2008 Product Catalogue - Chemical Protective Workwear - (Page 32) Use of Microgard® Chemical Protective Clothing in Ex-Zones Ex-Zones The purpose of ‘Zoning’ is to provide the basis for correct selection of a protection concept. Areas are classified depending on the properties of the flammable vapours, liquids, mists, gases or combustible fibres/dusts that may be present in the environment and the likelihood that a combustible concentration of that gas or dust is present. Zone 0 Zone 1 Zone 2 I IIC IIA IIB Zone 20 Zone 21 Zone 22 Where ignition sources cannot be eliminated and a flammable gas or dust area may be present, it is important to assess the extent and duration of the risk to select the correct equipment. This is normally referred to as ‘Zoning’ (Ex-Zones). An area in which a potentially explosive atmosphere, consisting of air and flammable substances – in the form of gas, vapour or mist – is continuously present or present for long period. An area in which a potentially explosive atmosphere, consisting of a mixture of air and flammable substances – in the form of gas, vapour or mist – is likely to occur in normal operation An area in which a potentially explosive atmosphere, consisting of a mixture of air and flammable substances – in the form of gas, vapour or mist – is not likely to occur in normal operation An area in which a potentially explosive atmosphere, in the form of a cloud of combustible dust in the air, is continuously present or present for long period. An area in which a potentially explosive atmosphere, in the form of a cloud of combustible dust in the air, is likely to occur in normal operation An area in which a potentially explosive atmosphere, in the form of a cloud of combustible dust in the air, is not likely to occur in normal operation Methane Metal Acetylene, Hydrogen, Carbon Disulphide Coal Dust Grain Dust Butadiene, Ethylene, Ethylene Oxide, Diethyl Ether Having conducted tests at the Swiss Safety Institute, Basel, the table below shows in which situation Microgard® and Microchem® protective clothing may be safely worn*. Ex-Zone definitions as specified by CENELEC/IEC.† Microgard® 2000 Plus Gas Explosion Groups Group I: Concerned with underground mining where coal dust and methane are present. Group II: Concerned with surface industries gases & dust. They are sub-grouped according to volatility - IIA being the least volatile and IIC the most volatile. Microchem® 3000 Microchem® 4000 *Ex-Zone testing conducted by the Swiss Safety Institute at 23°c and 30% relative humidity. The anti-static properties of Microgard® and Microchem® protective clothing depends on the take up of moisture from the air. The anti-static treatment is therefore only effective when the relative humidity is above 25%. Please note that only the clothing material is dissipative. In order to prevent the creation of a spark, the garment and the wearer should be properly grounded. According to requirements in relevant standards (i.e. BGR 132), clothes and protective suits must not be changed in Ex-Zones if the minimum ignition energy is <3mJ.Therefore Microgard® and Microchem® protective clothing should not be donned or removed in Ex-Zones. Microgard® and Microchem® protective clothing meet the requirements of EN1149-1. For more information please visit www.microgard.com †Sources: European (Cenelec) Standards www.cenelec.org, International (IEC) Standards www.iec.ch Propane, Ammonia, CO, Butane, Benzene, Acetone, Methanol www.microgard.com 32 http://www.microgard.com/content.asp?id=7&doc=11 http://www.cenelec.org http://www.iec.ch http://www.microgard.com/index.asp
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