understand the hazard being addressed and the criteria for mitigating the hazard. This will give him tremendous design freedom."
IEC 62368-1, is different from anything the IEC has written to date in the area of product safety. The hope is that 10 years from now, a design engineer will understand the objective of a given safety guideline so that the intent of the requirements is not lost over time. Tremendous work has been expended in developing this standard. TC108 started working on this generic approach back in 2002. The result is that now a new separate standard will not have to be developed every time the technology changes in the market.
Safety is paramount in conformity assessment
IEC 62368-1 is a very important standard too for CA (Conformity Assessment). Seventy per cent of all IECEE CA certificates issued each year concern safety in the three major industries under the scope of IEC 62368-1: communication technology, information technology and consumer electronics. IECEE is the System of Conformity Testing and Certification for Electrotechnical Equipment and Components.
TC 108 has also adopted a proactive role in reducing potential negative impact of technology on the environment, while preserving product safety properties. Another area of intensive work is related to energy efficiency.
Change in approach: From reactive to proactive, product-based to generic, the systems approach
Current product safety standards:
Incident-based standard
This type of standard takes into account particular incidents that analysis has shown can be prevented provided certain safety measurements are taken. An example would be the case of an external power supply that overheats, or where there's a risk of it catching fire. An incident-based standard therefore includes particular requirements to prevent mechanical movement of the connector and thus recurrence of the particular incident.
Product-specific standard
The standard is written for a specific product or product group. IEC 60065 is specific to consumer electronics such as TVs, audio systems, etc. IEC 60950-1, Information technology equipment – Safety – Part 1: General requirements, is written for computers and related equipment.
Construction-based approach
The standard specifies the actual constructions that make the product safe. Other constructions (which may be equally safe) are prohibited. An example of this could be a ventilation opening that must be of a specific size.
Reactive approach
The requirements of the standard mean that it provides for reactions to incidents or near-incidents, much in the way of an "incident-based" standard. An example here might be a reaction to field complaints that results in a mechanical securement of the power input connector on external power supplies.
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IEC 62368:
Hazard-based standard
The standard is based on the energy sources within the equipment. The publication classes the energy sources as either hazardous or non-hazardous. Example: Voltages above a certain level are hazardous, while those below a certain level are non-hazardous.
Technology-independent
The standard addresses safeguards against specific energy sources, independent of the function of the product. In today's world, computers and TVs are becoming complementary equipment, so the safety standard must be written to account for technology, not specific products. Example: The principles for protection against any energy source are applicable to any technology existing today and any future technology.
Performance-based
It is the safety performance of the equipment that is specified, not the construction. For example concerning the assembly of a power input connector of an external power supply, it is specified that it shall not stress the electrical connections.
Proactive approach
The standard addresses the sources of energy contained in the equipment. This allows hazardous energy to be anticipated and safeguards to be designed to prevent future safety incidents. This can be illustrated by solder which, under stress, is subject to cold-flow. If the connection were to fail and result in a hazardous condition, then the failure would need to be prevented, or the consequences of a failed connection mitigated. |
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