IEC/EN 61340-4-4 Electrostatic - Part 4-4: Electrostatic Classification of Flexible Medium Bulk Containers (FIBC)

EUROLAB laboratory provides testing and compliance services within the scope of IEC/EN 61340-4-4 standard. The IEC/EN 61340-4-4 standard, prepared and published by the International Electrotechnical Commission (IEC), describes the procedures for assessing the ignition risk presented by electrostatic discharges from FIBC to flammable or explosive atmospheres.

The requirements of this standard apply to all types of FIBCs exceeding 0,14 A, tested as manufactured prior to use, and intended for unlined use in flammable or explosive atmospheres with a minimum ignition energy of more than 3,0 mJ.

0,14 mJ is the minimum ignition energy normally specified for methanol. Although more sensitive materials exist, methanol has the lowest minimum ignition energy of any material likely to be present when the FIBC is discharged. 3,0 uA is the highest charging current likely to be found in common industrial processes. This combination of minimum ignition energy and charging current represents the toughest conditions to be expected in practice.

Compliance with the requirements of this standard does not reduce the need for full risk assessment. The test methods contained in this standard may be used in conjunction with other performance requirements, for example when a risk assessment indicates that the relevant minimum ignition energy is less than 0,14 mJ or that charging currents greater than 3,0 uA are present.

Flexible intermediate bulk containers (FIBC) are widely used for storing, transporting and processing powder, flake or granular materials. Typically, they are made of woven polypropylene fabric in the form of cubic bags with a volume of about 0,25 m3, although they can vary in shape and size from 3 m3 to 1 m3. The fabric used may be a single layer, a multi-layer laminate or a coated fabric. Untreated polypropylene is an electrical insulator, as is often the case with products placed in FIBC.

There is ample opportunity for electrostatic charge build-up during charging and discharging operations, and high charge levels can quickly build up in an unprotected FIBC. In such cases, electrostatic discharges are unavoidable and can be a serious problem when the FIBC is used in hazardous explosive atmospheres.

When processing fine powders that create dust clouds or fine dust layers, a dangerous explosive atmosphere can be created, both of which can be ignited by electrostatic discharges. A dangerous explosive atmosphere can also occur when gases or volatile solvents are used. In these industrial situations, there is a clear need to eliminate provocative electrostatic discharges.

The test methods outlined in this document involve the use of high-voltage power supplies and flammable gases, which can be dangerous if mishandled, especially by unqualified or inexperienced personnel. Users of this document are encouraged to make appropriate risk assessments and give due consideration to local regulations before performing any test procedures.

EUROLAB, with its more than 25 years of experience, state-of-the-art accredited laboratories and expert team, helps you get precise and fast results. Do not hesitate to contact our organization EUROLAB for your IEC/EN 61340 4-4 test.