For most people catastrophic explosions are associated with certain so-called Ex environments, like the oil and gas or chemical industries, mines and many more sectors. They frequently result in large number of casualties and/or significant and costly environmental damage.
The explosion that destroyed the North Sea Piper Alpha oil and gas offshore platform in July 1988 resulted in the death of 167 workers and damage in excess of USD 1 500 million at the time.
The explosion of the Deepwater Horizon drilling platform in the Gulf of Mexico in April 2010 killed 11 workers, caused major environmental damage that required a huge clean-up operation costing billions of dollars.
Hundreds have also died in explosion-related mining accidents across the world over the years, the worst recent one killed over 300 miners in Soma, Turkey, in 2014.
Accidents caused by explosions happen also in chemical plants, grain silos, sugar refineries and many other sites, such as laboratories.
To prevent these accidents, specially designed and properly installed and maintained equipment and systems are essential. International Standards for these are prepared by IEC TC 31.
IEC TC 31 was established in 1948 “to address the need to develop techniques for ensuring electrical equipment would not provide an explosion risk when used in explosive atmospheres involving gases, vapours and mists.”
The TC scope has been expanded over the years to meet additional needs and “to include classification, installation requirements and combustible dusts.”
The current structure of TC 31 includes three Subcommittees (SCs):
TC 31 has also 12 Working Groups that cover different aspects, such as electric machines (motors and generators), dusts, gas/dust hybrid mixtures, batteries in equipment for explosive atmospheres, etc.
As a result TC 31 is a provider of Standards to a number of other IEC TCs and maintains liaisons with committees from other organizations such as ISO/TC 197 WG 13: Hydrogen Detectors, a TC of the International Organization for Standardization (ISO), or the Petroleum and Chemical Industry Committee (PCIC) of the Institute of Electrical and Electronics Engineers (IEEE).
More than 510 experts from 39 National Committees take part in the TC’s work. The TC and its three SCs had issued 71 publications as of May 2017, and their current Work Programme includes development work on 19 other publications (including newer versions of existing ones). These Standards are also adopted in various countries at the national and regional level, either in whole (without differences), or in part (with identified differences).
Protecting installations and people against risks from explosive atmospheres is not only the result of comprehensive standardization work from IEC TC 31, its SCs and WGs. It is also due, to a great extent, to the work of the IEC System for Certification to Standards relating to Equipment for use in Explosive (Ex) Atmospheres, IECEx.
IECEx provides the following:
Stakeholders include both Participants group and Users group:
The Participants group, comprise, for instance:
The Users group consists of all those that have the need to correctly select equipment and services, such as:
The purpose of the IECEx System is to:
Taken together, standardization work by IEC TC 31 and the IECEx system provide a global comprehensive solution to address many of the risks found in Ex environments. Theirs is a work in constant development as new risks arise and as new solutions are found for these and for older risks.