IEC 61340-4-4:2018

Overview

IEC 61340-4-4:2018 - "Electrostatics - Part 4-4: Electrostatic classification of flexible intermediate bulk containers (FIBC)" defines electrostatic safety, test methods and classification for FIBC (0.25 m3 to 3 m3) intended for use in hazardous explosive atmospheres. The standard covers FIBC bodies, inner liners, labels and document pockets, and specifies test procedures, design/performance requirements, labelling and type qualification/certification. It also gives guidance for safe use in zones defined for combustible dusts (IEC 60079-10-2) and explosive gas atmospheres (IEC 60079-10-1).

Key topics and requirements

• Scope and classification: Defines FIBC types (Type A, B, C, D) and inner liner types (L1, L1C, L2, L3) based on electrostatic behaviour and construction.
• Test methods: Standardised procedures for electrical breakdown voltage, ignition testing, surface resistivity, and resistance to a groundable point; sampling, conditioning and detailed test reporting requirements are included.
• Design & performance: Requirements for construction, conductive elements, and insulating layers of liners and labels to mitigate electrostatic risks.
• Labelling: Mandatory classification and marking requirements for FIBC; a new labelling requirement references IEC TS 60079-32-1 for earthing guidance.
• Safe use & zones: Guidance for permitted combinations of FIBC and inner liners within explosion-hazard zones and for environments with combustible dust or flammable gases.
• Type qualification & certification: Procedures for factory testing, type qualification and certification, including provisions for inner liners.
• Significant 2018 changes:
  • Resistance-to-ground limit for Type C FIBC (and corresponding inner liners) increased from 10 MΩ to 100 MΩ.
  • Classification extended to Type L1C inner liners with conductive internal layers.
  • Labelling must reference IEC TS 60079-32-1 for earthing guidance.

Applications

• Selection, specification and procurement of FIBC for use where contents or external atmosphere may form explosive mixtures (chemical, pharmaceutical, food, mining, agriculture, plastics).
• Design and manufacture of FIBC, inner liners, labels and document pockets to meet electrostatic safety requirements.
• Testing laboratories and certification bodies performing type qualification, ignition and electrical tests.
• Health & safety, process and plant engineers implementing safe handling, earthing/grounding and storage procedures for bulk bags in hazardous areas.

Who should use this standard

• FIBC manufacturers and designers
• Third‑party testing and certification bodies
• Occupational safety and process engineers
• Regulatory authorities and procurement teams specifying bulk packaging for hazardous atmospheres

Related standards

• IEC 60079-10-1 (flammable gas zone classification)
• IEC 60079-10-2 (combustible dust zone classification)
• IEC TS 60079-32-1 (guidance on earthing of electrostatic hazards)

Keywords: IEC 61340-4-4, FIBC, electrostatics, electrostatic classification, inner liner, ignition testing, resistance to ground, hazardous explosive atmospheres, earthing, IEC 60079.