Zone 2 - Explosive atmospheres are unlikely to occur or present only infrequently and for a short period only. In this system, two bare wires were run along the length of a drift, and any miner desiring to signal the surface would momentarily touch the wires to each other or bridge the wires with a metal tool. August 2018 For liquids, gases and vapours: Zone 0, Zone 1 and Zone 2. Area classification documentations are reviewed and updated to reflect process changes. In 29 CFR 1910.307(c)(2)(ii), OSHA requires all equipment used in a hazardous location to be marked with the class, group and operating temperature or temperature range for which it is approved. Electrical equipment installed in such locations can provide an ignition source, due to electrical arcing, or high temperatures. Directly adjacent on the label one will find the mark of the listing agency. These generally give rise to areas classied as Zones 0, 1, and 2 respectively. Please read AddThis Privacy for more information. There are four zones in the IEC classification system: Zone 0: An area in which an explosive atmosphere is present continuously or for long periods. This can be achieved by blanketing with nitrogen or carbondioxide. Zone 1 is an area that is classified 'as a place in which an explosive atmosphere consisting of a mixture with air or flammable substances in the form of gas, vapours and mists is likely to occur occasionally during normal operation', whereas Zone 2 is an area that is classified 'as a place in which an explosive atmosphere consisting of a mixture Dust or other small particles suspended in air can explode. Comparisons between the two systems are not easily accomplished. 2: For the requirements for electrical and electronic. All areas in the facility that are not Zone 0, Zone 1, or Zone 2 are considered unclassified. Choose the right method for Hazardous Area Classification! Electric equipment depending on the protection techniques described by paragraph (g)(3)(i) of this section may not be suitable for use at temperatures lower than -20 C (-4 F) unless they are approved for use at lower temperatures. July 2021 d : HA - ha ea OA - oa Area classification - Divisions vs. zones Continuous hazard Intermittent hazard Hazard under abnormal conditions Zone 0 Zone 1 Zone 2 Division 1 Division 1 Division 2 Hazardous locations - CEC classifications Class I Equipment is non-incendive or non-sparking. Safety is ensured in the event of frequently occurring disturbances or equipment faults which normally have to be taken into account. Therefore, it is very important to make sure that you are using a suitable luminaire for your application by choosing your fitting based on its suitability for the Zone in which it will be located. Also known as non-hazardous or ordinary locations, these locations are determined to be neither Class I, Division 1 or Division 2; Zone 0, Zone 1 or Zone 2; or any combination thereof. Protecting against fire and explosion is of interest for both personnel safety as well as reliability reasons. Where pyrophoric materials are the only materials used or handled, these locations need not be classified. to EN 1127-1): After the hazard area classification is completed, then the ignition assessment starts. Refrigerated Container Within the European Union, these are defined by IEC/EN standards (IEC/EN 60079-10-1 or 2) as directed by ATEX. Motors, lighting, junction boxes, electronic equipment, This method, being by definition special, has no specific rules. September 2022 Empirical testing is done to determine parameters such as the maximum experimental safe gap (MESG), minimum igniting current (MIC) ratio, explosion pressure and time to peak pressure, spontaneous ignition temperature, and maximum rate of pressure rise. The plan may contain the list of chemicals with their group and temperature rating. 2: This classification includes, Informational Note No. of the autoignition temperature of the hazardous atmosphere. Marking "EEx d" in Accordance with EN 50 0 14 and 50 018 . NEC Div 1 Zone 1 Div 2 Zone 2Flammable during normal operation Most Safer Zone IEC Zone 0 DESRIPTIONHighly Flammable for long period DEFINITIONFlammable atmosphere present continuously (Typically 1000 hours / year). National Electrical Code (NEC) and the 1998 Canadian Electrical Code (CEC) now recognize the use of the Zone system for classification of hazardous areas. Class II combustible dusts are grouped into one of three (3) groups: E combustible metal dusts, F combustible carbonaceous dusts or G other combustible dusts. * Zone 1 a location in which explosive gas atmospheres are likely to occur during normal operation, or which is adjacent to a Zone 0 location. Atmosphere containing a flammable gas, a flammable liquid produced vapor, or a combustible liquid produced vapor mixed with air that may burn or explode, having either a MESG (Maximum Experimental Safe Gap)1) value less than or equal to 0.45 mm or aMIC (Minimum Igniting Current)2) ratio less than or equal to 0.40 - such as hydrogen or fuel and combustible process gases containing more than 30% hydrogen by volume - or gases of equivalent hazard such as butadiene, ethylene oxide, propylene oxide and acrolein. Unlike ATEX which uses numbers to define the safety "Category" of equipment, namely (1,2 3), the IEC continued to utilise the method used for defining the safe levels of intrinsic safety namely "a" for zone 0, "b" for zone 1 and "c" for zone 2 and apply this Equipment Level of Protection to all equipment for use in hazardous areas since 2009. Zone 1 . Whenever you are filling up your tank you are standing in a Zone 1 hazardous area. The IEC 60079 standard set has been adapted for use in Australia and New Zealand and is published as the AS/NZS 60079 standard set. The following content is only related to flammable substances and not to pyrotechnic substances or other instable substances, among those who can decompose. A Zone 0 location is a location in which one of the following . Atmospheres containing acetylene, hydrogen, carbon disulphide or gases and vapors of equivalent hazard. For explosion hazards caused by flammable liquids or gases, the following zones are defined: So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. Equipment shall be approved not only for the class of location, but also for the ignitable or combustible properties of the specific gas, vapor, dust, or fiber that will be present. There are several ways of how to perform hazardous area classification, all described in several standards or codes of practise. Employers may use the zone classification system as an alternative to the division classification system for electric and electronic equipment and wiring for all voltage in Class I, Zone 0, Zone 1, and Zone 2 hazardous (classified) locations where fire or explosion hazards may exist due to flammable gases, vapors, or liquids. Many items of EEx rated equipment will employ more than one method of protection in different components of the apparatus. Wide known is that al electrical equipment within hazardous areas must be Ex certified for use in the appropriate hazardous area (zone or class/division). Class II combustible dusts are grouped into one of three (3) groups: E combustible metal dusts, F combustible carbonaceous dusts or G other combustible dusts. Note to paragraph (c)(2)(i) of this section: NFPA 70, the National Electrical Code, lists or defines hazardous gases, vapors, and dusts by "Groups" characterized by their ignitable or combustible properties. RP 505 is referred to as the zone system. September 2018 The CE mark is complemented with the Ex mark: A yellow-filled hexagon with the Greek letters (epsilon chi), followed by the Group, Category, and, if Group II, G or D (gas or dust). Guidance on assessment of hazards is given in NFPA497 (explosive gas) and NFPA499 (dust). An area where combustible dusts or ignitable fibers and flyings are not likely to occur under normal operating conditions and do so only for a short period of time. Groups A, B, C, and D are for gases (Class I only). | For Dust this would be Zone 21. Classification of Hazardous Areas 0 100 200 300 400 500 600 T1 >450C T2 >300C 450C T3 >200C 300C T4 >135C 200C . Each room, section, or area shall be considered individually in determining its classification. Zone 0 - Explosive atmospheres present continuously long periods or frequently. . Such properties include flame temperature, minimum ignition energy, upper and lower explosive limits, and molecular weight. CLASSIFIED LOCATIONS: AREA CLASSIFICATION: AREA CLASSES: AREA GROUPS: LOCATION AS PER DIVISIONS: DIVISION 1 - Class I, Division 1 hazardous locations are defined (as per NEC code Article 500) as follows: DIVISION 2 - Class I Division 2 Locations are as follows: Area Classification by ZONES: DEFINITIONS: HAZARDOUS LOCATIONS: This leads to a lot of the confusion in the global marketplace because certifying equipment to these different systems can be time consuming and expensive, so many companies may only certify to one or the other. October 2019 The value is represented is volume percentage of oxygen. This means that the electrical equipment is safe for use within these area by applying special protection strategies. Class I Zone 2 Hazardous Areas. Group defines the type of the hazardous material in the surrounding atmosphere. Shown below is a summary of the applicable NEC Articles to reference to ensure the proper requirements are applied. Class I: hazardous because flammable gases or vapors are present in the air in quantities sufficient to produce explosive or ignitable mixtures: . Determining the Class, Division and Group or Zone and Group is critical to correctly applying the requirements for a given hazardous location. Outside of the United States, the IEC uses two different classifications: Gas & Vapor (Zones 0, 1, or 2) Dust (Zones 20, 21, or 22) Step 2: The next step is to determine how often the hazardous substance (s) is/are present. Area classification is not simply intended to identify hazardous areas on process plants where design has already been completed using only operational and economic factors as influence,. Electrical equipment can and does cause fires and/or explosions in certain atmospheres. An area where combustible dusts or ignitable fibers and flyings are present continuously or for long periods of time. 0. April 2021 Zone 1 is an area in which an explosive atmosphere is likely to occur occasionally in normal operation. >> NEC: Class II, Division 1, Group F. | IEC: Zone 20, Group IIC. So a zone 0 is the most hazardous zone and a zone 2 is a less hazardous zone. September 2019 CUTTING SKIPS . That flammable gas or vapor . FREEZER PROCESS OF CONTAINER Many people have heard terms like Class I, Division 2, Group E, or ATEX zone 21 but many of our customers only know what certification they require with little understanding of what they mean, so we thought it would be appropriate to write a blog post to help customers understand the broader implications of these terms. Equipment that is listed for a Zone 0 location may be installed in a Zone 1 or Zone 2 location of the same gas or vapor. Then, the level of risk of an explosion is based on the frequency and duration of the occurrence of an explosive atmosphere. The following Equipment Groups and Categories are applicable: Equipment in this category is only intended for use in the underground areas of mines, as well as those areas of surface installations of such mines endangered by firedamp and/or combustible dusts. In Northerm America, instead of the zone classification system, the Class/Division system is used. This level of risk is represented by classifying the hazardous area as Zone 0, Zone 1 or Zone 2 (for gas, vapour and mist atmospheres) or Zone 21 or Zone 22 for dust atmospheres. This concentration is substance specific and lies normally somewhere between the LEL and UEL. As mentioned, the first important step of achieving a safe work environment in relation to explosion safety is to identify and classify those areas, where a concentration of flammable gases or vapors within the flammable range can be present. To prevent explosions from happening in harsh environments whereby flammable gases or combustible dusts are present directives and guidelines are put in place to protect both the public, workforce, and environment. Atmosphere containing flammable gas, flammable liquid produced vapor, or combustible liquid produced vapor mixed with air that may burn or explode, having either a MESG value greater than 0.75 mm or a MIC ratio greater than 0.80 - such as gasoline, acetone, ammonia, benzene, butane, ethanol, hexane, methanol, methane, vinyl chloride, natural gas, naphtha, propane or gases of equivalent hazard. Equipment in this category is intended for use in areas in which explosive atmospheres caused by gases, vapours, mists or air/dust mixtures are likely to occur occasionally. Documentation requirements likewise vary. For non-ambient conditions, like process reactors or other enclosed systems, the Limiting Oxygen Concentration is often used for the prevention of explosive atmospheres within those enclosed areas. Reefer Container A: When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. Hazardous classified locations are areas where the possibility of fire or explosion hazards may exist under normal or abnormal conditions because of the presence of flammable, combustible or ignitable gases, vapors, liquids, dust, or fibers/flyings. Enclosures can be pressurized with clean air or inert gas, displacing any hazardous substance. It may exist because of repair, maintenance operations, or leakage. When equipment must be placed in a hazardous location, it can be designed to reduce the risk of fire or explosion. These would be then labeled with each of the individual methods. Zone 0 (hazardous area) An area in which an explosive gas-air mixture is continuously present or present for long periods. January 2023 (1) Zone 0. Pressurised Container Atmospheres containing propane, acetone, benzene, butane, methane, petrol, hexane, paint solvents or gases and vapors of equivalent hazard. IEC 60079-10-1 covers classification of explosive gas atmospheres, and IEC 60079-10-2 explosive dust. The types of protection are subdivided into several sub classes, linked to EPL: ma and mb, px, py and pz, ia, ib and ic. the National Fire Protection Association (NFPA) 70, National Electric Code(NEC). When the concentration of gas or vapor is above the UEL the gas mixture is too rich to burn. The specific hazardous materials within each group and their automatic ignition temperatures can be found in Article 500 of the National Electrical Code and in NFPA 497. Encapsulation "m" -- This protection technique is permitted for equipment in the Class I, Zone 1 locations for which it is approved. In Europe and the rest of the world - but also more and more in North America - the Zone system is used. Ignition sources can be divided in 13 categories (acc. Zone 0, 1, and 2 locations shall include those specified in 505.5 (B) (1), (B) (2), and (B) (3). MCC Shelter of Hazardous areas are those defined as areas of potential explosion risk due to the presence of flammable gas or vapor. 1.1 Scope. Zone 2 Explosive Mixtures not likely to occur /occur short duration in normal operation (lt10 Hrs/ Yr). Substance properties are specific for the amount of fuel needed to get an explosion when all other conditions are met. In some cases, it must be certified as meeting that standard. Where there is potential for an explosive atmosphere, special precautions are needed to prevent fires and explosions. IECEx Karandikar Certification The NEMA enclosure rating or IP code may also be indicated, but it is usually independent of the Classified Area suitability. February 2023 [4], Flammability of combustible liquids are defined by their flash-point. The Class/Division/Group system is based on Article 500 of the National Electrical Code (NEC) where. Container Accessories A Zone defines the general nature - if it is a gas or dust - and the probability of hazardous material being present in an ignitable concentration in the surrounding atmosphere. Each chemical gas or vapour used in industry is classified into a gas group. A high level of protection is ensured. Zones. In recent years also the EPL is specified for several kinds of protection. NEC has created an Americanized version of the IEC/CENELEC Zone system in a stand-alone article (Article 505). NEGATIVE PRESSURE And safety must be guaranteed in the case of two faults occurring independently of each other. Group II is for explosive gases (Zone 0, 1 and 2) and Group III is for explosive dusts (Zone 20, 21 and 22). Within a working area or installation an ignition can be created by many factors. When comparing Divisions and Zones, Division 2 is equivalent to Zone 2, but Division 1 is equivalent to either Zone 0 or 1. January 2022 eg Production Area, area surrounding zone 0. The lower explosion limit of a substance is the lowest concentration (in volume percentages for gases and liquids) of a gas or a vapor in air of producing a flash of fire in the presence of an ignition source. Therefor Hazardous Area Classification (HAC) is the first important step in achieving an explosion safe installation or work environment. Hazardous Areas - North America Classification, international method of area classification, Protection Techniques for Hazardous Areas - North America, Hazardous because combustible or conductive, Atmosphere containing combustible metal dusts, including. National Electric Code 2020 edition National Fire Protection Association. Type of protection "n" -- This protection technique is permitted for equipment in the Class I, Zone 2 locations for which it is approved. 2: For Group IIIC combustible dusts or metal combustible fibers/flyings, there shall only be Zone 20 or 21 locations. Class I, Zone 0 or Zone 1 locations may not abut Class I, Division 1 or Division 2 locations. August 2020 Coal mines, grain mills, elevators, and similar facilities likewise present the risk of a clouds of dust. The choice of which standard to use for the hazardous area classification is something which is very important. Upon detection, appropriate action is automatically taken, such as removing power, or providing notification. 1: As a guide to classification of Zone 22 locations, refer to ANSI/ISA 60079-10-2 (12.10.05)-2013, Explosive Atmospheres Part 10-2: Classification of areas Combustible dust atmospheres. Analysers, motors, control boxes, computers, Any arcs or sparks in this equipment has insufficient energy (heat) to ignite a vapour. Areas with possible fire or explosion risks due to explosive atmospheres and/or mixtures - are called hazardous (or classified) locations or areas. November 2020 An old British standard used letters to designate zones. As world trade becomes more globalized, international standards are slowly converging, so that a wider range of acceptable techniques can be approved by national regulatory agencies. 1) MESG (Maximum Experimental Safe Gap) - The maximum clearance between two parallel metal surfaces that has been found under specified test conditions to prevent an explosion in a test chamber from being propagated to a secondary chamber containing the same gas or vapor at the same concentration. This level of risk is represented by classifying the hazardous area as Zone 0, Zone 1 or Zone 2 (for gas, vapour and mist atmospheres) or Zone 21 or Zone 22 for dust atmospheres. For example, a socket outlet labeled EEx'de' might have a case made to EEx 'e' and switches that are made to EEx 'd'. - Zone 0: An area where an explosive gas-air mixture is continuously present or present for long time (continuous hazard, whose estimated duration is higher than 1000 hours/year) - Zone 1: An area where an explosive gas-air mixture is likely to occur during normal . Hazardous Area Classifications D103222X012 Product Bulletin 9.2:001 September 2019. . The equipment group . The Regulations define 3 zones that can exist within a hazardous area: Zone 0 - A place in which an explosive atmosphere is present continuously or for long periods. Is intended for us in Zone 2 (gases) or Zone 22 (dusts). An explosion is a rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases (wikipedia (https://en.wikipedia.org/wiki/Explosion). Dry Container Gas a. >> NEC: Class I, Division 2, Group D. | IEC: Zone 2, Group II. There are two systems in place, including the traditional North American Division system as well as the alternative Zone system. Magnesium, Titanium), IIB Nonconductive dusts (eg. As a guide for Zone 0, this can be defined as over 1,000 hours/year or >10% of the time. Different countries have approached the standardization and testing of equipment for hazardous areas in different ways. Zone 0 Zone 1 Zone 2 Fluid Occurrence of explosive atmosphere Gas mixtures Dust mixtures Not likely to occur or only for short period Zone 2 Zone 22 . In the US, the National Electrical Manufacturers Association (NEMA) defines standards for enclosure types for a variety of applications. In the United Kingdom, Sira and Baseefa are the most well known such bodies. May 2019 Note to paragraph (g)(4) of this section: Low ambient conditions require special consideration. The substance referred to by classhas a high probability of producing an explosive or ignitable mixture due to it being present continuously, intermittently, or periodically or fromthe equipment itself under normal operating conditions. In instances of areas within the same facility classified separately, Class I, Zone 2 locations may abut, but not overlap, Class I, Division 2 locations. Temperature classification, except for intrinsically safe apparatus. Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time. Zone 1: An area in which an explosive atmosphere is likely to occur in normal operation. less than 0.45 mm or MIC ratio is less than 0.40. Equipment approved for use in Class I hazardous locations cannot be used in Class II hazardous locations. The Zone system for classifying hazardous locations used in NFPA 70 NEC, IEC 60079, and the Canadian Electrical Code indicates the level of probability that a flammable concentration of a hazardous substance may be present. Standards and regulations exist to identify such locations, classify the hazards, and design equipment for safe use in such locations. Hazards in this group gas can be ignited very easily indeed. Area Classification - Hazardous Locations are classified by the likelihood of an ignitable concentration of combustible material being present. June 2019 No hidden fees. A differentiation is made between gas Ex zones and dust Ex zones: Gas Ex zones are 0/1/2 and dust Ex zones are 20/21/22. This was accompanied by electrically-initiated explosions of flammable gas such as fire damp (methane) and suspended coal dust. It is created based on input from the Process Flow Diagrams, Piping & Instrumentation Diagrams and the Equipment Location Plan . Some manufacturers claim "suitability" or "built-to" hazardous areas in their technical literature, but in effect lack the testing agency's certification and thus unacceptable for the AHJ (Authority Having Jurisdiction) to permit operation of the electrical installation/system. Equipment marked as suitable for IIB is also suitable for IIA but NOT for IIC.