T6-2 - Appropriate Labelling of FIBCs for their Use in Explosion Endangered Areas

Abstract

Explosive atmosphere are formed at the time of filling or emptying FIBCs. FIBCs are made of polypropylene woven fabric which as a highly insulating material impedes the dissipation of electrostatic charge, which has accumulated in the FIBC caused by the charged product. When bulk material or powder piles up in the FIBC, electrostatic charge builds up accordingly. To avoid electrostatic ignition sources caused by discharges of the FIBC the electrical charges inside and on the wall of the FIBC have to be dissipated to a non hazardous degree. The topic of electrostatic hazards has long been recognized as an important but often misunderstood subject. However, too often accidents have occurred in the processing industries including the Chemical Industry because of a lack of understanding static electricity. While filling or emptying Flexible Intermediate Bulk Containers (FIBC) fires and explosions have taken place. To design explosion prevention measures as is necessary in hazardous areas electrostatic ignition sources have to be taken into account. Thus, it seems reasonable to classify and to label such types of FIBCs which can be handled safely in the corresponding hazardous areas. It has to be considered that combustible dusts handled in the FIBCs particularly at filling and emptying operations can form explosive mixtures with air, which must not be ignited by the packing material as an electrostatic ignition source.