SIST-TP CLC/TR 60079-32-1:2019

Explosive atmospheres - Part 32-1: Electrostatic hazards, guidance (IEC/TS 60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)

IEC/TS 60079-32-1:2013(E) gives guidance about the equipment, product and process properties necessary to avoid ignition and electrostatic shock hazards arising from static electricity as well as the operational requirements needed to ensure safe use of the equipment, product or process. It can be used in a risk assessment of electrostatic hazards or for the preparation of product family or dedicated product standards for electrical or non-electrical machines or equipment. The purpose of this document is to provide standard recommendations for the control of static electricity, such as earthing of conductors, reduction of charging and restriction of chargeable areas of insulators. In some cases static electricity plays an integral part of a process, e.g. electrostatic coating, but often it is an unwelcome side effect and it is with the latter that this guidance is concerned. If the standard recommendations given in this document are fulfilled it can be expected that the risk of hazardous electrostatic discharges in an explosive atmosphere is at an acceptably low level. Keywords: risk assessment of electrostatic hazards, static electricity

Explosionsgefährdete Bereiche - Teil 32-1: Elektrostatische Gefährdungen, Leitfaden (IEC/TS 60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)

Atmosphères explosives - Partie 32-1: Risques électrostatiques - Guide (IEC/TS 60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)

IEC TS 60079-32-1:2013 fournit les recommandations relatives au matériel, au produit et aux propriétés de processus nécessaires pour éviter l'inflammation et les dangers de chocs électrostatiques liés à l'électricité statique, ainsi que les exigences de fonctionnement nécessaires pour garantir l'utilisation en toute sécurité du matériel, du produit ou du processus. Elle peut être utilisée dans le cadre d'une appréciation du risque des dangers électrostatiques ou de l'élaboration de normes de famille de produits ou de normes de produits spécifiques concernant des machines ou des équipements électriques ou non électriques.
L'objet du présent document est de fournir des recommandations normalisées pour le contrôle de l'électricité statique, telles que la mise à la terre des conducteurs, la réduction de l'électrisation et la restriction des zones électrisables des isolateurs. Dans certains cas, l'électricité statique fait partie intégrante d'un processus (revêtement électrostatique, par exemple), mais elle s'accompagne souvent d'un effet secondaire gênant, ce sur quoi portent les présentes recommandations. Si les recommandations normalisées indiquées dans le présent document sont respectées, le risque de décharges électrostatiques dangereuses attendues dans une atmosphère explosive peut être à un niveau bas acceptable.

Eksplozivne atmosfere - 32-1. del: Elektrostatske nevarnosti - Navodilo (IEC/TS 60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)

IEC/TS 60079-32-1:2013(E) podaja navodila o lastnostih opreme, izdelkov in postopkov, potrebnih za preprečevanje nevarnosti vžiga in elektrostatičnega udara zaradi statične elektrike, ter zahteve glede delovanja, potrebne za zagotavljanje varne uporabe opreme, izdelka ali postopka. Uporablja se lahko pri oceni tveganja elektrostatičnih nevarnosti ali pripravi skupine izdelkov oziroma ustreznih standardov za izdelke za električne ali neelektrične stroje/opremo. Namen tega dokumenta je podati standardna priporočila za zaščito pred statično elektriko npr. z ozemljitvijo vodnikov, zmanjšanjem napajanja in omejitvijo predelov izolatorjev pod napetostjo. V nekaterih primerih je statična elektrika sestavni del postopka (npr. elektrostatična prevleka), pogostokrat pa je nezaželen stranski učinek, kot je obravnavano v teh navodilih. Če so standardna priporočila, podana v tem dokumentu, upoštevana, se lahko pričakuje, da je stopnja nevarnosti elektrostatičnih razelektritev v eksplozivnem okolju sprejemljivo nizka. Ključne besede: ocena tveganja elektrostatičnih nevarnosti, statična elektrika

General Information

• Status: Published
• Publication Date: 18-Mar-2019
• ICS: 13.230 - Explosion protection
• ICS: 13.260 - Protection against electric shock. Live working
• Technical Committee: EXP - Product for explosive atmospheres
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 27-Dec-2018
• Due Date: 03-Mar-2019
• Completion Date: 19-Mar-2019
• Directive: 2016-01-1803 - Pravilnik o protieksplozijski zaščiti
• Ref Project: CLC/TR 60079-32-1:2018 - Explosive atmospheres - Part 32-1: Electrostatic hazards, guidance

Relations

• Replaces: SIST-TP CLC/TR 60079-32-1:2015 - Explosive atmospheres -- Part 32-1: Electrostatic Hazards - Guidance (IEC/TS 60079-32-1:2013)
• Effective Date: 18-Dec-2018

Overview

SIST-TP CLC/TR 60079-32-1:2019 (IEC/TS 60079-32-1:2013 + A1:2017) provides guidance on electrostatic hazards in explosive atmospheres. It explains the equipment, product and process properties and the operational controls needed to avoid ignition or electrostatic shock hazards arising from static electricity. The document is designed to support risk assessment of electrostatic hazards and to inform the preparation of product-family or dedicated standards for both electrical and non-electrical machines and equipment.

Key topics and technical requirements

The Technical Report covers practical recommendations, including:

• Fundamental guidance

  • Scope, terms and definitions, and general principles for managing electrostatic risk in hazardous areas.
  • How this guidance relates to IEC 60079-0 and other Ex requirements (summary included as an added clause).

• Materials and surfaces

  • Use of conductive or static-dissipative materials instead of insulating ones.
  • Restrictions on size and geometry of chargeable insulating surfaces.
  • Coatings, static-dissipative additives, humidification and ionisation as mitigation measures.

• Earthing and bonding

  • Earthing of conductors and avoidance of isolated conductive items to prevent hazardous discharges.

• Solid handling and conveyors

  • Guidance for conveyor belts and transmission belts, selection and testing to reduce charge generation.

• Liquids and liquid handling

  • Charging mechanisms for liquids, charge accumulation and classifications.
  • Practical controls for tanks, piping, hoses, pumps, filtering and sampling.
  • Special procedures for aircraft fuelling, road tanker deliveries, retail filling and mobile equipment.

• Process operations

  • Blending, mixing, spraying, jet mixing and tank cleaning - with specific precautions to limit ignition risk.

• Testing and verification

  • Cross-references to test methods (e.g., IEC/TS 60079-32-2 and IEC/61340 series) for assessing resistivity, charge decay and incendivity of discharges.

Practical applications and users

This guidance is intended for:

• Process, safety and design engineers in chemical, oil & gas, pharmaceuticals, food and paints/coatings industries
• Equipment manufacturers and integrators of pumps, hoses, conveyors, tanks and filling systems
• HSE professionals conducting risk assessments of electrostatic hazards
• Standards writers, certification bodies and competent authorities developing product or plant-level Ex requirements

Typical uses:

• Developing safe earthing/bonding procedures
• Selecting conductive/dissipative materials and coatings
• Defining safe operating and filling procedures to prevent static ignition
• Preparing product-family standards and compliance documentation

Related standards (select)

• IEC 60079-0 (Ex equipment general requirements)
• IEC/TS 60079-32-2 (electrostatics test methods)
• IEC 61340 series (electrostatic control)
• Relevant ISO, EN and ASTM test and material standards referenced in the Technical Report

Keywords: explosive atmospheres, electrostatic hazards, static electricity, risk assessment of electrostatic hazards, earthing, conductive materials, dissipative materials, liquid handling, conveyor belts.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2019
1DGRPHãþD
SIST-TP CLC/TR 60079-32-1:2015
Eksplozivne atmosfere - 32-1. del: Elektrostatske nevarnosti - Navodilo (IEC/TS
60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)
Explosive atmospheres - Part 32-1: Electrostatic hazards, guidance (IEC/TS 60079-32-
1:2013, IEC/TS 60079-32-1:2013/A1:2017)
Explosionsgefährdete Bereiche - Teil 32-1: Elektrostatische Gefährdungen, Leitfaden
(IEC/TS 60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)
Atmosphères explosives - Partie 32-1: Risques électrostatiques - Guide (IEC/TS 60079-
32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)
Ta slovenski standard je istoveten z: CLC/TR 60079-32-1:2018
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
December 2018
ICS 29.260.20 Supersedes CLC/TR 60079-32-1:2015
English Version
Explosive atmospheres - Part 32-1: Electrostatic hazards,
guidance
(IEC/TS 60079-32-1:2013, IEC/TS 60079-32-1:2013/A1:2017)
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- (IEC/TS 60079-32-1:2013, IEC/TS 60079-32-
1:2013/A1:2017) 1:2013/A1:2017)

This Technical Report was approved by CENELEC on 2018-10-22.

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, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TR 60079-32-1:2018 E

European foreword
This document (CLC/TR 60079-32-1:2018) consists of the text of IEC/TS 60079-32-1:2013 and
IEC/TS 60079-32-1:2013/A1:2017 prepared by IEC/TC 31 "Equipment for explosive atmospheres".

This document supersedes CLC/TR 60079-32-1:2015.

The technical specification IEC/TS 60079-32-1 is written as a general guidance document for products
in general and process properties necessary to avoid ignition hazards arising from static electricity in a
hazardous area.
The IEC standard IEC 60079-0 specifies the general requirements, including the requirements to
avoid electrostatic charging, for construction, testing and marking of Ex equipment and Ex
Components intended for use in explosive atmospheres.

In some cases, the requirements given in IEC 60079-0 are different from the information given in
IEC/TS 60079-32-1.
It was decided to have all information also given complete in the guidance document and therefore the
new Clause 14 was added to the IEC/TS 60079-32-1 summarizing the requirements given in
IEC 60079-0 for Ex equipment and Ex-Components as additional information.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The texts of the International Technical Specifications IEC/TS 60079-32-1:2013 and
IEC/TS 60079-32-1:2013/A1:2017 were approved by CENELEC as a Technical Report 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.

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 60079-0 2011 Explosive atmospheres - EN 60079-0 2012
Part 0: Equipment - General requirements

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 60079-14 - Explosive atmospheres - EN 60079-14 -
Part 14: Electrical installations design,
selection and erection
IEC 60079-20-1 - Explosive atmospheres - EN 60079-20-1 -
Part 20-1: Material characteristics for gas
and vapour classification - Test methods and
data
IEC 60079-32-2 2015 Explosive atmospheres - EN 60079-32-2 2015
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 - 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
IEC 61340-4-1 - Electrostatics - EN 61340-4-1 -
Part 4-1: Standard test methods for specific
applications - Electrical resistance of floor
coverings and installed floors

IEC 61340-4-3 - Electrostatics - EN 61340-4-3 -
Part 4-3: Standard test methods for specific
applications - Footwear
IEC 61340-4-4 2012 Electrostatics - EN 61340-4-4 2012
Part 4-4: Standard test methods for specific
applications - Electrostatic classification of
flexible intermediate bulk containers (FIBC)

Publication Year Title EN/HD Year
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 - EN ISO 21183-1 -
Part 1: Principal 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 E582-88 - Standard test method for minimum ignition - -
energy and quenching distance in gaseous
mixtures
ASTM E2019-03 - Standard test method for minimum ignition - -
energy of a dust cloud in air
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
Publication Year Title EN/HD Year
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
- - Resilient floor coverings - Determination of EN 1081 -
the electrical resistance
- - Protective clothing - Electrostatic EN 1149-3 -
properties - Part 3: Test methods for
measurement of charge decay
- - Protective clothing - Electrostatic EN 1149-5 -
properties - Part 5: Material performance
and design requirements
- - Rubber and plastic hoses and hose EN 1360 -
assemblies for measured fuel dispensing
systems - Specification
- - Rubber hoses and hose assemblies for EN 1361 -
aviation fuel handling - Specification

- - Non-electrical equipment for use in EN 13463-1 -
potentially explosive atmospheres -
Part 1: Basic method and requirements

- - Thermoplastic and flexible metal pipework EN 14125 -
for underground installation at petrol filling
stations
- - Conveyor belts for use in underground EN 14973 -
installations - Electrical and flammability
safety requirements
ISGOTT 2006 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 1.1 2017-03
FINAL VERSION
Explosive atmospheres –
Part 32-1: Electrostatic hazards, guidance

IEC TS 60079-32-1:2013-08+AMD1:2017-03 CSV(en)

– 2 – IEC TS 60079-32-1:2013+AMD1:2017 CSV
© IEC 2017
CONTENTS
FOREWORD . 11
INTRODUCTION . 13
1 Scope . 14
2 Normative references . 14
3 Terms and definitions . 17
4 Nomenclature . 20
5 General . 21
6 Static electricity in solid materials . 22
6.1 General considerations . 22
6.2 The use of conductive or dissipative materials in place of insulating ones . 24
6.2.1 General considerations . 24
6.2.2 Dissipative solid materials . 24
6.2.3 Earthing of conductive and dissipative items . 25
6.3 Precautions required when using insulating solid materials . 26
6.3.1 General . 26
6.3.2 Restrictions on the size of chargeable insulating surfaces . 27
6.3.3 Earthed metal meshes . 28
6.3.4 Insulating coatings on earthed conductive surfaces . 28
6.3.5 Conductive or dissipative coatings on insulating materials . 29
6.3.6 Static dissipative agents . 30
6.3.7 Humidification . 30
6.3.8 Ionisation / Charge Neutralisation . 30
6.3.9 Methods to determine the incendivity of discharges . 31
6.4 Conveyor belts and transmission belts . 32
6.4.1 General . 32
6.4.2 Conveyor belts . 32
6.4.3 Transmission belts . 33
7 Static electricity in liquids . 34
7.1 General considerations . 34
7.1.1 Occurrence of flammable atmospheres . 34
7.1.2 Ignition sensitivity and limitations to the scope of advice. 35
7.1.3 Charging mechanisms . 36
7.1.4 Charge accumulation and conductivity classifications . 36
7.1.5 Incendive discharges produced during liquid handling
operations . 37
7.2 Summary of precautions against ignition hazards during liquid handling
operations . 38
7.2.1 Earthing and avoidance of isolated conductors . 38
7.2.2 Restricting charge generation . 38
7.2.3 Avoidance of a flammable atmosphere . 39
7.2.4 Promoting charge dissipation . 39
7.3 Tanks and Containers . 39
7.3.1 General . 39
7.3.2 Conductive tanks and containers . 40
7.3.3 Tanks and containers made entirely of dissipative material . 53
7.3.4 Tanks and containers with insulating surfaces . 53

IEC TS 60079-32-1:2013+AMD1:2017 CSV – 3 –
© IEC 2017
7.3.5 Use of liners in containers . 57
7.4 High viscosity liquids . 58
7.5 High charging equipment . 58
7.5.1 Filters, water separators and strainers . 58
7.5.2 Pumps and other equipment . 59
7.6 Gauging and sampling in tanks . 60
7.6.1 General . 60
7.6.2 Precautions during gauging and sampling . 60
7.7 Pipes and hose assemblies for liquids . 61
7.7.1 General . 61
7.7.2 Pipes . 61
7.7.3 Hoses and hose assemblies . 64
7.8 Special filling procedures . 70
7.8.1 Aircraft fuelling . 70
7.8.2 Road tanker deliveries . 71
7.8.3 Retail filling stations . 72
7.8.4 Mobile or temporary liquid handling equipment . 76
7.9 Plant processes (blending, stirring, mixing, crystallisation and stirred
reactors) . 76
7.9.1 General . 76
7.9.2 Earthing . 76
7.9.3 In-line blending . 76
7.9.4 Blending in vessels or tanks . 77
7.9.5 Jet mixing . 77
7.9.6 High speed mixing . 78
7.10 Spraying liquids and tank cleaning . 78
7.10.1 General . 78
7.10.2 Tank cleaning with low or medium pressure water jets (up to
about 12 bar) . 78
7.10.3 Tank cleaning with low conductivity liquids . 79
7.10.4 Tank cleaning with high pressure water or solvent jets (above
12 bar) . 79
7.10.5 Steam cleaning tanks . 79
7.10.6 Water deluge systems . 80
7.11 Glass systems . 80
7.11.1 General . 80
7.11.2 Precautions to be taken for low conductivity liquids . 80
8 Static electricity in gases . 81
8.1 General . 81
8.2 Grit blasting . 81
8.3 Fire extinguishers . 82
8.4 Inerting . 82
8.5 Steam cleaning . 82
8.6 Accidental leakage of compressed gas . 82
8.7 Spraying of flammable paints and powders . 83
8.7.1 General . 83
8.7.2 Earthing . 83
8.7.3 Plastic spray cabinets . 83
8.8 Vacuum cleaners, fixed and mobile . 83

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© IEC 2017
8.8.1 General . 83
8.8.2 Fixed systems. 83
8.8.3 Portable systems . 84
8.8.4 Vacuum trucks . 84
9 Static electricity in powders . 84
9.1 General . 84
9.2 Discharges, occurrence and incendivity . 85
9.3 Procedural measures . 86
9.3.1 General . 86
9.3.2 Humidification . 86
9.3.3 Hoses for pneumatic transfer . 86
9.3.4 Ionisation . 86
9.4 Bulk materials in the absence of flammable gases and vapours . 87
9.4.1 General . 87
9.4.2 Equipment and objects made of conductive or dissipative
materials. 87
9.4.3 Equipment and objects made of insulating materials . 87
9.4.4 Dust separators . 88
9.4.5 Silos and Containers. 88
9.5 Additional requirements for bulk material in the presence of flammable
gases and vapours . 94
9.5.1 General . 94
9.5.2 Measures for resistivity greater equal 100 MΩ m . 94
9.5.3 Measures for resistivity less than 100 MΩ m . 94
9.5.4 Filling of bulk material into a container . 95
9.6 Flexible intermediate bulk containers (FIBC) . 96
9.6.1 General . 96
9.6.2 Additional precautions when using FIBC . 98
10 Static electricity when handling explosives and electro-explosive devices . 99
10.1 Explosives manufacture, handling and storage . 99
10.1.1 General . 99
10.1.2 First degree protection . 99
10.1.3 Intermediate protection . 99
10.1.4 Second degree protection . 99
10.2 Handling of electro-explosive devices . 100
10.2.1 General . 100
10.2.2 Earthing . 100
10.2.3 Precautions during storage and issue . 101
10.2.4 Precautions during preparation for use . 101
11 Static electricity on people . 101
11.1 General considerations . 101
11.2 Static dissipative floors . 102
11.3 Dissipative and conductive footwear . 102
11.4 Supplementary devices for earthing of people . 103
11.5 Clothing . 103
11.6 Gloves . 105
11.7 Other Items . 105
12 Electrostatic shock . 105
12.1 Introduction . 105

IEC TS 60079-32-1:2013+AMD1:2017 CSV – 5 –
© IEC 2017
12.2 Discharges relevant to electrostatic shocks . 106
12.3 Sources of electrostatic shock. 106
12.4 Precautions to avoid electrostatic shocks . 107
12.4.1 Sources of electrostatic shocks. 107
12.4.2 Reported shocks from equipment or processes . 107
12.4.3 Shocks as a result of people being charged . 107
12.5 Precautions in special cases . 108
12.5.1 Pneumatic conveying . 108
12.5.2 Vacuum cleaners . 108
12.5.3 Reels of charged film or sheet . 108
12.5.4 Fire extinguishers . 109
13 Earthing and bonding. 109
13.1 General . 109
13.2 Criteria for the dissipation of static electricity from a conductor . 110
13.2.1 Basic considerations . 110
13.2.2 Practical criteria . 110
13.3 Earthing requirements in practical systems . 112
13.3.1 All-metal systems . 112
13.3.2 Metal plant with insulating parts . 113
13.3.3 Insulating materials . 114
13.3.4 Conductive and dissipative materials . 115
13.3.5 Earthing via intrinsic safety circuits . 115
13.3.6 Earthing of ships . 115
13.4 The establishment and monitoring of earthing systems . 115
13.4.1 Design . 115
13.4.2 Monitoring . 116
14 Special requirements for equipment according to IEC 60079-0 . 116
14.1 General . 116
14.2 Electrostatic charges on external non-metallic materials . 117
14.2.1 Applicability . 117
14.2.2 Avoidance of a build-up of electrostatic charge on Group I or
Group II electrical equipment . 117
14.2.3 Avoidance of a build-up of electrostatic charge on equipment
for Group III . 120
14.3 Electrostatic charges on external conductive parts . 120
Annex A (informative) Fundamentals of static electricity . 121
A.1 Electrostatic charging . 121
A.1.1 Introduction . 121
A.1.2 Contact charging . 121
A.1.3 Contact charging of liquids . 121
A.1.4 Charge generation on liquids flowing in pipes . 122
A.1.5 Charge generation in filters . 125
A.1.6 Charge generation during stirring and mixing of liquids . 125
A.1.7 Settling potentials . 125
A.1.8 Breakup of liquid jets . 125
A.1.9 Contact charging of powders . 125
A.1.10 Charging by induction . 126
A.1.11 Charge transfer by conduction . 126
A.1.12 Charging by corona discharge . 126

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© IEC 2017
A.2 Accumulation of electrostatic charge . 126
A.2.1 General . 126
A.2.2 Charge accumulation on liquids . 127
A.2.3 Charge accumulation on powders . 128
A.3 Electrostatic discharges . 129
A.3.1 Introduction . 129
A.3.2 Sparks . 129
A.3.3 Corona . 130
A.3.4 Brush discharges . 130
A.3.5 Propagating brush discharges. 131
A.3.6 Lightning like discharges . 131
A.3.7 Cone discharges . 132
A.4 Measurements for risk assessment . 132
Annex B (informative) Electrostatic discharges in specific situations . 134
B.1 Incendive discharges involving insulating solid materials . 134
B.1.1 General . 134
B.1.2 Sparks from isolated conductors . 134
B.1.3 Brush discharges from insulating solid materials . 134
B.1.4 Propagating brush discharges from insulating solid materials . 134
B.2 Incendive discharges produced during liquid handling . 135
B.2.1 General . 135
B.2.2 Calculated maximum safe flow velocities for filling medium-
sized vertical axis storage tanks . 135
B.3 Incendive discharges produced during powder handling and storage . 137
B.3.1 General . 137
B.3.2 Discharges from bulk powder . 137
B.3.3 Discharges from powder clouds . 137
B.3.4 Discharges involving insulating containers and people . 137
B.3.5 The use of liners in powder processes . 137
B.3.6 Spark discharges in powder processes . 138
B.3.7 Brush discharges in powder processes . 138
B.3.8 Corona discharges in powder processes . 138
B.3.9 Propagating brush discharges in powder processes . 138
Annex C (informative) Flammability properties of substances . 140
C.1 General . 140
C.2 Effect of oxygen concentration and ambient conditions . 140
C.3 Explosive limits for gases and liquids . 140
C.4 Inerting . 140
C.5 Flash point . 141
C.6 Minimum ignition energies. 141
C.7 Combustible powders . 144
C.8 Biofuels. 144
Annex D (informative) Classification of hazardous areas . 145
D.1 Concept of zoning . 145
D.2 Classification . 145
D.3 Explosion groups . 145
D.3.1 General . 145
D.3.2 Group I . 145
D.3.3 Group II . 146

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D.3.4 Group III . 146
Annex E (informative) Classification of equipment protection level . 147
Annex F (informative) Flow chart for a systematic electrostatic evaluation . 148
Annex G (informative) Tests . 150
G.1 General . 150
G.2 Surface resistance . 150
G.2.1 General . 150
G.2.2 Principle . 150
G.2.3 Apparatus . 150
G.2.4 Test sample . 151
G.2.5 Procedure . 152
G.2.6 Acceptance criteria . 152
G.2.7 Test report . 152
G.3 Surface resistivity . 152
G.4 Leakage resistance . 153
G.4.1 General . 153
G.4.2 Principle . 153
G.4.3 Apparatus . 153
G.4.4 Test sample . 153
G.4.5 Procedure . 154
G.4.6 Acceptance criteria . 154
G.4.7 Test report . 154
G.5 In-use testing of footwear . 154
G.5.1 General . 154
G.5.2 Principle . 154
G.5.3 Apparatus . 154
G.5.4 Procedure . 155
G.5.5 Acceptance criteria . 155
G.5.6 Test report . 155
G.6 In-use testing of gloves . 155
G.6.1 General . 155
G.6.2 Principle . 155
G.6.3 Apparatus . 156
G.6.4 Procedure . 156
G.6.5 Acceptance criteria . 156
G.6.6 Test report . 156
G.7 Powder resistivity . 156
G.7.1 General . 156
G.7.2 Principle . 156
G.7.3 Apparatus . 157
G.7.4 Procedure . 157
G.7.5 Acceptance criteria . 158
G.7.6 Test report . 158
G.8 Liquid conductivity . 158
G.8.1 General . 158
G.8.2 Principle . 158
G.8.3 Apparatus . 158
G.8.4 Procedure . 159
G.8.5 Acceptance criteria . 159

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© IEC 2017
G.8.6 Test report . 159
G.9 Capacitance . 160
G.9.1 General . 160
G.9.2 Principle . 160
G.9.3 Apparatus . 160
G.9.4 Test sample . 160
G.9.5 Procedure for moveable items . 160
G.9.6 Procedure for installed items . 161
G.9.7 Acceptance criteria . 161
G.9.8 Test report . 161
G.10 Transferred charge . 162
G.10.1 General . 162
G.10.2 Principle .
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