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Flexible intermediate bulk containers (FIBC) are used in industry for storage and transport of powders and granules. They are commonly constructed from polypropylene fabric or similar strong and heavy-duty insulating materials. During the filling and emptying of the FIBC’s, electrostatic charges can be built up which accumulate on the product of the container. In the event of the release of the charge in the form of incendiary discharge, an ignition can occur in a flammable atmosphere.


The test is designed to classify the FIBC as type A, B, C or D in accordance with IEC 61340-4-4. Depending on the mechanism applied to exclude incentive discharges, the requirements which the different types of FIBC should meet may be evaluated through breakdown voltage conductivity measurements, surface resistivity measurements and electrostatic discharge testing.

The electrical breakdown voltage, surface resistivity, conductive measurements, electrostatic discharge and ignition testing are conducted at two different temperature and humidity-controlled laboratory of (23 ± 2) °C and (20 ± 5) % relative humidity; and (23 ± 2) °C and (60 ± 10) % relative humidity.

Applicable Standard

FIBC testing is performed in accordance with IEC 60243-1, ASTM D3755-20 and IEC 61340-4-4

Data interpretation

Type A FIBC are made from fabric or plastic sheet without any measures against the buildup of static electricity. These bags do not provide any protection against electrostatic discharges and are intended for use with non-flammable materials.

– Type B FIBC are made from fabric or plastic sheet designed to prevent the occurrence of sparks and propagating brush discharges. While they do not provide full protection against incendiary discharges, Type B bags reduce the risk of propagating incendiary discharges from the bag’s surface.

– Type C FIBC are made from conductive fabric or plastic sheet, or interwoven with conductive threads or filaments and designed to prevent the occurrence of incendiary sparks, brush discharges and propagating brush discharges. Type C FIBC are designed to be connected to earth during filling and emptying operations. These bags effectively dissipate electrostatic charges by facilitating grounding, preventing incendiary discharges and reducing the risk of ignition in the presence of flammable atmospheres.

– Type D FIBC are made from static protective fabric designed to prevent the occurrence of incendiary sparks, brush discharges and propagating brush discharges, without the need for a connection from the FIBC to earth. These bags prevent the accumulation of static charges on the bag’s surface and are suitable for handling materials that are at risk of ignition in flammable atmospheres.

When to perform FIBC Testing

FIBC (Flexible Intermediate Bulk Container) testing should be performed at various stages to ensure compliance with safety standards, quality assurance, and suitability for specific applications, especially during Product Development Phase, Quality Control in Manufacturing, Certification and Compliance, Periodic Inspections, Material Handling Applications, Transportation and Storage and Custom applications. The requirements and specifications that FIBC must meet and the ways in which they are used depend on the nature and sensitivity of any explosive atmosphere present during filling and emptying. The final goal for the construction of FIBC is to exclude incendiary discharges from the FIBC fabric during their intended use.

Why work with Prime Process Safety Center

  • Prime Process Safety Center is a leader in process safety testing with very experienced laboratory personnel. At Prime Process Safety Center our goal is to provide accurate, reliable and defensible data that meets industry and regulatory standards. We understand the need for the quality of your data, and we work assiduously to achieve just that.
  • We are knowledgeable and experienced in performing FIBC electrostatic test, ensuring accurate and reliable results.
  • We have state-of-the-art FIBC electrostatic testing equipment, providing precise and sensitive measurements.
  • We follow strict testing protocols and quality control measures to ensure consistent and reliable test results.
  • Our team can interpret and analyze the data obtained from the tests, providing valuable insights and recommendations for your specific application or research.


What is an FIBC?

Answer: An FIBC, also known as a bulk bag or super sack, is a large, flexible container used for transporting and storing bulk materials such as grains, powders, chemicals, and other granular substances. It is made of flexible fabric and typically features lifting loops for handling by forklifts or cranes.

What are the Different Types of FIBCs?

Answer: FIBCs are categorized into various types based on their construction and intended use, including Type A (non-conductive), Type B (with low breakdown resistance), Type C (conductive), and Type D (anti-static or static dissipative) bags. These types differ in their electrostatic properties and safety features.

What Are the Safety Features of FIBCs?

Answer: FIBCs are designed with safety features such as anti-static properties (in Type C and Type D bags) to prevent the buildup of electrostatic charges, grounding mechanisms (in Type C bags) for dissipating charges safely, and various strength and stability features to ensure safe handling and transportation.

What Are the Load Capacities of FIBCs?

Answer: FIBC load capacities, often referred to as Safe Working Load (SWL), vary based on their design, size, and construction. Standard FIBCs can typically hold loads ranging from 500 kg to over 2,000 kg, while customized or specialized bags might have different load capacities.

What Materials Can FIBCs Safely Handle?

Answer: FIBCs are used for handling a wide range of materials, including agricultural products (grains, seeds), chemicals, minerals, pharmaceuticals, and powdered or granular substances. The suitability of an FIBC for a specific material depends on its construction, strength, and compatibility with the substance’s properties. Evaluation of materials’ MIE and electrostatic features are essential to select the appropriate type of FIBC for safe handling of material.