Flexible Intermediate Bulk Containers (FIBCs), also known as bulk bags, are a commonly used type of industrial packaging. The tightly woven bags have a range of uses, including the storing and shipping of granulated materials and fine powders. When using fine powders, loading them into or out of FIBCs, the bags can release an electrostatic discharge, and it’s important to understand the risks associated with this.
The level of risk from an electrostatic discharge depends on the materials being stored in the bulk bags, with the risk being higher when combustible or explosive materials are being transported or stored in areas where there are flammable gases, vapours or dust clouds.
Type of electrostatic discharges
There are three types of electrostatic discharges that could come from bulk bags. They are:
1. Brush discharges, which come from standard insulating bulk bags and liners and can ignite flammable gases or vapours
2. Propagating brush discharges, also from standard insulating bulk bags and liners, which are powerful enough to ignite dust clouds.
3. Spark discharges from groundable bags that have not been grounded.
You can reduce the risks of electrostatic discharges by making sure you choose the right industrial packaging for your needs and taking the appropriate precautions. Before you transport any materials, make sure you understand:
– if the material is combustible or explosive
– the material’s minimum ignition energy
– whether there will be any flammable gases or vapours in the area where bulk bags will be stored
– the material’s electrostatic characteristics
– which bulk bag you need (A, B, C, or D), based on their qualification tests
Whatever type of bag you use, the electrostatic characteristics of the materials they are moving and storing will not change and this needs to be taken into consideration.
Bulk bag liners
Using liners in your bulk bags can affect the likelihood of an electrostatic discharge and the type of liner you are allowed to use will depend on the electrostatic characteristics of the materials you are transporting. There are three liners you can choose from:
– L1: conductive
– L2: semi-conductive or static dissipative
– L3: insulating
When selecting a liner, complete an appropriate risk assessment, speak to your industrial packaging provider and take into account surface resistivity, breakdown voltage, liner thickness and resistance.
Employee health and safety
Electrostatic discharges present a risk to staff handling the bulk bags and/or working in areas in which the bulk bags are stored. As an employer, it is your responsibility to make sure staff are kept safe and you should carry out risk assessments and put in place appropriate safeguards. These will depend on the materials being transported or stored and the level of risk for an electrostatic discharge. For example, if the minimum ignition energy is above 50 mJ, bulk bags should be grounded, and staff should be provided with grounding personal safety equipment, such as grounding wrist straps or footwear, and anti-static flooring or conductive mats should be used.