Which abrasive dusts are explosive?
Dusts which occur when grinding light alloys such as aluminium, magnesium or titanium, are deemed to be explosive. Suction and filter systems must be planned, implemented and operated according to the applicable ATEX Directive. Mixing with other emissions is to be prevented when this increases the risk of explosion. One example of this is presented by the extraction of grinding dusts from aluminium and steel processing in a system. The aluminium dusts are deemed to be explosive and sparks could get into the extraction system when grinding steel. Both a highly dangerous combination. Situations like these must be prevented through organisational and technical measures.
What exactly is an "explosion"?
The law defines explosions as "thermal or chemical energy converted into pressure or shock waves". Flames and heat, up to the destruction of entire installations and buildings, as well as expulsion of material and fragments, can occur as side effects and secondary effects. Explosion triggers are mostly combustion reactions of fuel-air mixtures.
The ATEX Directive is deemed to be the legal basis. ATEX is a portmanteau of the French terms ATmosphère EXplosibles. ATEX regulates, at European level, the common responsibility and liability for all companies that have potentially explosive atmospheres or provide facilities for such areas. ATEX aligns the laws of EU Member States and provides for a shared commitment of operators and manufacturers. The EU Directive is implemented through national legislation.
What are the obligations of the operators?
The operator must evaluate the explosion hazards and risks for all of its processes and different operating states. Based on the results, they are obliged to divide their processes according to risk and hazard levels (Ex-zones). To protect the health and lives of their employees, they are required to prepare an action plan. The operator is obliged to monitor compliance with the defined measures. Organisational measures must be controlled by operating instructions. The process is compiled in an explosion protection document, which contains all determined data and protection measures.
What are the obligations of the manufacturers?
Even plant and machine builders must abide by ATEX. They must submit a standardised design including the construction of the plant. The hazard potential of a system or machine is determined during the course of a risk analysis. Also the proper use and operating conditions have to be defined. The plant is classified into categories of equipment and can then be designed and constructed in accordance with standards and the risk analysis. A conformity assessment, including corresponding labelling, is also required. It has to be taken into account that it is not sufficient only to evaluate and characterize the individual components, but to make an overall assessment of the whole plant.
Who supports you?
We deal with the legal matters surrounding ATEX every day. That is why we are pleased to offer you our expertise for potential hazards in all aspects of air equipment. Of course, we can assist you in designing an optimal and, above all, safe solution at any time.
One of our customer recently phrased our support in the approval process like this: "When we informed the authorities that the air purification system would be planned and implemented with all EX protection measures by Kappa, they said: then the approval will go through without any hitch".
Steyr Gleink, February 2017