Reducing hazards in the home

The role played by IEC International Standards

By Elaine Clayton

By Elaine Clayton, 2011 IEC Young Professional

Elaine Clayton is one of three 2011 Young Professional Programme Leaders. Elaine Clayton is one of three 2011 Young Professional Programme Leaders.

IEC International Standards vital for the entire supply chain

IEC International Standards provide a vital tool for all participants in the supply chain to identify and reduce the hazards associated with domestic appliances. They provide specifications that are designed to facilitate trade and stimulate innovation. Through the participation of experts elected by each NC (National Committee) they also combine and integrate a wide variety of the different cultural and contextual factors that may impact on product safety.

Definition of safety as per ISO/IEC Guide 51

Safety is defined in ISO/IEC Guide 51 as the reduction of risk to an acceptable level. The level set is based on the culture and context in which a product is to be used. As a result, there can be geographic differences, as is the case with Class 0 and 01 appliances. Class 0 and 01 equipment incorporates only a basic level of insulation. However, without a secondary layer of protection or an earth connection, a single fault can cause an electric shock or other hazardous occurrence. And, although the products’ potential to harm is globally understood, the recognition takes such disparate forms that, in most regions, such equipment is banned. Where appliances of Class 0 and 01 construction may still be sold, they are gradually being phased out of electrical safety standards, partly due to increasing global harmonization.

National deviations are costly and time consuming

Since global harmonization is a goal of International Standards, it is in each Member country’s interest to ensure their demographic and geographic factors on product safety are taken into account from the outset of the standardization process. The IEC’s own risk evaluation process when developing and maintaining standards can consider only the hazards that are addressed by the national representatives at the TC (Technical Committee) level, i.e. the stakeholders. The IEC standardization process allows for the introduction of a national deviation to an International Standard, but to do so is not in the interest of an IEC NC. Any national deviation, particularly where a hazard or a risk reduction method is concerned, implies additional costs for the Member country concerned. It takes time to implement a national deviation and it reduces market access both for import and export.

Nevertheless, national deviations are instituted occasionally, particularly where risks are considered intolerable for geographic or demographic reasons. IEC 60335-2-6, Household and similar electrical appliances - Safety - Part 2-6: Particular requirements for stationary cooking ranges, hobs, ovens and similar appliances, which has a stability date of 2013, currently contains national deviations for Australia and New Zealand. They require a hot surface warning label to be applied to ovens that do not meet the reduced temperature limits of Annex Z. This requirement was introduced in 2002 and strengthened in 2007 because of an unacceptably high incidence of burns caused to young children by touching hot surfaces such as oven doors. Cultural and contextual factors as diverse as household design and parenting practices were cited as causal factors.

Another case of regional incident analysis led to national deviation to IEC 60335-2-30, Household and similar electrical appliances - Safety - Part 2-30: Particular requirements for room heaters, being introduced in Australia and New Zealand in 2009. This International Standard is at present approved for FDIS stage with an estimated publication date of 2013. A number of serious fires involving heaters of substantially plastic construction had caused growing concerns amongst local regulators and fire fighting organizations about the adequacy of the standard. A working group was convened in late 2008. Although the standard had previously been amended to include tests and requirements to reduce fire hazards, incidents were continuing to occur. One reported fire involved a heater that was subsequently shown to comply with the glow wire and needle flame tests of Clause 30.

Whilst heater fires are by no means unique to Australasia, cultural and contextual factors such as the higher supply voltage and prevalence of plastic bodied models contributed to this risk being considered unacceptable. Further risk reduction methods targeted at substantially non-metallic heater constructions were thus implemented as a national deviation. They included the introduction of 850 degree glow wire tests for all non-metallic materials within the enclosure, fan blades and structural elements.

Electrical safety standards help reduce risk

Electrical safety standards cannot encompass all of the potential hazards associated with a unique demographic profile, marketing strategy, intended user or design of an individual appliance. While they are never prescriptive or mandatory – that is the role of national governments and regulatory bodies – they do attempt to provide a framework for design that ensures a product can be sold in a particular market. At the same time, they provide guidance about risks commonly associated with the appliance type and its use. This allows members of the supply chain to identify the specific hazards associated with the products that they sell, and have mechanisms in place to reduce to an acceptable level any risks they pose.

Designing products with safety in mind

Increasingly, IEC International Standards take a systems approach in providing the requisite risk management framework for designers, manufacturers, importers, and retailers. This means that at each stage of the product introduction process, hazards can be recognized, and risks assessed and reduced where feasible. Ideally, safety should be designed and manufactured into consumer products from the outset. If products are not designed taking risk into account, it may not be feasible to re-design or re-tool at a later stage. The importer or retailer must then attempt to treat risk through secondary means such as labelling, instructions and marketing communications.

IEC 60335 series provides the framework for testing

The philosophy we promote at Black & White Engineering Solutions is that International Standards such as those in the IEC 60335 series provide us with the minimum framework and foundation in testing for a safe and reliable product. So long as new methodologies continue to ensure that products comply with an International Standard and are fully functional, we actively encourage any further measures that can be taken to enhance appliance safety.

Elaine Clayton is one of three 2011 Young Professional Programme Leaders. Elaine Clayton is one of three 2011 Young Professional Programme Leaders.