Tanker Safety Guide (Chemicals) - Sixth Edition

The ICS Tanker Safety Guide (Chemicals) is the trusted publication for chemical tankers since 1971. Now in its sixth edition, the guide continues to translate the regulatory requirements of MARPOL Annex II into practical on board procedures for safe and environmentally responsible operations.

Readers can expect updated and expanded guidance on:
- Annex I to Annex II cargo changeovers, including a practical flowchart that covers these tank cleaning operations step-by-step
- Safe enclosed space entry operations, helping crew better understand key safety requirements and building on updated guidelines from the IMO
- Washing water analysis, limiting the need for enclosed space entry and avoiding unnecessary risk
- Hot work hazardous zones and
- Safe use of shore power, reducing use of fuel and emissions

It is recommended that this guide and its companion, International Safety Guide for Oil Tankers and Terminals (ISGOTT), are on board all ships carrying hazardous and noxious chemicals in bulk. The Tanker Safety Guide (Chemicals) Sixth Edition is essential for anyone involved in the carriage of chemicals on ships, including crew on board chemical tankers, ship operators and managers, cargo interests and charterers, training institutes and terminal operators.

The first edition of the ICS Tanker Safety Guide (Chemicals) was published in 1971. Revisions to subsequent editions of the guide have established it as the go-to publication for chemical tankers, taking particular account of the need for chemical tankers to comply with IMO regulations.

This sixth edition continues to provide those serving on ships carrying hazardous and noxious chemicals in bulk with up-to-date information on recognised best practice for safe and pollution-free operations on ships regulated under MARPOL Annex II (Regulations for the Prevention of Pollution by Noxious Liquid Substances). New guidance aims to clarify Annex I to Annex II cargo changeovers, to ensure masters and shipowners are confident at every step during these tank cleaning operations.
This sixth edition also details new content on the safe use of shore power and hot work hazardous zones.

Reflecting that serious enclosed space accidents unfortunately continue to occur, primarily due to a failure to follow established procedures, the previous two editions of this guide provided updated and improved guidance on this essential safety topic. Following the updated enclosed space entry guidelines issued by the IMO, this sixth edition was further updated to help masters and crew understand the key safety requirements. As the industry moves toward limiting enclosed space entries wherever possible, ICS is pleased to include new guidance on washing water analysis that reduces the need for enclosed space entry and helps crew avoid unnecessary risk.

The guide deals primarily with operational matters and best safety practices. It does not make recommendations on the construction or maintenance of chemical carriers or their equipment: such standards are set by IMO, national administrations and classification societies. Likewise, the guide does not address the operation of specific items of equipment or their repair. However, in some cases general reference is made to these matters as well as to relevant regulations.

It is recommended that a copy of this guide be used on board all chemical tankers, which should also have on board the International Safety Guide for Oil Tankers and Terminals (ISGOTT) with which this guide is compatible and which should also be consulted, especially whenever oil cargoes are carried. This compatibility will provide consistent safe guidance and minimise the increasing burden associated with audits and vetting inspections. This guide is also a companion to the ICS Tanker
Safety Guide (Liquefied Gas).

Comments and suggestions for improvements are always welcome and should be addressed to: publications@ics-shipping.org

Abbreviations 16
Definitions 18
Editorial Note 27

Chapter 1
Hazards and properties of chemicals 29
1 Hazards and properties of chemicals 31
1.1 Introduction 31
1.2 Physical properties 31
1.2.1 Specific gravity and density 31
1.2.2 Volume expansion coefficient 32
1.2.3 Melting/freezing point 32
1.2.4 Vapour pressure 32
1.2.5 Boiling point 33
1.2.6 Vapour density 33
1.2.7 Viscosity 33
1.2.8 Water solubility 33
1.3 Flammability 34
1.3.1 Flashpoint 34
1.3.2 Explosive/flammable limits 34
1.3.3 The effect of inert gas on flammability 35
1.4 Static electricity 36
1.4.1 General 36
1.4.2 Charge separation 36
1.4.3 Charge accumulation and relaxation in liquids 37
1.4.4 Generation of static 38
1.4.5 Static generation during cargo operations 38
1.4.6 Static generation during tank cleaning 39
1.4.7 Static generating portable equipment 39
1.4.8 General precautions against static electricity hazards 39
1.5 Toxicity 40
1.5.1 General 40
1.5.2 Exposure to toxicity 40
1.5.3 Degrees of toxicity 41
1.5.4 Exposure limits 41
1.5.5 Precautionary principles 42
1.6 Reactivity 42
1.6.1 General 42
1.6.2 Unstable chemicals 42
1.6.3 Chemicals that react with oxygen 44
1.6.4 Chemicals that react with water 45
1.6.5 Reaction of acids with water 45
1.6.6 Incompatible chemicals 46
1.6.7 Reaction with construction materials 47
1.7 Corrosive substances 48
1.7.1 General 48
1.7.2 IBC Code requirements 49
1.8 Hazardous cargo information 49
1.8.1 Safety data sheet 49
1.8.2 SDS contents 49

Chapter 2
General precautions 53
2 General precautions 55
2.1 Introduction 55
2.2 Moorings 55
2.3 Emergency towing-off pennants (fire wires) 56
2.4 Access to the ship 56
2.4.1 Means of access (gangways or accommodation ladders) 56
2.4.2 Lighting 56
2.4.3 Unauthorised access 56
2.4.4 People smoking or intoxicated 57
2.5 Warning notices 57
2.5.1 Permanent 57
2.5.2 Temporary 57
2.6 Effects of other ships and berths 58
2.6.1 Other tankers at adjacent berths 58
2.6.2 Chemical carrier operations at general cargo berths 58
2.7 Weather precautions 58
2.7.1 Wind conditions 58
2.7.2 Electrical storms 58
2.7.3 Cold weather 58
2.7.4 Openings to the accommodation 59
2.7.5 Accommodation atmosphere control 59
2.8 Machinery spaces 59
2.8.1 Funnel sources of ignition 59
2.8.2 Blowing boiler tubes 60
2.8.3 Cargo vapour 60
2.9 Pressure surges 60
2.9.1 Introduction 60
2.9.2 Generation of pressure surge 60
2.10 Pumprooms and enclosed spaces 61
2.10.1 Cargo pumprooms 61
2.10.2 Enclosed spaces 61
2.11 Ship?s readiness to move 62
2.12 Helicopter operations 62
2.13 Communication equipment 62
2.13.1 Ship?s radio transmission equipment 62
2.13.2 Electrical maintenance and repairs 62
2.13.3 Transmitting devices 63
2.13.4 Personal electronic items 63
2.14 Hot work 65
2.14.1 Hot work zones on tankers 65
2.14.2 Safety precautions 66
2.14.3 Preparations before hot work 66
2.14.4 Checks by the officer responsible for safety during hot work 67
2.14.5 Use of hot work equipment 69
2.15 Cold work 70
2.16 Mechanically powered tools 70
2.17 Hand tools 71
2.18 Shore power 71

Chapter 3
Safety management, training and personal protective
equipment 75
3 Safety management, training and personal protective equipment 77
3.1 Introduction 77
3.2 Implementing a safety culture 77
3.2.1 What is a safety culture? 77
3.2.2 Key features of an effective safety culture 78
3.3 The ISM Code 78
3.4 Company responsibility 79
3.5 Safety information for shore personnel 79
3.6 Outside contractors 79
3.7 Risk assessments 80
3.7.1 Risk assessment process? 80
3.7.2 High risk activities and permits to work 83
3.7.3 Acceptable risk 83
3.7.4 Risk matrices 83
3.7.5 Deciding on the need for a risk assessment 84
3.7.6 Generic and task-based risk assessments 85
3.7.7 Competence for carrying out risk assessments 85
3.8 Safe operations 85
3.8.1 Routine operations 85
3.8.2 Non-routine operations 85
3.9 Incident investigations 86
3.10 Crew resources 87
3.10.1 Training 87
3.10.2 Familiarisation 89
3.10.3 Drills and exercises 90
3.10.4 Crew communication 90
3.10.5 Prevention of drug and alcohol abuse 90
3.11 Personal protective equipment 90
3.11.1 General 90
3.11.2 Safe working clothing 91
3.11.3 Protective clothing 91
3.11.4 Toxic or corrosive substance protection 91
3.11.5 Chemical-resistant clothing (protective suits) 93
3.11.6 Types of chemical-resistant clothing 93
3.11.7 Eye protection 95
3.11.8 Hand protection 96
3.11.9 Foot protection 96
3.11.10 Cargo-specific personal protective equipment 96
3.11.11 Respiratory protection 97
3.11.12 Self-contained breathing apparatus 97
3.11.13 Air-line breathing apparatus 97
3.11.14 Emergency escape respiratory protection 98
3.11.15 Canister or filter-type respirators 98
3.11.16 Maintenance 98
3.11.17 Training 98

Chapter 4
Regulatory framework 99
4 Regulatory framework 101
4.1 Introduction 101
4.2 Regulatory guidelines 101
4.3 IMO MARPOL regulations 101
4.3.1 MARPOL Annex I - Prevention of Pollution by Oil 102
4.3.2 MARPOL Annex II - Prevention of Pollution by Noxious Liquid Substances 103
4.3.3 Switching from MARPOL Annex I to Annex II/IBC cargoes 106
4.4 IMO International Code for the Construction and Equipment of Ships Carrying Dangerous
Chemicals in Bulk (IBC Code) 109
4.4.1 Tank types 110
4.4.2 IBC Code influence on the ship?s design and equipment 111
4.4.3 Vapour space environment control 112
4.4.4 Damage stability 113
4.5 Inert gas requirements for chemical carriers 113

Chapter 5
Ship and equipment 115
5 Ship and equipment 117
5.1 Introduction 117
5.2 Cargo tanks 117
5.3 Monitoring equipment 119
5.3.1 Introduction 119
5.3.2 Alarms and shutdowns 121
5.3.3 Air supply to control systems 121
5.3.4 Liquid level gauges 121
5.3.5 Overfill detection systems 124
5.3.6 Pressure indicating devices 125
5.3.7 Temperature monitoring equipment 125
5.4 Atmosphere monitoring 126
5.4.1 General 126
5.4.2 General precautions 126
5.4.3 Oxygen analysers 127
5.4.4 Flammable gas detectors 128
5.4.5 Toxic gas detectors 129
5.4.6 Hydrogen sulphide (H2
S) 132
5.4.7 Carbon monoxide 132
5.4.8 Carbon dioxide 132
5.5 Cargo pumps 132
5.5.1 General 132
5.5.2 Deepwell pumps 132
5.5.3 Cargo pumprooms 133
5.5.4 Booster pumps 133
5.5.5 Emergency cargo pumps 134
5.6 Piping systems and valves 134
5.7 Cargo manifold 135
5.8 Venting systems and P/V valves 137
5.9 Vapour return systems 138
5.10 Heating and cooling systems 141
5.10.1 Heating coils 141
5.10.2 Heat exchangers 141
5.10.3 Heating medium 141
5.10.4 Heating of toxic products 141
5.10.5 Cooling systems 141
5.11 Tank washing systems 142
5.11.1 Fixed tank washing machines 142
5.11.2 Portable tank washing machines and hoses 143
5.12 Gas freeing equipment 143
5.12.1 Permanently installed gas freeing equipment 143
5.12.2 Portable gas freeing equipment 143
5.12.3 Venting outlets 143
5.13 Inert gas systems 144
5.13.1 Introduction 144
5.13.2 Oxygen content 145
5.13.3 Sources of inert gas 145
5.13.4 Compressed nitrogen stored on board 145
5.13.5 Liquid nitrogen stored on board 146
5.13.6 Pressure swing adsorption nitrogen generators 146
5.13.7 Membrane separation nitrogen generators 146
5.13.8 Oil-fired inert gas generators 147
5.14 Cargo hoses 147
5.14.1 Introduction 147
5.14.2 Types of cargo hose 148
5.14.3 Certification, marking and testing 148
5.14.4 Storage and maintenance 149
5.14.5 Operational use 149
5.14.6 Cargo hose connections 150
5.14.7 Electrical continuity testing 150
5.15 Sampling systems 153
5.16 Electrical equipment and installations in hazardous areas 154
5.16.1 Introduction 154
5.16.2 Certified safe electrical equipment 154
5.16.3 Bonding and earthing 155
5.17 Ballast pumprooms 155
5.18 Openings in deckhouses and superstructures 155

Chapter 6
Cargo operations 157
6 Cargo operations 159
6.1 Introduction 159
6.2 Responsibility 159
6.2.1 Crew and resources 159
6.3 Planning cargo operations 160
6.3.1 Introduction 160
6.3.2 Cargo information 160
6.3.3 IMO certificate of fitness 160
6.3.4 Stowage planning 161
6.3.5 Specific cargo handling requirements 162
6.4 Preparation for cargo operations 164
6.4.1 Introduction 164
6.4.2 Pre-arrival information exchange 165
6.4.3 Cargo handling plan 165
6.4.4 Ship?s crew 167
6.4.5 Preparing the cargo system prior to arrival 167
6.5 Port arrival procedures 170
6.5.1 Pre-transfer conference 170
6.5.2 Ship/shore communications during cargo operations 171
6.5.3 Ship/shore safety checklist 172
6.5.4 Action prior to commencing transfer operations 172
6.6 Monitoring cargo operations 174
6.7 Cargo transfer operations 175
6.7.1 Inspection of cargo tanks prior to loading 175
6.7.2 Manifold connections 175
6.7.3 Cargo loading 177
6.7.4 Ship/shore electric currents 178
6.7.5 Cargo pumprooms 179
6.7.6 Correct operation of P/V valves 179
6.7.7 Vapour return 180
6.7.8 Tank atmosphere control 180
6.7.9 Dangers of pressurised loading 181
6.7.10 Topping off procedure 182
6.7.11 Sampling 183
6.7.12 Sample management 184
6.7.13 Sample storage 184
6.7.14 Ballasting and deballasting in port 185
6.7.15 Clearing shore pipelines 186
6.7.16 Completion of transfer 187
6.7.17 Disconnection of cargo hoses 187
6.7.18 Cargo discharging 187
6.7.19 Inerting and tank atmosphere control during discharging 188
6.7.20 Sweeping of cargo residues 188
6.7.21 Completion of discharge 189
6.8 Cargo care during the voyage 190
6.8.1 Tank integrity 190
6.8.2 Tank venting 190
6.8.3 Temperature-controlled cargoes 190
6.8.4 Inhibited cargoes 191
6.8.5 Maintaining an inert atmosphere during the voyage 192
6.8.6 Ballasting cargo tanks 192
6.9 Ship to ship transfer 192
6.9.1 General 192
6.9.2 Responsibility 193
6.9.3 Communications 193
6.9.4 Navigational warnings 193
6.9.5 Weather conditions and limitations 193
6.9.6 Pre-transfer preparations on each ship 194
6.9.7 Cargo transfer operations 194
6.9.8 Completion of cargo transfer 195

Chapter 7
Inert gas and nitrogen safety 197
7 Inert gas and nitrogen safety 199
7.1 Introduction 199
7.2 Inerting definitions 199
7.2.1 Inert gas 199
7.2.2 Inerting 199
7.2.3 Padding 199
7.2.4 Purging 199
7.2.5 Topping up 200
7.3 Dangers of nitrogen 200
7.4 Safe operations involving nitrogen 201
7.5 Inerting operations 202
7.5.1 Maintenance of an inert atmosphere 202
7.5.2 Inerting tanks containing cargo 202
7.5.3 Inerting empty tanks 202
7.5.4 Loading inerted tanks 203
7.5.5 Maintaining inerted tanks during the voyage 203
7.5.6 Maintaining an inert atmosphere during discharging 203
7.5.7 Tank cleaning and gas freeing under inert conditions 203
7.5.8 Nitrogen supplied from shore 204
7.6 Chemical tanker exemptions for using inert gas 206

Chapter 8
Tank cleaning and gas freeing 209
8 Tank cleaning and gas freeing 211
8.1 Introduction 211
8.2 Procedures and Arrangements Manual 211
8.3 Supervision and preparation 211
8.3.1 Responsibility 211
8.3.2 Tank cleaning plan 212
8.3.3 Pre-cleaning meeting 212
8.3.4 Preparations 212
8.4 Cargo tank washing and cleaning 213
8.4.1 General 213
8.4.2 Tank washing atmospheres 213
8.4.3 Prevention of toxic exposure during tank cleaning 214
8.4.4 Prevention of static generation during tank cleaning 214
8.4.5 Tank washing in an inert atmosphere 215
8.4.6 Tank washing in a non-inert atmosphere 215
8.5 Special cleaning methods 216
8.5.1 Introduction 216
8.5.2 Reactive cargoes 217
8.5.3 Manual cleaning 217
8.5.4 Use of tank cleaning additives 218
8.5.5 Steaming 218
8.5.6 Recirculation washing 218
8.5.7 Cleaning or gas freeing of cargo from non-cargo spaces 218
8.6 Monitoring tank cleaning operations 219
8.6.1 Washing water analysis 219
8.6.2 Precautions for sounding tanks when not using a sounding pipe 219
8.7 Arrangements for the disposal of tank washings and oily mixtures 219
8.7.1 General 219
8.7.2 Management of oily mixtures 220
8.7.3 Mandatory prewash water 220
8.8 Tank cleaning in port 221
8.9 Tank cleaning equipment 221
8.10 Ventilation of cargo residues 221
8.11 Gas freeing 221
8.11.1 Safe procedures for gas freeing after tank cleaning and cleaning by ventilation 221
8.11.2 Opening up cargo lines and handling equipment 222

Chapter 9
Entry into enclosed spaces 223
9 Entry into enclosed spaces 225
9.1 Introduction 225
9.2 IMO guidelines 226
9.3 Enclosed space register 226
9.4 The core roles involved with an enclosed space entry 227
9.5 Hazards 227
9.6 Assessing risks 229
9.7 Oxygen content in air 229
9.8 Oxygen deficiency 229
9.9 Presence of inert gas, including nitrogen 230
9.10 Atmosphere monitoring of deck areas 231
9.11 Toxic and/or flammable gases 231
9.12 Oxygen enrichment 231
9.13 Enclosed space entry training and drills 232
9.13.1 Training 232
9.13.2 Drills 232
9.14 Preparing for an enclosed space entry 233
9.14.1 Prevention of unauthorised entry into an enclosed space 233
9.14.2 Requirements for enclosed space entry 233
9.14.3 Planning 234
9.14.4 Testing of the atmosphere 236
9.14.5 Testing for entry in shipyards 240
9.14.6 Pre-entry meeting 240
9.14.7 Managing shore personnel 241
9.14.8 Enclosed space entry permit 242
9.15 Entry into an enclosed space where the atmosphere has been tested
and is considered safe 244
9.15.1 The role of the attendant 244
9.15.2 Entry into cargo tanks 244
9.15.3 Multi-space entry permits 246
9.15.4 Work in enclosed spaces 246
9.15.5 Entry into an enclosed space where the atmosphere is known or
suspected to be unsafe 247
9.16 Rescue from enclosed spaces 248
9.16.1 Team composition 248
9.16.2 Team roles 249
9.16.3 The rescue operation 249
9.16.4 Rescue and recovery equipment 251

Chapter 10
Emergency procedures 253
10 Emergency procedures 255
10.1 Introduction 255
10.2 Emergency organisation 255
10.2.1 Emergency/rescue team 255
10.2.2 Supporting crew 256
10.2.3 Emergency organisation in port 256
10.2.4 Vacating a berth or terminal in an emergency 256
10.3 Firefighting equipment 256
10.3.1 General 256
10.3.2 Fire control plans 257
10.3.3 International shore fire connection 257
10.3.4 Water 258
10.3.5 Foam 258
10.3.6 Foam monitors 258
10.3.7 Carbon dioxide 258
10.3.8 Halon 259
10.3.9 Dry powder 259
10.3.10 Inert gas systems 259
10.3.11 Firefighting clothing 259
10.4 Emergencies involving fire 259
10.4.1 Combustion 260
10.4.2 Fire triangle 260
10.4.3 Action to take in the event of a fire 260
10.4.4 Fires involving chemicals 261
10.5 Emergencies involving chemical spills or leaks 261
10.5.1 Chemical cargo spills 261
10.5.2 Deck valve and deck pipeline leaks 262
10.5.3 Tank leaks within the ship 263
10.5.4 Emergency discharge or jettison of cargo 263
10.5.5 Notification of spillage 264
10.6 Exposure to chemicals 264
10.6.1 Planning 264
10.6.2 Medical first aid guides 264
10.6.3 Toxic cargoes and antidotes 265
10.6.4 Medical first aid after exposure to chemicals 265
10.6.5 Emergency information on SDS 266

Appendices 267
Appendix A Visitor information card 269
Appendix B Ship/shore safety checklist 272
Appendix C Safety data sheet 290
Appendix D Certificate of protection 296
Appendix E Enclosed space entry permit 297
Appendix F Personal protective equipment matrix 300
Appendix G Relevant industry publications 302

ICS

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Established in 1921, ICS is concerned with all technical, legal, employment affairs and policy issues that may affect international shipping.

ICS represents shipowners with the various intergovernmental regulatory bodies that impact on shipping, including the International Maritime Organization.

ICS also develops best practices and guidance, including a wide range of publications and free resources that are used by ship operators globally.

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