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INTERNATIONAL MARITIME ORGANIZATION

IMO

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE 

54th session 

Agenda item 2 

MEPC 54/INF.6

 13 January 2006

 ENGLISH ONLY

HARMFUL AQUATIC ORGANISMS IN BALLAST WATER 

A Swedish Disinfection System 

Submitted by Sweden 

SUMMARY

Executive summary: This document contains information about a Swedish Disinfection 

System, a system which adds no chemicals or precursor substances to 

the water, to be used in a Ballast Water management system that is to 

be approved in accordance with Procedure for approval of Ballast 

Water Management systems that make use of Active Substances (G9) 

adopted by resolution MEPC.126(53). Sustainable test results for a 

proposal for Basic Approval are expected to be finalized in 

February 2006. After the competent authority in Sweden has verified 

the dossiers and believes them to satisfy the data requirements of the 

Procedure (G9) a proposal for approval is to be sent to 

GESAMP-Ballast Water Working Group and a document on the 

proposal for approval is to be submitted to MEPC 55. 

Action to be taken: Paragraph 5 

Related documents: MEPC 53/24/Add.1, BWM.2/Circ.2 

Introduction 

1 Regulation D-3.2 of the International Convention for the Control and Management of 

Ships’ Ballast Water and Sediments stipulates that Ballast Water Management systems that make 

use of Active Substances shall be approved by the Organization based on a procedure developed 

by the Organization. The procedure for approval of Ballast Water Management systems that 

make use of Active Substances (G9) was adopted during MEPC 53 as resolution MEPC.126(53). 

2 According to BWM.2/Circ.2 proposals for approval of Ballast Water Management 

systems that make use of Active Substances are to be sent to GESAMP-BWWG. In the 

meantime, a document on the proposal for approval containing all the non-confidential data 

related to the respecitve Active Substance shall be submitted to MEPC. 
MEPC 54/INF.6 - 2 - 

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3 This document contains information about a Swedish Disinfection System used in a 

Ballast Water Management system that is to be approved according to resolution MEPC.126(53) 

Procedure for approval of Ballast Water Management systems that make use of Active 

Substances (G9). Sustainable test results for a proposal for Basic Approval are expected to be 

finalized in February 2006. 

4 After the competent authority in Sweden has verified the dossiers and believes them to 

satisfy the data requirements of the Procedure (G9), a proposal for approval is to be sent to 

GESAMP-BWWG and a document on the proposal for approval is to be submitted to MEPC 55. 

Action requested of the Committee 

5 The Committee is invited to note the information provided in this document. 

*** 
MEPC 54/INF.6 

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ANNEX 

1 INTRODUCTION 

An advanced electrochemical system, the EctoSysTM, is proposed as the disinfection step in a 

complete system for ballast water treatment. EctoSysTM is an electrochemical system utilizing 

electrodes with high oxygen overpotential, and therefore producing powerful disinfectants such 

as the hydroxyl radical directly into the media and also providing direct oxidation of 

microorganisms and other contaminants on the electrode surface. No chemicals or precursor 

substances are added to the water. In addition small amounts of by-products (free active chlorine) 

from the cell will prevent biofouling and regrowth in the tanks, but the cell design and electrode 

configuration will also prevent the formation of secondary chlorinated organics such as for 

example trihalomethanes, THM. The EctoSysTM is designed for purification and disinfection of a 

wide range of water types and mainly in applications with high flow rates. A minimum of media 

conductivity is needed, but that criteria is well satisfied in natural sea water or brackish water. 

One single, compact EctoSysTM module can be dimensioned for treatment of flow rates up to 

500 m3/h, with no additional chemicals and a minimum of maintenance needed. The EctoSysTM 

is typically used for ballast water treatment as a disinfecting step after mechanical separation 

(i.e. filters, hydrocyclones etc.) of contaminants down to 40-45μm scale. 

An electrochemical cell working with a natural water media such as sea water could theoretically 

produce an endless number of various oxidative species. However, the oxidative species and 

by-products produced in the EctoSysTM either have a very short degradation time, are produced in 

extremely low concentrations (in the order of natural occurrence in sea water) or are completely 

harmless. The air emissions will contain oxygen gas and small amounts of hydrogen gas and 

carbon dioxide. Neither the hydroxyl radicals nor any of the theoretically and practically possibly 

formed by-products are bio accumulative, persistent or have endocrine disruptive properties and 

will (in detectable concentrations) ultimately degrade under environmental conditions to oxygen, 

water, carbon-dioxide and chloride ions. 

The key factors for the EctoSysTM electrochemical system are the electrode type and the cell 

design. Permascand AB has over 30 years of experience in developing, producing and 

characterizing different kinds of electrochemical cells, electrodes and catalytic coatings used by 

the electrochemical industry. Different kinds of electrochemical cells, electrodes and coatings are 

used for different industrial applications. In the case of treating ballast water by using 

catalytically inactive electrodes with high oxygen- and hydrogen overpotentials it is possible to 

selectively produce the desired highly oxidative species (e.g. hydroxyl radicals) without the 

problems associated with conventional chlorine electrolysis. 

2 COMPLIANCE WITH THE D-2 STANDARD 

The EctoSysTM electrochemical system is proposed to be used as the disinfecting step in a 

complete Ballast Water Management (BWM) system. The BWM system will treat the whole 

water stream, single flow, during ballasting or/and deballasting. The EctoSysTM will operate after 

a mechanical separation step. 

The results from pilot-scaled trials with this BWM concept indicates that the performance of such 

a system will be in compliance with the D-2 Standard at all points. The tests have been carried 

out using a worst-case scenario approach, e.g. regarding turbidity, temperature and dissolved 

organics. A complete full-scaled land based experimental system is currently being set up, and 

will be in operation during spring 2006 for ongoing tests and evaluation. 
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3 APPLICATION FOR THE USE OF CHEMICAL ACTIVE SUBSTANCE 

The hydroxyl radical specie is a subject of interpretation of the definitions and criteria given in 

the Procedure (G9) regarding “Active Substances”. A proposal for approval of Ballast Water 

Management systems that make use of Active Substances will be sent to GESAMP-BWWG 

according to BWM.2/Circ.2. A document on the proposal for approval containing all the 

non-confidential data related to the possible Active Substances, will be submitted to the 

MEPC accordingly. 

Due to the fact that the proposed electrochemical ballast water disinfection system EctoSysTM is 

not based on the supply or addition of any chemicals to the water to be treated, the guidance 

provided in the Procedure(G9) regarding the testing and characterization of the Active 

Substances are not applicable at all points. Furthermore, one of the Active Substances 

(e.g. hydroxyl radicals) in question has such a short half-life that it is not possible (or relevant) to 

characterize from the point of view of persistency, bio accumulation, endocrine disruption etc. 

which is a major part of the Procedure (G9). The disinfecting effect of the hydroxyl radicals 

produced will take place inside the electrochemical system itself within a few micrometers 

distance from the electrodes, and will not (beside a beneficial regrowth preventing effect 

originating from small amounts of residual free active chlorine species) occur in other parts of 

the ballast water system either on the ship or after discharge of the ballast water back to the sea. 

Risk assessment, toxicity data collection and environmental impact predictions regarding the use 

of EctoSysTM as a component in a complete BWM system will be thoroughly investigated and 

reported. The tests and assessments will be carried out by a well renowned environmental 

laboratory certified according to Good Laboratory Practice (GLP). The experimental approach 

will focus on whole-effluent toxicity testing and chemical specification of ballast water treated 

under relevant conditions. The guidance provided by the Procedure (G9) will be followed when 

applicable. The whole-effluent toxicity testing will also be supplemented by computer 

modulations of the dilution of discharged ballast water in a typical harbour area and possibly a 

specific case study of a European port. The whole-effluent toxicity evaluations and computer 

simulations will be finished and reported during March 2006, and will be submitted to 

GESAMP-BWWG as well as to the MEPC. 

4 WHOLE-EFFLUENT TOXICITY AND MODELLING APPROACH 

4.1 The approach to assessing the effluent from the EctoSysTM system is a practical one 

starting with basic acute toxicity testing of the effluent combined with modelling to show the 

potential area of impact in the environment. A tiered approach as recommended in the European 

Union Technical Guidance Document on Risk Assessment of new substances (EU TGD, 

Reference I), will be carried out for the study of the effluent. In the first instance toxicity testing 

is based on the following strategy: 

.1 Acute toxicity testing will be carried out to determine any short term effects from 

the effluent. This in itself will provide a significant safety factor since the 

timescale of dilution of the discharged effluent will be much shorter (of the order 

of a few minutes) than the timescale of the acute tests (72 or 96 hours); modelling 

will be used to confirm this and to show the extent of any toxic zone that may be 

present from extended discharge from a moored ship. 
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.2 The choice of species for the toxicity testing needs to be appropriate to the marine 

and estuarine situation (algae (Skeletonema costatum), Tisbe battagliai and turbot 

(Scophthalmus maximus) tests have been selected). 

.3 Species need to be selected from different trophic levels to represent species 

variations and lifestyles representing various feeding strategies (PARCOM, 

Reference II). 

The data from the acute toxicity tests will provide information to establish a PNEC (Predicted No 

Effect Concentration) for the effluent using an appropriate safety factor (EU TGD, Ref I). 

Further information is available from PARCOM (Refence II). It is anticipated that the results 

from the acute toxicity testing together with the modelling predictions (Reference III) would 

provide adequate information for assessing the safety of the effluent. It should be noted that the 

algae growth study is actually a chronic study since the organisms go through many generations 

during the time of the study (72 hours). If unexpected results should be obtained a higher tier of 

toxicity testing (including chronic tests) and more detailed modelling would be considered and a 

new proposal for work would be drawn up. 

4.2 EU Technical Guidance document provisions relevant to testing approach 

4.2.1 Reference I: EU TGD (tiered approach) 

(http://ecb.jrc.it/Documents/TECHNICAL_GUIDANCE_DOCUMENT/EDITION_2/tgdpart2_2

ed.pdf) 

The TGD provides information on safety factors for the PNEC, which depend on various issues, 

such as: 

• intra- and inter-laboratory variation of toxicity data; 

• intra- and inter-species variations (biological variance); 

• short-term to long-term toxicity extrapolation; and 

• laboratory data to field impact extrapolation (additive, synergistic and antagonistic 

effects from the presence of other substances may also play a role here). 

In particular the TGD states, in regard to safety factors: “The size of the assessment factor 

depends on the confidence with which a PNEC water can be derived from the available data. 

This confidence increases if data are available on the toxicity to organisms at a number of trophic 

levels, taxonomic groups and with lifestyles representing various feeding strategies. Thus lower 

assessment factors can be used with larger and more relevant datasets than the base-set data. 

Calculation of a PNEC using assessment factors is described in Section 3.3.1.1.” This is of 

particular importance in assessing if there is any need to carry out chronic toxicity tests. 

4.2.2 Reference II: PARCOM (species selection)

The CHARM model web site provides information on the application of toxicity testing and 

modelling to discharges from oil platforms in the North Sea. 

(http://www.eosca.com/Docs/CHARMManualFeb05.pdf) 
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PARCOM provides information on the selection of species. Ecotoxicity testing schemes for both 

single chemicals and mixtures of chemicals (e.g. aqueous effluents) are addressed and follow a 

similar approach. 

Measurement of the effect of chemicals on organisms from different trophic groups (e.g. algae 

[primary producers], invertebrates [primary consumers] and fish [secondary consumers]) 

provides an ecological perspective and accounts for potential differences in sensitivity among 

different organisms. Unfortunately, the ‘ideal’ organism does not exist although some organisms 

may meet many of the criteria listed above. 

In purely practical terms, organisms must be amenable to culture and testing in the laboratory and 

must be: 

- relevant to environment; 

- tried and tested methods for culture and testing; 

- representative of functional group to be protected; 

- susceptible to potential contaminants; 

- abundant, therefore readily available for testing; 

- scope for assessment of acute and chronic effects; 

- robust, allowing easy handling and manipulation; and 

- wide geographic distribution. 

The organisms selected are all of the above and recommended by e.g. PARCOM. 

4.2.3 Reference III: Modelling of discharges 

To support the toxicity testing of the effluent stream from the treatment system the construction 

of a generic model is proposed. This will be a generic simulation of dilution in a typical harbour 

or port and will provide predicted dilution, concentration or toxicity levels in the harbour based 

on the following assumptions: 

• a fixed water depth and tidal range; 

• a fixed size and shape of the harbour and its entrance; and 

• a fixed number of ships in the harbour or dock with an agreed number of these 

discharging the same type of effluent for defined periods of time. 

A report will be prepared describing the model and the predicted results. For different possible, 

but realistic, discharge scenarios (e.g. number and size of ships discharging) the size and duration 

of toxic zones will be presented. 

If further evidence should be needed a more detailed model could be developed, probably in the 

form of a case study for a European port. 

__________