Only the degree of measures taken to ensure said safety vary. There is one element however that is a concern in all workplaces: the occurrence of fires and explosions.
Offices and stores, restaurants, or public buildings, among others, may rely on fire extinguishers, smoke detectors and subject their staff to annual or semi-annual fire drills to cope with potential fire risks.
It becomes more complex for industrial facilities. Even more so when those facilities belong to companies that operate in explosive (Ex) atmospheres where the risk of fire and/or explosion is present day and night. Facilities in the Ex sector are outfitted with specific explosion-proof equipment, and their staff are trained to operate in these highly specialized environments.
The Ex sector is certainly quite vast. Apart from the obvious – oil refineries, rigs and processing plants, gas pipelines and distribution centres, underground coalmines – it includes chemical processing plant, food processing, sugar refineries, printing, paper and textile industries, grain handling and storage, woodworking areas, surface coating industries, sewerage treatment plants, aircraft refuelling and hangars, hospital operating theatres, and many more.
Many of the above are often not perceived as belonging to the Ex sector per se, but parts of their facilities may be places where flammable liquids, vapours, gases or dusts are likely to occur in quantities sufficient to cause a fire or an explosion. In other words, specific areas may be hazardous areas where risk of fire and/or explosion are real. Hazardous areas are classified into zones, based on an assessment of the frequency of the occurrence and duration of an explosive gas atmosphere, that are broken down as follows:
As with other issues pertaining to hazardous areas, the IEC has developed an international standard that specifically addresses the classification of areas: IEC 60079-10-1, Explosive atmospheres –Part 10-1: Classification of areas – Explosive gas atmospheres.
The third edition was published in December 2020 by IEC SC 31J, a subcommittee of IEC Technical Committee 31: Equipment for explosive atmospheres. SC 31J prepares international standards relating to the use of equipment – including area classification – the selection and installation, inspection and maintenance, repair, overhaul and reclamation of equipment where there is a hazard due to the possible presence of explosive atmospheres of gases, vapours, mists or combustible dusts.
This edition includes a commented version, which highlights all changes from the previous edition as well as provides comments explaining the most relevant changes. The commented version is meant to make use of the standard easier for all stakeholders.
IEC 60079-10-1 sets out the essential criteria for the classification of areas where there may be a fire or explosion risk due the possible presence of flammable gas or vapour. The standard provides guidance on factors relevant to such assessments as well as design and control parameters.
While the standard is primarily intended to aid in the selection and installation of equipment to prevent ignition sources in areas with explosion risks it is also a useful adjunct for other plant safety issues.
This new edition sets out more clearly the factors relevant to the classification of hazardous areas, helps avoid ambiguities and makes the standard more user-friendly.
It provides the basic principles for hazardous area classification and recognizes numerous national or industry codes that may provide further detail or specific examples of hazardous area classification. It also includes a number of simplified assessment tools for use in applications where the use of such tools is considered an acceptable option.
The standard is meant for engineers in a wide range of industries such as mining, oil and gas, petroleum distribution, petrochemical, printing, wastewater treatment, pharmaceutical, adhesives and paint manufacturing, cement production, shipyards, wood industry, food production and many others. It will also be a reference standard for many government agencies related to workplace safety and safe management of these types of industries.
Protecting installations and people against risks from explosive atmospheres is not only the result of comprehensive standardization work from IEC TC 31, it is also due, to a great extent, to the work of IECEx, the IEC System for Certification to Standards relating to Equipment for use in Explosive (Ex) Atmospheres.
The system helps make sure that equipment used in Ex areas meets the very strict requirements specified standards such as IEC 60079-10-1, as well as those put in place by national or regional regulations and legislation.
An IECEx certificate provides clear proof of compliance with international standards, an important assurance for anyone responsible for the safety of those working in such areas and the equipment they operate.
The System addresses the inspection (location and other), installation, maintenance and repair of equipment and systems and assesses the competence of personnel working in this highly specialized area.
IECEx has the mechanisms in place to help industry, authorities and regulators ensure that electrical and non-electrical equipment as well as the people working in Ex locations benefit from the highest level or safety.
The System is truly international and has been endorsed by the United Nations Economic Commission for Europe (UNECE) as the world’s best practice model for the verification of conformity to international standards for explosive atmospheres.
Testing and assessment under the IECEx certified equipment scheme are accepted in all its member countries and beyond. The System provides access to global markets and drastically reduces costs by eliminating multiple re-testing and certification.
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. Their work is ongoing, as new risks arise and as new solutions are found.