The explosive atmospheres (fire hazard classes A and B) must be classified into so-called zones (0, 1, 2, 20, 21, 22). The principles of zone classification are specified in directives, standards and national requirements.
Accurate information on the zones and their areas is important from several aspects. The applicability of devices, equipment and appliances (electric or non-electric products) used in explosive environments depends on the zone classification of the site. Improper zone classification may result in an accident or breakdown, or may cause unreasonable extra costs during the implementation of the investment. However, equipment and products that can be safely used in explosive atmospheres cannot be specified without zone classification. The use of any improperly qualified equipment in an explosive atmosphere may be a potential source of ignition and may result in an explosion.
If required, our Company’s employees perform the specification of the explosive zones in the given technological plant or its atmosphere, perform the zone classification related to the given room, zone or open space, and specify the areas of the zones.
This activity may be required in the case of installation of new equipment, introduction of new technologies, but the zone boundaries must be reviewed also in the case of modification of any existing equipment or technology. The zone classification is demanded also if any explosion protection documentation required in the legislation is made. In accordance with the relevant legislation, zone classification is required, among others, in the case of periodic fire prevention inspection of electric devices, so-called “ex inspection”, fire prevention inspection as well as control of protection against electrostatic charge for adequacy.
Joint Decree 3/2003. (11st March) FMM-ESzCsM
Based on Paragraph 8(1) of Regulation on the minimum requirements of safety and health at work in potentially explosive atmospheres “The employers must classify working places exposed to the risk of explosive atmospheres into zones specified in Annex 1.” Regulation 28/2011 (6th September) BM on the National Fire Prevention Rules requires the classification of several areas into zones (e.g. Paragraphs 214, 2456, 257, 280) in compliance with this Decree.
The method of classification into zones is specified in Standard MSZ EN 60079-10-1:2009 Explosive atmospheres. Part 10-1: Classification into zones. Explosive gaseous atmospheres (IEC 60079-10-1:2008) as well as Standard MSZ EN 60079-10-2:2010 Explosive atmospheres. Part 10-2: Classification into zones. Flammable dust atmospheres (IEC 60079-10-2:2009). However, regulations adopted for special industries and providing further details of the methodology and obligation of classification into general zones given in the above regulations are also applicable. They include e.g. Regulation 3/2009. (4th February) ÖM on the fire prevention technical requirements of facilities using renewable energy sources such as biogas, bioethanol, biodiesel.
Based on Section 5.1 of Standard MSZ EN 60079-10-1:2009: “The classification into zones must be performed by persons familiar with the properties of the flammable materials, the technological process and the equipment. They must consult safety technical, electricity, mechanical and other technical staff if necessary.” Considering that the classification into zones must be performed in the framework of Joint Decree 3/2003 (11 March) FMM-EszCsM the requirements of Paragraph 9(1) of the Decree on the personal terms of the classification into zones must be also met, which says that: “Drawing and inspection of the explosion protection documentation is a special labour safety activity and therefore a person with at least medium level fire prevention qualification must be involved in the inspection”