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.

Carcasses of electrical or non-electrical equipment operating in potentially explosive atmospheres must provide a certain degree of protection against access to hazardous parts, penetration of solid bodies and/or water penetration, which must be tested according to the specifications of the Ex protection types. Normal protection classes are indicated by the international IP code followed by two characteristic digits referring to the protection against penetration of solid foreign bodies and water protection, followed by optional letters if required by the beneficiary according to the imposed conditions of use. Within the ENExEMEIP laboratory, have been developed laboratory tests to verify the first characteristic figure of the standard degree of protection according to the standardized European method. In the paper is presented the test stand of the large gauge equipment, a stand made with state-of-the-art equipment that provides the necessary performance for the accreditation of the test according to the standardized requirements. Checking dustproof protection to equipment used in areas where explosive atmospheres generated by combustion dust may occur is particularly important for assessing compliance with the requirements of the ATEX Directive [5], as this protection is a basic requirement for explosion protection.

Potentially explosive atmospheres generated by the raw materials used, intermediate / final products or the resulting waste may form in all industries involving flammable / combustible substances. Thecreation of these atmospheres must be treated as a major risk, as the fires or explosions that may occur affect human health and safety as well as the environment. Reducing these risks requires the assessment of the risk of explosion and the establishment of measures to reduce it to acceptablelevels in accordance with the requirements of European standards and the ATEX Directive.The general standard SR EN 60079-0 requires that only electrical / non-electrical equipment, certified for safe use, be used in hazardous areas Ex, which must ensure an appropriate normal degree of protection through the outer casing, as this protection is a requirement basic explosion protection.The tests for determining the degree of protection were carried out in accordance with harmonized European requirements and in the area of high-performance stands in accordance with SR EN ISO / IEC 17025, and the validity of the test results was demonstrated by successful participation in interlaboratory competitions and test of laboratory competition.