Evidence shall show that knowledge has been acquired of safe working practices and classifying hazardous areas. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-EM052A Hazardous areas classification Evidence shall show an understanding of processes involved in gathering and analysing technical data to classify non-specific hazardous areas. The following aspects indicate the extent of understanding required. T1 Occupational Health and Safety responsibilities related to hazardous areas encompassing: the main features and purpose of a ‘clearance to work’ system (includes hot work permit systems). typical safety procedures that should be followed before entering a hazardous area; the purpose of gas detectors and their limitations; effects of temperature on gas and vapour detection; frequency of monitoring for presence of gas or vapours, i.e. effects of temperature rise; factors affecting the accuracy of gas detectors, for example, contamination, condensation, temperature; safety in use of gas detectors, for example, ‘read and run concept’ the safety precautions to be taken when working in a hazardous area. T2 The roles of the parties involved in the safety of hazardous areas encompassing: common Acts and Regulations related to the safety of hazardous areas and the Authorities responsible for their implementation; where assistance and further information can be obtained to assist persons with hazardous area responsibilities, for example, Standard bodies, experienced consultants; and the hazardous area responsibilities of the owner of premises in which a hazardous area exists; the occupier of premises in which a hazardous area exists; enterprises and personnel engaged in installation and/or maintenance of explosion-protection systems; enterprises and personnel engaged in the classification of hazardous areas and/or design of explosion-protection systems; enterprises and personnel engaged in the overhaul, modification and/or assessment of explosion-protected equipment; enterprises and personnel engaged in the inspection of explosion-protection installations; manufacturers of explosion-protected equipment; designated authorities; insurers. T3 Properties of combustible substances and their potential to create an explosive hazard encompassing: condition in the workplace that will lead to an explosion; the terms ‘combustion’, ‘ignition’ and ‘propagation’; explosive range of substances encountered in the workplace i.e. LEL/UEL; explosive parameters of substances as given in tables of substance properties Note: Combustible materials are gases, vapours (from liquids), and dusts; flash point. the difference between gases and vapours; and the toxic nature of gases and vapours and potential harmful consequences. T4 The nature of hazardous areas encompassing: the Standards definition of a ‘hazardous area’; the recommended methods for classifying the type and degree of explosion hazard in an area; hazardous area classifications as defined by Standards; and factors that are considered when a hazardous area is classified. the basics of how explosion-protection is achieved by the methods of exclusion, containment, energy limitation, dilution, avoidance of ignition source. T5 The process of classifying hazardous areas encompassing: methods by which an area can be classified; the characteristics/attributes of an area that should be considered in the classification process, for example, type of process, nature of plant, source and nature of release; the requirements and Standards for classifying a hazardous area; and the responsibilities of the owner/occupiers for classification of a hazardous area. T6 The likelihood (zoning) or risk assessment method of an explosive hazard encompassing: ignition properties of materials relevant to determining the likelihood and extent of an explosive hazard; sources for obtaining data on ignition properties of materials under the conditions in which they could be present in a given process; methods for assessment and calculation of factors such as release rate , ventilation and dispersion characteristics; and and means for reducing hazard risk. T7 The extent of an explosive hazard and classifying an area accordingly encompassing: the extent of zones for an area given data on the likelihood of the explosive hazard for that area; requirements for documenting the classification of a hazardous area; and the extent of the zones, temperature classes and gas groups on site drawings in a hazardous area. |