Ships and marine technology -- Ballast water management systems (BWMS)

This document provides requirements and recommendations for designers of BWMS using electrolytic methods to document the risk assessment and risk reduction process over the lifecycle of the equipment, and to support its approval for use on ships by administrations and classification societies. Specifically, this document provides basic terminology, principles and a methodology to identify and subsequently minimize the risk of hazards in the design of BWMS using electrolytic methods. It specifies the procedures for risk assessment and risk reduction following the guidance in ISOÂ 12100. Risks considered include: human health and safety; marine environment related to conditions on board; and ship installation, operation, maintenance and structural integrity. This document does not address the methodology for the risk assessment of corrosion effects, toxicity and ecotoxicity of active substances, relevant chemicals and/or other chemicals generated or used by BWMS using electrolytic methods, which is evaluated by the IMO GESAMP-Ballast Water Working Group as prescribed in the document IMO GESAMP, Methodology for the Evaluation of Ballast Water Management Systems using Active Substances[26]. This document does not address risks associated with the end of life disposition of the BWMS.

Navires et technologie maritime -- Systèmes de gestion de l'eau de ballast (BWMS)

General Information

Status
Published
Publication Date
16-Nov-2021
Current Stage
5060 - Close of voting Proof returned by Secretariat
Start Date
13-Oct-2021
Completion Date
12-Oct-2021
Ref Project

Buy Standard

Standard
ISO 23314-2:2021 - Ships and marine technology -- Ballast water management systems (BWMS)
English language
29 pages
sale 15% off
Preview
sale 15% off
Preview
Draft
ISO/FDIS 23314-2:Version 14-avg-2021 - Ships and marine technology -- Ballast water management systems (BWMS)
English language
29 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

INTERNATIONAL ISO
STANDARD 23314-2
First edition
2021-11
Ships and marine technology —
Ballast water management systems
(BWMS) —
Part 2:
Risk assessment and risk reduction of
BWMS using electrolytic methods
Navires et technologie maritime — Systèmes de gestion de l'eau de
ballast (BWMS) —
Partie 2: Appréciation du risque et réduction du risque des BWMS qui
utilisent des procédés électrolytiques
Reference number
ISO 23314-2:2021(E)
© ISO 2021
---------------------- Page: 1 ----------------------
ISO 23314-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
© ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 23314-2:2021(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction .............................................................................................................................................................................................................................. vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Strategy for risk assessment and risk reduction .............................................................................................................. 3

5 Risk assessment process .............................................................................................................................................................................4

5.1 General ........................................................................................................................................................................................................... 4

5.2 Information for risk assessment ............................................................................................................................................. 4

5.3 Determination of the limits ......................................................................................................................................................... 5

5.3.1 General ........................................................................................................................................................................................ 5

5.3.2 Use limits ................................................................................................................................................................................... 5

5.3.3 Space limits ............................................................................................................................................................................. 5

5.3.4 Time limits ............................................................................................................................................................................... 6

5.3.5 Environmental limits ..................................................................................................................................................... 6

5.4 Hazard identification ........................................................................................................................................................................ 7

5.4.1 General ........................................................................................................................................................................................ 7

5.4.2 Human interaction with the equipment over the entire life cycle of a BWMS

using the electrolytic method ................................................................................................................................. 7

5.4.3 Possible states of BWMS using the electrolytic method ................................................................. 8

5.4.4 Unintended behaviour of the operator or reasonably foreseeable misuse .................... 9

5.5 Risk estimation ...................................................................................................................................................................................... 9

5.5.1 General ........................................................................................................................................................................................ 9

5.5.2 Elements of risk ................................................................................................................................................................... 9

5.5.3 Aspects to be considered during risk estimation .............................................................................. 10

5.6 Risk evaluation .................................................................................................................................................................................... 11

6 Risk reduction .....................................................................................................................................................................................................12

6.1 General ........................................................................................................................................................................................................12

6.2 Inherently safe design ................................................................................................................................................................... 12

6.2.1 General .....................................................................................................................................................................................12

6.2.2 Considerations during the initial design ...................................................................................................12

6.2.3 Choice of appropriate technology .................................................................................................................... 13

6.2.4 Applying inherently safe design measures to control systems .............................................13

6.3 Safeguarding and/or complementary protective measures ...................................................................... 14

6.3.1 General ..................................................................................................................................................................................... 14

6.3.2 Safeguarding measures ............................................................................................................................................. 14

6.3.3 Complementary protective measures .......................................................................................................... 14

6.4 Information for use .......................................................................................................................................................................... 16

6.4.1 General ..................................................................................................................................................................................... 16

6.4.2 Installation guide ............................................................................................................................................................ 16

6.4.3 Commissioning procedure .................. .................................................................................................................... 16

6.4.4 Operation, maintenance and safety manual (OMSM) ..................................................................... 17

6.4.5 Maintenance scheme .................................................................................................................................................... 17

6.4.6 Calibration manual ........................................................................................................................................................ 17

6.4.7 Warning indication ........................................................................................................................................................ 18

6.4.8 Training plan and documentation ................................................................................................................... 18

7 Documentation of risk assessment ...............................................................................................................................................18

Annex A (informative) Example of a risk estimation matrix table in accordance with ISO/

TR 14121-2 ...............................................................................................................................................................................................................19

Annex B (informative) Example of a risk assessment and risk reduction worksheet —

Filtration unit .......................................................................................................................................................................................................20

iii
© ISO 2021 – All rights reserved
---------------------- Page: 3 ----------------------
ISO 23314-2:2021(E)

Annex C (informative) Example of a risk assessment and risk reduction worksheet —

Electrolysis unit .................................................................................................................................................................................................22

Annex D (informative) Example of a risk assessment and risk reduction worksheet –

Neutralization unit .........................................................................................................................................................................................26

Annex E (informative) Example of a training plan for BWMS using the electrolytic method .............27

Bibliography .............................................................................................................................................................................................................................28

© ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 23314-2:2021(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology.

A list of all parts in the ISO 23314 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2021 – All rights reserved
---------------------- Page: 5 ----------------------
ISO 23314-2:2021(E)
Introduction

A ballast water management system (BWMS) using the electrolytic method applies a combination

of filtration (if applicable), electrolysis and a neutralization process to treat ballast water to meet

[19]

Regulation D-2 of the International Maritime Organization (IMO) BWM Convention , or the ballast

water discharge standard (BWDS) requirements of port state administrations, e.g. the U.S. Coast Guard

[31]
(USCG) .

At the uptake of ballast water, the BWMS utilizes filtration (if applicable) and injection of active

substances (e.g. sodium hypochlorite) generated by an electrolysis process. The active substance can

be generated within the full flow of the ballast pipe (full stream) or generated from a smaller side

stream (either extracted from the ballast pipe or sourced from a brine tank) and then mixed with the

full ballast flow. The active substance in the ballast pipe is measured as total residual oxidants (TRO)

and the BWMS regulates the TRO level to ensure ballast water is treated to the threshold level. During

discharge, the residual TRO is monitored and neutralized prior to discharge overboard to ensure

that the amount of residual active substance entering the receiving environment is acceptable. The

treatment process is shown in Figure 1.
Key
or treatment flow
feedback signal
Figure 1 — Overview of BWMS using the electrolytic method
© ISO 2021 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 23314-2:2021(E)
Ships and marine technology — Ballast water management
systems (BWMS) —
Part 2:
Risk assessment and risk reduction of BWMS using
electrolytic methods
1 Scope

This document provides requirements and recommendations for designers of BWMS using electrolytic

methods to document the risk assessment and risk reduction process over the lifecycle of the

equipment, and to support its approval for use on ships by administrations and classification societies.

Specifically, this document provides basic terminology, principles and a methodology to identify

and subsequently minimize the risk of hazards in the design of BWMS using electrolytic methods. It

specifies the procedures for risk assessment and risk reduction following the guidance in ISO 12100.

Risks considered include: human health and safety; marine environment related to conditions on

board; and ship installation, operation, maintenance and structural integrity.

This document does not address the methodology for the risk assessment of corrosion effects, toxicity

and ecotoxicity of active substances, relevant chemicals and/or other chemicals generated or used

by BWMS using electrolytic methods, which is evaluated by the IMO GESAMP-Ballast Water Working

Group as prescribed in the document IMO GESAMP, Methodology for the Evaluation of Ballast Water

[26]
Management Systems using Active Substances .

This document does not address risks associated with the end of life disposition of the BWMS.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.

ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 12100 and the following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
active substance

substance or organism, including a virus or fungus, that has a general or specific action on or against

harmful organisms and pathogens

Note 1 to entry: For BWMS (3.3) using electrolytic methods (3.8), it means reaction products that are generated by

the electrolytic method for the ballast water treatment.
[SOURCE: IMO G9]
© ISO 2021 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 23314-2:2021(E)
3.2
ballast water

water with its suspended matter taken on board a ship to control trim, list, draught, stability or stresses

of the ship
3.3
ballast water management system
BWMS

system that processes ballast water (3.2) such that it meets or exceeds the ballast water discharge

performance standard in Regulation D-2 of the BWM Convention

Note 1 to entry: A BWMS includes ballast water treatment equipment, all associated control equipment, piping

arrangements within the BWMS as specified by the manufacturer, control and monitoring equipment, and

sampling devices.

Note 2 to entry: A BWMS does not include the ship's ballast water fittings, which can include piping, valves,

pumps, etc. that would be required if the BWMS was not fitted.

Note 3 to entry: A ballast water treatment system (BWTS) defined in Environmental Technology Verification

(ETV) is considered the same as BWMS.
[SOURCE: IMO BWMS Code]
3.4
dangerous gas

gas that can develop an explosive and/or toxic atmosphere hazardous to the crew and/or the ship

EXAMPLE Hydrogen (H ), hydrocarbon gas, ozone (O ), chlorine (Cl ), chlorine dioxide (ClO ).

2 3 2 2
3.5
electrical distribution conductor

conductor intended for distributing the electricity, such as bus bars or conductors of insulated cables

3.6
electrolysis unit

unit that mainly consists of one or several chambers making use of an electrolytic method (3.8) to

produce active substances (3.1) for the treatment of ballast water (3.2), including ventilation components

for the safe handling of dangerous gases (3.4) if applicable, as well as relevant piping, valves, electrical

and electronic components
3.7
electrolytic chamber

chamber that contains one or several sets of electrodes and associated power connections, and that

makes use of the electrolytic method (3.8) for the production of active substances (3.1) when water flows

through it
3.8
electrolytic method

treatment process in which water flows through a set of special electrodes, producing active substances

(3.1) when an electric current is applied
3.9
flammable liquid
liquid having a flash point not exceeding 60 °C (closed cup test)
3.10
global integrated shipping information system
GISIS

public integrated information database developed by the IMO, which is composed of several modules

that deal with ship particulars, maritime safety, chemicals associated with treated ballast water (3.2)

and other shipping-related information
© ISO 2021 – All rights reserved
---------------------- Page: 8 ----------------------
ISO 23314-2:2021(E)
3.11
life cycle

entire lifespan from the design, manufacturing, storage, installation, to operation and disposal of a

BWMS (3.3)
3.12
maximum allowable discharge concentration
MADC

maximum allowable concentration of active substances (3.1) during discharge of ballast water (3.2) as

defined by port state control or local regulation
3.13
neutralization unit

unit that mainly consists of neutralizing agent preparation and dosing equipment for the purpose of

neutralizing active substances (3.1) by adding neutralizing agent into the de-ballast pipe so as to reduce

TRO (3.14) concentration to achieve compliance with the MADC (3.12)
3.14
total residual oxidant
TRO

sum of the effect of oxidizing chemicals, such as hypochlorous acid (HClO), hypochlorite (ClO), chlorine

(Cl ), hypobromous acid (HBrO), hypobromite (BrO), bromine (Br ), chloramine compounds, bromine

2 2
compound
4 Strategy for risk assessment and risk reduction

The process for risk assessment and risk reduction is based on guidance from ISO 12100 and is

summarized in Figure 2.
© ISO 2021 – All rights reserved
---------------------- Page: 9 ----------------------
ISO 23314-2:2021(E)

Figure 2 — General procedure of risk assessment and risk reduction for BWMS using

the electrolytic method
5 Risk assessment process
5.1 General

The risk assessment for BWMS using the electrolytic method is comprised of risk analysis and risk

evaluation.

Risk analysis consists of determining the limits, identifying the hazards, and estimating risk over the

whole lifespan of a BWMS, as considered in 5.3 to 5.5. Risk analysis provides the information required

for the risk evaluation (see 5.6), which in turn allows judgment to be made about whether or not risk

reduction (see Clause 6) is required.
5.2 Information for risk assessment

The information for the risk assessment of a BWMS using the electrolytic method shall consider the

documentation described in the following list.
a) System description:
© ISO 2021 – All rights reserved
---------------------- Page: 10 ----------------------
ISO 23314-2:2021(E)

— documents related to installation guidance; the operation, maintenance and safety manual

(OMSM); schematic diagrams; process flow diagrams; and applicable test reports.
b) Regulations, standards and other applicable documents:
[19]

— ISO and IEC standards (e.g. IEC 60079), IMO regulations or circulars (e.g. BWM Convention ,

[21] [20] [27]

BWMS Code , Procedure G9 ), IACS Unified requirements (e.g. IACS UR M74 ), port state

[31]

administration rules (e.g. USCG 46 CFR 162.060 ), and classification society rules;

— safety data sheets (SDSs) of the active substance, neutralizing agent, TRO measurement reagent,

and dangerous gas (e.g. hydrogen);

— database of chemicals commonly associated with treated ballast water in the IMO GISIS.

c) Related to experience of use:

— known accidents, incidents or malfunction history of the actual or similar electrochlorination

systems (from database of marine incidents, e.g. GISIS):

— the potential for adverse effects from human exposure (e.g. to active substances);

— the experience of users of similar system e.g. electrochlorination system in power plant, waterworks,

etc.

The information used in the risk assessment shall be updated throughout the design process or when

modifications to the BWMS are required.
5.3 Determination of the limits
5.3.1 General

Risk assessment begins with the determination of the limits of the BWMS, taking into account all the

phases over the lifespan of the BWMS. This means considering the characteristics and performances

of both subsystems and the overall system as an integrated process. Characteristics of the system,

including its relationship with humans, the environment, and other products shall be identified in

terms of the limits of the BWMS as given in 5.3.2 to 5.3.5.

The purpose of this step is to identify all key parameters and their associated performance limits. These

parameters pertain to installation, operation, maintenance, personnel and the environment.

5.3.2 Use limits

Use limits include the intended use and the reasonably foreseeable misuse of the BWMS. Aspects to

account for include the following.

— The anticipated levels of training, experience or ability of the people who carry out installation,

commissioning, operation, and maintenance of the BWMS, e.g. unexpected system shutdown can be

activated due to misuse by an operator who is improperly trained or unfamiliar with the BWMS.

— Exposure of other persons to the hazards associated with the system that can be reasonably be

predicted, e.g. crew for other duties, administration officer or service personnel for other equipment

adjacent to the BWMS.
5.3.3 Space limits

Aspects of space limits shall address the requirements for safe installation, operation, and maintenance

of the BWMS. Considerations shall include:
— power supply and cabling;
— cooling water or ventilation air;
© ISO 2021 – All rights reserved
---------------------- Page: 11 ----------------------
ISO 23314-2:2021(E)
— operation and maintenance space;
— space for chemical storage (e.g. neutralizing agent, TRO measurement reagent);
— space for dangerous gas exhaust on open deck;
— installation location (e.g. hazardous area).
5.3.4 Time limits

Aspects of time limits shall consider specific operating and maintenance factors, including:

— life limit of parts that can wear due to corrosion, or life of critical components where a decline in

efficiency affects performance capabilities (e.g. electrode);
— recommended service and calibration intervals;
— holding time (minimum for efficacy and maximum based on regrowth);

NOTE The holding time can be dependent on water salinity, water temperature and TRO concentration.

— TRO measurement reagent service life/neutralizing agent shelf life in both solid (if applicable) and

aqueous forms (stored in ready to use form).
5.3.5 Environmental limits

Environmental limits shall consider the range of uptake water chemistries to be treated, operational

limits of process variables within the BWMS, limitations imposed by the shipboard environment on the

BWMS, hazardous by-products of the electrolytic process, and any environmental constraints on the

storage and use of chemicals associated with the BWMS. At a minimum, the following limits shall be

considered:
— recommended minimum salinity and temperature of the ballast water;

— recommended minimum salinity and minimum and maximum temperature of the electrolytic unit

feed water;
— recommended minimum inlet pressure of the filtration unit (if applicable);
— treatment rated capacity (TRC);

— maximum allowable discharge concentration (MADC), related to potential toxicity to the receiving

environment;
— lower TRO limit for treatment efficacy;
— upper TRO limit for the potential corrosive effects on ballast tanks;
— ambient marine environment related to locations on board;

— potential flammable and explosive atmospheres that can be created on board the vessel;

— potential health risks to personnel due to exposure to dangerous gas, and flammable and explosive

environments;
— personnel exposure to active substances or other relevant chemicals;
— TRO measurement waste (if applicable).

NOTE The limits including water salinity, water temperature, holding time, and TRO concentration are also

identified as representative system design limitations (SDL) for a BWMS using the electrolytic method as per the

[21]
BWMS Code .
© ISO 2021 – All rights reserved
---------------------- Page: 12 ----------------------
ISO 23314-2:2021(E)
5.4 Hazard identification
5.4.1 General

After determination of the limits of the BWMS, the next essential step is to identify the reasonably

foreseeable hazards (permanent hazards), unexpected hazards, hazardous situations, and hazardous

events during all lifecycle phases of the system, including:
— design;
— transportation, storage and installation;
— commissioning;
— operation;
— maintenance.

Only when hazards have been identified can steps be taken to eliminate them or to reduce risks.

Hazard identification shall identify the hazards associated with the operations to be performed by the

BWMS and the tasks to be performed by persons who interact with it while considering the different

components, mechanisms or functions of the system, and the environment in which the system can be

operated.

In addition to general mechanical and electrical hazards, the designer of the BWMS shall identify

hazards specific to the electrolytic method while considering the items in 5.4.2 to 5.4.4.

5.4.2 Human interaction with the equipment over the entire life cycle of a BWMS using

the electrolytic method

Over the course of building, installation, operation, maintenance and removal of a BWMS, personnel

can be exposed to a number of hazards. These can be a result of normal operation, or consequences of

maintenance or repair activities. Hazards shall be considered for the following conditions or activities.

a) Health effects due to contact with active substances or other relevant chemicals.

b) Start-up/shutdown of systems (i.e. electrical shock, water hammer, etc.).
c) In the case of an operator initiating emergency s
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 23314-2
ISO/TC 8
Ships and marine technology —
Secretariat: SAC
Ballast water management systems
Voting begins on:
2021-08-17 (BWMS) —
Voting terminates on:
Part 2:
2021-10-12
Risk assessment and risk reduction of
BWMS using electrolytic methods
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 23314-2:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. ISO 2021
---------------------- Page: 1 ----------------------
ISO/FDIS 23314-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/FDIS 23314-2:2021(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Strategy for risk assessment and risk reduction ................................................................................................................ 3

5 Risk assessment process .............................................................................................................................................................................. 4

5.1 General ........................................................................................................................................................................................................... 4

5.2 Information for risk assessment .............................................................................................................................................. 4

5.3 Determination of the limits .......................................................................................................................................................... 5

5.3.1 General...................................................................................................................................................................................... 5

5.3.2 Use limits ................................................................................................................................................................................ 5

5.3.3 Space limits ........................................................................................................................................................................... 5

5.3.4 Time limits ............................................................................................................................................................................ 6

5.3.5 Environmental limits.................................................................................................................................................... 6

5.4 Hazard identification ......................................................................................................................................................................... 7

5.4.1 General...................................................................................................................................................................................... 7

5.4.2 Human interaction with the equipment over the entire life cycle of

a BWMS using the electrolytic method ......................................................................................................... 7

5.4.3 Possible states of BWMS using the electrolytic method ................................................................ 8

5.4.4 Unintended behaviour of the operator or reasonably foreseeable misuse ................... 9

5.5 Risk estimation ....................................................................................................................................................................................... 9

5.5.1 General...................................................................................................................................................................................... 9

5.5.2 Elements of risk ................................................................................................................................................................ 9

5.5.3 Aspects to be considered during risk estimation .............................................................................10

5.6 Risk evaluation .....................................................................................................................................................................................11

6 Risk reduction ......................................................................................................................................................................................................12

6.1 General ........................................................................................................................................................................................................12

6.2 Inherently safe design ....................................................................................................................................................................12

6.2.1 General...................................................................................................................................................................................12

6.2.2 Considerations during the initial design ..................................................................................................12

6.2.3 Choice of appropriate technology ..................................................................................................................13

6.2.4 Applying inherently safe design measures to control systems .............................................13

6.3 Safeguarding and/or complementary protective measures .........................................................................14

6.3.1 General...................................................................................................................................................................................14

6.3.2 Safeguarding measures ...........................................................................................................................................14

6.3.3 Complementary protective measures ........................................................................................................14

6.4 Information for use ..........................................................................................................................................................................16

6.4.1 General...................................................................................................................................................................................16

6.4.2 Installation guide ..........................................................................................................................................................16

6.4.3 Commissioning procedure ...................................................................................................................................16

6.4.4 Operation, maintenance and safety manual (OMSM) ...................................................................17

6.4.5 Maintenance scheme .................................................................................................................................................17

6.4.6 Calibration manual ........................................................................................................................................... ...........17

6.4.7 Warning indication .....................................................................................................................................................18

6.4.8 Training plan and documentation .................................................................................................................18

7 Documentation of risk assessment ................................................................................................................................................18

Annex A (informative) Example of a risk estimation matrix table in accordance with

ISO/TR 14121-2 ..................................................................................................................................................................................................19

Annex B (informative) Example of a risk assessment and risk reduction worksheet —

Filtration unit ......... ...............................................................................................................................................................................................20

© ISO 2021 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/FDIS 23314-2:2021(E)

Annex C (informative) Example of a risk assessment and risk reduction worksheet —

Electrolysis unit ..................................................................................................................................................................................................22

Annex D (informative) Example of a risk assessment and risk reduction worksheet –

Neutralization unit ..........................................................................................................................................................................................26

Annex E (informative) Example of a training plan for BWMS using the electrolytic method .................27

Bibliography .............................................................................................................................................................................................................................28

iv © ISO 2021 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/FDIS 23314-2:2021(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 8, Ships and marine technology.

A list of all parts in the ISO 23314 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2021 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/FDIS 23314-2:2021(E)
Introduction

A ballast water management system (BWMS) using the electrolytic method applies a combination

of filtration (if applicable), electrolysis and a neutralization process to treat ballast water to meet

[19]

Regulation D-2 of the International Maritime Organization (IMO) BWM Convention , or the ballast

water discharge standard (BWDS) requirements of port state administrations, e.g. the U.S. Coast Guard

[31]
(USCG) .

At the uptake of ballast water, the BWMS utilizes filtration (if applicable) and injection of active

substances (e.g. sodium hypochlorite) generated by an electrolysis process. The active substance can

be generated within the full flow of the ballast pipe (full stream) or generated from a smaller side

stream (either extracted from the ballast pipe or sourced from a brine tank) and then mixed with the

full ballast flow. The active substance in the ballast pipe is measured as total residual oxidants (TRO)

and the BWMS regulates the TRO level to ensure ballast water is treated to the threshold level. During

discharge, the residual TRO is monitored and neutralized prior to discharge overboard to ensure

that the amount of residual active substance entering the receiving environment is acceptable. The

treatment process is shown in Figure 1.
Key
or treatment flow
feedback signal
Figure 1 — Overview of BWMS using the electrolytic method
vi © ISO 2021 – All rights reserved
---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 23314-2:2021(E)
Ships and marine technology — Ballast water management
systems (BWMS) —
Part 2:
Risk assessment and risk reduction of BWMS using
electrolytic methods
1 Scope

This document provides requirements and recommendations for designers of BWMS using electrolytic

methods to document the risk assessment and risk reduction process over the lifecycle of the

equipment, and to support its approval for use on ships by Administrations and classification societies.

Specifically, this document provides basic terminology, principles and a methodology to identify

and subsequently minimize the risk of hazards in the design of BWMS using electrolytic methods. It

specifies the procedures for risk assessment and risk reduction following the guidance in ISO 12100.

Risks considered include: human health and safety; marine environment related to conditions on

board; and ship installation, operation, maintenance and structural integrity.

This document does not address the methodology for the risk assessment of corrosion effects, toxicity

and ecotoxicity of active substances, relevant chemicals and/or other chemicals generated or used

by BWMS using electrolytic methods, which is evaluated by the IMO GESAMP-Ballast Water Working

Group as prescribed in the document IMO GESAMP, Methodology for the Evaluation of Ballast Water

[26]
Management Systems using Active Substances .

This document does not address risks associated with the end of life disposition of the BWMS.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.

ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 12100 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
active substance

substance or organism, including a virus or fungus, that has a general or specific action on or against

harmful organisms and pathogens

Note 1 to entry: For BWMS (3.3) using electrolytic methods (3.8), it means reaction products that are generated by

the electrolytic method for the ballast water treatment.
[SOURCE: IMO G9]
© ISO 2021 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO/FDIS 23314-2:2021(E)
3.2
ballast water

water with its suspended matter taken on board a ship to control trim, list, draught, stability or stresses

of the ship
3.3
ballast water management system
BWMS

system that processes ballast water (3.2) such that it meets or exceeds the ballast water discharge

performance standard in Regulation D-2 of the BWM Convention

Note 1 to entry: A BWMS includes ballast water treatment equipment, all associated control equipment, piping

arrangements within the BWMS as specified by the manufacturer, control and monitoring equipment, and

sampling devices.

Note 2 to entry: A BWMS does not include the ship's ballast water fittings, which can include piping, valves,

pumps, etc. that would be required if the BWMS was not fitted.

Note 3 to entry: A ballast water treatment system (BWTS) defined in Environmental Technology Verification

(ETV) is considered the same as BWMS.
[SOURCE: IMO BWMS Code]
3.4
dangerous gas

gas that can develop an explosive and/or toxic atmosphere hazardous to the crew and/or the ship

EXAMPLE Hydrogen (H ), hydrocarbon gas, ozone (O ), chlorine (Cl ), chlorine dioxide (ClO ).

2 3 2 2
3.5
electrical distribution conductor

conductor intended for distributing the electricity, such as bus bars or conductors of insulated cables

3.6
electrolysis unit

unit that mainly consists of one or several chambers making use of an electrolytic method (3.8) to

produce active substances (3.1) for the treatment of ballast water (3.2), including ventilation components

for the safe handling of dangerous gases (3.4) if applicable, as well as relevant piping, valves, electrical

and electronic components
3.7
electrolytic chamber

chamber that contains one or several sets of electrodes and associated power connections, and that

makes use of the electrolytic method (3.8) for the production of active substances (3.1) when water flows

through it
3.8
electrolytic method

treatment process in which water flows through a set of special electrodes, producing active substances

(3.1) when an electric current is applied
3.9
flammable liquid
liquid having a flash point not exceeding 60 °C (closed cup test)
3.10
global integrated shipping information system
GISIS

public integrated information database developed by the IMO, which is composed of several modules

that deal with ship particulars, maritime safety, chemicals associated with treated ballast water (3.2)

and other shipping-related information
2 © ISO 2021 – All rights reserved
---------------------- Page: 8 ----------------------
ISO/FDIS 23314-2:2021(E)
3.11
life cycle

entire lifespan from the design, manufacturing, storage, installation, to operation and disposal of a

BWMS (3.3)
3.12
maximum allowable discharge concentration
MADC

maximum allowable concentration of active substances (3.1) during discharge of ballast water (3.2) as

defined by port state control or local regulation
3.13
neutralization unit

unit that mainly consists of neutralizing agent preparation and dosing equipment for the purpose of

neutralizing active substances (3.1) by adding neutralizing agent into the de-ballast pipe so as to reduce

TRO (3.14) concentration to achieve compliance with the MADC (3.12)
3.14
total residual oxidant
TRO

sum of the effect of oxidizing chemicals, such as hypochlorous acid (HClO), hypochlorite (ClO), chlorine

(Cl ), hypobromous acid (HBrO), hypobromite (BrO), bromine (Br ), chloramine compounds, bromine

2 2
compound
4 Strategy for risk assessment and risk reduction

The process for risk assessment and risk reduction is based on guidance from ISO 12100 and is

summarized in Figure 2.
© ISO 2021 – All rights reserved 3
---------------------- Page: 9 ----------------------
ISO/FDIS 23314-2:2021(E)

Figure 2 — General procedure of risk assessment and risk reduction for BWMS using

the electrolytic method
5 Risk assessment process
5.1 General

The risk assessment for BWMS using the electrolytic method is comprised of risk analysis and risk

evaluation.

Risk analysis consists of determining the limits, identifying the hazards, and estimating risk over the

whole lifespan of a BWMS, as considered in 5.3 to 5.5. Risk analysis provides the information required

for the risk evaluation (see 5.6), which in turn allows judgment to be made about whether or not risk

reduction (see Clause 6) is required.
5.2 Information for risk assessment

The information for the risk assessment of a BWMS using the electrolytic method shall consider the

documentation described in the following list.
a) System description
4 © ISO 2021 – All rights reserved
---------------------- Page: 10 ----------------------
ISO/FDIS 23314-2:2021(E)

Documents related to installation guidance; the operation, maintenance and safety manual (OMSM);

schematic diagrams; process flow diagrams; and applicable test reports.
b) Regulations, standards and other applicable documents

— ISO and IEC standards (e.g. IEC 60079), IMO regulations or circulars (e.g. BWM Convention, BWMS

Code, Procedure G9), IACS Unified requirements (e.g. IACS UR M74), port state administration rules

(e.g. USCG 46 CFR 162.060), and classification society rules.

— Safety data sheets (SDSs) of the active substance, neutralizing agent, TRO measurement reagent,

and dangerous gas (e.g. hydrogen).

— Database of chemicals commonly associated with treated ballast water in the IMO GISIS.

c) Related to experience of use

— Known accidents, incidents or malfunction history of the actual or similar electrochlorination

systems (from database of marine incidents, e.g. GISIS).

— The potential for adverse effects from human exposure (e.g. to active substances).

— The experience of users of similar system e.g. electrochlorination system in power plant, waterworks,

etc.

The information used in the risk assessment shall be updated throughout the design process or when

modifications to the BWMS are required.
5.3 Determination of the limits
5.3.1 General

Risk assessment begins with the determination of the limits of the BWMS, taking into account all the

phases over the lifespan of the BWMS. This means considering the characteristics and performances

of both subsystems and the overall system as an integrated process. Characteristics of the system,

including its relationship with humans, the environment, and other products shall be identified in

terms of the limits of the BWMS as given in 5.3.2 to 5.3.5.

The purpose of this step is to identify all key parameters and their associated performance limits. These

parameters pertain to installation, operation, maintenance, personnel and the environment.

5.3.2 Use limits

Use limits include the intended use and the reasonably foreseeable misuse of the BWMS. Aspects to

account for include the following.

— The anticipated levels of training, experience or ability of the people who carry out installation,

commissioning, operation, and maintenance of the BWMS, e.g. unexpected system shutdown can be

activated due to misuse by an operator who is improperly trained or unfamiliar with the BWMS.

— Exposure of other persons to the hazards associated with the system that can be reasonably be

predicted, e.g. crew for other duties, administration officer or service personnel for other equipment

adjacent to the BWMS.
5.3.3 Space limits

Aspects of space limits shall address the requirements for safe installation, operation, and maintenance

of the BWMS. Considerations shall include:
— power supply and cabling;
— cooling water or ventilation air;
© ISO 2021 – All rights reserved 5
---------------------- Page: 11 ----------------------
ISO/FDIS 23314-2:2021(E)
— operation and maintenance space;
— space for chemical storage (e.g. neutralizing agent, TRO measurement reagent);
— space for dangerous gas exhaust on open deck;
— installation location (e.g. hazardous area).
5.3.4 Time limits

Aspects of time limits shall consider specific operating and maintenance factors, including:

— life limit of parts that can wear due to corrosion, or life of critical components where a decline in

efficiency affects performance capabilities (e.g. electrode);
— recommended service and calibration intervals;
— holding time (minimum for efficacy and maximum based on regrowth);

NOTE The holding time can be dependent on water salinity, water temperature and TRO concentration.

— TRO measurement reagent service life/neutralizing agent shelf life in both solid (if applicable) and

aqueous forms (stored in ready to use form).
5.3.5 Environmental limits

Environmental limits shall consider the range of uptake water chemistries to be treated, operational

limits of process variables within the BWMS, limitations imposed by the shipboard environment on the

BWMS, hazardous by-products of the electrolytic process, and any environmental constraints on the

storage and use of chemicals associated with the BWMS. At a minimum, the following limits shall be

considered:
— recommended minimum salinity and temperature of the ballast water;

— recommended minimum salinity and minimum and maximum temperature of the electrolytic unit

feed water;
— recommended minimum inlet pressure of the filtration unit (if applicable);
— treatment rated capacity (TRC);

— maximum allowable discharge concentration (MADC), related to potential toxicity to the receiving

environment;
— lower TRO limit for treatment efficacy;
— upper TRO limit for the potential corrosive effects on ballast tanks;
— ambient marine environment related to locations on board;

— potential flammable and explosive atmospheres that can be created on board the vessel;

— potential health risks to personnel due to exposure to dangerous gas, and flammable and explosive

environments;
— personnel exposure to active substances or other relevant chemicals;
— TRO measurement waste (if applicable).

NOTE The limits including water salinity, water temperature, holding time, and TRO concentration are also

identified as representative system design limitations (SDL) for a BWMS using the electrolytic method as per the

BWMS Code.
6 © ISO 2021 – All rights reserved
---------------------- Page: 12 ----------------------
ISO/FDIS 23314-2:2021(E)
5.4 Hazard identification
5.4.1 General

After determination of the limits of the BWMS, the next essential step is to identify the reasonably

foreseeable hazards (permanent hazards), unexpected hazards, hazardous situations, and hazardous

events during all lifecycle phases of the system, including:
— design;
— transportation, storage and installation;
— commissioning;
— operation;
— maintenance.

Only when hazards have been identified can steps be taken to eliminate them or to reduce risks.

Hazard identification shall identify the hazards associated with the operations to be performed by the

BWMS and the tasks to be performed by persons who interact with it while considering the different

components, mechanisms or functions of the system, and the environment in which the system can be

operated.

In addition to general mechanical and electrical hazards, the designer of the BWMS shall identify

hazards specific to the electrolytic method while considering the items in 5.4.2 to 5.4.4.

5.4.2 Human interaction with the equipment over the entire life cycle of a BWMS using

the electrolytic method

Over the course of building, installation, operation, maintenance and removal of a BWMS, personnel

can be exposed to a number of hazards. These can be a result of normal
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.