European Directives Explosive Atmospheres

HS(Rjl5 Administrative guidance on the European Community Explosive Atmospheres Directives (76/... 

One of the primary contents of the Treaties of the European Community (EC) is the elimination of trade barriers for technical equipment. These barriers have been based on different technical standards (and their legislation) in the member states of the EC. Referring to article 100 of the Treaties of the EC, some directives have been issued in order to harmonize the standardization for technical products (explosion protected electrical apparatus and systems, elevators). These directives describe precisely the technical requirements and list the relevant standards, in the field of explosion protection CENELEC Standards exclusively. Directive 82/130/EEC refers to mines endangered by firedamp and/or combustible dusts, and Directive 76/117/EEC covers areas hazardous due to potentially explosive atmospheres. The member states of the EC shall transform these directives into their national legislation within 18 months. 

Furthermore, the employer is required, to use or to provide only work equipment and protective devices which are in compliance with the European Community provisions on design, manufacture, and supply with respect to health and safety. This includes consistency with the provisions of the EU directive 94/9/EC [6-23] dealing with equipment and protecting systems intended for use in potentially explosive atmospheres, and consistency with the existing European technical standards. 

Directive 1994/94/EC of the European Parliament and the Council of 23 March 1994 on the approximation of the laws of Members of the States concerning equipment and protective systems intended for use in potentially explosive atmospheres. 

These regulations illustrate a trend that is occurring in safety legislation, which is now starting to move from a prescriptive approach with definitions of what has to be done in specific situations to a more risk-based approach where the precautions and actions taken are left to the individual user provided they meet certain risk-based criteria. A proposed European Directive concerning minimum requirements for improving the safety and health of workers potentially at risk from explosive atmospheres extends this concept to all work places where flammable atmospheres may be formed. When adopted, this will require all employers to carry out a hazard assessment to identify whether a flammable atmosphere is likely to exist and, where so, to demonstrate that appropriate technical, organisational and other measures appropriate to the nature of the operation have been taken to minimise the risk. 

Legislation concerning flammable solvents is not limited to situations where such solvents are being handled. In addition, equipment manufacturers who supply equipment for use in such situations are also controlled by an extensive array of regulations. These requirements are illustrated by the recent European Directive concerning equipment and protective systems intended for use in potentially explosive atmospheres [26]. This sets out essential safety requirements which will have to be met by equipment manufacturers before a product can be placed on the market in the future. 

The European directives for EC marking are intended for a wide range of products (industrial machines, explosives for civil use, toys...), with particular uses (explosive atmospheres) or with specific risks (low tension, pressurized equipment, electromagnetic compatibility). The conformity assessment of a product is consequently complex because it is necessary to ensure product conformity in all applicable directives. 

As discussed earlier, the European Union has adopted two harmonized directives on health and safety, known as ATEX 94/9/EC (also ATEX 95) and ATEX 99/92/EC (also ATEX 137). ATEX Directive 94/9/EC focuses on the essential safety requirements (SRSs) for products and protective systems for use in potentially explosive atmospheres and the respective conformity assessment procedures. ATEX Directive... 

The title of this chapter refers to the requirements on vacuum pumps intended for use in potentially explosive atmospheres which result from the European Directives 94/9/EC [1] (ATEX 95 i) and 99/92/EC [2] (ATEX 137 ). 

This directive is addressed to operating companies of equipment which is intended for use in potentially explosive atmospheres. It represents a valid European law as of 1 July 2003. In the member states of the European Community it became legal force by respective legal provisions and administrative instructions (in Germany, for example by the Betriebssicherheitsverordnung (BetrSichV) (Operational Safety Code) [4]). 

The European directives for explosion protection, Directives 99/92/EC [2] and 94/9/EC [1], define measures for the protection against explosions of explosive atmospheres under atmospheric conditions. The two directives define an explosive atmosphere, as previously mentioned, as a mixture of air and combustible gases, vapours, mists or dusts under atmospheric conditions in which, after an ignition, combustion processes propagate to the complete unburned mixture. However, the two directives do not define atmospheric conditions . 

The European Directives 99/92/EC [2] and 94/9/EC [1] contain the basic requirements for the prevention of explosions which can be caused by explosive atmospheres. The Directive 99/92/EC [2] points as a matter of priority to the operating companies of plants and equipment for a safe design of workplaces and processes. The Directive 94/9/EC [1] defines the basic requirements for a safe design of equipment and protective systems (i.e. free of ignition sources and/or poor in ignition sources) which are used in potentially explosive atmosphere. 

Directive 99/92/EC of the European Parliament and the Council of 16 December 1999 on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres, last corrigendum of 7 June 2000. Off. /. EC, 134, 36. 

Some years ago, Directive 94/9/EC (the so-called ATEX 100a Directive ), dated 1994-03-23 (following the title in French Atmospheres explosibles. .. and referring to article 100a of the Treaties of the European Community), introduced categories of explosion protected apparatus to give a guideline for their installation with respect to the risks that may be expected in different locations exposed to combustible atmospheres (Table 2.3). 

Runaway reactions were an underlying cause of other industrial accidents such as that which occurred in Seveso, Italy in 1976. The nearby chemical plant was producing 2,4,5-trichlorophenol, an intermediate for manufacturing of a medical disinfectant hexachlorophene. The runaway reaction of 1,2,4,5-tetrachlorobenzene with sodium hydroxide went out of control and resulted by an explosion and release into atmosphere of an unintended byproduct of this reaction, highly toxic 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The nearby communities were thus exposed to TCDD. This accident triggered industrial environmental safety regulations passed by the European Community in 1982 and termed Seveso Directive. 

Polyester and glass fibre reinforced polyester bodies are a popular choice for industrial plugs and sockets especially those destined to be used in hazardous environments where ATEX (from the French ATmospheres EXplosible ) directives apply. The relevant Directive 100a ATEX Directive (94/9/EC) was issued by the European Commission in 1994 and became law on July 1st 2003. 

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