ICEweb has nearly 100 Control, Instrumentation, Fire & Gas, Safety Instrumented Systems core pages and a total of more than 300 pages - It Really is Cool Engineering - By Engineers for Engineers it must be just about the World's first choice for Technical Information.

Whilst every effort is made to ensure technical accuracy of the information supplied on, Keyfleet Pty Ltd and its employees accept no liability for any loss or damage caused by error or omission from the data supplied. Users should make and rely on their own independent inquiries. By accessing the site users accept this condition. Should you note any error/omission or an article offends please do not ignore it, contact the webmaster and we will review, rectify and remove as necessary.

Transtek was formed as a Western Australian business in 1998.  The company's goal is to be seen as the premier specialist source for Portable Calibration, Configuration & Hazardous Area Mobile Devices in Australia. Their aim is to challenge the pervading supply trend of being a one-stop shop, or the 'supplier of everything, master of none' mentality.  Instead, Transtek aims to offer a high level of service and specialist product knowledge in the niche area of their clients’ business dealing with traceability, certification and electrical safety compliance.  Transtek clientele includes mining, oil and gas, processing, chemical, public utility companies, and their associated consulting, contracting and engineering suppliers. Contact Transtek .

With long term manufacturer-direct relationships, Transtek provides a local resource for products, service and support in the following specialist areas of their clients’ business: Management of ISO calibration standards and certification of test & calibration devices to meet their quality objectives,  HART instrument communications and calibration management practices and Hazardous area equipment certification and electrical equipment inspection responsibilities.

Transtek Online Catalogue and Store, launched in 2005, is a major part of their business.  Not only does it facilitate 24 hour access to their products and services, but also to technical information through a published series of white papers and FAQ's.

Electrical and Instrumentation Equipment in Hazardous Areas
Technical Information

Go to Specific Subject: Electrical Equipment for Hazardous Areas - Classification, Design and Standards | The Use of Aluminium in Hazardous Areas | Analyser Room Explosion Protection | Certification of Diesel Engines in Hazardous Areas | Dust Explosion Protection | Equipment Protection Levels (EPLs) | Fibre Optics Their Use in Hazardous AreasProcess Fluid Migration Along Cables | Electrical Equipment in Hazardous Areas Standards | Exd Immersion Heaters | Exd Weatherproofing | Other Electrical Equipment in Hazardous Area (Ex) Technical Papers | Installation, Maintenance and Inspection of Ex Equipment in Hazardous Areas | Mobile Solutions for Hazardous Areas | ATEX | ATEX Directives | IECEx | Wireless Considerations in Hazardous Areas | Hazardous Areas Ex Newsletters and Journals | Static Electricity Ignition Hazards | Electrical Equipment  in Hazardous Areas (EEHA)  - Training and Competency  

Electrical Equipment for Hazardous Areas - Classification, Design and Standards

Hazardous Areas Technical Guide- This excellent 90 page technical guide from ICEweb sponsor Weidmuller is a large pdf  download at 5 Megs, however it is worth the wait!
Intrinsic Safety, Barriers and Isolators - A full page of great links.
A Common Regulatory Framework for Equipment Used in Environments with an Explosive Atmosphere - This is a publication that helps address the hazards in environments with a high risk of explosion such as mines, refineries, chemical plants and mills. The booklet can be used by countries that lack regulation in this sector as a blueprint for their legislation, and also for aligning existing national regulations with internationally harmonized best practice.
Basics of Explosion Protection - from Stahl (
Electrical Apparatus and Hazardous Areas - Covers Hazardous Areas, Groups, Zones, Temperature Classes, Types of Protection,Equipment Protection Levels, Standards and ATEX - from Hexagon Technology.
Hazardous Area Classification and Control of Ignition Sources - This Technical Measures Document refers to the classification of plant into hazardous areas, and the systematic identification and control of ignition sources - from the UKHSE.

Electrical Information 
Including Cenelec and IEC hazardous Area Information,  North American Hazardous locations,  IP code information and Abbreviations, Acronyms and Definitions-From Hawke International
Hazardous Areas Technical Guide - This publication provides a brief overview of the essential aspects of explosion protection. Ultimately, safety in a potentially explosive atmosphere is a team effort. Manufacturers have a responsibility to ensure only safe equipment is placed on the market. Installers must follow the instructions provided and use the equipment only for its intended purpose. Finally, the user has a duty to inspect and maintain the equipment in a safe working order - from Warom.  
Hazardous Area Classifications and Protections - The intent of this document is to provide a broad overview of hazardous area classifications and the types of protection techniques involved – from Emerson Process Management.  
Hazardous Area Installations - How to make 92% of sites safer without increasing the costs of compliance - From Abhisam Software
How to Manage Hazardous Areas effectively by using Gas Monitors - Electrical equipment installed in hazardous areas, necessarily has to conform to the area classification for that area. However, frequently, practical problems arise, where the specified equipment may not be easily available. For example, an area classified as Zone 1 under the IEC system, theoretically can accept only Zone 1 equipment. However sometimes, especially in case of specialized equipment, Zone 1 certified equipment of that type may not be available. In such cases what could be done? This paper presents the background of such situations, possible solutions and current international practices regarding this issue - from Abhisam Software.
Minimum Ignition Energy (MIE) - In the following table MIE is quoted for flammable substances mixed with air. A reference is provided to indicate the source of the data. MIE values are provided  for guidance only. Please check references for specific measurement conditions - from Explosion Solutions.
Explosion Protection Fundamentals - An excellent document from the IEC detailing fundamentals of Explosion Protection.
Australian Hazardous Areas Selection Chart - A useful chart for the wall - from eflare.

The following papers and presentations are from the IDC Technologies "Hazardous Areas: Classifications and Equipment Conference 2007", these papers are recommended reading.
Electrical Equipment in Hazardous Areas - Field Inspections - Bill Rankin - This paper focuses on the problems which are directly related to the inspection process. It has been written from the perspective of the Ex inspection team who usually have no control over the design and installation process. It is acknowledged that the competency of the design and installation personnel will affect the quality of the installation that is to be inspected. The failure of Ex inspection campaigns can be attributed to four main areas:
- Poor planning of the Ex inspection activities
- Lack of competence of the Ex inspectors
- Lack of clarity of the inspectors’ roles
- Lack of clarity of the inspection scope
Ex Inspections—Potential Pitfalls - Alan Wallace- Inlec Engineering - Many, if not most, Ex inspection campaigns are grossly inefficient, and their
effectiveness is often questionable. This presentation discusses the four main reasons why Ex inspection campaigns fail to meet the clients’ expectations. It also offers recommendations to improve the quality and efficiency of Ex inspections.

The Application of Intrinsic Safety to Fieldbus Systems - Chris Towle Chairman: MTL Instruments Ltd - This excellent paper covers the technical aspects of FISCO, FNICO, Exe and Exi combination, Maintenance and Inspection along with Intrinsically Safe Ethernet.
Myths and Actual Practice with Industrial Data Communications and Hazardous Areas - Steve Mackay - IDC Technologies - This presentation covers Practical examination of data communications systems in hazardous areas for Ethernet, Foundation Fieldbus, Profibus or RS-485 along with Practical guidelines for best practice in designing your next industrial data communications system in a hazardous area.
The Current State of the IEC Intrinsically Safe Standards - Chris Towle - Chairman: MTL Instruments Ltd - A candid discussion on the IEC IS standards which includes IEC Organisation, Intrinsic Safety Standards, An Analysis of the Change from ‘nL’ to ‘ic’ and advice to the First-time Designer.
Changes to Certification and its Impact on Manufacturers - Des McDonell CSE-Ex Pty Ltd - This presentation covers product certification in Australia.
Gases and Vapours - Gases and Vapours (and Mists) mix more or less homogeneously with air and form flammable mixtures relatively quickly. While this is obvious for gases, vapours can travel very quickly and form flammable or explosive mixture with air in a very short time frame - from EPEE Consulting.
Flammable / Combustible Liquids
-While the dangers of flammable liquids are well known, combustible liquids can be as dangerous under certain conditions. The vapour space in storage tanks is a Zone 0 are even for combustible liquids. Should the ambient temperature approach the flash point of combustible liquid within 6 deg C, it has to be treated as if it were a flammable liquid - from EPEE Consulting.

The following papers and presentations are from the IDC Technologies "Hazardous Areas: Classifications and Equipment Conference 2009", these papers are recommended reading.
It’s Not Rocket Science Unless You Do It Wrong
- Dave Adams - Technical Advisor - Hazardous Locations Equipment: Canadian Standards Association International -  The certification of hazardous locations electrical equipment is changing, and will continue to change, for some time. There has never been a more confusing time for manufacturers, end-users, and certification agencies alike. This paper does not really have a point, or maybe it has several. While it provides answers, it will also raise new questions. It is really just a strung-together collection of miscellaneous observations, ramblings, and rants, garnered from 18 years in the business of certifying hazardous locations equipment.
Proper Grounding of Instrument and Control Systems in Hazardous Locations - Joe Zullo - Regional Sales Manager: MTL Americas - Grounding is defined as electrical equipment connected directly to mother earth, or to some conducting body that serves in place of the earth, such as the steel frame of a plant and its earth mat or the hull of a ship or oil drilling platform. Proper grounding is an essential component for safely and reliably operating electrical systems. Improper grounding methodology has the potential to bring disastrous results from both an operational as well as a safety standpoint. There are many different categories and types of grounding principles. This paper’s primary focus is to demonstrate proper grounding techniques for low voltage Instrument and Control Systems (IACS) that have been proven safe and reliable when employed in process control facilities.
The New Dimension of Intrinsic Safety - Rick Ogrodzinski - Project Leader - Global Projects Team, Process Automation Division: Pepperl + Fuchs, Inc -  intrinsic safety type of protection is currently achieved by limiting the available power. This limitation of power – usually to less than 2 W – provides intrinsic safety (Ex i) and is therefore mainly employed in the area of control and instrumentation in the power supply to actuators and sensors with low connected load. A significantly higher direct power with the simultaneous safeguarding of all the positive characteristics of intrinsic safety offers the user a new and essentially wider scope of application. These aims are achieved through DART technology (DART: Dynamic Arc Recognition and Termination). DART is a means of instantaneous tripping, which dynamically detects an undesired condition or a fault in the electrical system precisely as it occurs and instigates an immediate transition to a safe condition before any safety-critical parameters are exceeded. DART is based on the detection of fault conditions and their characteristic rate of rise of current.

The following papers and presentations are from the IDC Technologies "Hazardous Areas Conference 2015", these papers are recommended reading.
Hazardous Area Classification of Large Scale Plants - Paul Spresser - The hazardous area classification of a large scale plants can be problematical. A preference to use the generalised method of classification exists and its use is easily substantiated, for most aspects of these plants. However, unless some clear cut guidelines are established and allowance is made for a certain level of exceptions to the main adopted methodology, impractical solutions can result. Room must be left for use of the Source of Release by example and calculation methods for a practical classification solution – from EPEE consulting and IDC Technologies.
Explosive Hazardous Areas – In the Mining Environment - Aaron Drew - This paper discusses the effects on mine design, operation and maintenance as a result of the inclusion/use of chemicals that produce explosive atmospheres. A brief discussion in relation to the acceptance of EEHA principles within the mining community – the age old how can it be hazardous when you can eat it argument. Finally, mines are interesting in as much as they may have both dust and gaseous hazardous areas, what is the outcome when the hazardous zones overlap and a piece of equipment must be certified to both dust and gaseous requirements? Is such equipment readily available in the market? - from Primero Group and IDC Technologies.
Risk Based Prioritisation of Ex Equipment Non-Compliances - Alan Wallace - In most facilities, electrical equipment in hazardous areas must be installed in accordance with AS/NZS60079.14. Due to decay, damage, incorrect original installation, or maintenance, electrical installations in hazardous area may not be fully compliant with the installation standard.Many OpCos spend hundreds of thousands of dollars conducting periodic Ex inspection campaigns, in accordance with AS/NZS60079.17. It is usually not possible to rectify all of these Ex non-compliances immediately. This is especially true when there are many Ex non-compliances. The non-compliances are usually prioritised for rectification. However, in most cases there is no structured and justifiable basis for the prioritisation applied. This paper discusses a qualitative risk based approach to prioritisation to ensure that the Ex non-compliances creating the highest risk are addressed first. The methodology achieves a balance between being simple to apply vs. considering all of the factors that contribute to the risk – from Inlec Engineering Australasia
Training Competencies for Electrical Equipment in Hazardous Areas - Paul Egan - Within industry, there is much confusion, as whether it is a requirement to have nationally accredited competencies for any electrical work carried out with Electrical Equipment in Hazardous Areas (EEHA).The legislation in Western Australia calls up the Australian / New Zealand Standard 60079 series. AS/NZS Standard 60079-14 requires, anyone carrying out work in the areas of design, classification, installation, inspections and maintenance, be competent to the requirements of AS/NZS 4761:2008 Even though these standards clearly require certain competences to be able to carry out works in hazardous areas, there are many organisations that do not understand or don’t care to have their personnel correctly trained to these standards. It is also a requirement to have awareness training for anyone (non electrical) who is working in the hazardous area. There is also the issue of just obtaining the minimum required competencies, as this is often not enough. Further mentoring and milestone achievements are often required before a person can truly be deemed competent to carry out work in these areas. This presentation highlights the requirements for all training required and what training needs to be undertaken, to demonstrate competency in EEHA design, classification, installation, inspection and maintenance
Death by Standards - S. Srinivas Shastri - Technology has advanced significantly over the past several decades, and this has resulted in not only better materials of construction but also in tailor made instrumentation and tight process control. As accidents have occurred in the past (Piper Alpha, Bhopal, Flixborough, and other unfortunate events) there is a greater understanding of process systems and materials. All these advances have led to documenting best industry practice in the form of standards, codes and practices. Legislation has been implemented that often draws upon these standards, however, there application of the standards is not prescriptive. The interpretation and the application of standards is the role of the practicing engineer and s/he should draw upon wisdom in ensuring compliance and most critically safety of the operation. This paper has very few references as it is an ‘applied paper’, however it does draw heavily from the usual normative hazardous area classification standards relevant to Australia – AS/NZS 60079.10.1 and API RP 505 specifically. In the context of this paper these standards are those editions that were current as of 2014.This paper discusses two classification examples from a recent large LNG project.
Area Classification and Major Hazards - Lars Rogstadkjernet - Hazardous area classification and major hazards risk assessments have a common objective: to assure a plants operability and safety by preventing ignition. Yet, the two tasks are often carried out without much consideration of the other. Hazardous area classification is prescriptive and oriented toward high frequency events whereas risk analysis is usually performance oriented and focus on rare events. Legislative requirements for major hazards typically refer to rare events: those occurring every 10 000 or 100 000 years, with the requirement being that unacceptable events cannot occur more frequent than this. Consequently, the scenarios being of concern to the risk assessor can be much different to those normally thought of for zoning purposes even if they are somehow dealing with the same problem: preventing ignition. Ignition is a major factor in a risk analysis and a potent ignition source outside a classified area may be of crucial importance. Similarly there may be areas where classification is mandated but of lesser importance in the eyes of a risk assessor. A key point for this paper is ignition hazard beyond the boundaries of area classification. Case examples will be used to illustrate how ignition from non EX areas impact on risk as well as well as examples of where EX proofing is less critical – at least in the eyes of a risk assessor.
A Case Study: Hazardous Area Considerations for Diesel Storage in a Hot Climate - Daniel Bianchini, Justin Van Staden and Harrison Cox - Hazardous areas are most often associated with the storage and handling of flammable liquids. However, in certain circumstances hazardous areas can occur around combustible fuel installations. This paper explores a specific case study involving the above ground storage of diesel in a hot climate (Pilbara, WA) and investigates scenarios to inform the understanding as to when hazardous areas might occur. Issues reviewed include the relationship between ambient conditions and the temperature of the fuel being handled, spill scenarios, and the potential formation of sprays and mists.
Hazardous Area Classification: The Dangers of Using Standards for Determination of Hazard Zones - Kehinde Shaba, Colin Hickey - There are many benefits to using standards to determine the hazard radius in hazardous area classification applications. By codifying existing knowledge they ensure rapid and timely delivery of required results. However, they suffer from a number of limitations - chief of which is a lack of specificity. This paper discusses the pitfalls/challenges of using standards for establishing hazard radii and then discusses how they can be addressed by the use of detailed consequence modelling. A case study comparison of the two approaches is also outlined as well as the benefits of using a more targeted approach.
Machine Safety in Hazardous Areas - Ross De Rango – The principal interest of this paper is zoning. Other considerations of course need to be taken into account to ensure that equipment installed is safe for the location, but it is zoning that has the most impact in the context of design choices for machine safety systems in hazardous areas.

Fire and Explosion Protection of Electrical Installations with New Advanced Suppression Systems - Andrew Kim - Senior Research Officer - Fire Research Program, Institute for Research in Construction - National Research Council of Canada The National Research Council of Canada (NRC) has carried out projects to evaluate the fire and explosion protection effectiveness of new technologies technologies which will be examined and discussed.  There is a potential for a very large fire or explosion when using electrical equipment in areas where flammable gases could accumulate or in room containing power transformers. Recently, several new fire suppression technologies have been developed to provide protection in an environment with an explosive atmosphere or to provide suppression of a large fire involving electrical equipment, such as power transformers. In one project, the explosion suppression effectiveness of hybrid gas generators in providing safety to occupants in a compartment against a deflagration type explosion was evaluated. Hybrid gas generator systems combine gas generator technology with a liquid fire suppression agent. In another project, the effectiveness of a newly developed compressed-air-foam (CAF) system was evaluated to provide fire protection in power transformers. Thanks to the National Research Council Canada.
Comprehensive Global guide to Hazardous Locations -And boy is this comprehensive! It is an excellent technical resource from Cooper Crouse Hinds which includes virtually everything including: Basics of Explosion Protection, Area Classification, Methods of Explosion Protection, Equipment Selection, Installation & Wiring Practice.
Ex poster (inc  ATEX) -thanks to Endress + Hauser (
Flammable Risk- from Crowcon (
Flammable Material Characteristics  - From (
Hazardous Area Classification/ Flameproofing- From the UK Health and Safety Executive (
Hazardous Area Reference Chart - From Crouse-Hinds (
Installation of Electrical Equipment in Hazardous Areas - from GE
Extronics Wall Chart - Some Useful Ex Information here.
MTL Luton UK Technical Information - You will have to register to get access- it is quick, easy and worth it!
Flammable Facts Poster - This poster from MTL gives a quick look at the most important facts associated with Electrical Equipment in Hazardous Areas.
A Guide to Risk Based Assessments of In-situ Large Ex 'e' and Ex 'N' Machines -Whilst not free this guide provides a practical method to undertake a comparative evaluation of the risk of incendive discharges occurring in existing large Ex 'e' and Ex 'N' high voltage machines in potentially explosive atmospheres.

9.14 How Can You Manufacture Explosion-Proof Equipment and Systems to World-Class Safety Requirements? - Depending upon the Zone of usage, electrical, electronic and mechancial equipment intended for use in potentially hazardous environments must be independently evaluated for their impact on overall safety. The European Union’s ATEX Directive and the IECEx Certified Product Scheme are two assessment routes used for the safety of equipment used in such environments. This white paper provides an overview of these two routes and provides answers to frequently asked questions. You will have to register to download this paper from TÜV SÜD .

The Use of Aluminium in Hazardous Areas

Frictional Sparking Risks with Light Metals and their Alloys is very important and often misunderstood. This hazard is due to sparking when light metals and their alloys come into frictional contact with materials which are oxygen carriers, rust being the most common. Known as a thermite action, it can produce sparks capable of igniting a flammable gas or vapour. NO light metal alloy is permitted in a Zone 0 area. Fixed light metal alloy equipment is permitted in other zones subject to impact protection. Portable equipment of these materials is NOT permitted in Hazardous Areas unless equipment is otherwise protected (i.e. plastic coated or epoxy painted). A frequent breach of regulations can be seen with aluminium foil, aluminium Ladders, scaffolding, aluminium sunshades, aluminium paint and the "old style" aluminium hard hats.

The use of Mechanical Tools in Hazardous Areas - From time to time concern is expressed about the possible risk of frictional sparking caused by the use of steel tools in hazardous areas. This note attempts to put this risk in perspective and make a positive proposal on acceptable practice - from MTL.
Fact Sheet on the Use of Light Metals & Their Alloys - Light metals, most commonly aluminium, magnesium and titanium, and alloys containing them, are used in many industrial applications where lightness, hardness and ductility and resistance to corrosion are needed. They are widely considered to be near incapable of creating a frictional spark which is hot enough to ignite a flammable atmosphere. However, there are two exceptions to Electrical Equipment for Hazardous Areas - Classification, Design and Standards, this where light metal alloys can be potential ignition sources in flammable atmospheres (e.g. methane): (a) thermite reaction, and (b) incendive chips (titanium). Potentially hazardous light alloys are those in which the total weight of aluminium, magnesium and titanium together exceeds 15%, and/or in which the content of magnesium and titanium together exceeds6% by weight - from CANMET.

Analyser Room Explosion Protection

Explosion Protection for Process Analysis - Safe operation up to the explosion limit - Jürgen Poidl and Helmut Schulz - Gas analysers are used for the continuous on line measurement of the composition of process flows in chemical production systems. These measurements provide support to key process functions of controlling and monitoring the temperature, humidity, and chemical composition of gases and liquids.  In some cases, commercial considerations and demands are resulting in the operation of production processes in chemical plants increasingly close to the explosion limit. It is therefore essential that the explosion- protected gas analysers used for monitoring the explosion limit continuously supply the necessary and reliable data to the process control systems. Using the special safety systems it is possible to operate gas analysers, the electrical equipment and the safety devices even when the process conditions are close to the limit - from Stahl.

Certification of Diesel Engines in Hazardous Areas

Certification of Diesel Engines in Hazardous Areas - A useful technical information sheet from SIRA

Dust Explosion Protection

Basics of Dust Explosion Protection - This is a document of 32 pages packed with good information- From Stahl.
How to Make Sure Your Dust Collection System Complies with Combustible Dust Standards  - Tony Supine and Mike Walters - Combustible dust explosions are a risk in many areas of a plant, but one of the most common locations is the dust collection system. How do you know if your dust collection system complies? What do you do if it doesn’t? Are your employees at risk? What are the hazards and how do you identify them? The National Fire Protection Association (NFPA) sets standards and codes to protect buildings against fire and explosion risks, and the Occupational Safety & Health Administration (OSHA) is applying these standards with increasing vigilance. When it comes to combustible dust, several standards must be considered. This white paper reviews the current status of the OSHA National Emphasis Program for combustible dust, the NFPA standards that address how to prevent or limit explosion hazards, how to identify these hazards, and the types of equipment used to eliminate or control explosion hazards. We will also examine the most common shortfalls to compliance and how to avoid them - from Camfil.
Combustible Dust -Combustible dusts are not as well understood as a hazard as are, say, flammable gases and vapours. Ignition of combustible dusts can cause incredible destruction, usually due to the primary explosion raising the layers of dust, forming huge dust clouds which are ignited by the fires of the first explosion - from EPEE consulting.
The Hazards Associated with Combustible Dust - The hazards associated with the storage and handling of combustible dusts is often overlooked in comparison to those associated with flammable liquids and vapours. Indeed the risks associated with flammable liquids and vapours are generally well understood and appropriate control systems are in place to prevent releases and their ignition. In comparison, although many are aware of the possibility of explosions occurring from combustible dust, the controls implemented are rarely adequate - from Risk Tech

The Following Papers are from Explosion Solutions.
Electrostatic Ignition Hazards Associated with Flammable Substances in the Form of Gases , Vapours, Mists and Dusts -  M.Glor - The paper deals with the assessment of the electrostatic ignition hazards when flammable gases, liquids or powders are handled and processed in industry. It reviews the present state of knowledge in this field based on information available from literature, codes of practice and guidelines. In a short introduction the prerequisites for the ignition of a flammable atmosphere are described. The steps from charge separation to ignition of flammable atmospheres by discharges are outlined and the different types and incendivities of electrostatic discharges occurring in practice are discussed. Associated with the different flammable substances such as gases, liquids and powders and with the typical operations performed with these substances in industry, the electrostatic ignition hazards are reviewed. In addition the electrostatic hazards related to the different types of FIBCs are highlighted - from Explosion Solutions.  
Incendivity of Electrostatic Discharges in Dust Clouds - The Minimum Ignition Energy Problem - M. Bailey, P. Hooker and P. Caine - Minimum Ignition Energy of dust clouds is required to assess the electrostatic ignition risk. Recent studies are reported that indicate that the test methods in use to determine M.I.E. give markedly different values. The use of M.I.E. to define the incendivity of discharges from conductors and non-conductors is discussed and the value of data from present day tests is considered.
Frictional Ignition of Powders - Geoff Lunn- This paper is a review of the literature on the effects that frictional heating and sparking can have on combustible dusts, on the ways in which frictionally ignited dusts can burn, and on the methods by which combustion in burning dusts can ignite an explosive dust cloud or propagate into a more extensive dust accumulation.
Dust Explosion Protection Consistent with North American Practice - Helmut Greiner - This report describes how the European Standard  EN 61241-1 came into being and describes individual details of the design and  testing  requirements along with acceptance criteria.  

Australian Standards for Combustible Dust Atmospheres

AS/NZS 60079.10.2 - Explosive Atmospheres - Classification of Areas - Combustible Dust Atmospheres - The objective of this standard is to enable the identification and classification of areas where explosive dust atmospheres and combustible dust layers are present, in order to permit the proper assessment of ignition sources in such areas. This Standard is identical with, and has been reproduced from IEC 60079-10-2 Ed.1.0 (2009), Explosive atmospheres—Part 10-2: Classification of areas—Combustible dust atmospheres.

Equipment Protection Levels (EPLs)

Equipment Protection Levels (EPLs) : Not as Optional as you Think! - This paper from Inlec Engineering introduces the new concept of Equipment Protection Levels (EPLs) for hazardous area electrical equipment as introduced in the 2009 editions of AS/NZS60070.10.0, AS/NZS60079.14 and AS/NZS60079.17. It covers the impact that EPLs will have upon:
- Hazardous Area Classification
- Electrical Equipment Markings
- The selection and installation of electrical equipment and wiring systems for hazardous areas
Practitioners will need a good working understanding of this new 'alternative' approach, even if they chose not to apply it, because although the 'new' approach is optional, it impacts the use of the 'historical' method
Equipment Protection Levels and All That - One of the evil side effects of the ATEX Directive is that the IEC feels compelled to follow its more whimsical requirements. However the IEC must maintain its independence and consequently it follows similar principles but modifies the marking.The most recent manifestation of this phenomenon is the creation of Equipment Protection Levels (EPLs], which are the IEC equivalent of the ATEX categories - from MTL
Equipment Protection Level EPL: Extended Device Marking -Discover the importance of the new Equipment Protection Level (EPL) -  The selection of suitable apparatus plays an important role when setting up a plant in hazardous areas. Some of the main points include (a) Device functionality (b) Suitability for all anticipated ambient and operating conditions and (c) Explosion protection requirements - from Pepperl+Fuchs.
Equipment Protection Levels (EPLs] - which are the IEC equivalent of the ATEX categories, a discussion by MTL
Equipment Protection Level (EPL) - EN 60079-14 standard of March 2010 introduced a method for risk assessment that considers the equipment levels of protection (EPL). EPLs were introduced to allow an alternative approach to the methods currently used for the selection of Ex equipment. The traditional design approach assigns the appropriate types of protection for specific areas using statistical data, based on how is most likely or frequent an explosive atmosphere. EPL indicates the risk of ignition intrinsic to the equipment, independently from the type of protection adopted. It was recognized that it is advantageous to identify and mark all the products based on their intrinsic risk of ignition. This should make easier the equipment selection. This method is an alternative and not a substitute of the traditional one and so far has created some difficulty in understanding – from Cortem Group.  

Fibre Optics  - Their Use in Hazardous Areas

Ignition Risk Due to Optical Radiation in Hazardous Areas - Heino Bothe, Mario Graube and Ulrich Johannsmeyer - Optical systems are increasingly used in explosion hazardous areas. In terms of explosion protection, there are a number of advantages; on the one hand electrical sparking is not possible, and the electrical isolation realized by optical transmission media is often advantageous. However, on the usage of sources of optical radiation in hazardous areas it must be noted that radiation in the optical spectral range can produce a source of ignition, particularly if focused. There are primarily three different mechanisms that need to be considered. This excellent white paper from STAHL details technical details of the hazard and the concepts available to protect against the hazard - these are
Inherently Safe Optical Radiation “op is”
Protected Optical Radiation “op pr”
(3) Optical Systems with Interlock “op sh”

User Friendly Fibre Optic Networks in Hazardous Areas - Even for fibre optic networks, users must ensure that ignition is prevented if the cables lead through areas with explosive atmospheres where automation technology is connected. This is covered by IEC/EN 60079-0:2007 and mainly IEC/EN 60079-28:2006. Why optical radiation from fibre optic cables may cause a risk of ignition can be demonstrated easily: sunlight that falls through a magnifying glass onto an easily flammable object will quickly ignite it. The energy, which is focused onto a small spot, is much stronger in the focal point than in surrounding areas. And optical fibres do, after all, focus light onto a very small spot. In case of cable damage or an open plug connector, optical radiation can therefore cause an explosion – from STAHL
Safety of Optical Fibre Networks in Potentially Explosive Areas - Contrary to common assumption, fibre optic components also have to meet strict directives if they are to be deployed in explosion hazard areas, because even the luminous power emitted under certain circumstances represents a risk of explosion that should not be underestimated - from MICROSENS
Myths and Actual Practice with Industrial Data Communications and Hazardous Areas - Steve Mackay - Fibre optic cable can extend the distance of operation from 100m for copper to 2000 m depending on the type of fibre. However unfortunately even light can cause an explosion and due care has to be taken. There are three types of protection defined in IEC60079-28 standard: • Inherently safe optical radiation “op is” • Protected optical radiation “op pr” • Optical system with interlock “op sh” - from IDC.

IEC Standard IEC 60079-28 - Protection of Equipment and Transmission Systems using Optical Radiation

IEC Standard IEC 60079-28 - Protection of equipment and transmission systems using optical radiation - This part of IEC 60079 explains the potential ignition hazard from equipment using optical radiation intended for use in explosive gas atmospheres. It also covers equipment, which itself is located outside but its emitted optical radiation enters such atmospheres. It describes precautions and requirements to be taken when using optical radiation transmitting equipment in explosive gas atmospheres. You will need to purchase this standard.

Process Fluid Migration Along Cables

Rethink Process Seals - Craig McIntyre - Sealing Built into Instrumentation provides a number of advantages over traditional approaches - from Endress + Hauser
Process Seals, Secondary Seals, and “Single Seal” and “Dual Seal” Devices - Dave Adams  - A Process Seal is a device to prevent the migration of process fluids from the designed containment into the external electrical system. Electrical equipment with an interface in direct contact with process fluids under pressure must incorporate a “process seal” to prevent migration of the flammable fluid into the wiring system - from CPCA.

Electrical Equipment in Hazardous Areas Standards

Australian Standards for Electrical Apparatus in Hazardous Areas -From ICEweb
Australian Standards for Gas Detection/Ex- Equipment -From ICEweb  

Exd Immersion Heaters

Exd Immersion Heaters - Over the years it has been difficult to source Exd Certified immersion heaters and often this has led to a certification nightmare for those engineers responsible for the associated equipment packages. These IEC certified heaters may provide the solution - from Grimwood Heating.

Exd Weatherproofing 

The following technical articles are provided thanks to our valued sponsor Inlec Engineering
Exd Weatherproofing Alert
- Including the Use of Denso tape - thanks to Alan Wallace of Inlec Engineering

Other Electrical Equipment in Hazardous Area (Ex) Technical Papers

FISCO Intrinsically Safe Fieldbus Systems - This application note is a practical guide to the selection, installation and maintenance of equipment complying with the Fieldbus Intrinsically Safe Concept (FISCO). The document begins with a discussion of the origins of FISCO and an introduction to the main elements that should be considered when assembling FISCO systems. Later sections then develop each subject in more detail, with the intention of providing clear guidance to new and experienced Fieldbus users. From MTL. 
Fieldbus Non-Incendive Concept (FNICO) -Phil Saward (MTL)
EXia Intrinsically Safe Mobile Phone-At last a mobile phone that can be used in Australian Hazardous Areas, from dca intrinsically safe products (
The Safest Way to Calibrate - An introduction to intrinsically safe calibrators - There are industrial environments where calibrations should not only be made accurately and efficiently, but also safely. When safety becomes a top priority issue in calibration, intrinsically safe calibrators enter into the picture.
Reducing Ex Risk in Hospitals- When asked to name hazardous or explosive areas, most people will mention the oil and gas industry, mining and fuelling stations as obvious cases of high explosion risks. There are many more. Sugar refineries, flour mills, grain silos and the paper and textile sectors also belong in this category…as do hospitals. IECEx complements health-care certification programmes When asked to name hazardous or explosive areas, most people will mention the oil and gas industry, mining and fuelling stations as obvious cases of high explosion risks. There are many more. Sugar refineries, flour mills, grain silos and the paper and textile sectors also belong in this category…as do hospitals. High-risk areas in hospitals include storage rooms that contain flammable gas tanks and operating rooms and anterooms. Risks of fire and explosion are high in these areas because flammable gases are in abundant supply due to anaesthesia requirements. Operating rooms also have flammable materials that can fuel a fire, such as drapes, sponges and packaging. The main ignition sources are electrosurgical or laser equipment. Ignition of anaesthetic vapours can occur as a result of a spark due to unsuspected static electrification of the equipment. The use of oxygen, while a non-flammable gas, is an accelerant in fires and at high pressure poses similar risks.
Making Safe Waves in Hazardous Areas! - John Hartley - As wireless devices such as mobile phones and laptop computers become more reliable and cost effective, there is growing interest amongst the process industry as to the benefits to be found from enabling such devices to be used in hazardous areas. However, unlike most industries this is not a simple task. Installing wireless networks in hazardous areas requires careful, expert planning and execution. John Hartley, Managing Director of Extronics, explains the hazards posed by radio frequency sources and the issues involved when installing wireless networks in hazardous areas, and how to minimise the potential risk.

Installation, Maintenance and Inspection of Ex Equipment in Hazardous Areas

Installing Automation in Hazardous Areas - For most process plants, it’s not possible for all automation system components to be installed in non-hazardous areas. As a result, some form of protection is required to prevent fires and explosions that could occur when a hazardous gas and energy source combine. Fortunately, there are standards and associated products that if properly designed, installed and maintained virtually eliminate the risk of an accidental explosion in hazardous areas.  Although existing standards are proven in use, these standards aren’t harmonized worldwide. Most  of the world uses the IEC Zone classification system, while much of North America relies on the NEMA Class and Division system. This paper will compare, contrast and explain the IEC and NEMA standards. This paper will then explain how to protect automation system components using either standard via one of the three main methods of protection: Energy Limiting,Containment and Segregation - from Advantech and
Maintaining Installations In Hazardous Areas - Thomas Klatt and Andreas Hennecke  - Flameproof enclosure (Ex d) and intrinsic safety (Ex i) are very common equipment protection methods in Process Automation.  One reason to use Exd is the amount of energy which could not be provided via Exi. This disadvantage has gone with the introduction of intrinsically safe, dynamic methods of arc prevention such as DART or Power-i. This white paper shows that when using intrinsic safety, installation, maintenance and inspection costs will be reduced.  This paper addresses decision makers and professionals responsible for automation systems in hazardous areas. A good understanding of the principles of explosion protection is required – from PEPPERL+FUCHS.  
Practitioner's Handbook - Electrical Installation, Inspection and Maintenance in Potentially Explosive Atmospheres - Whilst not free this publication from EEMUA offers guidance for safe electrical installation work in potentially explosive atmospheres, in such areas as petroleum and petrochemical plants, processing industries, power plants, fuel filling stations and more, when the failure to adopt safe working practices could result in the ignition of flammable gases or combustible dusts. This fifth edition provides a significant update to the chapter specific to installations in garage forecourts and similar places where flammable materials are stored, used or dispensed. It now deals with all types of fuel filling stations, including those dispensing Autogas besides petrol and diesel fuels. The publication is closely associated with the CompEx® training and competency assessment scheme which provides trainees with essential knowledge and practical skills for safe working in potentially explosive atmospheres.
Ex d Enclosures: Understanding the Standards - Toni Ott - When specifying explosion-proof (Ex d) enclosures to house electrical apparatus for use in explosive atmospheres, engineers need to understand the implications of modifying the enclosure as part of the certified equipment prior to and after installation - from Control Engineering.
Periodic Inspection of HA equipment - Part of the DSEAR regulations is to conduct an inspection of the existing equipment in hazardous areas, to confirm that it has been designed, constructed, installed, maintained and operated in such a way as to minimise the risk of an explosion. This typically occurs once the site has been classified - from Sira Certification.  
Inspections, Documentation and Remediation
- While the maximum inspection frequency quoted by AS/NZS 2381.1 is 3 years, it is not recommended that such a great inspection interval be adopted - from EPEE Consulting.

Mobile Solutions for Hazardous Areas

Thanks to our sponsor TRANSTEK and ECOM Mobile Safety for the Following Technical Information. They supply a range of really neat devices including Intrinsically Safe Mobile Phones, Mobile Computing, Portable Lighting, Measurement and Calibration and Lone Worker Protection. 
Mobile Solutions for Hazardous Environments -This webinar details the basics of explosion protection and then covers potential benefits which can be achieved by deploying mobile computing solutions in hazardous areas to achieve a Return on Investment or RoI.
WWAN - Expanded Wireless Connectivity - More than 60% of manufacturers have the need for intrinsically safe devices within hazardous environments like oil & gas and the chemical and pharmaceutical industries. this webinar details mobile solutions, merging safety with performance where there are opportunities to help grow your profits.


ATEX is the name commonly given to the framework for controlling explosive atmospheres and the standards of equipment and protective systems used in them. It is based on the requirements of two European Directives.

ABB’s ATEX jargon buster - Explains the terminology users are likely to encounter when purchasing equipment for hazardous areas.
ATEX and Explosive Atmospheres - Explosive atmospheres in the workplace can be caused by flammable gases, mists or vapours or by combustible dusts. Explosions can cause loss of life and serious injuries as well as significant damage. These pages from the UK HSE will tell you more about explosive atmospheres and ATEX:
ATEX Questions and Answers - This Technical Information sheet from Control and Instrumentation covers ATEX, ATEX Directive, What ATEX applies to, Product Compliance and Marking - from Control and Instrumentation.

ATEX Directives

The ATEX Directive - The ATEX directive consists of two EU directives describing what equipment and work environment is allowed in an environment with an explosive atmosphere – from Wikipedia
ATEX Directive 94/9/EC - European Directives - This white paper from ASCO details the objectives of the directives.
ATEX 137- The use directive from SIRA
The Full Version of the ATEX Directive - from Extronics


The objective of the IECEx Scheme is to facilitate international trade in electrical equipment intended for use in explosive atmospheres (Ex equipment). The IECEx Scheme provides the means for manufacturers of Ex equipment to obtain certificates of conformity that will be accepted at national level in all participating countries.

IECEx 01 IEC Scheme for Certification to Standards relating to Equipment for use in Explosive Atmospheres (IECEx Scheme) – Basic Rules
IECEx 02 IEC Scheme for Certification to Standards for Electrical Equipment for Explosive Atmospheres (IECEx Scheme)- Rules of Procedure

IECEx Standards - The IECEx Scheme is based on the use of specific international IEC Standards for type of protection of Ex equipment.
The ExTR Database- This database provides an official listing of IECEx Ex Test Reports issued in accordance with the scheme rules, IECEx 02
The IECEx Scheme - Description from the National Electrical Manufacturers Association
Explosive Atmospheres- A useful bulletin from IECex

Wireless Considerations in Hazardous Areas

Resilient Wireless Ethernet on an FPSO - The need to provide Ethernet connectivity to locations round production plant or other facilities is becoming more common place due to the fact that most modern control and instrumentation equipment is now supplied with an Ethernet interface as the primary means of communicating with the device. In many cases it is simply a matter of running an Ethernet cable from the switch to the device as this more often than not provides power as well using the 802.3af POE standard. From Extronics.
Making Safe Waves in Hazardous Areas White Paper - As wireless devices such as mobile phones and laptop computers become more reliable and cost effective, there is growing interest amongst the process industry as to the benefits to be found from enabling such devices to be used in hazardous areas. However, unlike most industries this is not a simple task. Installing wireless networks in hazardous areas requires careful, expert planning and execution. From Extronics.

E-learning course on Hazardous Area Instrumentation - From Abhisam Software - Hazardous areas comprise a large portion of most petrochemical plants, refineries, oil tank farms and many chemical plants. The instrumentation, control systems and electrical systems used in these hazardous or classified locations is designed specially to prevent dangerous incidents. However, unfortunately, many people are unaware of the methods of area classification, methods of protection, maintenance & installation of this kind of equipment- this course addresses and covers;
  • Basic Concepts - History of  hazardous areas, Fire triangle, flash point, LEL & UEL
  • Classification (Area, Material, Temperature), concepts of area classification, material classification, national and International standards
  • Methods of Protection (Explosionproof, Intrinsic Safety, Increased safety, Pressurization and others) - How Protection Techniques like explosion proofing  & Intrinsic Safety actually work
  • Certification & Labeling- Symbols and correct Hazardous Area use of Ex Marked Equipment
  • Implementing Fieldbus  in Hazardous Areas, FISCO and FNICO in fieldbus systems.
  • Inspections & Maintenance- Details the requirements for ongoing inspection and maintenance

On Line Hazardous Areas Ex Newsletters and Journals

HazardEx: The Journal - A bi-monthly publication distributed to 8,500 readers in the months of January, March, May, July, September and November.

Static Electricity Ignition Hazards

The Following are from Newson Gale
Achieving Safe Tanker Truck Loading / Unloading - The loading and unloading of tank trucks containing flammable or combustible products, has long been recognized as one of the most serious fire and explosion risks for hazardous industry operations. A study conducted by the American Petroleum Institute in 1967, for example, identified static discharges as being responsible for more than 60 incidents in tank truck loading operations. Since then more stringent preventive standards have been developed and significant advancements have been made in the technology of static electric discharge prevention. Yet accidents traced to static electric discharges still occur with sometimes tragic results.
Static Grounding Clamps & Cables, Key Factors Too Often Overlooked -Michael O’Brien - According to reports from NFPA in the Unites States and from HSE in the UK and continental Europe, reports of static electricity incidents are much more common that one would expect, given that simple and reliable means of prevention is readily at hand.
You Don’t have to be a Rocket Scientist… To Guard against Static Electricity Hazards - For the person who is responsible for the safety of employees, colleagues, plant equipment and plant property, one of the most potentially confusing aspects of providing a safe operating environment is determining if the manufacturing or handling processes have the potential to discharge static sparks into flammable or combustible atmospheres.
Controlling Static Hazards is Key to Preventing Combustible Cloud Explosions - Michael O’Brien - Recent studies covering plants in the U.S., UK and Germany show that controlling static electricity build-up is the key to preventing combustible cloud explosions. In the U.S. alone during the period 1980 to 2005 The Chemical Safety Board reported 281 explosions caused by ignitable combustible dust atmospheres. They resulted in 199 fatalities and 718 injuries. Similar data was compiled in the UK, where the Health and Safety Executive reported 303 explosions over a nine year period. And German records show 426 similar incidents over a 20 year period.
Static Electricity: The Hidden Danger in Hazardous Area - National Fire Protection Association (NFPA) codes and guidelines highlight safe working practices in hazardous areas, and specifically how to control static electricity, which in many cases is capable of providing the ignition source for a fire or explosion.
Road Tanker Earthing - The loading and unloading of road tankers with flammable and combustible products, presents one of the most serious fire and explosion risks for site operations within the hazardous process industries. A study conducted by the API in 1967 identified static discharges as being responsible for over 60 incidents in road tanker loading operations and demonstrates just how long this potential threat has been acknowledged. The natural presence of static electricity in product transfer operations, combined with its associated ignition hazards, ensures that regulators take static control precautions for road tankers very seriously - from Newson Gale.
Technical Articles on Static Control - This link from Newson Gale contains in-depth technical information that enables you to research static control hazards that may pose an ignition risk for your manufacturing and distribution processes.

Electrical Equipment  in Hazardous Areas (EEHA)  - Training and Competency

EEMUA CompEx® Growth Confirms Status as the World's Pre-eminent IEC 'Ex' Personnel Competence Scheme - Over 32,000 Certificates of Core Competency now issued! EEMUA CompEx®, the world's pre-eminent scheme for certifying competency of personnel for IEC 'Ex' hazardous area working, has passed a new milestone in recent weeks with more than thirty-two thousand (32,000) CompEx Certificates of Core Competency now issued since the scheme's inception.This latest achievement underlines the position of CompEx as by far the world's most important international 'Ex' personnel certification scheme recognising core competency for safe working in potentially hazardous flammable or explosive atmospheres. Since it was introduced in the 1990s, CompEx has grown strongly every year due to the unique characteristics of the scheme:

Find more information here.

Electrical Equipment  in Hazardous Areas (EEHA) - This post-trade course provides qualified electrical mechanics with the skills and knowledge to work in the field of Electrical Equipment in Hazardous Areas (EEHA) - from Queensland TAFE.