EN 61340-4-4:2012

SLOVENSKI STANDARD
01-maj-2012
(OHNWURVWDWLNDGHO6WDQGDUGQHSUHVNXVQHPHWRGH]DSRVHEQHDSOLNDFLMH
(OHNWURVWDWLþQDUD]YUVWLWHYSURåQLKYPHVQLKYVHEQLNRY),%&
Electrostatics - Part 4-4: Standard test methods for specific applications - Electrostatic
classification of flexible intermediate bulk containers (FIBC)
Elektrostatik - Teil 4-4: Normprüfverfahren für spezielle Anwendungen - Einordnung
flexibler Schüttgutbehälter (FIBC) in elektrostatischer Hinsicht
Electrostatique - Partie 4-4: Méthodes d'essai normalisées pour des applications
spécifiques - Classification électrostatique des grands récipients pour vrac souples
(GRVS)
Ta slovenski standard je istoveten z: EN 61340-4-4:2012
ICS:
17.220.99 Drugi standardi v zvezi z Other standards related to
elektriko in magnetizmom electricity and magnetism
55.180.99 Drugi standardi v zvezi z Other standards related to
distribucijo blaga s prevozom freight distribution of goods
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 61340-4-4
NORME EUROPÉENNE
March 2012
EUROPÄISCHE NORM
ICS 17.220.99; 29.020; 55.080 Supersedes EN 61340-4-4:2005

English version
Electrostatics -
Part 4-4: Standard test methods for specific applications -
Electrostatic classification of flexible intermediate bulk containers (FIBC)
(IEC 61340-4-4:2012)
Electrostatique -  Elektrostatik -
Partie 4-4: Méthodes d'essai normalisées Teil 4-4: Normprüfverfahren für spezielle
pour des applications spécifiques - Anwendungen -
Classification électrostatique des grands Einordnung flexibler Schüttgutbehälter
récipients pour vrac souples (GRVS) (FIBC) in elektrostatischer Hinsicht
(CEI 61340-4-4:2012) (IEC 61340-4-4:2012)

This European Standard was approved by CENELEC on 2012-02-22. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the CEN-CENELEC Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland, Turkey and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels

© 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61340-4-4:2012 E
Foreword
The text of document 101/346/FDIS, future edition 2 of IEC 61340-4-4, prepared by IEC TC 101,
"Electrostatics" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
(dop) 2012-11-22
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2015-02-22
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61340-4-4:2005.
4:2005:
a) Adoption of a type classification system for FIBC based on four types: A, B, C and D.
b) Guidance for safe use of FIBC in relation to hazardous areas and hazardous zones defined in
EN 60079-10-1 and EN 60079-10-2 is added.
c) Resistance to groundable points and electrical breakdown voltage measurements on FIBC shall be
measured at low humidity only.
d) Requirements for labelling FIBC are changed to improve clarity and ease of recognition by end users.
e) Classification, performance requirements and guidance for safe use of inner liners in combination with
FIBC are added.
f) An informative annex giving guidance on test methods for quality control and inspection testing is
added.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent
rights.
Endorsement notice
The text of the International Standard IEC 61340-4-4:2012 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 61340-2-1 NOTE  Harmonized as EN 61340-2-1.

- 3 - EN 61340-4-4:2012
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.
Publication Year Title EN/HD Year

IEC 60079-10-1 - Explosive atmospheres - EN 60079-10-1 -
Part 10-1: Classification of areas - Explosive
gas atmospheres
IEC 60079-10-2 - Explosive atmospheres - EN 60079-10-2 -
Part 10-2: Classification of areas -
Combustible dust atmospheres
IEC 60243-1 1998 Electrical strength of insulating materials - EN 60243-1 1998
Test methods -
Part 1: Tests at power frequencies

IEC 60243-2 - Electric strength of insulating materials - Test EN 60243-2 -
methods -
Part 2: Additional requirements for tests using
direct voltage
IEC 60417 Data- Graphical symbols for use on equipment - -
base
IEC 61241-2-3 - Electrical apparatus for use in the presence of - -
combustible dust -
Part 2: Test methods - Section 3: Method for
determining minimum ignition energy of
dust/air mixtures
IEC 61340-2-3 - Electrostatics - EN 61340-2-3 -
Part 2-3: Methods of test for determining the
resistance and resistivity of solid planar
materials used to avoid electrostatic charge
accumulation
ISO 7000 2004 Graphical symbols for use on equipment - - -
Index and synopsis
ISO 21898 - Packaging - Flexible intermediate bulk EN ISO 21898 -
containers (FIBCs) for non-dangerous goods

ASTM E582 - Standard test method for minimum ignition - -
energy and quenching distance in gaseous
mixtures
IEC 61340-4-4 ®
Edition 2.0 2012-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrostatics –
Part 4-4: Standard test methods for specific applications – Electrostatic

classification of flexible intermediate bulk containers (FIBC)

Électrostatique –
Partie 4-4: Méthodes d'essai normalisées pour des applications spécifiques –

Classification électrostatique des grands récipients pour vrac souples (GRVS)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX X
ICS 17.220.99; 29.020; 55.080 ISBN 978-2-88912-851-8

– 2 – 61340-4-4  IEC:2012
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 8
3 Terms and definitions . 8
4 Classification . 10
4.1 Principles of classification for FIBC . 10
4.1.1 Type A . 10
4.1.2 Type B . 10
4.1.3 Type C . 10
4.1.4 Type D . 10
4.2 Principles of classification and requirements for inner liners . 11
4.2.1 Surface resistivity measurements for inner liners . 11
4.2.2 Special cases . 11
4.2.3 Type L1 . 11
4.2.4 Type L2 . 11
4.2.5 Type L3 . 12
4.3 Combination of FIBC and inner liners . 12
5 Safe use of FIBC . 13
6 Labelling . 14
7 Requirements for FIBC . 17
7.1 General remarks. 17
7.2 Requirements for dust environments with ignition energies greater than 3 mJ
(apply to Type B FIBC, Type C FIBC and Type D FIBC) . 17
7.3 Requirements for vapour and gas atmospheres and for dust environments
with ignition energies of 3 mJ or less . 17
7.3.1 Type C FIBC . 17
7.3.2 Type D FIBC . 18
8 Atmosphere for conditioning, calibrating and testing . 18
8.1 Conditioning time . 18
8.2 Electrical breakdown voltage and resistance to groundable point testing . 18
8.3 Ignition testing . 18
9 Test procedures . 18
9.1 Electrical breakdown voltage . 18
9.2 Ignition testing . 19
9.2.1 Apparatus . 19
9.2.2 Establishing correct charging current . 26
9.2.3 Ignition tests . 26
9.3 Resistance to groundable point . 28
9.3.1 Apparatus . 28
9.3.2 Test procedure . 29
10 Report . 30
10.1 For all types of testing . 30
10.2 For electrical breakdown voltage testing . 31
10.3 For ignition testing . 31

61340-4-4  IEC:2012 – 3 –
10.4 For resistance to groundable point testing . 31
10.5 For surface resistivity testing of inner liners . 31
10.6 For test reports issued by accredited testing authorities . 31
Annex A (normative) Electrical breakdown voltage – Typical voltage/time graphs . 33
Annex B (normative) Polypropylene pellets for ignition testing . 34
Annex C (informative) Guidance on test methods for manufacturing quality control . 35
Annex D (normative) Classification of hazardous areas and zones. 37
Annex E (informative) Risks associated with cone discharges . 38
Annex F (informative) Explanation for resistance and resistivity limits . 39
Bibliography . 40

Figure 1 – Example of a label for Type B FIBC . 15
Figure 2 – Example of a label for Type C FIBC . 15
Figure 3 – Example of a label for Type D FIBC . 16
Figure 4 – Example of a label for Type C FIBC designated earth bonding points . 16
Figure 5 – Ignition probe . 20
Figure 6 – Perforated metal plate for use in ignition probe . 21
Figure 7 – Gas control and mixing apparatus (schematic) . 22
Figure 8 – FIBC filling rig (schematic) . 24
Figure 9 – Corona charging unit (schematic) . 25
Figure A.1 – Example of voltage/time graph for material showing distinct breakdown . 33
Figure A.2 – Example of voltage/time graph for material showing reduction in rate of
voltage rise because of conduction within the test material . 33

Table 1 – Permissible configurations and requirements for Type L1 inner liners . 11
Table 2 – Permissible configurations and requirements for Type L2 inner liners . 12
Table 3 – Permissible configurations and requirements for Type L3 inner liners . 12
Table 4 – Use of different types of FIBC . 13
Table 5 – Inner liners and FIBC: combinations that are permissible and not permissible
in hazardous explosive atmospheres . 13
Table 6 – Volume concentrations of flammable gas mixture . 21
Table 7 – Example of full sample description to be included in test report . 32
Table B.1 – Particle size distribution of polypropylene pellets . 34
Table D.1 – Classification of hazardous areas in IEC 60079-10-1 and IEC 60079-10-2 . 37
Table D.2 – Classification of zones in IEC 60079-10-1 and IEC 60079-10-2 . 37

– 4 – 61340-4-4  IEC:2012
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROSTATICS –
Part 4-4: Standard test methods for specific applications –
Electrostatic classification of flexible intermediate bulk containers (FIBC)

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61340-4-4 has been prepared by IEC technical committee 101:
Electrostatics, in cooperation with ISO subcommittee 3: Performance requirements and tests
for means of packaging, packages and unit loads, of ISO technical committee 122: Packaging.
This second edition cancels and replaces the first edition, published in 2005, and constitutes
a technical revision.
The main changes with respect to the first edition are listed below:
a) Adoption of a type classification system for FIBC based on four types: A, B, C and D.
b) Guidance for safe use of FIBC in relation to hazardous areas and hazardous zones
defined in IEC 60079-10-1 and IEC 60079-10-2 is added.
c) Resistance to groundable points and electrical breakdown voltage measurements on FIBC
shall be measured at low humidity only.

61340-4-4  IEC:2012 – 5 –
d) Requirements for labelling FIBC are changed to improve clarity and ease of recognition by
end users.
e) Classification, performance requirements and guidance for safe use of inner liners in
combination with FIBC are added.
f) An informative annex giving guidance on test methods for quality control and inspection
testing is added.
The text of this standard is based on the following documents:
FDIS Report on voting
101/346/FDIS 101/353/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 61340 series, published under the general title Electrostatics,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – 61340-4-4  IEC:2012
INTRODUCTION
Flexible intermediate bulk containers (FIBC) are widely used for the storage, transportation
and handling of powdered, flaked or granular material. Typically, they are constructed from
woven polypropylene fabric in the form of cubic bags of about 1 m volume, although they can
3 3
vary in shape and in size from 0,25 m to 3 m . 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 the products placed in FIBC. There is ample opportunity for the
generation of electrostatic charge during filling and emptying operations and in unprotected
FIBC high levels of charge can quickly build up. In such cases, electrostatic discharges are
inevitable and can be a severe problem when FIBC are used in hazardous explosive
atmospheres.
A hazardous explosive atmosphere can be generated when handling fine powders that create
dust clouds or thin layers of powder, both of which can be ignited by electrostatic discharges.
A hazardous explosive atmosphere can also be generated when using gases or volatile
solvents. In these industrial situations there is clearly a need to eliminate incendive
electrostatic discharges.
As with any industrial equipment, a thorough risk assessment should always be conducted
before using FIBC in potentially hazardous situations. This part of IEC 61340 describes a
system of classification, test methods, performance and design requirements and safe use
procedures that can be used by manufacturers, specifiers and end-users as part of a risk
assessment of any FIBC intended for use within a hazardous explosive atmosphere. However,
it does not include procedures for evaluating the specific risks of electrostatic discharges
arising from products within FIBC, e.g. cone discharges, from personnel or from equipment
used near FIBC. Information on risks associated with cone discharges is given in Annex E.
CAUTION: The test methods specified in this standard involve the use of high voltage power
supplies and flammable gases that may present hazards if handled incorrectly, particularly by
unqualified or inexperienced personnel. Users of this standard are encouraged to carry out
proper risk assessments and pay due regard to local regulations before undertaking any of
the test procedures.
61340-4-4  IEC:2012 – 7 –
ELECTROSTATICS –
Part 4-4: Standard test methods for specific applications –
Electrostatic classification of flexible intermediate bulk containers (FIBC)

1 Scope
This part of IEC 61340 specifies requirements for flexible intermediate bulk containers (FIBC)
3 3
between 0,25 m and 3 m in volume, intended for use in hazardous explosive atmospheres.
The explosive atmosphere may be created by the contents in the FIBC or may exist outside
the FIBC.
The requirements include:
− classification and labelling of FIBC;
− classification of inner liners;
− specification of test methods for each type of FIBC and inner liner;
− design and performance requirements for FIBC and inner liners;
− safe use of FIBC (including those with inner liners) within different zones defined for
explosion endangered environments, described for areas where combustible dusts are, or
may be, present (IEC 60079-10-2), and for explosive gas atmospheres (IEC 60079-10-1);
− procedures for type qualification and certification of FIBC, including the safe use of inner
liners.
NOTE 1 Guidance on test methods that may be used for manufacturing quality control is given in Annex C.
The requirements of this standard are applicable to all types of FIBC and inner liners, tested
as manufactured, prior to use and intended for use in hazardous explosive atmospheres:
Zones 1 and 2 (Groups IIA and IIB only) and Zones 21 and 22 (see Annex D for classification
of hazardous areas and explosion groups). For some types of FIBC, the requirements of this
standard apply only to use in hazardous explosive atmospheres with minimum ignition energy
of 0,14 mJ or greater and where charging currents do not exceed 3,0 µA.
NOTE 2 0,14 mJ is the minimum ignition energy of a typical Group IIB gas or vapour. Although more sensitive
materials exist, 0,14 mJ is the lowest minimum ignition energy of any material that is likely to be present when
FIBC are emptied. 3,0 µA is the highest charging current likely to be found in common industrial processes. This
combination of minimum ignition energy and charging current represents the most severe conditions that might be
expected in practice.
Compliance with the requirements specified in this standard does not necessarily ensure that
hazardous electrostatic discharges, e.g. cone discharges, will not be generated by the
contents in FIBC. Information on the risks associated with cone discharges is given in Annex
E.
Compliance with the requirements of this standard does not mitigate the need for full risk
assessment. For example, metal and other conductive powders and toner powders may
require additional precautions to prevent hazardous discharges from the powders.
NOTE 3 In the examples mentioned in the paragraph above, additional precautions may be necessary in the case
of metal or other conductive powder because if the powder is isolated and becomes charged, incendiary sparks
may occur, and in the case of toner powders, incendiary discharges may occur during rapid filling and emptying
operations. Future IEC/TS 60079-32 [1] gives guidance on additional precautions that may be necessary.
———————
Figures in square brackets refer to the bibliography.

– 8 – 61340-4-4  IEC:2012
Test methods included in this standard may be used in association with other performance
requirements, for example when a risk assessment has shown the minimum ignition energy of
concern is less than 0,14 mJ, charging currents are greater than 3,0 µA, or the ambient
conditions are outside of the range specified in this standard.
Compliance with the requirements specified in this standard does not necessarily ensure that
electric shocks to personnel will not occur from FIBC during normal use.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60079-10-1, Explosive atmospheres – Part 10-1: Classification of areas – Explosive gas
atmospheres
IEC 60079-10-2, Explosive atmospheres – Part 10-2: Classification of areas – Combustible
dust atmospheres
IEC 60243-1:1998, Electric strength of insulating materials – Test methods – Part 1: Tests at
power frequencies
IEC 60243-2, Electric strength of insulating materials – Test methods – Part 2: Additional
requirements for tests using direct voltage
IEC 60417-5019:2006, Graphical symbols for use on equipment. Available at: symbols.info/equipment>"
IEC 61241-2-3, Electrical apparatus for use in the presence of combustible dust – Part 2: Test
methods – Section 3: Method for determining minimum ignition energy of dust/air mixtures
IEC 61340-2-3, Electrostatics – Part 2-3: Methods of test for determining the resistance and
resistivity of solid planar materials used to avoid electrostatic charge accumulation
ISO 7000:2004, Graphical symbols for use on equipment – Index and synopsis
ISO 21898, Packaging – Flexible intermediate bulk containers (FIBCs) for non-dangerous
goods
ASTM E582, Standard test method for minimum ignition energy and quenching distance in
gaseous mixtures
3 Terms and definitions
For the purposes of this document, the following terms and definitions, as well as those given
in IEC 60079-10-1, IEC 60079-10-2 and ISO 21898, apply.
3.1
quenching
effect of solid objects acting as heat sinks in close proximity to gas
3.2
critical quenching distance
maximum separation distance between opposing electrodes below which quenching prevents
ignition at a specified energy

61340-4-4  IEC:2012 – 9 –
NOTE For ignitions to take place, the gap between electrodes should be greater than the critical quenching
distance.
3.3
flammable substance
substance in the form of gas, vapour, liquid, solid, or mixture of these, capable of propagating
combustion when subjected to an ignition source
3.4
explosive atmosphere
mixture with air, under atmospheric conditions, of flammable substances in the form of gases,
vapours, mists or dusts in which, after ignition has occurred, combustion spreads to the entire
unburned mixture
3.5
hazardous explosive atmosphere
explosive atmosphere present in such quantities that precautions against ignition are required
3.6
minimum ignition energy
least electrical energy of a purely capacitive spark (i.e. no added inductance) required to
ignite a dust, gas or vapour
3.7
charging current
quantity of charge per unit time flowing into FIBC
3.8
cone discharge
electrostatic discharge running outwards across the surface from the top of highly charged,
insulating powder heaps in large containers
3.9
brush discharge
electrostatic discharge from a non-conductive, solid or liquid surface
3.10
spark
electrostatic discharge from an electrically isolated conductive object or surface
3.11
propagating brush discharge
highly energetic discharge from an insulating sheet, layer or coating on a conductive surface,
or a material of high resistivity and high break down voltage with the two surfaces highly
charged to opposite polarity
3.12
inner liner
integral or removable container which fits into the FIBC (synonymous with liner)
3.13
surface resistivity
equivalent to the surface resistance of a square area of material, having electrodes at two
opposite sides
3.14
volume resistivity
equivalent to the volume resistance of a cube of material with unit length, having the
electrodes at two opposite surfaces

– 10 – 61340-4-4  IEC:2012
3.15
type qualification testing
testing used to determine the type of FIBC as specified in 4.1 and to demonstrate that FIBC
meet the requirements of Clause 7
3.16
quality control testing
testing designed to provide manufacturers and users with information that demonstrates all
FIBC produced and delivered are substantially the same as the sample FIBC used to qualify
the FIBC design
3.17
groundable point
point on FIBC designated by the manufacturer as a location to attach a grounding or earth
bonding cable or other means of earthing FIBC
NOTE There may be one or more groundable points on each FIBC. Lift loops may also be designated as
groundable points, but fortuitous earthing via lifting hooks should not be relied as these may be painted/coated, or
covered with powder etc., and so may not guarantee an adequate earth path.
4 Classification
4.1 Principles of classification for FIBC
FIBC are classified according to one of four types: Type A, Type B, Type C and Type D. The
types are defined by the construction of the FIBC, the nature of their intended operation and
associated performance requirements.
An individual design of FIBC may only be classified as one single type; for example one FIBC
cannot be simultaneously classified as both Type B and Type D, or as Type CD.
4.1.1 Type A
Type A FIBC are made from fabric or plastic sheet without any measures against the build up
of static electricity. Any FIBC that does not meet the requirements specified in Clause 7, or
which has not been tested against the requirements is classified as Type A.
4.1.2 Type B
Type B FIBC are made from fabric or plastic sheet designed to prevent the occurrence of
sparks and propagating brush discharges.
4.1.3 Type C
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.
4.1.4 Type D
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.

61340-4-4  IEC:2012 – 11 –
4.2 Principles of classification and requirements for inner liners
4.2.1 Surface resistivity measurements for inner liners
Surface resistivity shall be measured according to IEC 61340-2-3. A minimum of ten
measurements shall be made at points evenly distributed over the inner liner surface. All
measurements shall be within the limits specified for the type of inner liner being tested.
4.2.2 Special cases
Inner liners made from materials that contain a conductive layer sandwiched between two
insulating layers shall not be used in Type B or Type D FIBC. If such an inner liner is used in
Type C FIBC, the conductive layer shall be securely bonded to earth. The thickness of the
insulating layers shall be less than 700 µm, and the breakdown voltage measured between an
electrode placed on each surface in turn and the conductive layer shall be less than 4 kV,
measured according to 9.1 under the conditions specified in 8.2.
NOTE In order to avoid incendiary brush discharge, the thickness of any exposed insulating layers in contact with
non-insulating layers is limited to a maximum of 700 µm.
4.2.3 Type L1
Type L1 inner liners are made from materials with surface resistivity on at least one surface
Ω (see Annex F), measured under the conditions specified in
less than or equal to 1,0 × 10
8.2. of this standard. Type L1 inner liners may be used in Type C FIBC.
If the material is multi-layered, or if the material has one surface with surface resistivity
greater than 1,0 × 10 Ω, the breakdown voltage through the material shall be less than 4 kV,
measured according to 9.1 under the conditions specified in 8.2.
The thickness of any layer with surface resistivity greater than 1,0 × 10 Ω on the inside
(product side) of the inner liner material shall be less than 700 µm.
Permissible configurations and requirements for type L1 inner liners are summarized in
Table 1.
Table 1 – Permissible configurations and requirements for Type L1 inner liners
Parameters
Resistivity of Resistivity of
Configuration
Breakdown voltage Thickness
inside surface outside surface
V d
B
ρ ρ
I O
7 7
ρ ≤ 1,0 × 10 Ω ρ ≤ 1,0 × 10 Ω No measurement required No limit
I O
7 12
2A No measurement required No limit
ρ ≤ 1,0 × 10 Ω ρ ≤ 1,0 × 10 Ω
I O
12 7
2B No measurement required No limit
ρ ≤ 1,0 × 10 Ω ρ ≤ 1,0 × 10 Ω
I O
7 12
3 V < 4 kV No limit
ρ ≤ 1,0 × 10 Ω ρ > 1,0 × 10 Ω
B
I O
12 7
4 ρ > 1,0 × 10 Ω ρ ≤ 1,0 × 10 Ω V < 4 kV d <700 µm
I O B
4.2.4 Type L2
Type L2 inner liners are made from materials with surface resistivity on at least one surface
9 12
between 1,0 × 10 Ω and 1,0 × 10 Ω (see Annex F), measured under the conditions
specified in 8.3. Type L2 inner liners may be used in Type B, Type C and Type D FIBC.

– 12 – 61340-4-4  IEC:2012
If Type L2 inner liners are used in Type C FIBC, the charging current shall not exceed 3 µA.
If the material is multi-layered, or if the material has one surface with surface resistivity
Ω, the breakdown voltage through the material shall be less than 4 kV,
greater than 1,0 × 10
measured according to 9.1 under the conditions specified in 8.2.
The thickness of any layer with surface resistivity greater than 1,0 × 10 Ω on the inside
(product side) of the inner liner material shall be less than 700 µm.
Permissible configurations and requirements for Type L2 inner liners are summarized in
Table 2.
Table 2 – Permissible configurations and requirements for Type L2 inner liners
Parameters
Resistivity of Resistivity of Breakdown
Configuration
Thickness
inside surface outside surface voltage
d
ρ ρ V
I O B
No
9 12 9 12
1 1,0 × 10 Ω ≤ ρ ≤ 1,0 × 10 Ω 1,0 × 10 Ω ≤ ρ ≤ 1,0 × 10 Ω measurement No limit
I O
required
9 12 12
2 V < 4 kV No limit
1,0 × 10 Ω ≤ ρ ≤ 1,0 × 10 Ω ρ > 1,0 × 10 Ω
B
I O
12 9 12
3 V < 4 kV d <700 µm
ρ > 1,0 × 10 Ω 1,0 × 10 Ω ≤ ρ ≤ 1,0 × 10 Ω
B
I I
4.2.5 Type L3
Type L3 inner liners are made from materials with surface resistivity of greater than
1,0 × 10 Ω, measured under the conditions specified in 8.2. Type L3 inner liners may be
used in Type B FIBC.
The breakdown voltage through the material shall be less than 4 kV, measured according to
9.1 under the conditions specified in 8.2.
Permissible configurations and requirements for Type L3 inner liners are summarized in
Table 3.
Table 3 – Permissible configurations and requirements for Type L3 inner liners
Parameters
Resistivity of Resistivity of Breakdown
Configuration
Thickness
inside surface outside surface voltage
d
ρ ρ V
I O B
12 12
1 V < 4 kV No limit
ρ > 1,0 × 10 Ω ρ > 1,0 × 10 Ω
B
I O
4.3 Combination of FIBC and inner liners
The inclusion of an inner liner in FIBC does not change the type classification of the FIBC.
For example, Type A FIBC with Type L1 inner liners are still Type A FIBC and are subject to
all the restrictions on use of Type A FIBC.
The requirements for breakdown voltage for FIBC and inner liners shall be applied separately.
For Type B, Type C and Type D FIBC with inner liners for which there is a breakdown voltage
requirement, two sets of breakdown voltage measurement shall be required: one set on the
FIBC material and one set on the inner liner material. For example, if a Type B FIBC is fitted

61340-4-4  IEC:2012 – 13 –
with a Type L3 inner liner, the breakdown voltage of the FIBC material shall be measured on
its own and shall be less than 6 kV and a separate breakdown voltage measurement shall be
made on the inner liner material and it shall be less than 4 kV.
5 Safe use of FIBC
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. FIBC constructed in compliance with the
requirements specified in this standard do not necessarily ensure that hazardous electrostatic
discharges, e.g. cone discharges, will not be generated by the contents in FIBC. Information
on the risks associated with cone discharges is given in Annex E.
The igniting ability of electrostatic discharges, i.e. sparks, brush discharges and propagating
brush discharges, is different for each type of discharge. The necessity of their exclusion and
thus the requirements and specifications for FIBC depend on the intended use of the FIBC.
The conditions in which each type of FIBC shall be used is shown in Table 4.
Table 4 – Use of different types of FIBC
Bulk product in FIBC Surroundings
b
Gas zones 1-2
b
(Explosion groups IIA/IIB)
b
Non-flammable Dust zones 21-22
a
MIE of dust or
a
atmosphere
(1 000 mJ ≥ MIE > 3 mJ) b
dust zones 21-22
a
(MIE ≤ 3 mJ)
c
A,B,C,D B,C,D C,D
MIE > 1 000 mJ
c
1 000 mJ ≥ MIE > 3 mJ B,C,D B,C,D C,D
c
d
C,D C,D C,D
MIE ≤ 3 mJ
NOTE 1 Additional precautions are usually necessary when a flammable gas or vapour atmosphere is present
inside the FIBC, e.g. in the case of solvent wet powders.
NOTE 2 Non-flammable atmosphere includes dusts having a MIE > 1 000 mJ.
a
Measured in accordance with IEC 61241-2-3, capacitive discharge circuit (no added inductance).
b
See Annex D for explanation of hazardous areas, zones and explosion groups.
c
Use of Type D shall be limited to explosion groups IIA/IIB with MIE ≥ 0,14 mJ.
d
See Annex E for explanation of the 3 mJ limit in relation to cone discharges.

The ability to safely use FIBC in hazardous explosive atmospheres may change if an inner
liner is installed in the FIBC. Combinations of FIBC and inner liner that can be used safely in
hazardous explosive atmospheres are shown in Table 5. In addition to the separate
requirements for FIBC and inner liners, there are requirements that certain com
...