CLC/TR 60079-32-1:2015

SLOVENSKI STANDARD
01-julij-2015
1DGRPHãþD
SIST-TP CLC/TR 50404:2003
Eksplozivne atmosfere - 32-1. del: Elektrostatske nevarnosti - Navodilo (IEC/TS
60079-32-1:2013)
Explosive atmospheres -- Part 32-1: Electrostatic Hazards - Guidance (IEC/TS 60079-32
-1:2013)
Explosionsgefährdete Bereiche - Teil 32-1: Elektrostatische Gefährdungen, Leitfaden
(IEC/TS 60079-32-1:2013)
Atmosphères explosives - Partie 32-1: Risques électrostatiques - Guide (IEC/TS 60079-
32-1:2013)
Ta slovenski standard je istoveten z: CLC/TR 60079-32-1:2015
ICS:
13.230 Varstvo pred eksplozijo Explosion protection
13.260 9DUVWYRSUHGHOHNWULþQLP Protection against electric
XGDURP'HORSRGQDSHWRVWMR shock. Live working
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT CLC/TR 60079-32-1

RAPPORT TECHNIQUE
TECHNISCHER BERICHT
April 2015
ICS 29.260.20 Supersedes CLC/TR 50404:2003
English Version
Explosive atmospheres - Part 32-1: Electrostatic Hazards -
Guidance
(IEC/TS 60079-32-1:2013)
Atmosphères explosives - Partie 32-1: Risques Explosionsgefährdete Bereiche - Teil 32-1: Elektrostatische
électrostatiques - Guide Gefährdungen, Leitfaden
(IEC/TS 60079-32-1:2013) (IEC/TS 60079-32-1:2013)

This Technical Report was approved by CENELEC on 2014-06-02.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, 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.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TR 60079-32-1:2015 E

Foreword
This document (CLC/TR 60079-32-1:2015) consists of the text of IEC/TS 60079-32-1:2013 prepared
by IEC/TC 31 "Equipment for explosive atmospheres ".

This document supersedes CLC/TR 50404:2003

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/TS 60079-32-1:2013 was approved by CENELEC as a
European Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60243-1 NOTE Harmonized as EN 60243-1.
IEC 60243-2 NOTE Harmonized as EN 60243-2.
IEC 60247 NOTE Harmonized as EN 60247.
IEC 61340-2-1 NOTE Harmonized as EN 61340-2-1.
IEC 61340-4-5 NOTE Harmonized as EN 61340-4-5.
IEC 61340-4-7 NOTE Harmonized as EN 61340-4-7.
ISO 8028 NOTE Harmonized as EN ISO 8028.
ISO 8330 NOTE Harmonized as EN ISO 8330.
ISO 13688 NOTE Harmonized as EN ISO 13688.
ISO 20344 NOTE Harmonized as EN ISO 20344.
ISO 20345 NOTE Harmonized as EN ISO 20345.

- 3 - CLC/TR 60079-32-1:2015
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 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year

IEC 60079-0 -  Explosive atmospheres -- Part 0: EN 60079-0 -
Equipment - General requirements
- -  +A11 -
IEC 60079-10-1 -  Explosive atmospheres -- Part 10-1: EN 60079-10-1 -
Classification of areas - Explosive gas
atmospheres
IEC 60079-10-2 -  Explosive atmospheres -- Part 10-2: EN 60079-10-2 -
Classification of areas - Combustible dust
atmospheres
IEC 60079-14 -  Explosive atmospheres -- Part 14: EN 60079-14 -
Electrical installations design, selection
and erection
IEC 60079-20-1 -  Explosive atmospheres - Part 20-1: EN 60079-20-1 -
Material characteristics for gas and vapour
classification - Test methods and data
IEC 60079-32-2 -  Explosive atmospheres -- Part 32-1: - -
Electrostatics hazards - Tests
IEC 60093 -  Methods of test for volume resistivity and HD 429 S1 -
surface resistivity of solid electrical
insulating materials
IEC 60167 -  Methods of test for the determination of the HD 568 S1 -
insulation resistance of solid insulating
materials
IEC 61340-2-3 -  Electrostatics -- Part 2-3: Methods of test EN 61340-2-3 -
for determining the resistance and
resistivity of solid planar materials used to
avoid electrostatic charge accumulation
IEC 61340-4-1 -  Electrostatics -- Part 4-1: Standard test EN 61340-4-1 -
methods for specific applications -
Electrical resistance of floor coverings and
installed floors
IEC 61340-4-3 -  Electrostatics -- Part 4-3: Standard test EN 61340-4-3 -
methods for specific applications -
Footwear
IEC 61340-4-4 2012 Electrostatics - Part 4-4: Standard test EN 61340-4-4 2012
methods for specific applications -
Electrostatic classification of flexible
intermediate bulk containers (FIBC)
ISO 284 -  Conveyor belts - Electrical conductivity - EN ISO 284 -
Specification and test method
ISO 6297 -  Petroleum products - Aviation and distillate - -
fuels - Determination of electrical
conductivity
ISO 8031 -  Rubber and plastics hoses and hose EN ISO 8031 -
assemblies_- Determination of electrical
resistance and conductivity
ISO 9563 -  Belt drives; electrical conductivity of - -
antistatic endless synchronous belts;
characteristics and test method
ISO 12100-1 -  Safety of machinery_- Basic concepts, EN ISO 12100-1 -
general principles for design_- Part_1:
Basic terminology, methodology
ISO 16392 -  Tyres - Electrical resistance - Test method - -
for measuring electrical resistance of tyres
on a test rig
ISO 21178 -  Light conveyor belts - Determination of EN ISO 21178 -
electrical resistances
ISO 21179 -  Light conveyor belts - Determination of the EN ISO 21179 -
electrostatic field generated by a running
light conveyor belt
ISO 21183-1 -  Light conveyor belts - Part 1: Principal EN ISO 21183-1 -
characteristics and applications
ASTM D257 -  Standard Test Methods for DC Resistance - -
or Conductance of Insulating Materials
ASTM D2624-07a -  Standard Test Methods for Electrical - -
Conductivity of Aviation and Distillate Fuels
ASTM D4308-95 -  Standard Test Method for Electrical - -
Conductivity of Liquid Hydrocarbons by
Precision Meter
ASTM E2019-03 -  Standard test method for minimum ignition - -
energy of a dust cloud in air
ASTM E582-88 -  Standard test method for minimum ignition - -
energy and quenching distance in gaseous
mixtures
ASTM F150 -  Standard Test Method for Electrical - -
Resistance of Conductive and Static
Dissipative Resilient Flooring
ASTM F1971 -  Standard Test Method for Electrical - -
Resistance of Tires Under Load On the
Test Bench
BS 5958-1 -  Code of practice for control of undesirable - -
static electricity - Part 1: General
considerations
BS 5958-2 -  Code of practice for control of undesirable - -
static electricity - Part 2:
Recommendations for particular industrial
situations
BS 7506-2 -  Methods for measurements in - -
electrostatics - Part 2 Test methods
DIN 51412-1 -  Testing of petroleum products; - -
determination of the electrical conductivity -
Part 1: laboratory method
DIN 51412-2 -  Testing of petroleum products; - -
determination of the electrical conductivity -
Part 2: field method
EN 1081 -  Resilient floor coverings - Determination of - -
the electrical resistance
EN 1149-3 -  Protective clothing - Electrostatic - -
properties - Part 3: Test methods for
measurement of charge decay
- 5 - CLC/TR 60079-32-1:2015
EN 1149-5 -  Protective clothing - Electrostatic - -
properties - Part 5: Material performance
and design requirements
EN 13463-1 -  Non-electrical equipment for use in - -
potentially explosive atmospheres - Part 1:
Basic method and requirements
EN 1360 -  Rubber and plastic hoses and hose - -
assemblies for measured fuel dispensing
systems - Specification
EN 1361 -  Rubber hoses and hose assemblies for - -
aviation fuel handling - Specification
EN 14125 -  Thermoplastic and flexible metal pipework - -
for underground installation at petrol filling
stations
EN 14973 -  Conveyor belts for use in underground - -
installations - Electrical and flammability
safety requirements
ISGOTT -  International Safety Guide for Oil Tankers - -
and Terminals (ISGOTT), fifth edition,
International chamber of shipping, 2006
JNIOSH TR 42 -  Recommendations for Requirements for - -
Avoiding Electrostatic Hazards in Industry
NFPA 77 -  Recommended practice on static electricity - -
SAE J1645 -  Surface vehicle recommended practice - - -
Fuel systems and Components -
Electrostatic Charge Mitigation

IEC/TS 60079-32-1 ®
Edition 1.0 2013-08
TECHNICAL
SPECIFICATION
Explosive atmospheres –
Part 32-1: Electrostatic hazards, guidance

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XH
ICS 29.260.20 ISBN 978-2-8322-1055-0

– 2 – TS 60079-32-1 © IEC:2013(E)
CONTENTS
FOREWORD . 10
INTRODUCTION . 12
1 Scope . 13
2 Normative references . 13
3 Terms and definitions . 16
4 Nomenclature . 19
5 General . 20
6 Static electricity in solid materials . 21
6.1 General considerations . 21
6.2 The use of conductive or dissipative materials in place of insulating ones . 23
6.2.1 General considerations . 23
6.2.2 Dissipative solid materials . 23
6.2.3 Earthing of conductive and dissipative items . 24
6.3 Precautions required when using insulating solid materials . 25
6.3.1 General . 25
6.3.2 Restrictions on the size of chargeable insulating surfaces . 26
6.3.3 Earthed metal meshes . 27
6.3.4 Insulating coatings on earthed conductive surfaces . 27
6.3.5 Conductive or dissipative coatings on insulating materials . 28
6.3.6 Static dissipative agents . 29
6.3.7 Humidification . 29
6.3.8 Ionisation / Charge Neutralisation . 29
6.3.9 Methods to determine the incendivity of discharges . 30
6.4 Conveyor belts and transmission belts . 31
6.4.1 General . 31
6.4.2 Conveyor belts . 31
6.4.3 Transmission belts . 32
7 Static electricity in liquids . 33
7.1 General considerations . 33
7.1.1 Occurrence of flammable atmospheres . 33
7.1.2 Ignition sensitivity and limitations to the scope of advice. 34
7.1.3 Charging mechanisms . 35
7.1.4 Charge accumulation and conductivity classifications . 35
7.1.5 Incendive discharges produced during liquid handling
operations . 36
7.2 Summary of precautions against ignition hazards during liquid handling
operations . 37
7.2.1 Earthing and avoidance of isolated conductors . 37
7.2.2 Restricting charge generation . 37
7.2.3 Avoidance of a flammable atmosphere . 38
7.2.4 Promoting charge dissipation . 38
7.3 Tanks and Containers . 38
7.3.1 General . 38
7.3.2 Conductive tanks and containers . 39
7.3.3 Tanks and containers made entirely of dissipative material . 52

TS 60079-32-1 © IEC:2013(E) – 3 –
7.3.4 Tanks and containers with insulating surfaces . 52
7.3.5 Use of liners in containers . 56
7.4 High viscosity liquids . 57
7.5 High charging equipment . 57
7.5.1 Filters, water separators and strainers . 57
7.5.2 Pumps and other equipment . 58
7.6 Gauging and sampling in tanks . 59
7.6.1 General . 59
7.6.2 Precautions during gauging and sampling . 59
7.7 Pipes and hose assemblies for liquids . 60
7.7.1 General . 60
7.7.2 Pipes . 60
7.7.3 Hoses and hose assemblies . 63
7.8 Special filling procedures . 69
7.8.1 Aircraft fuelling . 69
7.8.2 Road tanker deliveries . 70
7.8.3 Retail filling stations . 71
7.8.4 Mobile or temporary liquid handling equipment . 75
7.9 Plant processes (blending, stirring, mixing, crystallisation and stirred
reactors) . 75
7.9.1 General . 75
7.9.2 Earthing . 75
7.9.3 In-line blending . 75
7.9.4 Blending in vessels or tanks . 76
7.9.5 Jet mixing . 76
7.9.6 High speed mixing . 77
7.10 Spraying liquids and tank cleaning . 77
7.10.1 General . 77
7.10.2 Tank cleaning with low or medium pressure water jets (up to
about 12 bar) . 77
7.10.3 Tank cleaning with low conductivity liquids . 78
7.10.4 Tank cleaning with high pressure water or solvent jets (above
12 bar) . 78
7.10.5 Steam cleaning tanks . 78
7.10.6 Water deluge systems . 79
7.11 Glass systems . 79
7.11.1 General . 79
7.11.2 Precautions to be taken for low conductivity liquids . 79
8 Static electricity in gases . 80
8.1 General . 80
8.2 Grit blasting . 80
8.3 Fire extinguishers . 81
8.4 Inerting . 81
8.5 Steam cleaning . 81
8.6 Accidental leakage of compressed gas . 81
8.7 Spraying of flammable paints and powders . 82
8.7.1 General . 82
8.7.2 Earthing . 82
8.7.3 Plastic spray cabinets . 82

– 4 – TS 60079-32-1 © IEC:2013(E)
8.8 Vacuum cleaners, fixed and mobile . 82
8.8.1 General . 82
8.8.2 Fixed systems. 82
8.8.3 Portable systems . 83
8.8.4 Vacuum trucks . 83
9 Static electricity in powders . 83
9.1 General . 83
9.2 Discharges, occurrence and incendivity . 84
9.3 Procedural measures . 85
9.3.1 General . 85
9.3.2 Humidification . 85
9.3.3 Hoses for pneumatic transfer . 85
9.3.4 Ionisation . 85
9.4 Bulk materials in the absence of flammable gases and vapours . 86
9.4.1 General . 86
9.4.2 Equipment and objects made of conductive or dissipative
materials. 86
9.4.3 Equipment and objects made of insulating materials . 86
9.4.4 Dust separators . 87
9.4.5 Silos and Containers. 87
9.5 Additional requirements for bulk material in the presence of flammable
gases and vapours . 93
9.5.1 General . 93
9.5.2 Measures for resistivity greater equal 100 MΩ m . 93
9.5.3 Measures for resistivity less than 100 MΩ m . 93
9.5.4 Filling of bulk material into a container . 94
9.6 Flexible intermediate bulk containers (FIBC) . 95
9.6.1 General . 95
9.6.2 Additional precautions when using FIBC . 97
10 Static electricity when handling explosives and electro-explosive devices . 98
10.1 Explosives manufacture, handling and storage . 98
10.1.1 General . 98
10.1.2 First degree protection . 98
10.1.3 Intermediate protection . 98
10.1.4 Second degree protection . 98
10.2 Handling of electro-explosive devices . 99
10.2.1 General . 99
10.2.2 Earthing . 99
10.2.3 Precautions during storage and issue . 100
10.2.4 Precautions during preparation for use . 100
11 Static electricity on people . 100
11.1 General considerations . 100
11.2 Static dissipative floors . 101
11.3 Dissipative and conductive footwear . 101
11.4 Supplementary devices for earthing of people . 102
11.5 Clothing . 102
11.6 Gloves . 104
11.7 Other Items . 104
12 Electrostatic shock . 104

TS 60079-32-1 © IEC:2013(E) – 5 –
12.1 Introduction . 104
12.2 Discharges relevant to electrostatic shocks . 105
12.3 Sources of electrostatic shock. 105
12.4 Precautions to avoid electrostatic shocks . 106
12.4.1 Sources of electrostatic shocks. 106
12.4.2 Reported shocks from equipment or processes . 106
12.4.3 Shocks as a result of people being charged . 106
12.5 Precautions in special cases . 107
12.5.1 Pneumatic conveying . 107
12.5.2 Vacuum cleaners . 107
12.5.3 Reels of charged film or sheet . 107
12.5.4 Fire extinguishers . 108
13 Earthing and bonding. 108
13.1 General . 108
13.2 Criteria for the dissipation of static electricity from a conductor . 109
13.2.1 Basic considerations . 109
13.2.2 Practical criteria . 109
13.3 Earthing requirements in practical systems . 111
13.3.1 All-metal systems . 111
13.3.2 Metal plant with insulating parts . 112
13.3.3 Insulating materials . 113
13.3.4 Conductive and dissipative materials . 114
13.3.5 Earthing via intrinsic safety circuits . 114
13.3.6 Earthing of ships . 114
13.4 The establishment and monitoring of earthing systems . 114
13.4.1 Design . 114
13.4.2 Monitoring . 115
Annex A (informative) Fundamentals of static electricity . 116
A.1 Electrostatic charging . 116
A.1.1 Introduction . 116
A.1.2 Contact charging . 116
A.1.3 Contact charging of liquids . 116
A.1.4 Charge generation on liquids flowing in pipes . 117
A.1.5 Charge generation in filters . 120
A.1.6 Charge generation during stirring and mixing of liquids . 120
A.1.7 Settling potentials . 120
A.1.8 Breakup of liquid jets . 120
A.1.9 Contact charging of powders . 120
A.1.10 Charging by induction . 121
A.1.11 Charge transfer by conduction . 121
A.1.12 Charging by corona discharge . 121
A.2 Accumulation of electrostatic charge . 121
A.2.1 General . 121
A.2.2 Charge accumulation on liquids . 122
A.2.3 Charge accumulation on powders . 123
A.3 Electrostatic discharges . 124
A.3.1 Introduction . 124
A.3.2 Sparks . 124
A.3.3 Corona . 125

– 6 – TS 60079-32-1 © IEC:2013(E)
A.3.4 Brush discharges . 125
A.3.5 Propagating brush discharges. 126
A.3.6 Lightning like discharges . 126
A.3.7 Cone discharges . 127
A.4 Measurements for risk assessment . 127
Annex B (informative) Electrostatic discharges in specific situations . 129
B.1 Incendive discharges involving insulating solid materials . 129
B.1.1 General . 129
B.1.2 Sparks from isolated conductors . 129
B.1.3 Brush discharges from insulating solid materials . 129
B.1.4 Propagating brush discharges from insulating solid materials . 129
B.2 Incendive discharges produced during liquid handling . 130
B.2.1 General . 130
B.2.2 Calculated maximum safe flow velocities for filling medium-
sized vertical axis storage tanks . 130
B.3 Incendive discharges produced during powder handling and storage . 132
B.3.1 General . 132
B.3.2 Discharges from bulk powder . 132
B.3.3 Discharges from powder clouds . 132
B.3.4 Discharges involving insulating containers and people . 132
B.3.5 The use of liners in powder processes . 132
B.3.6 Spark discharges in powder processes . 133
B.3.7 Brush discharges in powder processes . 133
B.3.8 Corona discharges in powder processes . 133
B.3.9 Propagating brush discharges in powder processes . 133
Annex C (informative) Flammability properties of substances . 135
C.1 General . 135
C.2 Effect of oxygen concentration and ambient conditions . 135
C.3 Explosive limits for gases and liquids . 135
C.4 Inerting . 135
C.5 Flash point . 136
C.6 Minimum ignition energies. 136
C.7 Combustible powders . 139
C.8 Biofuels. 139
Annex D (informative) Classification of hazardous areas . 140
D.1 Concept of zoning . 140
D.2 Classification . 140
D.3 Explosion groups . 140
D.3.1 General . 140
D.3.2 Group I . 140
D.3.3 Group II . 141
D.3.4 Group III . 141
Annex E (informative) Classification of equipment protection level . 142
Annex F (informative) Flow chart for a systematic electrostatic evaluation . 143
Annex G (informative) Tests . 145
G.1 General . 145
G.2 Surface resistance . 145
G.2.1 General . 145

TS 60079-32-1 © IEC:2013(E) – 7 –
G.2.2 Principle . 145
G.2.3 Apparatus . 145
G.2.4 Test sample . 146
G.2.5 Procedure . 147
G.2.6 Acceptance criteria . 147
G.2.7 Test report . 147
G.3 Surface resistivity . 147
G.4 Leakage resistance . 148
G.4.1 General . 148
G.4.2 Principle . 148
G.4.3 Apparatus . 148
G.4.4 Test sample . 148
G.4.5 Procedure . 149
G.4.6 Acceptance criteria . 149
G.4.7 Test report . 149
G.5 In-use testing of footwear . 149
G.5.1 General . 149
G.5.2 Principle . 149
G.5.3 Apparatus . 149
G.5.4 Procedure . 150
G.5.5 Acceptance criteria . 150
G.5.6 Test report . 150
G.6 In-use testing of gloves . 150
G.6.1 General . 150
G.6.2 Principle . 150
G.6.3 Apparatus . 151
G.6.4 Procedure . 151
G.6.5 Acceptance criteria . 151
G.6.6 Test report . 151
G.7 Powder resistivity . 151
G.7.1 General . 151
G.7.2 Principle . 151
G.7.3 Apparatus . 152
G.7.4 Procedure . 152
G.7.5 Acceptance criteria . 153
G.7.6 Test report . 153
G.8 Liquid conductivity . 153
G.8.1 General . 153
G.8.2 Principle . 153
G.8.3 Apparatus . 153
G.8.4 Procedure . 154
G.8.5 Acceptance criteria . 154
G.8.6 Test report . 154
G.9 Capacitance . 155
G.9.1 General . 155
G.9.2 Principle . 155
G.9.3 Apparatus . 155
G.9.4 Test sample . 155
G.9.5 Procedure for moveable items . 155

– 8 – TS 60079-32-1 © IEC:2013(E)
G.9.6 Procedure for installed items . 156
G.9.7 Acceptance criteria . 156
G.9.8 Test report . 156
G.10 Transferred charge . 157
G.10.1 General . 157
G.10.2 Principle . 157
G.10.3 Apparatus . 157
G.10.4 Test sample . 158
G.10.5 Procedure . 158
G.10.6 Acceptance criteria . 159
G.10.7 Test report . 159
G.11 Ignition test . 160
G.11.1 General . 160
G.11.2 Apparatus . 160
G.11.3 Procedure . 163
G.11.4 Acceptance criteria . 163
G.11.5 Test report . 163
G.12 Measuring of charge decay . 164
G.12.1 General . 164
G.12.2 Principle . 164
G.12.3 Apparatus . 164
G.12.4 Test sample . 165
G.12.5 Procedure . 165
G.12.6
...