Current legislation regulates the obligations and responsibilities of persons who perform design, manufacture and use of equipment and installations in potentially explosive atmospheres with regard to compliance with explosion prevention requirements. There are two European Directives, so-called ATEx Directives, which regulate the placing on the European market of products intended for use in potentially explosive atmospheres and their safe use: Directive 2014/34/EU and Directive 1999/92/EC. The paper presents some aspects regarding the border situations where the two directives apply, in the case of assemblies of equipment to be assessed by a manufacturer in accordance with the Directive 2014/34/EU for putting on the market and the installations that are equipment assembled by the user under his responsibility and have to be assessed by users toward with the Directive 1999/92/EC requirements.

In industrial plants many types of combustible dusts are generated, processed, handled and stored. When ignited, they can burn rapidly and with a considerable explosion force, when mixed with air in proper proportions. This is the reason why adequate precautions have to be adopted, to ensure all equipment is appropriately protected so that the ignition likelihood of the explosive atmosphere is diminished. Explosion preventing and protection precautions aim to stop explosion occurrence, by eliminating or avoiding the conditions leading to explosions. The paper presents methods of determining dust explosion characteristics and combustion as well as their importance for a proper development and selection of prevention and protection measures. Once known, the protection/prevention measures can be correlated with the safety characteristics. For explosion protection and prevention a series of minimum mandatory requirements have to be fulfilled, for a safe handling and processing of solid materials having fine particle dimensions, among which some are mentioned: knowing the characteristics influencing safety, control and monitoring dust releases in technological processes, installations design for migrating and accumulation of dusts, respectively implementing a rigorous cleaning program at workplaces.

The explosion danger in all industries where explosive atmospheres generated by the mixture of combustible dusts or flammable gases with air may form, must be treated as a major hazard, as the explosions that may occur can seriously affect both health and safety people, as well as the environment. It is therefore necessary to assess the explosion risk and to establish appropriate measures to reduce it to acceptable levels in accordance with the requirements of the European Directives. An essential element in the assessment of the explosion risk for electrical and non-electrical equipment intended for use in potentially explosive atmospheres is the way in which an appropriate normal degree of protection is provided through the equipment housing (protection against touching of dangerous parts inside the equipment housing and protection against the ingress of dust and water inside it). The aim of the paper is to highlight compliance with the requirements of the ATEX Directive, given that this protection is a basic requirement for explosion protection and to present the important elements to be considered for the assessment of the normal degree of protection and the development of harmonized test methods with the requirements of European standards.

Abstract. Explosive risk occurs in all activities involving flammable substances in the form of gases, vapors, mists or dusts which, in mixture with air, can generate an explosive atmosphere. As explosions can cause human losses and huge material damage, the assessment of the explosion risk and the establishment of appropriate measures to reduce it to acceptable levels according to the standards and standards in force is of particular importance for the safety and health of people and goods

Static electricity represents one of the potential ignition sources for the explosive atmospheres. The test methods for materials, in general, and especially the test methods for textile fabrics for assessment of the protective performances in static electricity, have known a permanent evolution alongside newly developed electrostatically dissipative materials. Within the National Institute of Research and Development for Safety in Mines and Explosion Protection (INCD-INSEMEX) new testing stands had been developed and new testing methods had been implemented for assessment of the charge dissipative capacity, in accordance with the European standards requirements. By modernizing the laboratory testing/research-development capacity, the physical tools for testing of materials are assured, having in view conformity assessment with the European Directives requirements, in the framework of the Notified Body for Conformity Assessment (OEC-INSEMEX). The paperwork presents aspects regarding competency testing provided in the RENAR policy for accredited or accrediting-in-progress laboratories, as requirement for proving and monitoring laboratory competency for testing/calibration in the field for which accreditation was applied for/granted.

For any type of combustible dust, several important explosive parameters must be taken into account when designing and using protection systems: namely the ease with which dust clouds ignite and their burning rate, maximum explosion pressure, maximum pressure rise speed. of explosion. The accuracy of the results obtained necessary for the design and use of protection systems depends on a number of factors but also on the accuracy of the application of the test method (s) by the personnel involved. Test quality assurance is a requirement of EN ISO / IEC 17025 for the accreditation of testing laboratories. The standard requires laboratories to have a procedure in place to monitor the validity of test results, which involves participation in interlaboratory comparisons. This paper presents some specific issues highlighted during the successful participation of INSEMEX-GLI in several rounds of interlaboratory comparisons for the tests to determine explosive parameters of the combustible dust-air mixtures.

In industrial sectors that use, process, transport or store, substances such as combustible dusts could exist some workplaces with explosion hazard due to the possibility of dust/air explosive formation and ignition, both inside the installations and in the surrounding atmosphere. Methods and means of protection aim to prevent the development of explosive atmospheres, followed by preventing the occurrence of ignition sources and then limiting the effects of explosions. To assess the risk of ignition of the explosive atmosphere, there must be known first of all, the explosive atmosphere’s sensitivity to ignition by electrostatic discharge, respectively, the minimum ignition energy of the explosive mixture, afterwards being required an analysis on the possibilities of formation and discharge of electrostatic charge. For the most common combustible dusts, the minimum ignition energy is given, but for new types of flammable substances this parameter defining the sensitivity to ignition of the mixture by electrostatic discharges must be determined. The paper presents the results of research carried out in order to develop the methods and standards for determining the minimum ignition energy of the combustible dust / air mixture and of the methods for the assessment of the risk of ignition of the dust/air explosive atmosphere by electrostatic discharge.

The paper describes the results obtained during the experimentation of a new method that allows an in site verification of the electric systems for ignition of the electric detonators part of the special trucks for prospecting works, aiming to reach an adequate level of safety in operation. By this method, for in field verification of the electric detonators' ignition system that is mounted in the special trucks for prospecting works, based on the acceptance criteria and the operating ways on the safety parameters, the following are tested: insulation resistance, output energy and output voltage. Employing the verification method in situ prevents the operators electrocuting hazards, unexpected firing of electric detonators or misfiring in the blasting work itself, after the explosive charge was lowered into the prospecting hole. The method has successful experimented on site for 4 special trucks and it has implemented to INCD-INSEMEX Petrosani for testing programme of electric initiation system integrated in prospecting trucks in order to assessing the conformity of products in the voluntary field.