While the terms “explosive (Ex) atmospheres” are more often than not associated with the oil/gas and mining industries, in reality they apply to many more sectors. Indeed, any business where combustible dust is present in the workplace qualifies as an Ex area.
Dust is dust but it comes from many different sources. Businesses that use agricultural products such as cellulose, corn, egg white, flour and soy flour, powdered milk, spices, starch, sugar, tobacco, wood or fertilizer are potentially hazardous. That goes as well for industries that rely on metals like aluminium, iron, magnesium, titanium or zirconium; or plastics like epoxy or phenolic resin, melamine, polyethylene or polypropylene. Biosolids, dyes, rubber, soap, sulphur or pharmaceuticals are also potential hazards.
Even very small amounts of dust accumulating in the workplace can set off a fire or an explosion that could cause destruction, injuries and deaths.
Worker protection and explosion-proof equipment
It is essential for businesses to protect workers against fire and explosion hazards. This can be done by installing dust collection systems as well as keeping all surfaces, including hidden spaces, clean at all times. A key factor is to ensure that all areas that may contain dust have equipment designed, manufactured and installed for Ex atmospheres. Providing specialized training for employees working in hazardous areas is an additional step that enhances safety.
Today, businesses that operate in hazardous areas can choose from a vast selection of equipment specifically designed and manufactured for Ex atmospheres. From electric motors to valves, from lighting fixtures to cameras and smartphones, Ex areas can be fitted with explosion-proof devices and equipment.
All pieces of equipment and devices used in explosive atmospheres, whether large or small, electrical or non-electrical, must be designed and built in compliance with the strict requirements set out in standards and specifications, most notably in the IEC 60079 or ISO/IEC 80079 series of International Standards developed by IEC Technical Committee (TC) 31: Equipment for explosive atmospheres, and its subcommittees.
Testing and certification are a must
In addition to designing and building devices in compliance with IEC International Standards, they must be tested and certified, to ensure that any piece of equipment meets the required criteria. Products associated with a certificate of conformity satisfy the criteria for safe usage in hazardous environments.
IEC, through IECEx, the IEC System for Certification to Standards Relating to Equipment for Use in Explosive Atmospheres, has established the processes to help industry, authorities and regulators ensure that equipment (electrical and non-electrical) as well as the people working in Ex locations benefit from the highest level or safety.
IECEx operates the only global online certificate system dedicated to the Ex sector, allowing instant verification of claims of compliance of certificates issued by more than 100 IECEx certification bodies (ExCBs) throughout the world.
These certificates of conformity are issued via the following three schemes:
- IECEx certified equipment scheme
- IECEx certified service facilities scheme
- IECEx scheme for certification of personnel competence
In addition, the IECEx conformity mark licensing system operates in association with the IECEx certified equipment scheme. IECEx certificates issued by the ExCBs are centrally located and available for full public access on the IECEx online certificate system.
Personal competence training
The IECEx recognized training provider (RTP) programme, launched a few years ago to assist applicants in their preparation for the certificate of personnel competence (CoPC), is growing fast. The RTPs provide candidates with knowledge and understanding of the terminology and protection concepts for electrical and non-electrical equipment used in explosive atmospheres, based on the IEC 60079 and the ISO/IEC 80079 series of international standards prepared by IEC TC 31.
The number of certificates issued by all IECEx schemes is steadily growing, with special emphasis on the certificates of personnel competence (CoPCs). These provide assurance that the persons working with design, selection, installation, inspection and maintenance of Ex equipment have had their knowledge and competence independently verified. Almost 3 000 CoPCs have been issued so far.
Safety is of the utmost importance in hazardous locations and equipment must be fire- or explosion-proof. For non-electrical equipment, the source of ignition comes from the action of the machinery that may create frictional contact, thus causing a spark or hot surface. Examples include: hydraulic pumps, gear boxes and crushers.
United Nations endorsement
Since 2011, the United Nations Economic Commission for Europe (UNECE), has endorsed the use of IEC TC 31 standards supported by the IECEx schemes as the “world best practice model for demonstrating conformity in the highly specialized Ex field”. This was reflected in the UNECE common regulatory objective (CRO), also published in 2011. The UNECE endorsement continues to assist IECEx recognition among regulators, for example, the US Coast Guard use of IECEx for equipment used on foreign flagged ships within their jurisdiction.