When deciding which type of FIBC bulk bag will work best for their application, one important characteristic that companies must consider is the FIBC’s electrostatic classification. Failure to take the electrostatic hazards into consideration could result in damage to property and injury to employees.
Different products and work environments will designate which classification of FIBC will be required for that particular application. The different classifications for FIBC fabric are Type A, Type B, Type C, and Type D. Type A bags are at one end of the spectrum and they do not have any dissipative qualities. At the other end of the spectrum are Type D bags which have the most dissipative properties. Type B and Type C bags fall somewhere in between. You can see the requirements for each FIBC type below:
|Bulk product in FIBC||Surroundings|
|MIE of dust||Non-flammable|
|Dust Zones 21-22|
(1,000 mJ >MIE > 3 mJ)
|Gas zones 1-2|
(Explosion groups IIA/IIB)
or dust zones 21-22
(MIE ≤ 3 mJ)
|IE > 1 000 mJ||A,B,C,D||B,C,D||C,D|
|1,000 mJ > MIE > 3 mJ||B,C,D||B,C,D||C,D|
|MIE ≤ 3 mJ||C,D||C,D||C,D|
In addition to the fabric requirements for each level of electrostatic classification, there are labeling requirements for each level as well. The label should be yellow in color with black type so that it stands out and is easily readable. The label material must also meet standards for each electrostatic classification. Type C and Type D bags have always required labels whereas Type A bags do not. New regulations adopted by FIBCA in 2013 require that Type B bags be labeled as well.
If the bags have a liner, the liner must also meet standards in order to be used in an electrically charged environment. The three types of bulk bag liner classifications are type L1, L2, and L3. Different types of liners are compatible with different FIBC classifications. The table showing which liner can be used with which FIBC can be found below:
FIBC Bulk Bag Liner
|Liner Type||Surface Resistivity||FIBC Type|
|L1||≤ 107 Ω||C|
|L2||109 Ω to 1012 Ω||B, C & D|
|L3||greater than 1012 Ω||B|
As of January 2014, Material Motion, Inc. now has been approved to weave CROHMIQ ® Static Protective Type D FIBC Fabric. If you have any questions about the electrostatic classification of FIBC’s, please contact your Material Motion representative.