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HazLoc Primer

An introduction to the hazardous location market

Despite of its crucial importance to the safety of equipment and personnel, the hazardous location (HazLoc) market is poorly understood outside the small circle of people who are directly involved with it. Even insiders often struggle with describing what "HazLoc" really means, what "intrinsic safety" is, and what all the various classifications pertaining to hazardous location safety mean. In general, it's assumed that "HazLoc" is something military or something with poisons and perhaps industrial waste.

In fact, "hazardous locations" are those where flammable liquids, vapors, gases, and other combustibles are, or may be, present, and "intrinsic safety" relates to the property of electrical equipment that may be may be used or installed in such areas. Mobile computers are electrical equipment, and they are increasingly deployed in various HazLoc areas. Which means this is a potentially very attractive market for manufacturers and integrators of rugged mobile computing gear, and a considerable concern of agencies and enterprises who need to procure such equipment.

At we're seeing a need to bring some clarity to this issue. It's a potentially significant opportunity for our industry, especially since this is one areas where just getting some inexpensive consumer gear from Best Buy just won't do. Given the complexity of defining hazardous locations as well as the widespread uncertainty of what's required of electrical equipment, and specifically mobile computers, to operate in such areas, we reached out to experts in this field. compiled the following questions with the intent of bringing clarity into the area of designing and deploying enterprise mobility solutions in various types of hazardous locations. BARTEC, a world leader in explosion protection, was kind enough to supply an expert to answer our questions.

-- Conrad H. Blickenstorfer, Editor-in-Chief,, 12/2016


1. What, exactly, does "hazardous location" mean?

Mirko Lampe (Strategic Marketing Manager, International — Automation & Enterprise Mobility, BARTEC): Hazardous locations are areas where flammable liquids, vapors, gases, and dusts are present and form potentially explosive atmospheres (under atmospheric conditions).

Potentially explosive atmospheres are classified differently depending on the frequency and duration of the explosive atmosphere.

Flammable liquids, vapors, gases, and dusts are also classified depending on ignition temperature in temperature class and depending on ignition energy in explosion groups.

2. What does "intrinsically safe" mean?

Lampe: Intrinsically safe is a protection method for electrical equipment. Intrinsically safe equipment is based on intrinsically safe circuits. These are circuits in which no spark or thermal effect occurring under the test conditions laid down in the standard can ignite the explosive atmosphere. The test conditions cover normal operation and certain fault conditions stipulated in the standard. Voltage and current are kept permanently so low that no impermissible temperatures can occur, and, in the event of open circuit or short-circuit, sparks and electric arcs possess so little energy that they are unable to ignite an explosive atmosphere.

3. Who requires safe devices?

Lampe: Anyone operating electronic equipment within hazardous locations. These include, but are not limited to, Oil & Gas, Refinery, Chemical, Pharma, On- and Offshore, Power, and Mining.

4. Who classifies locations?

Lampe: The operator of a refinery or offshore platform has to define a hazardous location. They classify locations into different zones depending on type of atmosphere. All electronic equipment installed within these locations, also known as ex-areas, must be explosion-proof according to the governing requirements of the classified location.

5. What measures needs to be taken in hazardous locations?

Lampe: The operator must take appropriate measures depending on the operation to ensure the health and safety of workers in accordance with the following basic principles:
  • Prevent explosive atmospheres from forming
  • If it is not possible to prevent formation of explosive atmospheres due to the nature of the operations, you will need to avoid ignition of explosive atmospheres by securing possible sources of ignition, such as electronics.

6. How does one make a device "safe" for hazardous locations?

Lampe: Safety measures need to comply with the pertaining requirements of the Ex area. Implement conformity according to relevant directives and certification process with notified body. A notified body is a third party that controls and approves the product.

7. What classification systems are there?

Lampe: There are a variety of national entities that handle these classifications.

In Europe, ATEX (the European ATEX directive, ATEX coming from the French ATmospheres EXplosives), the IECEx System of the International Electrotechnical Commission, and various national regulations define hazardous areas as "zones." Zones 0, 1, 2 describe areas with gasses always/likely/occasionally present, and Zones 20, 21, 22 areas where flammable dust is always/likely/occasionally present.

In the United States, NEC (North American National Electric Code) defines hazardous locations as "divisions." You may see references to Division 1 (substance present all the time) or Division 2 (substance present occasionally).

For a detailed description of the entire classification system, also see BARTEC's Basic Concepts for Explosion Protection document.

8. Who classifies devices?

Lampe: Manufacturer classify their devices according to the Ex system covering the equipment in question:
  • ATEX: product categories 1G, 2G, 3G or 1D, 2D, 3D and EPLs
  • IECEx: EPLs Ga, Gb, Gc or Da, Db, Dc
  • NEC: specific equipment is assigned to a specific division

9. What do the codes mean (equipment)?

Lampe: Here's an example of how ATEX uses codes:

II 2G — II refers to the equipment group, 2 to the equipment category, and G indicates the type of flammable material (G is for gas, D for dust).

Ex ib IIC T4 Gb NB10ATEX1234 XEx ib means it's an electrical device according to EN/IEC, with the protection type intrinsic safety; II C is the ex subgroup (can be A, B, or C); T4 stands for the temperature class (can be from 1 to 6); Gb stands for Gas (can be Dust), and b is the equipment protection leve;l (can be a, b, or c); NB10ATEX1234 describes the type of the examination certificate; and X says that there are specific conditions as detailed in the certificate.

10. Why do we use different protection methods for electrical equipment?

Lampe: Different protection methods for electrical equipment have been developed to allow the use of electrical products in potentially explosive atmospheres, to create efficient solutions and to satisfy technical progress. The essential criteria for selecting one or combinations of protection methods, e.g. flameproof Ex d or pressurization Ex p or increased safety Ex e or intrinsic safety Ex i is the required technical solution, the installation or handling of the equipment, the operational system, the national regulations and standards (EN, NEC, IEC etc.).

11. Are standard rugged mobile devices safe to use in hazardous locations?

Lampe: They are only safe if they have no potential ignition source and designed according to the requirements for the given hazardous location. Equipment within a ex-area needs to be tested and certified so that under no circumstances will enough energy be emitted to cause an explosion. Rugged is not Ex-proof.

12. Can regular devices be retrofitted for use in hazardous locations?

Lampe: Theoretically yes, but it requires significant effort. Safety requirements need to be identified, designed, implemented, tested, and certified. It is far more practical (and more cost-efficient in the long run) to go with products specifically designed from scratch for use in different hazardous location areas.