Plain Bag - No Static Protection
Do not use:
Type A FIBC are made from plain polypropylene or other non-conductive material. Static electricity is generated as products move over the inside surface of bulk bags when they are filled or emptied. An inherent electrostatic hazard with Type A bulk bags is that they do not have any mechanism for dissipating static electricity and will not prevent the occurrence of highly energetic, and dangerous propagating brush discharges (PBD). As there are no requirements for static control in this type of bulk bag, there are no electrostatic tests specified in standards and no requirements for labelling. Although it is permissible to label bulk bags as Type A FIBC, this is rarely done. Bulk bags that are not labelled as Type B, Type C or Type D, can be assumed to be Type A.
As there is no static protection provided by Type A FIBC, it is essential that they are not used to store or transport combustible materials or used in flammable or combustible environments. Many organic materials such as sugar, flour, corn starch, milk powder, wood pulp, etc. and chemicals such as bisphenol-A, benzoic acid, toner powders, etc. can form combustible dust clouds or layers that can be ignited by electrostatic discharges from Type A FIBC. The safe option for packaging materials of this nature is to use antistatic FIBC that offer full protection against electrostatic hazards, such as Bulkbigbags Static Protective Type D FIBC.
Inert, non-combustible materials such as titanium dioxide (TiO2) are often used in processes that involve flammable solvents. There is a high risk of solvent vapours being ignited by electrostatic discharges from Type A FIBC. It is essential that only bulk bags with full static protection are used in any process that involves flammable solvents. In these situations Bulkbigbags Static Protective Type D FIBC is the safe option.
|Inside FIBC||Atmosphere Surrounding FIBC|
|Non-Flammable Atmosphere||Explosive Dust Atmosphere||Explosive Gas or Vapour|
MIE > 1000 mJ
|A B C D||B C D||C D|
|MIE 3 mJ to 1000 mJ||B C D||B C D||C D|
|MIE < 3 mJ||C D||C D||C D|
|FIBC Type A||FIBC Type A are made from non-conductive fabric and provide no protection against static electricity.|
|FIBC Type B||FIBC Type B are made from non-conductive fabric. They differ from FIBC Type A in that the breakdown voltage through the fabric, including any coating, shall be low enough to prevent propagating brush discharges.Spark discharges may occur from the surface of FIBC Type B if they become contaminated or coated with conductive material (e.g. water, grease or oil). Precautions should be taken to avoid such contamination and to avoid conductive objects such as tools or metal clips being placed on the FIBC.|
|FIBC Type C||FIBC Type C are made entirely from conductive fabric or from a non-conductive fabric with interconnected conductive threads or filaments. The pattern of conductive threads or filaments is either:a grid enclosing an area of non-conductive fabric no greater than 25 cm2,or a 20 mm stripe, in which case each thread or filament must be interconnected at two separate places (usually at both ends).
FIBC Type C must be provided with a grounding point to which all conductive panels, threads or filaments are electrically bonded. The resistance to the grounding point from anywhere on a conductive fabric and from conductive threads or filaments must be less than 108 ohm (updated to less than 107 ohm in the second edition of IEC 61340-4-4 – see below).
The lift loops of FIBC Type C must also contain conductive threads or filaments with a resistance to the grounding point of less than 108ohm (updated to less than 107 ohm in the second edition of IEC 61340-4-4 – see below).
FIBC Type C must also meet the breakdown voltage requirements of FIBC Type B.
In order to prevent spark discharges that might ignite a flammable or explosive atmosphere, it is essential that FIBC Type C are always securely grounded. A label should be attached to the FIBC indicating the position of the grounding point(s) and clearly stating the requirement for grounding. Ungrounded people may become charged through normal activity and could then discharge to ground when touching Type C FIBC. It is essential to follow normal safe practice and ensure that all conductors, including people, are grounded in the presence of flammable or explosive atmospheres.
|FIBC Type D||FIBC Type D are made from fabric that allows charge to be dissipated without being connected to ground. FIBC Type D fabrics usually contain conductive threads or filaments that dissipate charge safely into the atmosphere by low energy corona discharges. Some FIBC Type D have low resistivity coating that may reduce the risk of incendiary discharges.Grounding of FIBC Type D is not required.To be qualified as safe for use in the presence of flammable or explosive atmospheres it must be first demonstrated that FIBC Type D do not produce incendiary discharges under realistic conditions.
Note: The conditions and procedures of test used to demonstrate the absence of incendiary discharges are specified in the draft IEC 61340-4-4.
FIBC Type D must also meet the breakdown voltage requirements of FIBC Type B.
Ungrounded conductors such a metal drums or people may become charged when positioned close to some FIBC Type D. It is essential to follow normal safe practice and ensure that all conductors are grounded in the presence of flammable or explosive atmospheres.
Spark discharges may occur from the surface of FIBC Type D if they become contaminated or coated with conductive material (e.g. water, grease or oil). Precautions should be taken to avoid such contamination and to avoid conductive objects such as tools or metal clips being placed on the FIBC.