For reasons of economy, this document is printed in a limited number. Delegates are 

kindly asked to bring their copies to meetings and not to request additional copies.

I:\MEPC\59\2.doc 

INTERNATIONAL MARITIME ORGANIZATION

IMO 

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE 

59th session 

Agenda item 2 

MEPC 59/2

 28 November 2008

 Original: ENGLISH

HARMFUL AQUATIC ORGANISMS IN BALLAST WATER 

Application for Final Approval of the RWO Ballast Water Management System 

(CleanBallast) 

Submitted by Germany 

SUMMARY

Executive summary: This document contains the non-confidential information related to 

the application for Final Approval of the RWO Ballast Water 

Management System (CleanBallast) under the “Procedure for 

approval of ballast water managment systems that make use 

of Active Substances (G9)” adopted by resolution MEPC.169(57) 

Strategic direction: 7.1 

High-level action: 7.1.2 

Planned output: 7.1.2.4 

Action to be taken: Paragraph 5 

Related documents: BWM/CONF/36; MEPC 53/24/Add.1; MEPC 55/23; MEPC 57/2/3; 

MEPC 57/2; MEPC 57/21; BWM.2/Circ.13 and BWM.2/Circ.15 

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 to comply with the Convention shall be approved by the Organization. 

2 Germany submits herewith an application for Final Approval according to the “Procedure 

for approval of ballast water management systems that make use of Active Substances (G9)”. 

This procedure stipulates that the required information (MEPC 57/21, annex 1, paragraph 4.2.1), 

which, according to section 6, should be evaluated by the Organization. In accordance 

with BWM.2/Circ.15, this document contains the non-confidential part of the manufacturer’s 

application dossier in the annex. The complete dossier will be made available to the experts of 

the GESAMP-BWWG with the understanding of confidential treatment. 
MEPC 59/2 - 2 - 

I:\MEPC\59\2.doc 

3 Basic Approval of the Active Substance used has been granted at MEPC 55 

(MEPC 55/23, paragraph 2.16). Final Approval as applied for in document MEPC 57/2/3 has not 

been granted at MEPC 57 (MEPC 57/21, paragraph 2.12). 

4 After carefully taking into account the recommendations contained in annex 6 of 

the Report of the fourth meeting of the GESAMP-BWWG (MEPC 57/2) the receiving competent 

authority has verified the application dossier and believes it to satisfy the requirements of the 

Procedure (G9) adopted by resolution MEPC.169(57). 

Action requested of the Committee 

5 The Committee is invited to consider the proposal for approval and decide as appropriate. 

*** 
MEPC 59/2 

I:\MEPC\59\2.doc 

ANNEX 

NON-CONFIDENTIAL INFORMATION ON THE RWO BALLAST WATER 

MANAGEMENT SYSTEM (GERMANY) 

1 INTRODUCTION 

The applicant is proposing a combined system using disc filtration for mechanical separation and 

the advanced EctoSys® electrolysis for disinfection as a complete system for ballast water 

treatment. Previously this complete ballast water treatment system was described 

as Technology No. 1 in annex 1 of document MEPC 55/2/17 and of document MEPC 56/2/10 

and in an oral presentation on October 7, 2008 during MEPC 58. The CleanBallast system was 

developed and is manufactured by RWO GmbH Marine Water Technology (Bremen, Germany), 

which is part of Veolia Water. It is commercialized under the name of CleanBallast (please note 

that in contrast to earlier nomination CleanBallast is written now without an exclamation mark at 

the end for marketing and readability reasons). The applicant hereby proposes the 

complete CleanBallast system to receive Final Approval under Procedure (G9) adopted by 

resolution MEPC.169(57). 

1.1 Status of the CleanBallast system and type approval testing 

The development of the CleanBallast system started in 2003 as a publicly funded R&D project. 

Hereby, different treatment devices for mechanical separation and disinfection (including the 

advanced EctoSys® electrolysis) were tested in parallel, achieving a direct comparison of their 

performance at the naturally changing inlet water quality. Based on these comparative tests, the 

best technology was evaluated and consequently the full-scale CleanBallast system was designed. 

After scaling-up to 500 m3/h flow rate, the full-scale CleanBallast system underwent again a 

rigorous testing at the container pier in Bremerhaven (Germany) since January 2007, in close 

proximity to container ships carrying out ballasting operations. 

The advanced EctoSys® electrolysis received Basic Approval of Active Substances at 

the MEPC 55 in Oct 2006 (MEPC 55/2/4 and MEPC 55/2/16, annex 7). On March 1, 2007, 

RWO GmbH purchased the EctoSys® technology from the former owner Permascand (Sweden) 

including all rights (BWM.2/Circ.11). 

In summer 2007, the CleanBallast system ran successfully the land-based type approval 

procedure on a barge set up at two locations offering brackish and fresh water salinities: the 

harbours of Bremerhaven and Bremen. As required by Procedure (G9), tests related to the 

application for Final Approval were carried out in parallel. A worst-case approach was chosen 

concerning the operation (i.e. the use of Active Substances) of the CleanBallast system as well as 

the water quality (i.e. realistic ballasting conditions) for the testing. The application 

for Final Approval was submitted to MEPC 57 (MEPC 57/2/3), but following the 

recommendations of the GESAMP-BWWG (MEPC 57/2, annex 6) the Final Approval was not 

granted by MEPC 57 (MEPC 57/21, paragraph 2.12). 

Thereupon, the applicant considered the recommendations by GESAMP-BWWG 

(cf. MEPC 57/2, annex 6) and repeated completely the testing for the land-based type approval 

and for the Final Approval at nominal working conditions of the CleanBallast system at 

the NIVA test facility in Solbergstrand (Norway). Det Norske Veritas (DNV) was the 

verification organization of the testing and reporting according to Guidelines (G8) and Procedure 

(G9) at the test facility NIVA. The German Administration BSH (Federal Maritime 

and Hydrographic Agency) involving the Competent Authorities approved the test programme, 
MEPC 59/2 

ANNEX 

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set-up and the CleanBallast system as well as final reports as the certifying authority of Germany 

for the applicant. The full Quality Assurance Project Plan (QAPP) of the test facility NIVA, can 

be found in Appendix E of the application dossier. 

For the shipboard type approval, a 500 m3/h CleanBallast system was installed on a container 

ship (2890 TEU) owned by one of the world-largest container fleet owners (due to a confidential 

agreement the name of the ship and the owner cannot be revealed currently). The shipboard 

type approval procedure is planned to be finalized in spring 2009. Furthermore, the first 

four CleanBallast systems were delivered for newbuildings (20,000 dwt Multipurpose Heavy Lift 

Carriers) since early summer 2008. 

1.2 Short description of the CleanBallast system and control

1.2.1 CleanBallast unit operations and system components 

The ballast water treatment process performed by the CleanBallast system comprises two main 

unit operations: mechanical separation (filtering) and disinfection (advanced electrochemical 

oxidation). The CleanBallast system contains the following main components: ballast water disc 

filters, EctoSys® electrochemical cell, gas trap and de-aeration pipe, rectifier, control cabinet 

with Panel PC, monitoring equipment, e.g., conductivity sensor, TRO (Total Residual Oxidants) 

sensor, Algae Monitor, hydrogen gas sensor, pressure sensors (please refer to the 

confidential Appendix A of the application dossier). 

A neutralization system for further decrease of the TRO concentration if required in high salinity 

seawater before discharge at deballasting is an optional component (Please see TRO data in 

section 6.2 and in the confidential part of the application dossier Appendix N). 

1.2.2 Operation of the CleanBallast system 

The CleanBallast system is operated inline using disc filtration (50 μm filter fineness) and the 

advanced EctoSys® electrolysis for disinfection during ballast water uptake. 

Treatment at ballast water uptake: 

- In the first step, the disc filters remove particles, sediments and organisms of the 

larger size classes. This allows the following disinfection step to minimize the use 

of Active Substances. 

- In the second step, organisms of the smaller size class and bacteria remaining in 

the filtrate are effectively disinfected by the advanced EctoSys® electrolysis. 

A controlled limited current input from the rectifier to the EctoSys® cell assures that 

the Maximum Dosage Disinfectant Concentration proportional to the volume flow rate is kept at 

all times. In marine waters, this maximum is 2 mg/L Total Residual Oxidant (TRO). In fresh 

water any residual oxidants (Active Substances) are not detectable due to the fact that the 

only Active Substance species formed is the short-lived hydroxyl radical (compare to 

section 2.1.2). Thereafter, the treated water is pumped into the ballast water tanks. 
MEPC 59/2 

ANNEX 

Page 3 

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Whilst the ship is en route to the next port of call, potential regrowth of organisms in the ballast 

water tank must be considered. To ensure that the IMO Ballast Water Performance Standard is 

met when discharging the ballast water from the ship, the disinfection process is used a second 

time at deballasting. 

Treatment at ballast water discharge: 

- The disc filters are bypassed. 

- The water from the ballast water tanks is treated once more by the 

advanced EctoSys® electrolysis. At this treatment during deballasting, the 

maximum input current applied to the EctoSys® electrodes is limited at all times 

ensuring the Maximum Dosage Concentration of < 2 mg/L TRO in marine waters. 

Furthermore, in waters of all salinities the applied current is mitigated by using the 

Algae Monitor (see also section 2.1.4, appendix and the confidential Appendix C) 

to monitor and only allow generating the level of disinfectants necessary at 

deballasting (if needed at all). By using this measure the TRO discharge 

concentration is minimized in marine water qualities, and use of hydroxyl radicals 

is minimized in fresh water. 

The correct term reflecting the EctoSys® disinfection would be maximum producible 

concentration; nevertheless, the common term Maximum Dosage Concentration is used in this 

application, although no dosing of chemicals is applied for the operation and production 

of Active Substances by the EctoSys® electrolysis – please see for further information below. 

1.2.3 Active Substances produced by the advanced EctoSys® electrolysis 

The main electrochemical reactions producing Active Substances are described below. 

Previously, a full description of the electrochemical reactions was given in the application 

for Basic Approval in paragraphs 4.3 and 5.2.3 of document MEPC 55/2/4. 

The EctoSys® cell produces disinfectants inline within the main pipe using an electrochemical 

process, whereby flows of up to 500 m3

/h can be disinfected from organisms and bacteria using a 

single EctoSys® module of a footprint < 1 m2. For this, the rectifier receives AC power and 

supplies a direct current to the electrodes of the EctoSys® cell. 

Due to the specific properties of the anodes, the production of hydroxyl radicals is favoured with 

high selectivity in the whole salinity range from river water to seawater. By favouring the 

formation of hydroxyl radicals simultaneously the production of oxygen is suppressed. 

In contrast to conventional chlorine electrolysis, where the addition of salt or a brine solution is 

necessary to low salinity waters, the advanced EctoSys® electrolysis functions in river water 

comparably to seawater without loss of immediate disinfection efficiency. This is due to its 

ability to form hydroxyl radicals as disinfectant directly from water and the direct oxidation of 

contaminants on the electrodes. In river and fresh water (< 3 psu), the only Active Substance 

(disinfectant) produced by the EctoSys® are hydroxyl radicals. Equation (1) gives the anodic 

reaction: 

H2O → OH* + H+ + e- (1) 
MEPC 59/2 

ANNEX 

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I:\MEPC\59\2.doc 

Hydroxyl radicals are extremely short-living (life time of approx. 10-9s – please refer to the Basic 

Approval application dossier MEPC 55/2/4) and therefore give no residual, long-lasting effect 

after the treatment. 

In brackish and seawater, the EctoSys® produces simultaneously the hydroxyl radicals according 

to Equation (1) and chlorine according to Equation (2): 

2 Cl- → Cl2 + 2 e-

 (2) 

Due to the strong pH dependency of the three chlorine species Cl2, HOCl and OCl-

, the formed 

chlorine gas Cl2 is immediately converted into hypochloric acid HOCl in water above pH 4 −

please see equation (3) and in document MEPC 55/2/4, Figure 1 on page 14. 

Cl2 + H2O → HCl + HOCl (3) 

This conversion of chlorine gas Cl2 is facilitated further by the strong water mixing effect caused 

by the arrangement of the electrodes in the EctoSys® cell. 

Especially in marine waters, hypochloric acid HOCl is reduced by bromide Br- in an irreversible 

reaction (Harp 2002) to chloride Cl-

 under the formation of the more stable hypobromic 

acid HOBr. 

HOCl + Br- → HOBr + Cl- (4) 

Hydroxyl radicals and Free Active Chlorine (HOCl/OCl-) are regarded as Active Substances and 

the secondarily formed Free Active Bromine HOBr/OBr- as a Relevant Chemical. For details, 

please refer to section 3.2. 

Besides chlorine and bromine, also other compounds such as manganese (Mn2+) and hydrogen 

peroxide (H2O2) give a response to the DPD-method commonly used to determine 

the concentration of Total Residual Oxidants (TRO; Harp 2002). All concentrations 

of Total Residual Oxidants are given as equivalent chlorine in this application dossier for reasons 

of better comparability. For example, resolution MEPC.159(55) requires 0.5 mg/L chlorine for 

the discharge of treated effluents by sewage treatment plants on board ships. 

Furthermore, the applicant would like to stress that during testing at different locations, relative 

high blank TRO concentrations between 0.1 - 0.3 mg/L were found in the untreated raw and 

control waters. Such values are in the range of the residual concentration as applied in drinking 

water treatment. At least part of the blank concentration can be attributed to phytoplankton such 

as dinoflagellates and green algae, which are capable of producing superoxide O2

-

 and hydrogen 

peroxide H2O2, etc. (Marshall et al. 2005 a and b) as well as volatile halocarbons 

(Crane et al. 1980). Superoxide and hydrogen peroxide formed by algae give a response to 

the DPD-method for the determination of TRO. 

1.2.4 Control of the CleanBallast system and disinfection process 

In normal operation the CleanBallast system is automatically controlled by 

a PLC (Programmable Logic Controller). The system maybe supervised locally by means of a 

panel PC or remotely for instance on the bridge of the ship. This allows the operation sequences, 

status messages and alarms to be monitored. 
MEPC 59/2 

ANNEX 

Page 5 

I:\MEPC\59\2.doc 

TRO and hydroxyl radicals additional to the background level are solely formed in 

the CleanBallast disinfection unit, the EctoSys® (MEPC 55/2/4). The EctoSys® electrochemical 

reaction is controlled by varying the input current to the electrode sets. The maximum permitted 

input current is calculated continuously using real-time data for both water flow rate and 

conductivity measurements. Decreasing flow rate and increasing conductivity (i.e. salinity) 

adjusts the permitted current down. Signals from flow measurements and conductivity 

measurements are processed within the PLC and then used to adjust the current set-point on the 

rectifier supplying the current to the EctoSys® electrochemical cell. 

Throughout the ballasting and deballasting process, the Algae Monitor continuously measures the 

content of viable phytoplankton in the water. If during deballasting the measured level of viable 

phytoplankton is below a specific value, then the system is designed to allow the algae control 

loop to reduce the total current output set point. This prevents an unnecessary discharge of 

excess Active Substances into the output stream, and efficiently reduces the impact on the 

receiving environment to an absolute minimum. 

In addition to the mitigating function of the Algae Monitor, a final fail-safe in the form of a TRO 

measurement device is installed. This TRO measurement device continuously monitors the TRO 

concentration after the EctoSys® disinfection unit and ensures that the actual concentration does 

not exceed the set limit. As soon as the preset warning limit, which can be set to any value up to 

the Maximum Allowable Dosage limit of 2 mg/L TRO at ballasting treatment, is reached, 

the TRO control loop immediately reduces the total current output set point further in marine 

waters above 3 psu. 

The system control software allows a number of the limit values to be adjusted. Certain values 

are able to be set by the manufacturer only and others remain changeable by a suitably qualified 

user. To ensure that system values are not changed by unauthorized personnel, a number of 

password protected security levels have been implemented. 

Several pressure/flow rate sensors are installed, which safely automatically shut down the system 

and open the bypass in case of leakage. Likewise, the system is automatically shut down in a safe 

manner and the bypass opened if the hydrogen gas concentration measured in the de-aeration 

pipe after the EctoSys® cell exceeds 2 Vol. %. For further information please see the application 

dossier in confidential Appendix A. The comprehensive control philosophy of the CleanBallast 

is described in confidential Appendix D in the application dossier. 

1.3 Contents of the application for Final Approval 

The application for Final Approval consists of two parts: the non-confidential application 

document, which contains a summary of results and conclusions of the complete dossier and is 

also submitted by the Member directly to the MEPC, as well as the confidential part of the 

application dossier, which includes additional information such as complete test reports and 

references. Besides covering the requirements of Procedure (G9), the dossier also includes data, 

justifications and answers to the questions raised by the GESAMP-BWWG in the review 

(MEPC 57/2, annex 6) of previous application of Final Approval (MEPC 57/2/3). The summary 

document has, to the widest extent possible, been arranged according to the “Methodology for 

information gathering and the conduct of work of GESAMP-BWWG” (MEPC 58/2/7, annex 4) 

regarding paragraph references in order to simplify the review by the GESAMP-BWWG. 
MEPC 59/2 

ANNEX 

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The confidential part of the dossier includes: 

Appendix A: Manual of the CleanBallast system 

Appendix B: Process diagram of the CleanBallast system 

Appendix C: Detailed description of the Algae Monitor 

- Functional description of the Algae Monitor 

- Patent description of the Algae Monitor 

- Certificate on Environmental Testing of the Algae Monitor according to 

Guidelines (G8), Part 3 

Appendix D: Description of the control philosophy of the CleanBallast system 

Appendix E: Quality Assurance Project Plan (QAPP) of test facility NIVA 

Appendix F: Report on the testing for Final Approval by NIVA 

Appendix G. Data set on land-based type approval testing in fresh water 

- Physical and chemical parameters 

- TRO concentrations 

- Concentrations of disinfection by-products 

- Results of aquatic toxicity testing 

Appendix H: Data on hydrogen and oxygen gas concentrations from CleanBallasts’ data 

recording system (according to Guidelines (G8), paragraph 4.1.3) 

Appendix I: Data on long-term corrosion tests 

- Certificate on compatibility of the CleanBallast system with epoxy-based 

ballast water tank coating systems issued by the Germanischer Lloyd 

- Technical Report “Testing of the influence of CleanBallast on coated and 

uncoated steel” by Germanischer Lloyd 

- Full corrosion test report by approved corrosion test institute 

Appendix J: Discharge modelling 

Appendix K: Human Exposure Scenario (HES) 

Appendix L: Key Data Summaries 

Appendix M: Substance Data and Fate Properties of Active Substances and Relevant Chemicals 

Appendix N: Data on an optional neutralization system. Included as a contingency measure in 

case the TRO discharge concentration exceeds the allowable concentration 

Appendix O: Literature 
MEPC 59/2 

ANNEX 

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2 GENERAL 

2.1 Response to the recommendations made by the GESAMP-BWWG at its 

fourth meeting (MEPC 57/2, annex 6) 

2.1.1 MEPC 57/2, annex 6, paragraph 9.4. 2: Active Substances and Relevant Chemicals 

The Group noted that the proposed system treat the ballast water both on uptake and at 

discharge. The use of a secondary treatment at discharge is to address any potential for 

re-growth of organisms in the ballast tank. At uptake the ballast water is filtered and then treated 

by electrolysis directly in the ballast water pipe. At discharge the ballast water is treated by 

electrolysis only. Chemicals are not required to be stored on board. However, it was noted that, 

e.g., Hydroxyl radicals, Chlorine gas and Hydrogen gas are produced and should be regarded 

as Active Substances and Relevant Chemicals. In addition a number of Disinfection By-Products 

(DPB) were identified by the Applicant and should be regarded as Relevant chemicals. 

Response: 

All Active Substances and Relevant Chemicals including brominated DBPs (Disinfection 

By-Products) are identified by this application, and have been quantitatively analysed in 

whole-effluent samples of treated water of several qualities (e.g., fresh, brackish and full 

salinity). Please refer to section 6.2 of this document. 

2.1.2 MEPC 57/2, annex 6, paragraph 9.4.3: Maximum Allowable Discharge Concentration 

The required concentrations of Active Substances in seawater, measured as Total Residual 

Oxidants, are given by the submission as maximum 2 mg/L. The Group noted that no such levels 

were given for fresh water. Therefore, the Group considers the concentration of 2 mg/L as both 

the Maximum Dosage and the Maximum Allowable Discharge Concentration according to 

the G9-evaluation, respectively. 

Response: 

In freshwater (< 3 psu), e.g., river water and lake harbours, the only Active Substance formed by 

the EctoSys® is the hydroxyl radical (compare equation (1)). Because of the extremely short life 

time of approximately 10-9s which is equivalent to a distance of less than 1 nanometre (< 10-9 m) 

at the designed flow rate of 500 m3/h hydroxyl radicals will evidently not be released from 

the EctoSys® cell to the water flow. Particularly due to their extremely short lifetimem hydroxyl 

radicals are not residual and therefore give no response to the common DPD-method for 

measuring Total Residual Oxidants. Consequently, no TRO concentrations additional to the 

background level (section 1.2.3) can be detected in case of CleanBallast treatment of fresh water. 

As shown in section 6.2 as well as in Appendix G of the application dossier, 

the TRO concentrations in fresh water of the treated water are identical to the control and the 

natural concentrations in the raw (untreated) water. Since hydroxyl radicals are the 

only Active Substances formed during fresh water treatment, the concentrations of disinfection 

by-products are close to the limits of quantification in fresh water (compare section 6.2.1.1 and 

full data in Appendix G of the confidential dossier). Consequently, terms such as 

Maximum Dosage and Maximum Allowable Discharge Concentration concerning hydroxyl 

radicals are not relevant in the case of CleanBallast operation in fresh water. 
MEPC 59/2 

ANNEX 

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2.1.3 MEPC 57/2, annex 6, paragraph 9.4.4: Risks to the safety of the ship 

The Group noted that the Applicant had explained that high levels of disinfection by-products 

such as THM were due to the fact that the EctoSys® system was run differently in the land-based 

tests than it will be in normal operation on board ships. The Group further considered that a full 

chemical characterization of water treated by the CleanBallast! system run in normal mode 

should be provided together with toxicity tests with the same water. 

Response: 

For the previous submission for Final Approval (MEPC 57/2/3) in summer 2007, 

the CleanBallast system was operated taking a worst case approach, i.e. the maximum current 

was applied to the electrodes, consequently generating concentrations close to the 

maximum TRO limit of 2 mg/L in marine waters at all times. This was done both at ballasting 

and at deballasting treatment in order to allow a worst case approach in the subsequent risk 

assessment. This procedure was applied regardless of an actual need for such high maximum 

concentration to achieve the biological efficiency defined by Guidelines (G8). 

In this new application, the CleanBallast system including the EctoSys® electrolysis was run 

according to normal operation conditions, whereby the TRO concentration/current applied at 

deballasting treatment is minimized by control, nevertheless fulfilling the performance criteria 

given by the Guidelines (G8). Tables in section 3.6 provide a full chemical characterization of 

water treated by the CleanBallast system. The toxicity studies were done with the same water 

from full-scale land-based type approval testing. The summary results are presented in 

section 3.3 and the full study is reported in the confidential Appendix F of the application 

dossier. Concentrations of disinfection by-products and aquatic toxicity are lower at normal 

operation of the CleanBallast presented in this dossier compared to the worst case testing data 

submitted earlier (MEPC 57/2/3). The results of the toxicity tests are also in compliance with, or 

considerably lower, than results presented during the evaluation for Basic Approval 

(summarized in MEPC 55/2/4). 

2.1.4 MEPC 57/2, annex 6, paragraph 9.4.5: TRO control scheme 

The Group noted that no detailed information about the control system which could ensure that 

the maximum designed TRO-concentration is maintained was included in the CleanBallast! 

system. However, the dossier indicated that an algae monitor sensor is to be included in the 

industrialized version of the system installed on board ships. This sensor was still under 

development and the Group therefore concludes that the control system was not fully developed 

and therefore not an integrated part of the system under evaluation by the Group. 

Response: 

The Maximum Dosage Concentration of 2 mg/L TRO in marine waters is ensured by restricting 

the current distributed from the rectifier to the electrodes depending on the flow rate and 

conductivity. Thus, it is in no way linked to the function or operation of the Algae Monitor. 

Furthermore, the recommendation of GESAMP-BWWG on maintaining the maximum 

TRO concentration was considered and an additional TRO online sensor was included in 

the CleanBallast system for monitoring and controlling the produced TRO concentration in 

marine waters. 
MEPC 59/2 

ANNEX 

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Thus, the Algae Monitor is not used for the measurement of the chemical properties of the 

effluent such as TRO levels. The Algae Monitor is used to continuously analyse the direct effect 

of the treatment on phytoplankton and, by a feedback loop to the disinfection unit operation 

system (EctoSys®), to minimize the use of Active Substances at concentrations below 

the Maximum Dosage of 2 mg/L TRO. The Algae Monitor is a mitigation measure for the 

second EctoSys® treatment, reducing disinfection at deballasting only to a level needed for 

achieving the G8 efficiency (please refer to section 1.2.4 for control of the CleanBallast system). 

As shown in section 6.2.2, the actually discharged TRO concentration is maximum 1.2 mg/L in 

seawater, below 0.5 mg/L in brackish water, and in fresh water no TRO additional to the 

background level is formed at the treatment during deballasting. 

The function and features of the Algae Monitor are described in detail in Appendix C of the 

confidential part of the application dossier, and summarized in the appendix to this 

non-confidential document. The detailed control philosophy of the CleanBallast system using the 

EctoSys® disinfection step, verifying the Maximum Dosage Concentration of 2 mg/L TRO, is 

found in Appendix D of the confidential part of the application dossier. 

2.1.5 MEPC 57/2, annex 6, paragraph 9.4.6: Recommendations for hydrogen and oxygen 

measurements 

The Applicant carried out hydrogen measurements in a full-scale system. The lowest explosion 

limit for hydrogen gas is 4% under standard conditions. The highest measured value was 0.25%, 

which is 16 times below the explosion limit. It is also noted that a de-aeration component has 

been added immediately following the electrolysis phase and that a hydrogen content monitor 

has been included to monitor the discharge from the de-aeration pipe that will shut down the 

system should hydrogen concentrations at this point reach dangerous levels. The Group 

considers that the information provided together with the mitigation measures incorporated are 

acceptable in addressing this identified risk. The group recognized that the formation of oxygen 

in a full-scale test has not been investigated. 

As well as in MEPC 57/2, annex 6, paragraph 9.4.10: recommendation concerning risk for the 

crew and ship: 

The Group noted that the risk of explosion due to the generation of Hydrogen gas in the 

electrolysis process identified during the assessment for Basic Approval of this system had been 

fully considered by the applicant. A de-aerator has been incorporated to the system that includes 

a hydrogen monitor in its vent arrangement that will shut down the system should dangerous 

level of hydrogen be detected as an additional risk mitigation measure. The Group therefore 

considers that this risk has been adequately addressed and controlled by the applicant.
MEPC 59/2 

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Response: 

During normal operation of the CleanBallast system, the hydrogen gas measurements were 

repeated by an online gas analyser installed in the de-aeration pipe after the EctoSys® electrolysis 

(for details see MEPC 57/2/3, paragraph 3.5.2.2.2 and Appendices A, B) as well as with a 

portable analyser at different locations, e.g., the storage tanks. All analysed hydrogen gas 

concentrations were far below 0.25 Vol. %. Besides the measurements of the dissolved oxygen 

concentration in water, an additional oxygen gas analyser was installed in the de-aeration pipe, 

likewise, in the testing for the Final Approval. A slight increase of the dissolved oxygen 

concentration was measured in the effluent water of the CleanBallast system, which was in the 

range of the dissolved oxygen saturation concentration (see section 6.2.3). In accordance with the 

still low dissolved oxygen concentration, the measured oxygen gas concentrations were in the 

normal range of 20 Vol. % (for full data please see in the confidential part of the application 

dossier, Appendices F and H). 

Together with the hydrogen gas formed as by-product, the by-produced oxygen gas is also 

removed by the deaerator. In the above-mentioned shipboard installations the de-aeration pipe is 

installed through the chimney directly to the ambient air well above the main deck or through the 

deck with the pipe ending well above the height of a human. 

2.1.6 MEPC 57/2, annex 6, paragraph 9.4.7: Recommendations on corrosion testing 

The Group noted that the long-term corrosion testing that had been advised in the 

Basic Approval evaluation has not yet commenced. 

As well as in MEPC 57/2, annex 6, paragraph 9.4.11: Recommendations on corrosion testing: 

The Group noted that tests to determine the corrosive properties of the treated ballast water had 

yet to commence, and therefore the level of the potential risk of accelerated corrosion to the 

ballast water piping and structure that may be raised by use of this system remains to be 

assessed.

Response: 

Comprehensive corrosion studies have been commenced in co-operation with a leading European 

corrosion institute and under supervision of Germanischer Lloyd as the accredited quality 

controlling authority (please refer to section 7.1.1). The result showed that the CleanBallast 

system does not have any negative influence on the tested coating systems, which are intended 

for the use in seawater ballast tanks on ships. Consequently, Germanischer Lloyd has issued the 

“Certificate on compatibility of the CleanBallast system with epoxy-based ballast water tank 

coating systems” for use on board ships. The certificate and technical report issued 

by Germanischer Lloyd as well as the full report of the performing institute covering the test 

methodology, ISO standards used, raw data, etc., can be found in the application dossier, 

confidential Appendix I. 
MEPC 59/2 

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2.1.7 MEPC 57/2, annex 6, paragraph 9.4.8: Recommendations on chronic aquatic toxicity 

The Group noted that chronic aquatic toxicity studies were not carried out in a land-based 

installation as required by the G9 guideline, but in a lab-based installation. The Applicant 

emphasizes that it is the TRO concentration which is relevant in relation to the toxicity of the 

treated water and not the scale of the installation. The Group considers both the level of TRO 

and organic matter essential for the quantity of halogenated by-products (DBP) and therefore 

also for the toxicity of the treated water. Toxicity tests with water samples from the land-based 

efficacy tests as required by the G8 and G9 guidelines will ensure that adequate levels of TRO 

and organic matter is used in all tests and the chemical characterization of treated water. 

Response: 

Acute and chronic aquatic toxicity studies with six different species on three trophic levels and 

five phyla were carried out using water treated in the full-scale CleanBallast system during 

land-based type approval testing at the test facility NIVA. The tests and equipment were 

fulfilling the criteria given by the Guidelines (G8), as required by Procedure (G9). Water quality 

also fulfilled the inlet criteria. The full-scale land-based CleanBallast unit was operated 

according to normal procedures, similar as on board a ship. The treatment efficiency fulfilled the 

D-2 standard criteria. 

A summary of the whole-effluent toxicity data including endpoints and other relevant 

information can be found in section 3 of this document. Chemical characterization of inlet water, 

treated water (including by-products, oxygen) can be found in section 6.2. The complete 

description and data-set of the toxicity studies and chemical characterization of the water can be 

found in the confidential part of the application dossier in Appendices E and F, respectively. 

2.1.8 MEPC 57/2, annex 6, paragraph 9.4.9: Human Exposure Scenario 

The Group considered that Brominated DBPs (Disinfection By-Products) are the toxicological 

relevant compounds generated by the process. As the applicant couldn’t provide information 

concerning the Human Exposure Scenario (3.9. MEPC 57/2/3), the Group noted that an 

adequate conclusion as to the outcome of the Human Risk Assessment could not be achieved. 

Therefore, the Group recommended that human exposure when handling ballast water treatment 

operations should be restricted and RMM put in place.

Response: 

Human Exposure Scenarios (HES) of Active Substances and Relevant Chemicals, including 

brominated disinfection by-products, originating from treated ballast water have been 

evaluated according to guidance given by the GESAMP-BWWG (MEPC 58/2/7, annex 4, 

paragraph 7.2.3) and elaborated from templates and principles used in the available TGD 

(Technical Guidance Document, issued by the EU Commission) as well as reflecting the 

recommendations given by the GESAMP-BWWG concerning HES (i.e. MEPC 58/2/7, annex 4, 

appendix 2). Occupational as well as exposures via the environment have been addressed. 

Inhalation, dermal route as well as oral route have been evaluated. Please refer to the conclusion 

summaries in section 7.2.3 of this document, and more thoroughly the comprehensive study 

on HES in the confidential part of the application dossier Appendix K, performed by external 

relevant expertise. 
MEPC 59/2 

ANNEX 

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During normal handling of ballast water operations on board the ship such as ballasting, ballast 

water storage and ballast water discharge, there is no dermal or oral exposure route 

of Active Substances or Relevant Chemicals to the crew, due to the in situ production principle 

of EctoSys® cell in the CleanBallast system directly in the main ballast pipe. The inhalation route 

has raised concern, since brominated and other disinfection by-products might enter into the gas 

phase. Therefore, especial attention was taken to this potential risk when developing the HES. 

The HES concludes that the predicted concentration in the air for inhalation is far below 

existing OEL (occupational exposure limit) - values. Thus, no risk to the crew on the ships is 

expected. Also, as the predicted daily uptake considering all uptake routes simultaneously is far 

below existing TDI values, no risk to the public from the TRO, its degradation products or 

by-products is expected from the environment. 

In case of damage to any equipment carrying treated ballast water (e.g., the ballast water piping), 

the CleanBallast system is automatically shut down. However, a leakage will provide a possible 

exposure route. The Maximum Dosage Concentration of 2 mg/L Active Substances (MEPC 57/2, 

annex 6, paragraphs 0.3 and 9.4.3) will never be exceeded in any step of the process, thus the 

acute toxicity of treated water is evaluated to have no dermal effect on humans, should there be 

a direct exposure outside normal operation, i.e. leakage. The exposure dose (low concentrations 

well below acute dermal toxicity levels, based on data provided by MSDS for each substance), 

duration and frequency of such events are assessed as neglectable to the risk assessment. 

For human exposure risk assessment at these concentrations of the Active Substances and 

relevant concentrations of Relevant Chemicals, please refer to section 7.2 of this document 

and Appendix K of the confidential part of the application dossier. 

2.1.9 MEPC 57/2, annex 6, paragraph 9.4.12: Risk for the environment 

Based on information provided in the application for Basic approval, a PEC/PNEC ratio of 

discharged ballast water in Rotterdam harbour can be calculated to 0.85. Based on this ratio 

the Group concludes that under the conditions of the test there would be low risk for the 

environment. For a final risk assessment to the environment the Group needs, however, a better 

explanation of the presence and performance of the algae monitor and information on the 

validity and applicability of the model used. For reference reasons also calculations with 

the MAMPEC-model are recommended using as many as possible the same parameter values. 

Under the assumptions of the applicant there seems no risk for the environment but the Group 

needs more confidence in the applied tools and methods. 

Response: 

Meeting the recommendation by the Group, the applicant has used MAMPEC (ver. 6) in addition 

to previous custom-made simulations to assess conservative PECTRO values for large commercial 

harbours comparable to Rotterdam. Using (as far as possible) the same input parameters 

(i.e. standard commercial harbour + EU OECD commercial harbour) as for previous evaluations, 

the PEC/PNEC ratios for TRO as derived by MAMPEC for discharge concentrations relevant for 

normal operation of the CleanBallast operated in natural waters are <1. The risk characterization 

is further based on input parameters varying over the whole range from the unrealistically 

conservative default assumptions on, e.g., discharge quantities to a more balanced assessment of 

the discharge into the receiving environment. Please refer to section 6.3.3, where also a 

summary of PEC/PNEC ratios for Relevant Chemicals can be found. 
MEPC 59/2 

ANNEX 

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In addition to calculating predicted steady-state concentrations (using MAMPEC, see above), 

plume modelling has been adopted to examine the acute exposure of receiving waters 

to Active Substances and Relevant Chemicals. Properly defined real case harbours have been 

used in order to simplify future comparisons. Immediate exposure during discharge as well as 

dilution/diffusion over time has been considered. The results have been compared to the 

outcome of the acute toxicity studies, calculated NOEC of the most sensitive species and 

literature references (please refer to the summary in section 6.3 of this document and Appendix J 

of the application dossier). 

3 APPLICATION DATA SET 

3.1 General 

3.1.1 The dossier contains the information specified in Procedure (G9). In cases where 

information requested in accordance with Procedure (G9) has not been submitted, it is either not 

applicable or a justification is provided. 

3.1.2 For Active Substances and Relevant Chemicals, data on physical, chemical and 

environmental fate properties have been included, if applicable, and can be found in the form 

of Key Data Summaries in Appendix L of the application dossier, or in report form 

“Theoretical evaluation of the fate and effect of disinfection by-products” found in Appendix M. 

3.1.3 Fate and effect evaluation on Active Substances and Relevant Chemicals (G9: 5.3.1, 

including degradation, bioaccumulation, etc.) have been performed using theoretical methods and 

literature. Justification for not testing each chemical is given by the nature of the disinfection 

process where the Active Substances and Relevant Chemicals are formed. The Active Substances 

and Relevant Chemicals are not dosed, but formed in situ in the ballast water by an 

electrochemical process. Furthermore, the formed Active Substances and Relevant Chemicals 

(and their concentrations) are depending on the water quality (e.g., seawater, brackish water or 

fresh water). Thus, fate (i.e. by-product formation) and effect studies (i.e. toxicity) directly 

testing whole-effluents of treated ballast water of different origins, including 

the 100% concentration in the dilution series, are more suitable. 

3.1.4 Acute and chronic toxicity data have been provided for treated ballast water (G9: 5.2.2). 

The discharge toxicity tests include chronic test methods performed as part of the land-based type 

approval process with test species (fish, invertebrate, algae) that address the sensitive life stage 

(G9: 5.2.4). The results include acute LC50 values and chronic NOECs or similar endpoints, 

respectively (G9: 5.2.5). Dilution series including 100% concentrations of samples of ballast 

water discharge have been used (G9: 5.2.6). Acute toxicity data for brackish and fresh water have 

also been provided for treated ballast water whole-effluent samples taken at full-scale land-based 

type approval process tests which were performed at locations of real ballasting operation. 

Tests on additional taxonomic groups have been added, as requested by the GESAMP-BWWG 

(MEPC 58/2/7, annex 4). 
MEPC 59/2 

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3.2 Identification of the Substance or Preparation (G9: 4.1) 

Active Substances used by the CleanBallast are solely formed in and by the electrochemical 

disinfection process. The disinfection unit operation is performed by the advanced 

electrochemical EctoSys® technology, which received Basic Approval at MEPC 55 

(MEPC 55/2/4). Active Substances were identified in document MEPC 55/2/4, paragraph 3, as 

follows: 

.1 Hydroxyl Radicals (OH·) 

.2 Free Active Chlorine (HOCl/OCl-

) 

These Active Substances are primarily formed in the electrochemical disinfection process. 

Secondary by-products, degradation products, etc. (some of which may have an oxidative 

“active” effect) are regarded as Relevant Chemicals as defined by paragraph 1.1.6 

“Relevant Chemicals” of the Methodology which can be detected in discharged ballast water 

(or in the gas phase above the treated water) treated by the CleanBallast are: 

.1 Free Active Bromine (HOBr/OBr-

) 

.2 Dibromochloromethane CHClBr2

.3 Tribromomethane, Br3CH 

.4 Dichloroacetic acid (DCAA) 

.5 Trichloroacetic acid (TCAA) 

.6 Dibromoacetic acid (DBAA) 

.7 Bromochloroacetic acid (BCAA) 

.8 1.2.3-trichloropropane 

.9 Bromate 

.10 Hydrogen 

Other components such as by-products formed and chemical sum parameters that may be 

influenced by the CleanBallast disinfection process are: 

.1 Oxygen 

.2 AOX (Adsorbable organically bound halogens) 

.3 EOX (Extractable organohalogen compounds) 

3.2.1 Preparations: The CleanBallast system does not include the addition of any chemicals or 

chemical preparations. The Active Substances used by and Relevant Chemicals related to 

the CleanBallast disinfection process are produced in situ from the components of natural waters 

and electrical direct current. Thus, Preparations as defined by paragraph 1.1.3 of 

the Methodology are not relevant for the CleanBallast system or the application 

for Final Approval. 
MEPC 59/2 

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3.2.2 Active Substances: 

3.2.2.1 Hydroxyl radical 

Trade name N/A 

Chemical (IUPAC) name Hydroxyl radical 

CAS number 3352-57-6 

UN number/Proper shipping name N/A 

Molar mass (g/mol) 17.01 

Empirical formula HO 

Structural formula H*O 

Classification (UN GHS) N/A 

Purity/Identification of impurities N/A 

Stabilizers/Necessary additives N/A 

3.2.2.2 Free Active Chlorine 

(OCl-/HOCl, in the form of sodium 

hypochlorite)Trade name 

Sodium hypochlorite 

Chemical (IUPAC) name Sodium hypochlorite 

CAS number 7681-52-9 

UN number/Proper shipping name 1791 

Molar mass (g/mol) 74,5 

Empirical formula NaOCl 

Structural formula 

Purity/Identification of impurities N/A 

Stabilizers/Necessary additives N/A 
MEPC 59/2 

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3.2.3 Relevant Chemicals (G9: 2.1.4) 

3.2.3.1 Free Active Bromine (OBr-/HOBr, in the form of Sodium hypobromite) 

Chemical (IUPAC) name Sodium hypobromite 

CAS number 7726-95-6 

Molar mass (g/mol) 159.8 

Empirical formula NaOBr 

Structural formula 

3.2.3.2 Dibromochloromethane 

Chemical (IUPAC) name Dibromochloromethane 

CAS number 124-48-1 

Molar mass (g/mol) 208.3 

Empirical formula CHClBr2

Structural formula 

3.2.3.3 Bromoform 

Chemical (IUPAC) name Tribromomethane 

CAS number 75-25-2 

Molar mass (g/mol) 252.7 

Empirical formula Br3CH 

Structural formula 

3.2.3.4 Dichloroacetic acid (DCAA) 

Chemical (IUPAC) name Dichloroacetic acid

CAS number 79-43-6 

Molar mass (g/mol) 128.9 

Empirical formula CHCl2COOH 

Structural formula 
MEPC 59/2 

ANNEX 

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3.2.3.5 Trichloroacetic acid (TCAA) 

Chemical (IUPAC) name Trichloroacetic acid 

CAS number 76-03-9 

Molar mass (g/mol) 163.4 

Empirical formula CCl3COOH 

Structural formula 

3.2.3.6 Dibromoacetic acid (DBAA) 

Chemical (IUPAC) name Dibromoacetic acid 

CAS number 631-64-1 

Molar mass (g/mol) 217.8 

Empirical formula CHBr2COOH 

Structural formula 

3.2.3.7 Bromochloroacetic acid (BCAA) 

Chemical (IUPAC) name Bromochloroacetic acid 

CAS number 5589-96-8 

Molar mass 173.39 

Empirical formula CHBrClCOOH 

Structural formula 

3.2.3.8 1.2.3-Trichloropropane 

Chemical (IUPAC) name 1.2.3-Trichloropropane 

CAS number 96-18-4 

Molar mass (g/mol) 147 

Molecular formula C3H5Cl3

Structural formula 

3.2.3.9 Bromate (in the form of sodium bromate) 

Chemical (IUPAC) name Sodium bromate 

CAS number 7789-38-0 

Molar mass (g/mol) 150.89 

Molecular formula NaBrO3

Structural formula 
MEPC 59/2 

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3.2.3.10 Hydrogen (g) 

Chemical (IUPAC) name Hydrogen 

CAS number 1333-74-0 

Molar mass (g/mol) 2.02 

Molecular formula H2

Structural formula H-H 

The new measurements of hydrogen gas during the repeated land-based type approval testing at 

the test facility NIVA showed that all analysed hydrogen gas concentrations were far 

below 0.25 Vol. % in the de-aeration pipe installed after the EctoSys® disinfection as well as at 

different locations of the storage tank (cf. NIVA report in Appendix F and data on hydrogen and 

oxygen gas concentrations from CleanBallasts’ data recording system (according to 

Guidelines (G8) in Appendix H). 

3.2.4 Other chemicals 

3.2.4.1 Oxygen 

Oxygen (O2, gaseous) is formed as a by-product of the electrochemical process (MEPC 55/2/4, 

paragraph 4.3.2). The oxygen dissolves in the treated water until the dissolved oxygen saturation 

concentration is reached and surplus oxygen will leave the water in the form of gas via the 

deaerator. This is installed after the EctoSys® disinfection and allows free gases to be removed 

after the CleanBallast system, leaving the ship via the de-aeration pipe to the atmosphere. By this 

measure, no hazards are posed to the crew, ship or environment. The changes in dissolved 

oxygen content of water treated by the CleanBallast system have been analysed during the 

land-based type approval procedure as well as oxygen gas measured in the de-aeration pipe. 

These results can be found paragraphs 6.2.3.1 to 6.2.3.3 and in Appendix H of the application 

dossier. Due to the high natural occurrence of oxygen in natural waters and in the 

atmosphere/biosphere, the substance is not regarded as a Relevant Chemical by the applicant. 

3.2.4.2 AOX 

AOX (Adsorbable Organic Halogen; also Total Organic Halogen TOX) is a sum parameter, 

which is widely used in waste water and environmental analysis for the quantification of 

organically bound halogens. The AOX includes chlorinated and brominated adsorbable organics, 

e.g., trihalomethanes (THM), which were analysed separately as single compounds during the 

land-based type approval procedure. While AOX concentration was also analysed in addition to 

single disinfection by-products, the sum parameter AOX as such is not regarded as 

a Relevant Chemical by the applicant. The maximum AOX concentration after the deballasting 

treatment, with 0.07 mg/L (also see section 6.2.1), was relatively low compared to concentrations 

between 0.02 - 0.28 mg/L TOX analysed in supplied drinking water in the United States 

(Reemtsma and Jekel, 2002). These low AOX concentrations are in accordance with previous 

results (see MEPC 57/2/3, Table 1). 
MEPC 59/2 

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3.2.4.3 EOX 

Likewise, the EOX (Extractable Organic Halogen) is a sum parameter for the quantification of 

organically bound halogens, which can be extracted from solids. Therefore, it is mostly used to 

characterize soil or seldom for particles in water. Similar to AOX, the EOX concentration was 

analysed during the land-based type approval testing and rather in a low concentration range 

(maximum 0.03 mg/L; see also section 6.2.1). Therefore, the sum parameter EOX as such is not 

regarded as a Relevant Chemical by the applicant. 

3.3 Data on effects on aquatic plants, invertebrates and fish, and other biota, including 

sensitive and representative organisms (G9: 4.2.1.1) 

3.3.1 For every Active Substance and Relevant Chemical data are presented and discussed 

either on the basis of toxicological tests (treated ballast water) or existing toxicological 

knowledge for separate Active Substances and Relevant Chemicals. 

3.3.2 Acute aquatic toxicity 

3.3.2.1 Short-term L(E)Cx from freshwater or saltwater representatives of three taxonomic 

groups (algae, crustaceans and fish) representing three trophic levels are provided, if available. 

3.3.2.2 In the case of whole effluent testing (paragraph 3.3.2.3.4 “Treated ballast water”) 

short-term methods deemed qualitatively equivalent to US EPA for estimating the acute toxicity 

have been used. 

3.3.2.3 Acute aquatic toxicity for Preparations, Active Substances, Relevant Chemicals and 

treated ballast water. 

3.3.2.3.1 Preparations is not an applicable term to the CleanBallast process or the toxicity tests 

related hereto (paragraph 3.2.1). 

3.3.2.3.2 Active Substances 

Due to the nature of the electrochemical disinfection process, individual Active Substances 

cannot be separately obtained in order to perform toxicity studies. Acute toxicities of individual 

substances have been reviewed using literature, and further used for PNEC evaluations. For 

Active Substances, data on individual acute toxicity is provided and evaluated for Free Active 

Chlorine. Please refer to the complete risk assessment previously submitted for Basic Approval, 

paragraphs 3.3.2.3.2.1 and 3.3.2.3.2.2 below and Appendix L of the application dossier. 

3.3.2.3.2.1 Hydroxyl radical 

Due to the nature of radical species, toxicity studies cannot be performed specifically using such. 

The toxic effect caused by radical mediated oxidation has been investigated and discussed in the 

submitted application dossier for Basic Approval and summarized in document MEPC 55/2/4, 

paragraph 5.1.1.3. Toxicity of separate degradation and disinfection by-products generated by the 

electrochemical process is provided in the Key Data Summaries in Appendix L, where such data 

is available. 
MEPC 59/2 

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3.3.2.3.2.2 Free Active Chlorine 

The toxicity of free active chlorine (FAC) has been thoroughly investigated by many scientists 

over a long period of time. A vast number of species from > 3 taxonomic groups and many 

methods have been used. A comprehensive summary of the toxicity studies performed was 

compiled and presented in the submitted dossier for Basic Approval (MEPC 55/2/4, 

paragraph 5.2.9). A complete risk assessment on sodium hypochlorite was also included in the 

submission. Toxicity of degradation and disinfection by-products generated by the 

electrochemical process is summarized in further sections. The sodium hypochlorite PNEC for 

brackish water and seawater organisms was determined at 0.04 μg FAC/L, including the safety 

factor of 50 (MEPC 55/2/4, paragraph 5.2.10). Also see Appendix M of the application dossier, 

the report “Theoretical evaluation of the fate and effect of disinfection by-products” where 

almost the same PNEC value (0.06 μg FAC/L) was derived based on available ecotoxicity data. 

The ecotoxicity data on most sensitive species selected for PNEC calculation are summarized 

in Table 1 below. Acute aquatic toxicity data on most sensitive species from three taxonomic 

groups are summarized in the key data summary sheet. 

Table 1: Summary of ecotoxicity data selected for the determination of the sodium 

hypochlorite PNEC for brackish and seawater organism 

Specie Endpoint Result Reference/Justification 

of missing data 

Fish Leiostomus 

xanthurus

96 h LC50 0.09 mg/L Bellanca & Bailey 

(1977) 

Fish Oncorhynchus 

kisutch

96 h LC50 0.032 mg/L Thatcher (1978) 

Other Crassostrea 

virginica 

(Mollusc, Bivalve)

48 h EC50 0.026 mg/L Robert and Gleeson 

(1978) 

Fish Menidia 

peninsulae 

28 d NOEC 0.04 mg/L Goodman et al. (1983) 

Other Crassostrea 

virginica 

(Mollusc, Bivalve) 

15 d NOEC 0.007 mg/L 

(TRC) 

Liden et al. (1980) 

Table 2: Acute toxicity data for sodium hypochlorite, three trophic levels 

Specie Endpoint Result Reference/Justification 

of missing data 

Fish Leiostomus 

xanthurus 

96 h LC50 0.09 mg/L Bellanca & Bailey 

(1977) 

Crustacea Crangon 

nigricauda 

96 h LC50 0.134 mg/L Thatcher (1978) 

Algae Thalassiosira 

pseudonana 

24 h LC50 0.075 mg/L Gentile (1976) 
MEPC 59/2 

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3.3.2.3.3 Relevant Chemicals 

Due to the nature of the electrochemical disinfection process, individual Relevant Chemicals 

cannot be separately produced in order to perform toxicity studies. Acute toxicity of individual 

substances has been reviewed using literature, where available, and can be found in 

the Key Data Summaries (Appendix L) and in Appendix M report “Theoretical evaluation of the 

fate and effect of disinfection by-products”. The data is further used for the PNECs derived 

in Appendix M of the application dossier, the report “Theoretical evaluation of the fate and effect 

of disinfection by-products”. 

3.3.2.3.4 Treated ballast water (G9: 5.2.3) 

In accordance with paragraph 5.2.1 of Procedure (G9) for Final Approval, the discharge testing 

has been performed as part of the land-based type approval process using the treated ballast water 

discharge. All toxicity data disclosed were obtained at land-based type approval test cycles 

meeting Ballast Water Performance Standard concerning biological efficiency. Tests were 

carried out with water from several consecutive cycles and the most conservative values are 

reported in the summary tables below. 

3.3.2.3.4.1 Fresh water (0.4 psu) 

Table 3: Acute aquatic acute toxicity in treated fresh water (cf. Appendix G) 

Specie Endpoint Result Reference/Justification 

of missing data 

Fish Danio rerio LC50 

(ml/L) 

n.r.* DIN 38415-T6 

Crustacea Daphnia magna EC50 

(ml/L) 

n.r.* DIN 38412-L30 

Algae Scenedesmus sp. EC50 

(ml/L) 

n.r.* DIN 38412-L33 

Other Vibrio fisheri 

(Microtox©) 

EC50 

(ml/L) 

n.r.*

 ISO 11348-2 

*

 n.r. = not reached 

3.3.2.3.4.2 Brackish water (22 psu) 

Table 4: Acute aquatic acute toxicity in treated brackish water (cf. Appendix F) 

Specie Endpoint Result Reference/Justification of 

missing data 

Fish Scopthalmus 

maximus

LC50, %*

 >100 OECD 203 

Crustacea Acartia tonsa LC50, %*

 >100 ISO 14669 

Algae Skeletonema 

costatum

EC10, %*

EC50, %*

61 

>100 

ISO 10253 

(

*

 percentage of treated ballast water diluted in control water) 
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3.3.2.3.4.3 Sea water (32-35 psu) 

Table 5: Acute aquatic acute toxicity in treated sea water (cf. Appendix F) 

Specie Endpoint Result Reference/Justification of 

missing data 

Fish Scopthalmus 

maximus

LC50, %* 74 OECD 203 

Crustacea Acartia tonsa LC50, %*

 60.5 ISO 14669 

Algae Skeletonema 

costatum

EC10, %*

EC50, %*

14 

19 

ISO 10253 

(

*

 percentage of treated ballast water diluted in control water) 

3.3.3 Chronic aquatic toxicity 

3.3.3.1 Long-term NOECs or ECx from three freshwater or saltwater species representing 

three trophic levels have been provided, if available. Justifications for missing data have 

been made. 

3.3.3.2 In the case of whole effluent testing (paragraph 3.3.3.3.4 “Treated ballast water”) 

short-term methods deemed equivalent to US EPA for estimating the chronic toxicity are 

provided, since the identification of the sensitive sub-lethal endpoints and vulnerable life-stages 

is the ultimate aim of the long-term testing. 

3.3.3.3 Chronic aquatic toxicity for Preparations, Active Substances, Relevant Chemicals and 

Treated ballast water. 

3.3.3.3.1 Preparations is not an applicable term to the CleanBallast process or the toxicity tests 

related hereto (paragraph 3.2.1). 

3.3.3.3.2 Active Substances 

Due to the nature of the electrochemical disinfection process, individual Active Substances 

cannot be separately obtained in order to perform toxicity studies. Chronic toxicity of individual 

substances has been reviewed using literature. 

3.3.3.3.2.1 Hydroxyl radical 

Due to the nature of radical species, toxicity studies cannot be performed specifically using such. 

The toxic effect caused by radical mediated oxidation has been investigated and discussed in the 

submitted application dossier for Basic Approval and summarized in document, MEPC 55/2/4, 

paragraph 5.1.1.3. Toxicities of degradation and disinfection by-products generated by the 

electrochemical process are summarized in further sections. 
MEPC 59/2 

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3.3.3.3.2.2 Free Active Chlorine (HOCl/ OCl-, in the form of sodium hypochlorite) 

Table 6: Chronic aquatic acute toxicity for sodium hypochlorite 

Species 

NOEC 

(mg/ L/duration) 

Reference/Comments/ 

Justification for missing data 

Fish 

Menidia 

peninsulae 0.04 (28d NOEC) Goodman et al. (1983) 

Crustacea 

Crassostrea 

virginica 0.11 (60d NOEC) Scott et al. (1979) 

Algae N/A N/A 

Supportive information on 

long-term algae toxicity studies 

can be found in MEPC 55/2/4 

reference 

3.3.3.3.3 Relevant Chemicals 

Due to the nature of the electrochemical disinfection process, individual Relevant Chemicals 

cannot be separately produced in order to perform toxicity studies. Chronic toxicity of individual 

substances has been reviewed using literature, where available, and can be found in 

the Key Data Summaries (Appendix L) and in Appendix M report “Theoretical evaluation of the 

fate and effect of disinfection by-products”. The data is further used for the PNECs derived 

in Appendix M of the application dossier, report “Theoretical evaluation of the fate and effect of 

disinfection by-products”. 

3.3.3.3.4 Treated ballast water (G9: 5.2.3) 

In accordance with paragraph 5.2.1 of Procedure (G9) for Final Approval, the discharge testing 

has been performed as part of the land-based type approval process using the treated ballast water 

discharge. All toxicity data disclosed are obtained at land-based type approval test cycles 

meeting Ballast Water Performance Standard concerning efficiency. Tests were carried out with 

water from several consecutive cycles and the most conservative values are disclosed in the 

summary tables below. 

Chronic toxicity in treated fresh water was not evaluated due to the results of the acute tests and 

in view of the fact that no potentially toxic Active Substances need to be expected, and only very 

low concentrations of disinfection by-products (close to the limit of quantification) were detected 

in fresh water (compare to section 6.2.1.1). 
MEPC 59/2 

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3.3.3.3.4.1 Brackish water (22 psu) 

Table 7: Chronic aquatic toxicity in treated brackish water (cf. Appendix F) 

Specie Endpoint Result Reference/Justification of 

missing data 

Fish Scopthalmus 

maximus

NOEC, % 56 OECD 215 

Crustacea Nitocra 

spinipes

NOEC, % >32* Danish standard 

reproduction test 

Algae Skeletonema 

costatum

EC10, %*

EC50, %*

61 

> 100 

ISO 10253 

Other Brachionus 

plicatilis

EC50, % 

NOEC, % 

> 100 

> 100 

ISO/DC 20666 

Chronic rotifer test *

 Highest tested concentration was 32% 

3.3.3.3.4.2 Sea water (32-35 psu) 

Table 8: Chronic aquatic toxicity in treated sea water (cf. Appendix F) 

Specie Endpoint Result Reference/Justification of 

missing data 

Fish Scopthalmus 

maximus

NOEC, % 56 OECD 215 

Crustacea Nitocra spinipes NOEC, % >32*

 Danish standard 

reproduction test 

Algae Skeletonema 

costatum

EC10, %*

EC50, %*

14 

19 

ISO 10253 

Other Crassostrea gigas 

Brachionus 

plicatilis 

LC50, % 

NOEC, % 

EC50, % 

NOEC, % 

62 

46 

> 100 

56 

ASTM E724 

Chronic oyster embryo test 

ISO/DC 20666 

Chronic rotifer test *

 Highest tested concentration was 32% 

3.3.4 Endocrine disruption 

3.3.4.1 There are no indications, e.g., from the structure of the substance or results of other 

available studies that any of Active Substances or Relevant Chemicals causes endocrine 

disruption. None are found listed as endocrine disruptors (US EPA EDSP, Danish EPA, EU 

Priority list). 

3.3.5 Sediment toxicity 

3.3.5.1 Active Substances and Relevant Chemicals have been assessed for persistence in 

natural waters and concerning accumulation potential in sediments. All substances have log Kow 

values < 3 and thus very low accumulation potential in sediments. 
MEPC 59/2 

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3.3.6 Bioavailability/biomagnification/bioconcentration 

3.3.6.1 Reviewing log Pow values for Active Substances and Relevant Chemicals, it is 

concluded that the bioaccumulation potential should be considered very low. 

3.3.7 Food web/population effects 

3.3.7.1 Biomagnification and persistence in the food web is not considered as a potential risk 

based on the results from aquatic toxicity testing, low PEC values, mammalian toxicity 

evaluation and bioaccumulation and biodegradation data. 

3.3.7.2 Secondary poisoning from Active Substances and Relevant Chemicals are considered 

of no concern based on the very low bioaccumulation potential. 

3.4 Data on mammalian toxicity (G9: 4.2.1.2) 

3.4.1 General 

Mammalian toxicity studies have not been performed separately for Active Substances 

or Relevant Chemicals formed during or after application of the CleanBallast system. Testing 

with vertebrate animals should be avoided if other type of information is available that allows an 

assessment of hazards and risks to humans. Testing the Active Substances hydroxyl radical for 

mammalian toxicity is not feasible due to its short lifetime (half-life = approx. 10-9 sec) and a 

high reactivity. For details, please refer to the section on biological impact of radical species 

submitted for Basic Approval, summarized in document MEPC 55/2/4, paragraph 5.1.1.3. 

Free Active Chlorine, also defined as an Active Substance in marine waters, has been extensively 

studied for mammalian toxicity, due to its wide use and many applications in the industry. 

The worst-case maximum concentration (2 mg/L) from CleanBallast effluents in marine water is 

below the WHO Drinking Water Guideline Value (5 mg/L). In view of the rapid decay of FAC 

and TRO in natural waters (see paragraphs 6.2.2.1 to 6.2.2.3 and MEPC 55/2/4, paragraph 5.2.7), 

the in situ generation of Active Substances in the ballast water and the resulting worst-case 

maximum concentration of TRO (2 mg/L) in marine water the conduct of new animal toxicity 

studies is not considered to be required. For explicit data, please refer to the separate 

comprehensive Risk Assessment for sodium hypochlorite submitted for the Basic Approval. 

The formation of detectable disinfection by-products, which are therefore identified 

as Relevant Chemicals, are in the range of internationally recognized drinking water guidelines 

and are thus not considered justifying the conduct of separate tests for mammalian toxicity. 

For explicit data (where available) please refer to the MSDSs for each Relevant Chemical 

provided in Appendix M of the application dossier. 

3.5 Data on environmental fate and effect under aerobic and anaerobic conditions 

(G9: 4.2.1.3) 

3.5.1 General 

Data on the rate and route of abiotic and/or biotic degradation of the Active Substances 

and Relevant Chemicals have been retrieved (G9: 5.3.4). Please refer to the evaluation reported 

in Appendix M of the application dossier, “Theoretical evaluation of the fate and effect of 

disinfection by-products”. Half-lifes of Active Substances and Relevant Chemicals have been 

assessed conservatively being in the order of nanoseconds up to two years depending on the 

substance. 
MEPC 59/2 

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3.5.2 Biodegradability 

The Active Substances are assessed for biodegradability (Appendix M, report: “Theoretical 

evaluation of the fate and effect of disinfection by-products”). 

3.5.3 Bioaccumulation, partition coefficient, octanol/water partition coefficient 

Partition coefficient, octanol/water partition coefficients have been assessed 

for Active Substances and Relevant Chemicals. Partition coefficients were used in the evaluation 

of environmental fate. A summary of fate properties used, including partition coefficients, can be 

found in Appendix M, report “Theoretical evaluation of the fate and effect of disinfection 

by-products”, Table 2.2. 

3.5.4 Reaction with organic matter 

The reaction of the Active Substances produced by the electrochemical process with organic 

matter has been addressed by identifying main reaction routes, so as to identify if products of 

concern to the environment would form. Please refer to Appendix M of the application dossier. 

3.5.5 Potential residues in seafood 

Potential risks arising from residues of the Active Substances or Relevant Chemicals ending up 

in seafood have been evaluated within the HES, please refer to Appendix K of the application 

dossier. It was concluded that impact on, e.g., consumer safety need not be expected. 

3.5.6 Any known interactive effects 

No knowledge on interactive effects of the Active Substances or Relevant Chemicals associated 

with CleanBallast system can be reported. 

3.6 Physical and chemical properties for the Active Substances, Relevant Chemicals and 

treated ballast water (G9: 4.2.1.4) 

3.6.1 Data on physical and chemical properties are retrieved, if applicable, and submitted for 

the Active Substances and Relevant Chemicals to allow for the identification of hazards to the 

crew, the ship and the environment. Such data are submitted for each substance in the form of 

key summary sheets, and report tables including source material in Appendices L 

(Key Data Summaries) and M (Substance Data and Fate Properties of Active Substances 

and Relevant Chemicals). “Preparations” is not an applicable term for the use of the CleanBallast 

system (section 3.2.1). Physical and chemical parameters of treated ballast water of different 

salinities used in the land-based type approval process are provided together with the 

quantification of formed Active Substances and Relevant Chemicals (Tables 9, 10 and 11). 

Reactivity towards container material has been assessed in an extensive corrosion study, please 

refer to Appendix I. 
MEPC 59/2 

ANNEX 

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I:\MEPC\59\2.doc 

3.6.2 The summarized physical and chemical properties on Active Substances 

and Relevant Chemicals can be found in the key data summary sheets provided in Appendix L of 

the application dossier and include (where applicable): 

.1 melting point 

 .2 boiling point 

 .3 flammability (flash point) 

 .4 density (relative density) 

 .5 vapour pressure, vapour density 

 .6 water solubility/dissociation constant 

 .7 oxidation/reduction potential 

 .8 corrosivity 

 .9 auto-ignition temperature 

 .10 explosive properties 

 .11 oxidizing properties 

 .12 surface tension 

 .13 viscosity 

3.6.3 The summarized physical and chemical properties on treated ballast water can be found in 

the following paragraphs and include: 

 .1 pH 

 .2 salinity 

 .3 TOC 

 .4 DOC 

 .5 POC 

3.6.3.1 Physical and chemical properties of fresh water used in the full-scale land-based type 

approval tests. 
MEPC 59/2 

ANNEX 

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Table 9: Physical and chemical properties of treated fresh water and control from 

in the full-scale land-based type approval tests 

Parameter Unit Method Mean Raw 

Water 6 7 8 9 10 Mean 6-10 6 7 8 9 10 Mean 6-10

Temperature °C instrument manual 18.2 21.5 16.5 18.0 19.4 15.1 18.1 19.6 17.6 20.0 19.6 16.5 18.7

pH-value - DIN 38404-C 5 1984-

01(A)* 7.45 7.26 7.41 7.19 7.33 7.21 7.28 7.29 7.30 7.13 7.30 7.11 7.23

Practical salinity 

units psu DIN EN 27888 (C8) 

1993-11(A)* 0.4 0.5 0.4 0.4 0.4 0.4 0.4 0.6 0.5 0.4 0.4 0.4 0.5

Total Suspended 

Solids (TSS)

mg/L 

C

DIN 38409-H2 1987-

03(A)* 71 11 5 9 5 9 8 12 8 13 7 16 11

Total Organic 

Carbon (TOC)

mg/L 

C

DIN EN 1484 

(H3)1997-08(A)* 87.8 7.8 3.9 5.4 6.2 7.6 6.2 6.7 5.1 9.3 6.8 9.4 7.5

Dissolved Organic 

Carbon (DOC)

mg/L 

C

DIN EN 1484 

(H3)1997-08(A)* 50.9 5.6 3.0 5.0 5.4 7.2 5.3 4.1 3.2 5.9 4.8 9.1 5.4

Particular Organic 

Carbon (POC)

mg/L 

C

DIN EN 1484 

(H3)1997-08(A)* 36.9 2.1 0.8 0.3 0.8 0.4 0.9 2.6 2.0 3.4 2.0 0.3 2.0

Effluent treatment deballasting Effluent control deballasting

LBTA cycle

For further physical and chemical parameters extensively analysed during the land-based type 

approval please also see Appendix G. 

3.6.3.2 Physical and chemical properties of brackish water used in the full-scale land-based 

type approval tests. 

Table 10: Physical and chemical properties of treated brackish water and control 

from in the full-scale land-based type approval tests 

Parameter Unit 6 7 8 9 10 Mean 6-10 6 7 8 9 10 Mean 6-10

Temperature oC Instrument manual 10.9 10.3 10.9 10.1 9.4 9.5 10.0 10.2 10.9 11.5 10.3 9.4 10.5

pH - Instrument manual 8.1 7.8 7.7 7.6 7.8 7.7 7.7 8.0 7.9 8.2 8.1 7.9 8.0

Salinity PSU Instrument manual 20.9 20.2 21.4 20.9 20.9 21.1 20.9 20.3 21.4 21.0 20.9 21.1 20.9

Total Suspended 

Solids (TSS) mg/L

NIVA (method B1/2) 

in accordance to NSEN 872 and NS 473360.7 20.2 24.3 25 15 13.2 19.6 9.3 18.3 12.7 10 13.3 12.7

Dissolved Organic 

Carbon (DOC) mg/L C

Norwegian Standard 

NS-ISO 8245 (NIVA 

method G5-3)

6.4 5.9 6 5.6 5.6 6.3 5.9 5.6 5.7 5.7 5.9 6.4 5.9

Particular Organic 

Carbon (POC) mg/L C NIVA (method G6) 7.5 1.2 1.4 1.4 1.0 0.9 1.2 0.9 1.2 1.1 1.3 1.4 1.2

Total Organic 

Carbon (TOC) mg/L C

Norwegian Standard 

NS-ISO 8245 (NIVA 

method G5-3)

13.9 7.1 7.4 7.0 6.6 7.2 7.1 6.5 6.9 6.8 7.2 7.8 7.0

Mean raw 

water

LBTA cycle

Effluent treatment deballasting Effluent control deballasting

For further physical and chemical parameters analysed during land-based type approval please 

also see Appendix F. 
MEPC 59/2 

ANNEX 

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3.6.3.3 Physical and chemical properties of seawater used in the full-scale land-based type 

approval tests. 

Table 11: Physical and chemical properties of treated seawater and control from 

in the full-scale land-based type approval tests 

Parameter Unit Method 1a (12) 2 3 4 5 Mean 1a (12) 2 3 4 5 Mean

Temperature oC Instrument manual 9.5 9.5 11.0 10.3 9.4 8.6 9.8 6.8 10.8 10.4 9.5 8.7 10.3

pH - Instrument manual 7.98 8.12 7.87 7.83 8.00 7.96 7.9 8.09 7.93 7.83 7.92 7.95 7.89

Salinity PSU Instrument manual 32.8 32.2 32.3 32.6 32.9 33.4 32.8 32.2 32.5 32.6 32.9 33.0 32.8

Total 

Suspended 

Solids (TSS)

mg/L C

NIVA (method B1/2) 

in accordance to NSEN 872 and NS 473314.2 7.40 5.5 5.5 8.9 10.60 7.6 6.10 5.6 5.4 7.2 6.7 6.225

Dissolved 

Organic 

Carbon 

(DOC)

mg/L C

Norwegian Standard 

NS-ISO 8245 (NIVA 

method G5-3) 

2.36 2.50 3.3 3.3 2.7 2.50 3.0 2.10 2.2 2.8 2 1.9 2.2

Particular 

Organic 

Carbon 

(POC)

mg/L C NIVA (method G6) 2.28 0.90 0.7 0.7 0.7 0.70 0.7 0.60 0.7 0 0.7 0.7 0.5

Total Organic 

Carbon 

(TOC)

mg/L C

Norwegian Standard 

NS-ISO 8245 (NIVA 

method G5-3) 

4.6 3.4 4 4 3.4 3.2 3.7 2.7 2.9 2.8 2.7 2.6 2.8

Mean 

Raw 

LBTA cycle

Effluent treatment deballasting Effluent control deballasting

For further physical and chemical parameters analysed during land-based type approval, please 

also see Appendix F. 

3.7 Analytical methods at environmentally relevant concentrations (G9: 4.2.1.5) are provided. 

See also separate reports of respective performing institute in Appendices F and G. 

4 USE OF THE ACTIVE SUBSTANCE OR THE PREPARATION

4.1 The application technique 

4.1.1 Active Substances are applied by an electrochemical disinfection process, whereby 

Active Substances are produced in situ from electrical current and the components of natural 

waters. Disinfection is achieved by multiple mechanisms, including also direct oxidation, which 

will differ for different salinities. Concerning TRO, the Maximum Allowable Discharge/Dosage 

Concentrations for marine waters should be 2 mg/L as recommended by the GESAMP-BWWG. 

The terms “Required dosage” and “retention time” (G9: 4.2.6) are not applicable. As discussed 

previously, no Maximum Allowable Discharge/Dosage Concentrations for the Active Substance 

hydroxyl radical can be given for freshwater because this specie is not discharged to the 

environment due to its extremely short half-life (see section 2.1.2). 

5 MATERIAL SAFETY DATA SHEETS (G9: 4.2.7) 

5.1 The term Preparation is not applicable to the CleanBallast system (paragraph 3.2.1) and 

MSDS can consequently not be provided according to Procedure (G9), paragraph 6.3.2. 

5.2 MSDSs are submitted for Active Substances and Relevant Chemicals. These can be found 

in Appendix M. 
MEPC 59/2 

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6 RISK CHARACTERIZATION 

6.1 Screening for persistence, bioaccumulation and toxicity (G9: 5.1) 

6.1.1 Persistence (G9: 5.1.1.1) 

None of Active Substances is considered to fulfil the persistence criteria. 

Some Relevant Chemicals (1.2.3-Trichloropropane, bromate, trichloroacetic acid) are considered 

to fulfil the persistence criteria due to their predicted overall half-life >60 days, see 

further Appendix M, the report “Theoretical evaluation of the fate and effect of disinfection 

by-products”, Table 2.2. 

6.1.2 Bioaccumulation (G9: 5.1.1.2) 

The assessment of the bioaccumulation potential considering log Pow values did not give rise to 

any concern, thus the bioaccumulation criteria is not met by any Active Substances 

or Relevant Chemicals. 

6.1.3 Toxicity tests (G9: 5.1.2.3) 

Acute and/or chronic ecotoxicity data covering the sensitive life stages was used for the 

assessment of the toxicity criterion. The toxicity criterion consequently was not considered to be 

met by Active Substances and Relevant Chemicals. 

6.1.4 Consequently, none of Active Substance or Relevant Chemicals related to 

the CleanBallast treatment of different water qualities meets all three criteria for PBT 

(Procedure (G9), Table 1). 

6.2 Evaluation of the treated ballast water (G9: 5.2) 

6.2.1 Toxicity tests and chemical analysis with samples of ballast water treated with 

the CleanBallast system from the land-based test set-up were done (G9: 5.2.1.2 and 5.2.3), the 

test fully meeting the requirements of G8. Toxicity results are summarized in section 3.3; also 

see Appendix F for the full results in brackish and seawater. For summaries of disinfection 

by-products formed in different water qualities, see paragraphs 6.2.1.1 to 6.2.1.3 

In order to study the TRO decay in the effluent of the CleanBallast system after the second 

deballasting treatment, samples from the effluent were taken at all three salinities and stored in 

the dark. Sub-samples were analysed for TRO after different storage times. These samples 

represent the water before discharge to and before dilution in the receiving water. 

Disinfection by-products as Relevant Chemicals were analysed for test cycles in samples from all 

three salinities. Furthermore, chemical fate analysis was carried out for the disinfection 

by-products formed in brackish water and seawater (see Appendix F). For the latter, different 

sub-samples of the stored effluent after the deballasting treatment were taken in one test cycle 

and the reaction was stopped by dosing sodium thiosulphate to each sample after different 

storage times (see Appendix E, paragraph 4.7), which allows to record the disinfection 

by-product concentration over the time after the deballasting treatment. 
MEPC 59/2 

ANNEX 

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Furthermore, the by-product oxygen was measured as dissolved oxygen concentration in the 

water during ballasting and deballasting treatment as well as in the control. As given by 

the Henry-coefficient the dissolved oxygen concentration in the water is in equilibrium with the 

oxygen gas concentration. In addition to the measurement of the dissolved oxygen concentration, 

the oxygen gas concentration was measured in the de-aeration pipe after the gas trap, which is 

installed after the EctoSys® cell to remove free gases formed by the electrochemical process. 

In accordance with the still low dissolved oxygen concentration (please see below), the measured 

oxygen gas concentrations were in the normal range of 20 Vol. % (for full gas concentration data 

please see Appendix H). 

6.2.1.1 Active Substances and Relevant Chemicals formed in fresh water 

Table 12: Active Substances and Relevant Chemicals formed in fresh water (cf. Appendix G) 

Parameter Unit DL Effluent treatment Effluent control WHO Method

Trichloromethane 

Cl3CH μg/L 0.3 0.38 (<0.3-0.7) 0.32 (<0.3-0.40) 300 DIN EN ISO 10301 

(F4) 1997-08

Dichlorobromomethane 

CHBrCl2

μg/L 0.1 0.38 (0.2-0.6) <0.1 (<0.1-<0.1) 60 DIN EN ISO 10301 

(F4) 1997-08

Dibromochloromethane 

CHClBr2

μg/L 0.1 0.82 (0.3-1.10) <0.1 (<0.1-<0.1) 100 DIN EN ISO 10301 

(F4) 1997-08

Tribromomethane 

Br3CH μg/L 0.1 1.44 (0.44-3.40) <0.1 (<0.1-<0.1) 100 DIN EN ISO 10301 

(F4) 1997-08

Sum THM μg/L 3.02 (0.9-5.8) 560 DIN EN ISO 10301 

(F4) 1997-08

Monochloroacetic acid 

(MCAA) μg/L 0.1 0.21 (<0.1-0.38) <0.1 (<0.1-<0.1) 20 DIN 38407-25-F25 

Dichloroacetic acid 

(DCAA) μg/L 0.1 0.87 (0.46-1.40) 0.14 (<0.1-0.28) 50 DIN 38407-25-F25 

Trichloroacetic acid 

(TCAA) μg/L 0.05 0.5 (<0.05-2.00) 0.08 (<0.05-

0.23) 200 DIN 38407-25-F25 

Monobromoacetic acid 

(MBAA) μg/L 0.1 0.15 (<0.1.-0.22) <0.1 (<0.1-<0.1) DIN 38407-25-F25 

Dibromoacetic acid 

(DBAA) μg/L 0.1 1.28 (0.21-2.20) <0.1 (<0.1-<0.1) DIN 38407-25-F25 

Bromochloroacetic acid 

(BCAA) μg/L 0.1 1.07 (0.50-1.6) <0.1 (<0.1-<0.1) DIN 38407-25-F25 

Sum HAA μg/L 4.08 (1.42-7.8)

Bromate μg/L 1 2.6 (<1-4.4) <1 (<1-<1) 10 Laboratory method*

AOX mg/L 

C 0.02 0.14 (0.04-0.2) 0.1 (0.03-0.15) DIN EN 1485 (H 14) 

1996-11(A)

Mean TRO mg/L 0.22 0.12

Deballasting LBTA 6 - 10, 0.4 psu Mean concentration (Min - Max)

* Customized laboratory method (based on IC-ICP-MS technique) to avoid chloride interference in high salinity 

water. 

In compliance with the production of hydroxyl radicals specified as Active Substance the 

concentrations of disinfection by-products were very low; they were mostly close to the limit of 

quantification (LOQ) in fresh water treated by the CleanBallast system. 
MEPC 59/2 

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6.2.1.2 Active Substances and Relevant Chemicals formed in brackish water: 

Table 13: Active Substances and Relevant Chemicals formed in brackish water (cf. Appendix F) 

Parameter Unit LOQ Drinking 

Water Limits

Mean 6-10 min max Mean 6-10 min max WHO Method

Trichloromethane 

Cl3CH <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 300 DIN EN ISO 10301-F4:1997 

Dichlorobromometh

ane CHBrCl2 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 60 DIN EN ISO 10301-F4:1997 

Dibromochlorometh

ane CHClBr2 6 3.5 7.7 <0.50 <0.50 <0.50 100 DIN EN ISO 10301-F4:1997 

Tribromomethane 

Br3CH 147 96 240 1.05 <0.5 1.4 100 DIN EN ISO 10301-F4:1997 

SUM THM <155 <100 <249 <6 <2.0 <2.9 560 DIN EN ISO 10301-

F4:1997 

Monochloroacetic 

acid (MCAA) <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 20 ISO 23631 (2006)- Water quality

Dichloroacetic acid 

(DCAA) <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 50 ISO 23631 (2006)- Water quality

Trichloroacetic acid 

(TCAA) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 200 ISO 23631 (2006)- Water quality

Monobromoacetic 

acid (MBAA) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 ISO 23631 (2006)- Water quality

Dibromoacetic acid 

(DBAA) 22 2.2 120 <0.47 <0.10 1.7 ISO 23631 (2006)- 

Water quality

Bromochloroacetic 

acid (BCAA) <0.6 <0.10 1.1 <0.10 <0.10 <0.10 ISO 23631 (2006)- 

Water quality

SUM HAA <8.8 <6.2 <19.3 <1.74 <1.4 <3.0 ISO 23631 (2006)- 

Water quality

Bromate (BrO3) μg/L 1.0 26 24 29 <1.0 <1.0 <1.0 10 Laboratory method* 

AOX 0.06 0.03 0.07 <0.010 <0.01 <0.01 DIN EN ISO 

9562:2004

EOX 0.01 0.01 0.015 <0.010 <0.01 <0.01 DIN 38409-H8:1984

Mean TRO mg/L 

Cl2 0.40 0.39 0.42 0.06 0.01 0.12

DPD-method 

(American Public 

Health Association, 

1989)

Test Cycle 6 -10 Salinity <22 psu

μg/L

μg/L 0.1-0.5

0.5

mg/L 0.01

Effluent control deballasting Effluent treatment 

deballasting

* Customized laboratory method (based on IC-ICP-MS technique) to avoid chloride interference in high 

salinity water. 

In the normal operation of the CleanBallast system the disinfection by-product concentrations are 

significantly lower than reported earlier for the worst-case operation in brackish water 

(compare to Table 1 in MEPC 57/2). 

The drinking water standard limits of the World Health Organization (WHO) is provided for 

comparison to existing guidelines. However the relevance of drinking water standards to 

concentrations in treated ballast water, which as such is not used for drinking purposes but is 

discharged to the environment, can be discussed. In cases where the maximum detected level 

of DBPs exceeds the WHO Drinking Water Standard (as well as for all detected disinfection 

by-products), attention has been taken in the form of developing Human Exposure Scenarios and 

evaluating the environmental risk using PEC/PNEC ratios. Please refer to Appendix M, report 

“Theoretical evaluation of the fate and effect of disinfection by-products”. 
MEPC 59/2 

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6.2.1.3 Active Substances and Relevant Chemicals formed in seawater 

Table 14: Active Substances and Relevant Chemicals formed in seawater (cf. Appendix F) 

Parameter Unit LOQ

Drinking 

Water 

Limits

Mean 1a-5 Min Max Mean 1a-5 Min Max WHO Method

Trichloromethane 

Cl3CH <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 300 DIN EN ISO 10301-F4:1997 

Dichlorobromometh

ane CHBrCl2 <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 60 DIN EN ISO 10301-F4:1997 

Dibromochlorometh

ane CHClBr2 5.3 4.3 6.5 <0.50 <0.50 <0.50 100 DIN EN ISO 10301-F4:1997 

Tribromomethane 

Br3CH 135 86 190 <1.43 <0.51 4.0 100 DIN EN ISO 10301-F4:1997 

SUM THM <141 <91.3 <197.5 <2.9 <2 <5.5 560 DIN EN ISO 10301-

F4:1997 

Monochloroacetic 

acid (MCAA) <0.50 <0.50 <0.50 <0.50 <0.50 <0.50 20 ISO 23631 (2006)- Water quality

Dichloroacetic acid 

(DCAA) <0.30 <0.30 <0.30 <0.30 <0.30 <0.30 50 ISO 23631 (2006)- 

Water quality

Trichloroacetic acid 

(TCAA) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 200 ISO 23631 (2006)- Water quality

Monobromoacetic 

acid (MBAA) <0.20 <0.20 <0.20 <0.20 <0.20 <0.20 ISO 23631 (2006)- 

Water quality

Dibromoacetic acid 

(DBAA) 5.0 2.7 9.3 <0.22 <0.10 0.43 ISO 23631 (2006)- Water quality

Bromochloroacetic 

acid (BCAA) <0.17 <0.1 0.43 <0.10 <0.10 <0.10 ISO 23631 (2006)- Water quality

SUM HAA <6.4 <4 <10.9 <1.52 <1.4 <1.73 ISO 23631 (2006)- 

Water quality

Bromate (BrO3) μg/L 1.0 9.9 6.0 19.0 <1.0 <1.0 <1.0 10 Laboratory method* 

AOX 0.05 <0.01 0.07 0.012 <0.01 0.02 DIN EN ISO 

9562:2004

EOX 0.03 <0.01 0.06 <0.010 <0.01 <0.01 DIN 38409-H8:1984

Mean TRO mg/L 

Cl2 1.10 0.84 1.47 0.08 0.01 0.18

DPD-method 

(American Public 

Health Association, 

1989)

mg/L 0.01

μg/L 0.1-0.5

Effluent treatment deballasting Effluent control deballasting

μg/L 0.5

Test Cycle 1a (12)-5 Salinity > 32 psu

* Customized laboratory method (based on IC-ICP-MS technique) to avoid chloride interference in high salinity

water. 

6.2.2 The decay rate and degradation curve of TRO is different for different water qualities. 

TRO has a major impact on aquatic acute toxicity. TRO decay curves from the land-based type 

approval tests from three different water qualities are shown in paragraphs 6.2.2.1 to 6.2.2.3 after 

five days’ tank storage and deballasting treatment. During the previous ballasting treatment the 

highest mean TRO concentration of 1.90 ± 0.09 mg/L was determined for the test cycles in 

seawater by the TRO online measurement of the CleanBallast system (cf. Control philosophy 

in Appendix D), which was recorded according to Guidelines (G8), paragraph 4.1.3 with data 

storage rate of 10 seconds. This mean concentration is slightly below the Maximum TRO Dosage 

Concentration of 2 mg/L in seawater at ballasting treatment, which is limited due to the limited 

current applied to the EctoSys® electrodes. 
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The relation (i.e. the ratio) between the different Active Substances (i.e. hydroxyl radicals 

and TRO) formed in the EctoSys® disinfection unit has a strong dependency on the salinity of the 

treated ballast water (see further MEPC 55/2/4, paragraph 4.3.2). The relative formation of 

hydroxyl radicals increases when the salinity decreases, while the formation of TRO is at the 

same time lowered. Reflecting this, the mean TRO concentration formed during ballasting 

treatment in brackish water was 1.16 mg/L (for all test cycles measured by the TRO online 

measurement) and thus lower compared to the test cycles carried out in full salinity seawater. 

6.2.2.1 Decay curve of TRO in fresh water 

TRO as Total Chlorine in treated fresh water and control

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 10 20 30 40 50 60 70 80

Minutes after deballasting 

TRO as Total Chlorine mg/L Cl2

Mean treated effluent

Mean Control

Figure 1: Decay curve of TRO in treated fresh water and control before discharge 

to receiving water (mean of five test cycles 1-6) 

As described above, the only Active Substance is the hydroxyl radical formed by 

the CleanBallast system in fresh water, which gives no response to the analysis of TRO in 

effluent water, since it will never exist outside the disinfection unit reaction zone. Considering 

the standard deviations of the treated and control samples, no differences between the TRO 

concentrations of treated and control water can be stated. In both cases, the TRO concentrations 

are in the range of natural TRO concentrations of 0.1 - 0.3 mg/L TRO found at different locations 

(compare to section 1.2.3). 
MEPC 59/2 

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6.2.2.2 Decay curve of TRO in brackish water 

TRO as Total Chlorine in treated brackish water and control

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50

Hours after deballasting

TRO as Total Chlorine mg/L Cl2

Mean treated effluent

Control

Figure 2: Decay curve of TRO in treated brackish water and control before discharge 

to receiving water (mean of five test cycles 6 to 10) 

6.2.2.3 Decay curve of TRO in seawater 

TRO as Total Chlorine in treated seawater and control

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50

Hours after deballasting

TRO as Total Chlorine mg/L Cl2

Mean treated effluent 

Control

Raw water

Figure 3: Decay curve of TRO in treated seawater and control before discharge 

to receiving water (mean of five test cycles 1a (12)-5) 
MEPC 59/2 

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In seawater the mean discharge concentration is 1.04 ± 0.22 mg/L TRO as analysed by the test 

facility NIVA (cf. Appendix F). Compared to the TRO decay curve for brackish water in 

Figure 2, the high standard deviations of the TRO concentrations in the treated water at each 

sampling time is noticeable. Furthermore, the rather slow decay of TRO in Figure 3 is in 

contradiction to previously reported results, where half-life of TRO was 30 min in a polluted 

harbour (compare to Figure 3 in MEPC 57/2/3). 

Simultaneously to the manual TRO analysis shown in Figure 3, the TRO was measured online in 

the effluent of the CleanBallast system (cf. Control philosophy in Appendix D) and recorded 

according to Guidelines (G8), paragraph 4.1.3, whereby a data storage rate of 10 seconds was 

used. For the five test cycles the mean TRO concentration after deballasting treatment 

was 0.88 ± 0.39 mg/L, thus in the mean lower than the discharge concentration mentioned above. 

6.2.2.4 Holding time 

Due to the direct formation of the disinfectants in situ, the EctoSys® disinfection unit of 

the CleanBallast system provides an immediate disinfectant effect based on the principles and 

mechanisms described in the application for Basic Approval (MEPC 55/2/4, paragraph 4.3), thus 

requiring no holding time. Furthermore, it operates also in fresh water where no residual oxidants 

(TRO) are formed, hence no residual effect is obtained. Ballast water is treated by the EctoSys®

disinfection unit a second time directly before discharge. For these reasons, the determination of 

requested holding time of the treated ballast water is not applicable. 

6.2.3 Dissolved oxygen concentrations 

6.2.3.1 Dissolved oxygen concentrations in fresh water 

Table 15: Dissolved oxygen concentrations in fresh water (raw water, treated water and control) 

during ballasting and deballasting 

Bremen 2007, 0.4 psu, mean LBTA 6-10

Ballasting Deballasting

20°C Raw water Treatment Control Treatment Control

Dissolved oxygen mg/L 5.6 7.4 6.1 6.5 4.1

Only a slight increase of the dissolved oxygen concentration was measured in the effluent water 

of the CleanBallast system after ballasting and deballasting treatment. The slight increase in 

dissolved oxygen concentration, which is formed by the electrochemical EctoSys® cell, is always 

below the dissolved oxygen saturation concentration, which is 9 mg/L at 20°C and atmospheric 

pressure. At deballasting the dissolved oxygen concentration in the control was significantly 

lower than in the original raw water and after the second treatment, due to the stronger 

microbiological activity consuming dissolved oxygen during the five days storage in the 

control tank. 
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6.2.3.2 Dissolved oxygen concentrations in brackish water 

Table 16: Dissolved oxygen concentrations in brackish water (raw water, treated water 

and control) during ballasting and deballasting 

NIVA 2008, 21 psu, mean LBTA 6-10

Ballasting Deballasting

10°C Raw water Treatment Control Treatment Control

Dissolved oxygen mg/L 8.6 8.7 8.7 7.3 8.1

For comparison the dissolved oxygen saturation concentration is 9.9 mg/L at 10°C and 

atmospheric pressure. 

6.2.3.3 Dissolved oxygen concentrations in seawater 

Table 17: Dissolved oxygen concentrations in seawater (raw water, treated water 

and control) during ballasting and deballasting 

NIVA 2008, 33 psu, mean LBTA 1 - 5

Ballasting Deballasting

10°C Raw water Treatment Control Treatment Control

Dissolved oxygen mg/L 10.1 9.7 9.7 10.1 8.7

For comparison, the dissolved oxygen saturation concentration is 9.2 mg/L at 10°C and 

atmospheric pressure. 

Concerning both brackish water (Table 16) and seawater results (Table 17), the difference 

between treatment and control is not so distinctive in these trials compared to the fresh water 

results (Table 15). In brackish water and seawater testing, the observed increase in the dissolved 

oxygen concentration cannot be attributed to the formation by electrochemical EctoSys® cell 

alone. The reasons are given as follows: 

- a mixing device was used in the storage tanks directly before sampling 

(see Appendix E, QAPP NIVA, paragraph 3.1.3), which could have increased the 

dissolved oxygen concentrations in all tanks; 

- due to the lower water temperature the microbiological activity in the control tank 

was probably lower; and 

- in general the oxygen gas formation by the electrochemical EctoSys® cell is 

lower with increasing salinity. 

However, at all salinities the dissolved oxygen saturation concentration is not reached in the 

treated effluent indicating a low formation of oxygen by the electrochemical EctoSys® cell in 

the CleanBallast system. In accordance with the still low dissolved oxygen concentration, the 

measured oxygen gas concentrations were in the normal range of 20 Vol. % (for full data please 

see the confidential part of the application dossier, Appendices F and H). 
MEPC 59/2 

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6.3 Risk characterization and analysis 

6.3.1 Aquatic toxicity tests with samples of ballast water treated with the CleanBallast system 

from the land-based test set-up have been conducted (G9: 5.2.1.2 and 5.2.3). The reaction 

of Active Substances with organic matter has been addressed by their chemical properties 

(e.g., oxidation potential) in order to identify potential further Relevant Chemicals that may be of 

concern to the environment; please refer to Appendix M in the application dossier. 

Active Substances and Relevant Chemicals have been analysed during whole effluent testing 

during land-based type approval. 

6.3.2 Routes and rate of degradation (G9: 5.3.5) have been assessed and characterized, where 

applicable. Please refer to the separate report “Theoretical evaluation of the fate and effect of 

disinfection by-products”, Table 2.2, in Appendix M in the application dossier. 

6.3.3 Prediction of discharge and environmental concentrations 

Discharge concentrations of Active Substances and Relevant Chemicals at selected time intervals 

can be predicted (G9: 5.3.8), using the literature degradation data (section 6.3.2), measured 

discharge concentrations in different waters (section 6.2) and measured decay rates from the tests 

(paragraphs 6.2.2.1 to 6.2.2.3, please refer to Appendices F and G). Ballast water discharge 

customized PEC evaluations for different generic scenarios, and realistic case studies including 

the land-based type approval test location were performed during the evaluations undertaken 

for Basic Approval (MEPC 55/2/4) and previous submission for Final Approval (MEPC 57/2/3). 

According to the recommendation of the GESAMP-BWWG, this was supplemented 

with MAMPEC simulations, please refer to paragraph 6.3.5 for details. 

6.3.3.1 Discharge concentrations of Active Substances 

6.3.3.1.1 Due to the short half-life of the Active Substance hydroxyl radical, this species will 

never occur outside the electrochemical reaction zone and the discharge concentration will thus 

be zero after treatment of water of all qualities. 

6.3.3.1.2 Discharge concentrations of the Active Substance HOCl/OCl- are aggregated into the 

generally known TRO parameter together with the Relevant Chemical HOBr/OBr-

 

(due to the limited specificity of the analysis methods available). From the land-based type 

approval testing, the TRO decay curves in effluents after the second treatment at deballasting 

(see paragraphs 6.2.2.1 to 6.2.2.3) represent the TRO concentrations in stored samples without 

discharge to the receiving water and without dilution in the receiving water. Based on these data 

it can be concluded that: 

- in fresh water (< 3 psu) the discharge TRO concentration (given as chlorine) is within 

the natural background range of approximately 0.1 – 0.3 mg/L, thus always below the 

discharge limit of 0.5 mg/L chlorine as regulated by resolution MEPC.159(55) for 

sewage treatment plants on board ships; 

- in brackish water the mean TRO concentration directly after the deballasting 

treatment was 0.40 ± 0.02 mg/L (Table 13). Thus, it can be concluded that the effluent 

of the CleanBallast system is below the discharge limit of 0.5 mg/L chlorine regulated 

by resolution MEPC.159(55) for sewage treatment plants on board ships; and 
MEPC 59/2 

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- in seawater (> 32 psu), as discussed above, drawing a clear conclusion on 

the TRO discharge concentration is hampered due to the large standard deviation of 

the TRO measurements (see Figure 3). Using the TRO limit of 0.5 mg/L this could 

already be achieved after 4 h or later without dilution in the receiving water. Due to 

the large standard deviation of the TRO measurements and scarcity of sample points 

between 4 and 48 hours, theoretical calculations were done also on the TRO decay. 

Based on the physical and fate properties of each substance (please refer to the report 

“Theoretical evaluation of the fate and effect of disinfection by-products” in 

Appendix M) a generally accepted half-life of TRO (both hypochlorite and 

hypobromite) of 0.5 h has been determined. Theoretical calculations show that an 

initial concentration of 1.2 mg/L TRO (mean concentration with upper standard 

deviation, see section 6.2.2.) reached the limit concentration of 0.5 mg/L TRO 

within 40 min, based on a half-life of 30 min without dilution. The half-life of 30 min 

is in full compliance with previous results (see Figure 3 in MEPC 57/2/3): The limit 

of 0.5 mg/L TRO was reached after 40 min in polluted harbour water at real ballasting 

locations (Bremerhaven). For comparability, the half-life value of 0.5 h for TRO was 

also used in the MAMPEC simulations (see paragraph 6.3.5). 

Overall, before discharge of the deballasting water to the receiving water and dilution 

therein, TRO concentrations in water treated by the CleanBallast system are in most cases 

immediately below the discharge limit set by resolution MEPC.159(55) for sewage treatment 

plants on board ships of 0.5 mg/L chlorine. In accordance with earlier results (cf. MEPC 55/2/4 

and MEPC 57/2/3) as well as considering the earlier evaluation of the concentration of 2 mg/L as 

both the Maximum Dosage and the Maximum Allowable Discharge Concentration by 

the GESAMP-BWWG (MEPC 57/2, paragraph 9.4.3), the applicant is of the opinion that an 

additional neutralization system is not necessary at regular operation for destroying the 

remaining TRO concentration before discharge. 

Specifically, the only case where the TRO discharge concentration might exceed 0.5 mg/L is 

treating unpolluted seawater inoculated with test organisms at very high densities, in which the 

mean TRO discharge concentrations have been shown to be always below 1.2 mg/L during 

land-based type approval testing. In nature such high organism densities are unlikely to be found 

in natural seawater, especially due to the low level of nutrients in seawater for phytoplankton 

growth (cf. also MEPC 57/2/12). This is reflected by Guidelines (G8) requiring for shipboard 

type approval only > 100 viable organisms per mL for the size ≥ 10 μm and < 50 μm, 

and 100 per m3 for the size ≥ 50 μm in the inlet to the treatment system: in contrast, densities as 

high as at least 1,000 per ml and 100,000 per m3 are required for land-based type approval 

testing. However, since ballast water treatment already takes place at ballast water uptake on 

board using the maximum TRO concentration of 2 mg/L in seawater, it results in effective 

reduction of organisms density and little or no regrowth in the ballast tanks during the voyage. 

Therefore numbers of still viable organisms at deballasting are expected to be very low, thus 

requiring application of only a fraction of the maximum TRO concentration. Because the Algae 

Monitor as a mitigation measure reduces the EctoSys® disinfection at deballasting only to the 

level actually needed (if needed at all), the TRO discharge concentration will be much lower than 

the 1.2 mg/L found in seawater inoculated with test organisms during land-based type approval 

testing. 

For comparison, the maximum dosage chlorine concentration allowed for drinking water 

treatment is 1.2 mg/L in Germany and according USPH EPA (2005) even 5 mg/L for drinking 

water treatment on board ships. Reflecting the rather low Maximum Dosage and similar 

maximum Discharged Concentration of 1.2 mg/L in land-based type approval testing, treating 
MEPC 59/2 

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seawater the level will be in the range of the discharge limit of 0.5 mg/L chlorine regulated by 

resolution MEPC.159(55) for sewage treatment plants on board ships by a dilution of 1:1 at 

discharge. 

Furthermore, the applicant is concerned that the fine-tuning by the Algae Monitor would become 

redundant in case an additional neutralization system has to be fitted in the effluent of 

the CleanBallast system. The main advantage of the Algae Monitor is that disinfection is 

controlled directly by its biological effect on phytoplankton, because ballast water is 

characterized by the great variability and diversity of marine organisms and water qualities 

worldwide (refer further to the appendix at the end of this document and “Functional description 

of the Algae Monitor” in Appendix C of the confidential part of the dossier). 

However, because of the ongoing debate on acceptable TRO discharge levels, the 

full-scale CleanBallast system was also tested during land-based type approval testing at the test 

facility NIVA according to Guidelines (G8) using an additional neutralization system after 

deballasting. The full data set from this test cycle can be found in Appendix F and more details 

on the neutralization system in Appendix N for evaluation of the GESAMP-BWWG. 

6.3.3.2 Discharge concentrations of Relevant Chemicals 

The quantitative formation of Relevant Chemicals (by-products of the electrochemical 

disinfection process) is linked to the formation of Active Substances. The qualitative formation is 

also linked to dissolved species (reactants) in the water. Thus, discharge concentrations 

of Relevant Chemicals are evaluated based on the highest measured concentrations found during 

the land-based type approval tests in all three water qualities, reaching from fresh water to full 

salinity marine water. Risk assessment, PEC calculations (section 6.3.4), etc. have also been 

performed using these levels of the Relevant Chemicals. 

6.3.3.2.1 In fresh water discharge concentrations of disinfection by-products are very low, close 

to the limit of quantification and far below the WHO Drinking Water Guideline Values. 

6.3.3.2.2 In brackish water and seawater, the sum concentration of trihalomethane THM and 

haloacetic acids HAA is below the sum WHO Drinking Water Guideline Value. Here, the single 

compound bromoform can exceed its respective WHO Drinking Water Guideline Value 

of 100 μg/L in brackish water and seawater, and bromate can exceed its respective 

WHO Drinking Water Guideline Value of 10 μg/L in brackish water approximately by a factor 

of 2. Therefore, by a dilution of 1:1 at discharge to seawater, the level will be in the range 

accepted for drinking water (cf. NIVA report, Appendix F). 

6.3.3.2.3 Discharged concentrations of dissolved oxygen as well as oxygen gas concentrations 

are in the range of natural fluctuations and are therefore not considered further in 

the Risk Assessment. 
MEPC 59/2 

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6.3.4 Effects on aquatic organisms 

6.3.4.1 Appropriate freshwater and marine Predicted No-Effect Concentrations (PNEC) have 

been derived for Active Substances and Relevant chemicals. A summary can be found 

in Table 18 below. For details, please refer to the report “Theoretical evaluation of the fate and 

effect of disinfection by-products” found in Appendix M, including the complete underlying data 

sets, the assessment factors used including justification and the derivation of the 

proposed PNEC values of Active Substances and Relevant Chemicals. The magnitude of the 

assessment factor applied has been set to between 50 and 10,000, depending on amount and 

quality of available data. 

Table 18: PNEC values of Active Substances and Relevant Chemicals 

CAS Name 

PNEC 

(Fresh) 

μg/l 

PNEC 

(Marine) μg/l 

7681-52-9 Sodium Hypochlorite 0.06 0.06 

13824-96-9 Sodium Hypobromite 0.06 0.06 

124-48-1 Dibromochloromethane 1 0.1 

75-25-2 Tribromomethane 70 70 

7789-38-0 Sodium Bromate 14 1,4 

10102-75-7 Calcium Bromate 14 1.4 

7758-01-02 Potassium Bromate 4 0.4 

79-43-6 Dichloroacetic Acid 23 2 

76-03-9 Trichloroacetic Acid 0.2 0.02 

631-64-1 Dibromoacetic Acid 62 6 

5589-96-8 Bromochloroacetic Acid 39*

 3*

96-18-4 1,2,3-Trichloropropane 50 5 

(

*

 = Calculated assuming same molar ecotoxicity of chlorine and bromine compound) 

6.3.4.2 PNEC values have been derived for any substances that were detected in treated ballast 

water at concentrations that may be of concern for the aquatic environment. 

6.3.4.3 Available data for additional taxonomic groups, for example, rotifers, echinoderms or 

molluscs, have also been used in a previous attempt to derive a PNEC for the Active Substance 

free active chlorine (MEPC 55/2/4). The outcome of this previous PNEC calculation (0.04 μg/L) 

was very close to the latest result (0.06 μg/L) 

6.3.5 PEC values calculated using MAMPEC 

In addition to the custom-made ballast water discharge modelling work conducted 

for Basic Approval and the previous submission for Final Approval, PEC values 

for Active Substances and Relevant Chemicals have been derived for two generic cases 

in MAMPEC ver. 2.0: the “Commercial harbour scenario” and the “OECD-EU Commercial 

harbour”. The “commercial harbour” scenario of MAMPEC is a greater harbour based on and 

comparable to the Rotterdam harbour in the Netherlands. Noting that the water quality 

of Rotterdam is not full salinity, the maximum discharge TRO concentration should be 
MEPC 59/2 

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rather < 500 μg/L in the real case (please refer to section 6.3.7). The OECD-EU Commercial 

harbour (for smaller harbours) is essentially the same as the “commercial harbour” scenario 

of MAMPEC but differs in dimensions and the size of the harbour. The results are summarized 

in Table 19 below. MAMPEC outcome on the TRO species hypochlorite and hypobromite has 

been provided for different effluent concentrations at and below the unrealistic 2 mg/L 

(2000 μg/L) TRO, for comparison to the modelling presented previously (MEPC 55/2/4 

and MEPC 57/2/3). Therefore, the applicant would like to point out that in the normal operation 

of the CleanBallast system the TRO discharge concentration is maximum 1.2 mg/L (1200 μg/L) 

in seawater, below 0.5 mg/L (500 μg/L) in brackish water, and in fresh water no TRO additional 

to the background level is formed at the treatment during deballasting (mean 200 μg/L). 

Disinfection by-product concentrations used in MAMPEC were the highest concentration found 

during the normal operation of the CleanBallast system in the land-based type approval testing. 

For methods, input parameters, assumptions on traffic, etc. see Appendix J of the application 

dossier. 

Table 19: PEC values of Active Substances and Relevant Chemicals, calculated 

by MAMPEC v.6.0 for two standard harbours 

Name 

Initial 

concentrations 

in discharged 

marine water, 

μg/L 

Commercial 

(Marine) 

Harbour, 

μg/l 

 OECD-EU 

Commercial 

(marine) 

Harbour, 

μg/l 

Initial 

concentrations 

in discharged 

fresh water, 

μg/l 

 OECD-EU 

Commercial 

(fresh 

water) 

Harbour, 

μg/l 

2000 0.23 0.222 0 --- 

1200 0.135 0.133 0 --- 

500 0.056 0.055 0 --- Sodium Hypochlorite 

200 0.023 0.022 0 --- 

2000 0.23 0.222 0 --- 

1200 0.135 0.133 0 --- 

500 0.056 0.055 0 --- Sodium Hypobromite 

200 0.023 0.022 0 --- 

Dibromochloromethane 8.2 0.05 0.030 1.1 0.0039 

Tribromomethane 190 1.25 0.708 3 0.0112 

Bromate 19 0.47 0.136 4.4 0.0314 

Dichloroacetic Acid 0.97 0.00 0.005 1.4 0.0085 

Trichloroacetic Acid 0.28 0.01 0.003 2 0.0141 

Dibromoacetic Acid 9.3 0.17 0.062 2.2 0.0145 

Bromochloroacetic Acid 0.43 0.01 0.003 1.6 0.0105 

1,2,3-Trichloropropane 1 0.01 0.005 0 0.0000 

6.3.6 Plume modelling 

Besides MAMPEC modelling and in addition to previous customized plume modelling work 

conducted for Basic Approval (MEPC 55/2/4) and previous submission for Final Approval 

(MEPC 57/2/3), dispersion (plume) modelling using software (“MIKE 3” + “ECOLAB”) 

developed by the engaged the third party external relevant expertise was performed. MIKE 3 is a 

three-dimensional hydraulic model, enabling the description of the water movements on the basis 

of information on amount of water exchange, wind, and bathymetry of the water body. 

The hydraulic model was combined with a fate model for the TRO and its degradation products 

in as it is called an ECOLAB template. The output of the model is predicted environmental 
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concentrations (PEC) varying in time and space close by as well as more distant areas from the 

outlet of the ship. The derived PECs was then compared with the PNEC values 

of Active Substances and Relevant Chemicals for the risk assessment. Described in this 

document is only the general set-up and conclusions. The full description of the model set-up, 

assumptions, results and conclusions can be found in Appendix J, as well as set in the context of 

the complete risk assessment in Appendix M, report “Theoretical evaluation of the fate and effect 

of disinfection by-products”. 

The harbour basin chosen for the study was one of the basins of the Esbjerg port complex. 

Esbjerg port is a Danish port located in the Ho Bay on the North of the Walden Sea, in the 

southern part of Denmark. 

The amount of ballast water and the flow discharge depends on the ship size. In the study, 

five different sizes of ships – or discharge rates were modelled: 

 - Ship type 1: from 50 m to 100 m with a flow discharge of 0.083 m3/s (300 m3/h); 

 - Ship type 2: from 100 m to 150 m with a flow discharge of 0.3056 m3/s (1,100 m3/h); 

 - Ship type 3: from 150 m to 200 m with a flow discharge of 0.5278 m3/s (1,900 m3/h); 

 - Ship type 4: from 200 m to 250 m with a flow discharge of 0.75 m3/s (2,700 m3/h); and 

 - Ship type 5: from 250 m to 300 m with a flow discharge of 0.9722 m3/s (3,500 m3/h). 

These five sources were distributed in the basin depending of the ships size (Figure 4). 

Figure 4: 2D location of the sources (ships type 1-5) in Esbjerg port 
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The behaviour of the plume depends on the salinity of the discharged water. Three types of 

ballast water were simulated: 

- fresh water 

- brackish water 

- saline water 

The simulation was carried out in the very conservative way that all ships were assumed to 

discharge the same type (same salinity) of ballast water during one complete day. 

The hydrodynamic model was combined with a fate model. The same degradation rates and 

concentrations in the ballast water as were used in the MAMPEC modelling were applied. 

The study resulted in a vast amount of data. Only a few selected results of the simulations are 

presented here. Films showing results of the plume modelling in more details have been 

prepared and an example is given in Appendix J4. 

Figures 5 to 8 show the predicted risk quotients (RQ) for TRO for different assumed 

concentration in the ballast water: 2 mg/L, 1.2 mg/L, 0.5 mg/L and 0.2 mg/L. Only results from 

the discharge of saline ballast water are shown (most conservative approach). The RQ was 

calculated by dividing the average concentration of TRO during the complete day of ballasting, 

on which the discharge takes place, by the PNEC for TRO (HOCl/OCl-

, HOBr/OBr-). Please note 

again that a discharge concentration of 2 mg/L is much higher than from the normal operation of 

the CleanBallast system at deballasting. 
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Figure 5: Discharge TRO concentration: 2 mg/L

Layer 1: Bottom 

Figure 6: Discharge TRO concentration: 2 mg/L 

 Layer 8: Surface 

Figure 7: Discharge TRO concentration: 

0.5 mg/L, Layer 1: Bottom 

Figure 8: Discharge TRO concentration.: 

0.5 mg/L, Layer 8: Surface 

From the plots it was concluded that: 

- the area of impact increases with discharge rate, as the area of impact for the large ships 

tends to be bigger than for the smaller ships; 

- the risk quotients increases with depth. This is not surprising, as the discharge takes place 

below water line closer to the bottom of the basin; and 

- the risk quotients are well below 1 outside the basin area. 
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Figure 9: Risk quotient scale 

As can be seen, even under these unrealistic assumptions of discharge concentrations and 

total discharge periods, the acute risks for the environment are dropping very rapidly with 

distance away from the point of discharge. Thus, no harm to immediate receiving environment is 

expected. 

6.3.7 Deriving PEC/PNEC ratios 

PEC/PNEC ratios were calculated for Active Substances and Relevant Chemicals, based on the 

values given in Tables 18 and 19. The results are summarized in Table 20. Please refer to the 

section “Risk Assessment” below, paragraph 7.3.2. 

Table 20: PEC/PNEC ratios for Active Substances and Relevant Chemicals 

Name 

Initial 

concentrations in 

discharged 

marine water, μg/l 

Commercial 

(Marine) 

Harbour 

OECD-EU 

Commercial 

(marine) 

Harbour 

Initial 

concentrations in 

discharged fresh 

water, μg/l 

OECD-EU 

Commercial 

(fresh 

water) 

Harbour 

2000 5.64 5.54 0 --- 

1200 3.39 3.32 0 --- 

500 1.41 1.39 0 --- Sodium Hypochlorite 

200 0.56 0.55 0 --- 

2000 5.64 5.54 0 --- 

1200 3.39 3.32 0 --- 

500 1.41 1.39 0 --- Sodium Hypobromite 

200 0.56 0.55 0 --- 

Dibromochloromethane 8.2 0.51 0.30 1.1 0.004 

Tribromomethane 190 0.02 0.01 3 0.000 

Bromate 19 0.34 0.10 4.4 0.010 

Dichloroacetic Acid 0.97 0.00 0.00 1.4 0.000 

Trichloroacetic Acid 0.28 0.29 0.14 2 0.071 

Dibromoacetic Acid 9.3 0.03 0.01 2.2 0.000 

Bromochloroacetic Acid 0.43 0.003 0.001 1.6 0.00027 

1,2,3-Trichloropropane 1 0.00 0.00 0 0.000 
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Hereby, the PEC/PNEC of 5.64 does not represent the normal operation of the CleanBallast 

system. As shown above, please note that in the normal operation of the CleanBallast system in 

land-based type approval testing, the TRO (chlorine/bromine) discharge concentration is 

maximum 1.2 mg/L (1200 μg/L) in seawater, below 0.5 mg/L (500 μg/L) in brackish water, and 

in fresh water no TRO additional to the background level is formed at the treatment during 

deballasting (mean 200 μg/L). Similarly, disinfection by-product concentrations used 

in MAMPEC were the highest concentration found during the normal operation of 

the CleanBallast system in the land-based type approval testing. While MAMPEC assumes a 

salinity of 34 psu for Rotterdam harbour, in reality the salinity is in the range of 0.3 - 28.6 psu 

(DNV, 2005). Nijs et al. (2008) in a time series over 1.5 months found a salinity in the range 

of 5-25 psu at Hook of Holland, of 0 - 18 psu at Botlek Harbour (about 16 km up-estuary 

of Hook of Holland), whereby the water 3 m below the surface was freshwater with 

around 2 psu, and a salinity of 0 - 10 psu at Lek Harbour (about 25 km up-estuary of Hook 

of Holland). Therefore in reality, due to presence salinities ranging from brackish water to 

freshwater in the Rotterdam harbour maximum discharge TRO concentration should 

be < 500 μg/L giving a PEC/PNEC value < 1. 

7 RISK ASSESSMENT 

The potential risks to the safety of the ship, crew and environment raised by the operation of the 

CleanBallast system have been assessed by an independent expert institution, also taking into 

account the identified risk mitigation measures and brominated disinfection by-products. 

7.1 Risk to safety of ship 

7.1.1 Corrosion tests 

Extensive long-term corrosion tests advised in the Basic Approval evaluation have been finalized 

(MEPC 57/2, annex 6, paragraph 9.4.7). No risk of increased corrosion induced by 

the CleanBallast system could be found. Thus, the level of the potential risk of accelerated 

corrosion to the ballast water piping and structure that may be raised by use of this system can be 

properly assessed (MEPC 57/2, annex 6, paragraph 9.4.11) as being zero. 

The corrosion evaluation of the CleanBallast effluent was developed and performed in 

co-operation with the classification society Germanischer Lloyd (GL) and a well-recognized 

independent third party corrosion institute in northern Europe. The test included an accelerated 

comparative exposure phase (using full salinity sea water) and thereafter an evaluation phase. 

GL concluded a number of ISO/ASTM standard corrosion test methods which were used for the 

evaluation phase. After evaluation, a certificate was issued by GL concerning shipboard use of 

the CleanBallast system, recognizing no increased risk for corrosion. 

The full documentation, including reports from the performing corrosion institute, from GL (also the 

certificate), and from coating and material sub-suppliers, etc. can be found in Appendix I.

The influence of the CleanBallast system on common sealing material such as EPDM used in 

ballast water piping was evaluated. EPDM is known as a sealing material being highly resistant 

to seawater, various chemicals, acids and bases. Therefore, it is assumed that the EPDM seals are 

durable to the disinfection products produced by the CleanBallast system. Neither hypochloric 

nor hypobromic acid is assessed to have an effect on EPDM material properties. As discussed in 
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section 2.1.2, due to their extremely short lifetime hydroxyl radicals cannot come into contact 

with the sealing material. 

7.1.2 Fire and explosion 

The CleanBallast equipment and process does not contain any component or step increasing the 

risk of fire. Like all electrolytic processes in water solutions, a small by-production of hydrogen 

gas (RC) will occur. Hydrogen and oxygen mixtures can be explosive in a certain concentration 

range, whereby the lowest explosion limit is 4 Vol. % hydrogen gas. The potential hydrogen 

formation, along with the extensive testing and monitoring, was discussed and submitted through 

the previous application for Final Approval (MEPC 57/2/3). A de-aeration component is included 

immediately following the EctoSys® electrolysis as well as a hydrogen content sensor monitoring 

the discharge from the de-aeration pipe, which is directed to the ambient air outside the ship. 

The system will immediately be shut down if hydrogen concentrations at this point reach a level 

of 2 Vol. %. The GESAMP-BWWG considered that the information provided together with the 

mitigation measures incorporated was acceptable for addressing this identified risk 

(MEPC 57/2/2, paragraph 9.4.6). 

The new measurements of hydrogen gas during the repeated land-based type approval testing at 

the test facility NIVA showed that all analysed hydrogen gas concentrations were far 

below 0.25 Vol. % in the de-aeration pipe as well as at different locations of the storage tank. 

Oxygen gas concentrations were in the normal range of 20 Vol. % (for full data please refer to 

the confidential part of the application dossier, Appendices F and H). 

7.1.3 Storage and handling of the substances 

Active Substances and Relevant Chemicals are produced in situ during the electrochemical 

disinfection process in the closed cell housing and will neither be stored nor handled by the crew, 

thus posing no threat to the ship. 

7.1.4 Contact with, or inhalation of, process products 

Potential skin contact, or inhalation of, process products have been evaluated (using literature 

studies) in the human exposure assessment (section 7.2.3 and Appendix K). 

7.1.5 Noise 

The CleanBallast system does not generate any specific noise, which could exceed the high noise 

level common in machinery rooms. 

7.2 Risks to human health 

7.2.1 The human health risk assessment is based on the Human Exposure Scenario (HES), 

please refer to section 7.2.3. Risks are not considered to be relevant where no exposure routes 

exist. The acute toxicity of treated water is evaluated to have no dermal effect on humans, should 

there be a direct exposure outside normal operation, i.e. leakage, because the exposure dose 

(low concentrations well below acute dermal toxicity levels, based on data provided by MSDS 

for each substance), duration and frequency of such events are assessed as neglectable. Direct 

oral exposure of treated water is not considered as a realistic case. Furthermore, evaluation of 

indirect oral exposure did not give rise to any concern (e.g., none of Active Substances 

or Relevant Chemicals will persist or accumulate in sea food at detectable quantities), please 
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refer to the Human Exposure Scenario provided in Appendix K of the application dossier. 

Disinfection by-products detected in non-diluted treated water were furthermore below or in the 

range of drinking water standards, e.g., WHO. In the Human Exposure Scenario (HES) special 

focus was laid on the inhalative uptake of brominated THM, according to the main concern 

raised by the GESAMP-BWWG − please refer to the conclusion in section 7.2.3 below and 

the HES in Appendix K of the application dossier. 

7.2.2 The effects assessment of the Active Substances and Relevant Chemicals including the 

screening for carcinogenic, mutagenic and endocrine disruptive properties did not give rise to 

concerns at concentrations corresponding to 100% discharge water. This screening was 

performed using literature data separate MSDS, please refer to Appendix M of the application 

dossier. No further effects assessment was considered necessary (G9: 5.3.12). 

7.2.3 A Human Exposure Scenario (HES) was developed in co-operation with an independent 

third party, a leading European environmental institute. The HES is provided by the applicant as 

part of the risk assessment procedure for the CleanBallast system. (G9: 6.3.3). The complete 

HES, including the calculated data for humans from respective exposure route, is submitted 

as Appendix K of the application dossier. 

7.2.3.1 Occupational exposure 

The occupational exposure to TRO, degradation products and DBPs was assessed based on the 

following assumptions: 

- Sampling from the system. Sampling is expected to be carried out only to a very 

limited extent and only by technicians appointed by the applicant/manufacturer of 

the CleanBallast system, thus no exposure to the crew on the ship due to sampling is 

expected. 

- Upon loading of the ballast tanks with water, the excessive air in the ballast tanks is 

replaced by water in the ballast tanks, resulting in potential inhalation exposure of 

humans to the exhaust air mixing with the outside air mass on board the ship. 

The predicted equilibrium concentrations (without dilution/venting) in air were first compared 

with the OEL-values found for the various substances for various countries, and a potentially 

required dilution in order to obtain concentrations in air below the OEL was calculated. A simple 

model for predicting the average concentration in inhaled air, further described in the HES, was 

set up. 

Regarding inhalation of exhaust air emitted from the ballast tanks (occupational exposure), it was 

concluded that the predicted concentration in the air is far below existing OEL-values. Thus, 

no risk to the crew on the ships is expected 

7.2.3.2 Exposure via the environment 

Human exposure to TRO and its degradation products related to the use of the CleanBallast 

system may occur as: 

- oral intake due to bioaccumulation of the substances in bivalves and fish; and 

- oral, inhalative and dermal exposure during bathing in areas close to the ballast 

water outlet. 
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All routes of exposure were thoroughly evaluated based on very conservative assumptions. 

The risks related to exposure via the environment due to eating the fish from the harbour area and 

due to swimming in the harbour area were evaluated. As the predicted daily uptake considering 

all uptake routes simultaneously is far below existing TDI values, no risk to the general public 

from the TRO, its degradation products or by-products is expected. 

7.2.4 The quantitative risk assessment, taking into account identification of hazardous 

substances, dose response relationships, exposure routes and frequency, etc., did not give any 

indications of concern for human health. 

7.2.5 The unit operations used in the whole CleanBallast process are identified as a first 

mechanical separation step (filtration) and a disinfection step (the EctoSys® advanced 

electrolysis). Assessment of Human exposure to Active Substances and Relevant Chemicals is 

only relevant after the unit operation of disinfection (but not filtration), where the substances are 

produced in situ. 

7.2.6 The risk assessment for human health was conducted under full consideration of the 

technical description of the ballast water treatment process – please refer to Appendices A and B 

of the application dossier. For each system component, including connecting piping, possible 

routes of exposure were evaluated. No Personal Protective Equipment especially related to the 

operation or use of the CleanBallast system was deemed to be necessary. 

7.2.7 Maintenance, equipment failure and accident situations were considered separately from 

conditions of normal operation. No Personal Protective Equipment, especially related to the 

above-mentioned special cases, was deemed to be necessary. 

7.2.8 Taking into account the above, risks on human health related to treatment by 

the CleanBallast system are considered to have been thoroughly addressed. No potential risks 

could be identified. 

7.3 Risks to the aquatic environment 

7.3.1 The potential risks to the aquatic environment during experimental development and type 

approval testing were assessed, based on toxicity studies and evaluations undertaken 

during Basic Approval, first submission for Final Approval (MEPC 57/2/3) and the tests and 

evaluations undertaken for this application for Final Approval. The specifically developed plume 

model for the land-based type approval test set-up used 2007 was adopted to assess the risks 

associated with further type approval testing and evaluations for Final Approval. The validity of 

the model was confirmed by experimental tests of the water (MEPC 57/2/3, Table 10), where the 

predictions of environmental concentrations made by the model were confirmed by on-site 

sampling and analysis. The risk assessment for the further tests related to the approval process 

according to the Guidelines (G8) and Procedure (G9) did not raise any concern. 

7.3.2 Acute and chronic aquatic toxicity of the treated ballast water at discharge was found to 

be considerably lower than the level reported during the evaluation for Basic Approval 

(MEPC 55/2/4). The risks of separate Active Substances and Relevant Chemicals were assessed 

using estimated ratios between predicted concentrations (PECs, using MAMPEC in the 

standardized OECD-EU commercial harbour) of the Active Substances or Relevant Chemicals 

and the respective PNEC values. The PEC/PNEC ratio (including appropriate assessment factors) 

for the Active Substance hydroxyl radical is neither relevant nor possible to calculate, due to the 
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properties (short half-life) of the substance (MEPC 55/2/4). The PEC/PNEC ratio for TRO is 

estimated using calculated values for hypochlorite and hypobromite (including appropriate 

assessment factors). Using MAMPEC and the same unrealistic conservative worst-case 

assumptions made for previous submission for Final Approval (MEPC 57/2/3, paragraph 3.8.3) 

the PEC/PNEC ratio is calculated at <1 for initial TRO concentrations of < 0.4 mg/L. This can be 

compared to the results from the custom-made ballast water discharge modelling undertaken for 

previous submissions; at an initial TRO concentration of 2 mg/L the PEC/PNEC ratio equals 

to 0.4. The PEC/PNEC ratios (including appropriate assessment factors) for Relevant Chemicals 

are below 1, thus no further assessment of direct toxic effects to the aquatic environment is 

considered to be necessary (section 6.3.7). In seawater matrix, bromate concentrations in 

the μg/L range are extremely difficult to analyse. Specialized equipment and methods are needed. 

It is noted that bromate was not considered by the applicants to raise any concern 

using conventional chlorination as a disinfection step in BW systems submitted 

for Basic and Final Approval, since this substance was not detected during the approval process. 

7.3.3 Dilution and/or degradation of toxic substances is necessary to ensure that the 

PNEC values are not exceeded following direct release of treated ballast water to the receiving 

aquatic environment. PECs have been calculated using several appropriate models (including 

MAMPEC as recommended by the Group) for relevant controlled use and discharge scenarios 

during deballasting. 

7.3.4 The potential risks to the aquatic environment resulting from full-scale application 

on board ships and discharge of treated ballast water under representative conditions have been 

assessed using several models and calculations throughout the approval process. Case studies of 

the port of Rotterdam, together with representative plume modelling on the port of Esbjerg of 

ballast water discharge based on worst case scenarios concerning concentrations have been 

submitted. Even under unrealistically high assumptions of discharge concentrations and 

total discharge periods, the acute risks for the environment are dropping very rapidly with 

distance away from the point of discharge. Thus, no harm to immediate receiving environment is 

expected. The extensive material provided by the applicant can be regarded as the first stage of a 

tiered approach to the development of a full Emission Scenario Document (ESD) for ballast 

water treatment systems, when more data on potential discharges and technologies becomes 

available (G9: 6.4.4). 

7.3.5 Taking into account the above, the risks for the environment related to treatment by 

the CleanBallast system are considered to be thoroughly addressed. Proper mitigation measures 

to prevent unnecessary stress to receiving environment have been implemented, e.g., specifically 

the use of the Algae Monitor (see sections 1.2 and 2.1.4, appendix of this document and 

Appendix C of the confidential part) at deballasting, and the fail-safe mechanism of the 

TRO measurement before discharge. 

8 ASSESSMENT REPORT (G9: 4.3) 

A risk assessment was carried out for the previous submission for Final Approval (MEPC 57/2/3) 

based on the worst-case data submitted in the context of this application. The risk assessments for 

crew, ship and environment, respectively, is based on data and evaluations as summarized in the 

following paragraphs 8.1 to 8.5.

8.1 The data and endpoints on which the risk characterization according to section 6 

of Procedure (G9) is based are considered sufficient. The quality of test reports are judged to be 

satisfactory and in compliance with the guidelines given in Procedure (G9). 
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8.2 The assessments of risks to the safety of ships, crew (human health), the environment and 

natural resources (e.g., fisheries) in accordance with section 6 of Procedure (G9) have been 

performed. Conclusions from these assessments can be found in sections 7.1 to 7.3. 

8.3 The available data on environmental exposure and the estimates of environmental 

concentrations obtained upon application of mathematical models using all available 

environmental fate parameters, along with an identification or description of the 

modelling methodology, are considered sufficient for assessment. For details please refer 

to Appendices J, K and M of the application dossier. 

8.4 The qualitative statements of and the level of uncertainty in the evaluations performed by 

the test facilities and institute performing the theoretical assessments are considered to be 

sufficient. 

8.5 A review of risk management possibilities, e.g., emergency shutdown of the system, 

de-aeration pipe for removal of potentially formed hydrogen, fail-safe monitoring of 

TRO concentration, mitigation by the Algae Monitor, etc. has been given. Because of the 

ongoing debate on acceptable TRO discharge levels, the full-scale CleanBallast system was also 

tested during land-based type approval testing at the test facility NIVA according to Guidelines 

(G8) using an additional neutralization system. The full data set from this test cycle can be found 

in Appendix N for the evaluation of the GESAMP-BWWG. 

8.6 In conclusion, it is considered that all potential risks to crew, ship or environment are 

covered by the respective risk assessments. 

9 MODIFICATIONS TO THE APPLICATION 

9.1 The manufacturer will report any modifications in names, including trade and technical 

name, composition or use of the Active Substances in the ballast water management systems 

approved by the Organization, to the Members of the Organization. The Members of 

the Organization will inform the Organization accordingly (G9: 8.4.1). 

9.2 If the manufacturer intends to significantly change any part of a ballast water 

management system that has been approved by the Organization or the Active Substances 

and Preparations used in it, a new application will be submitted (G9: 8.4.2). 

10 FINAL APPROVAL 

10.1 Tests of treated ballast water 

In accordance with paragraph 5.2.1 of Procedure (G9) for Final Approval, the discharge testing 

has been performed as part of the land-based type approval process using the discharged treated 

ballast water. 
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10.2 Criteria met to obtain Final Approval 

In accordance with section 8.2 of Procedure (G9), the following criteria were met by the 

applicant: 

.1 Basic Approval have been given (MEPC 55/2/4). 

.2 The Members of the Organization have conducted the Type Approval tests 

in accordance with Guidelines for approval of ballast water management 

systems (G8). The results have been conveyed to the Organization for 

confirmation that the residual toxicity of the discharge conforms to the evaluation 

undertaken for Basic Approval. 

.3 The results of the residual toxicity tests are included in the proposal for Final 

Approval in accordance with Procedure (G9). 

.4 If Final Approval under the Procedure (G9) is given, then the applicant should not 

have to retrospectively submit new data if there is a change in the Methodology as 

agreed by the Organization (G9: 8.2.3). 

.5 Toxicity testing has been done on three types of seawater at two appropriate time 

intervals after treatment. Organisms normally found in the selected types of 

seawater were used for toxicity testing. Several additional toxicity studies have 

been performed as submitted in the previous application for Final Approval. 

.6 Information related to Total Residual Oxidants (TROs) and the chemicals 

included in such groupings, including their concentrations, was provided to 

the GESAMP-BWWG for Final Approval as recommended in its evaluation 

for Basic Approval. 

.7 In addition to the basic data set needed for the treated ballast water and 

the individual chemicals produced by the system – as identified in the 

Methodology for Basic Approval – estimated PEC/PNEC ratios were submitted 

for Final Approval. 

.8 The application for Final Approval reflects the concerns identified during 

consideration of Basic Approval. It also reflects the concerns that were raised 

during first consideration for Final Approval. The data for acute and chronic 

ecotoxicity was required and consequently submitted. 

11 TERMS AND DEFINITIONS 

11.1 Definitions 

Definitions used in this document are intended to supplement those in the Ballast Water 

Management Convention: 

.1 Ballast Water Management Convention means the International Convention for 

the Control and Management of Ships’ Ballast Water and Sediments, 2004. 

.2 Ballast Water Management means mechanical, physical, chemical and biological 

processes – either singularly or in combination – to remove, render harmless, or 

avoid the uptake or discharge of harmful aquatic organisms and pathogens within 

ballast water and sediments. 
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.3 Preparation means any commercial formulation containing one or 

more Active Substances including any additives. This term also includes 

any Active Substances generated on board for purposes of ballast water 

management and any relevant chemicals formed in the ballast water management 

system that makes use of Active Substances to comply with the Convention. 

.4 Active Substance means a substance or organism, including a virus or a fungus 

that has a general or specific action on or against harmful aquatic organisms and 

pathogens. 

.5 Other components of a preparation means any other substances in a preparation, 

other than the Active Substance(s) or Relevant Chemicals, produced during the 

treatment of ballast water. 

.6 Relevant Chemicals means transformation or reaction products that are produced 

during and after employment of the ballast water management system in the 

ballast water or in the receiving environment that may be of concern to the ship’s 

safety, aquatic environment and/or human health. 

.7 Basic Approval means the preliminary approval of Active Substances and the 

ballast water management system making use of them in order to comply with 

the Ballast Water Management Convention. 

.8 Final Approval means the approval of a ballast water management system using 

an Active Substance or Preparation to comply with the Convention, including a 

review of the Type Approval tests in accordance with Guidelines for approval of 

ballast water management systems (G8). 

.9 GESAMP–Ballast Water Working Group (GESAMP-BWWG) means 

the Technical Group consisting of independent experts acting in their individual 

capacity reviewing the proposals for approval of ballast water management 

systems making use of Active Substances submitted by the Administration and 

report, through GESAMP, to MEPC. 

11.2 Abbreviations used in the text 

Abbreviations: 

AC alternating current 

AOX adsorbable organic halogen 

BW ballast water 

°C degree Celsius (Centigrade) 

CAS Chemical Abstract Service 

d day(s) 

DIN Deutsches Institut für Normung (German Institute for Standardization) 

DOC dissolved organic carbon 

dwt deadweight tonnage 

EC50 effect concentration, 50% (median effective concentration) 

EOX extractable organic halogen 

EPDM ethylene propylene diene M-class rubber 

FAC Free Active Chlorine 
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g gram 

GHS Globally Harmonized System 

GL Germanischer Lloyd 

G9 Procedure for approval of ballast water management systems that make use of 

Active Substances (G9), as revised, adopted by resolution MEPC.169(57) 

in April 2008. 

h hour 

HAA Haloacetic acids 

IMO International Maritime Organization 

ISO International Organization for Standardization 

IUPAC International Union of Pure and Applied Chemistry 

kg kilogram 

Koc organic carbon-water partition coefficient 

L litre 

LBTA land-based type approval 

LC50 lethal concentration, 50% 

LD50 lethal dose, 50% 

Log Pow logarithm of the octanol/water partition coefficient 

LOQ limit of quantification 

MEPC Marine Environment Protection Committee 

m metre 

m2 square metre 

m3 cubic metre 

mg milligram 

mL millilitre 

n.r. not reached 

N/A not applicable 

NOEC No-observed-effect concentration 

OECD Organization for Economic Co-operation and Development Organization 

OEL Occupational Exposure Limit 

PC personal computer 

PEC predicted environmental concentration 

PLC programmable logic controller 

PNEC predicted no-effect concentration 

POC particulate organic carbon 

Pow Octanol/water partition coefficient 

psu practical salinity units 

QAPP Quality Assurance Project Plan 

RQ risk quotient 

s second 

TDI Tolerable Daily Intake 

TGD Technical Guidance Document 

THM trihalomethane 

TRO Total Residual Oxidants 

US EPA United States Environmental Protection Agency 

WHO World Health Organization 

wt weight 
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APPENDIX 

NON-CONFIDENTIAL SHORT DESCRIPTION OF THE ALGAE MONITOR 

The Algae Monitor is a fundamental part of the CleanBallast system used to continuously analyse 

the direct effect of the treatment on phytoplankton and, by a feedback loop to the disinfection 

system (EctoSys®), to minimize the use of Active Substances at concentrations below the 

maximum concentration of 2 mg/L Total Residual Oxidant (TRO). The Algae Monitor is a key 

mitigation measure for the second EctoSys® treatment during deballasting, ensuring a reduction 

of disinfection down to only the level absolutely necessary to reach adequate biological 

efficiency. 

The advantage of the Algae Monitor is that it measures directly the effect of the disinfection on 

phytoplankton. This is important: 

- because the residual disinfectant concentration (TRO) is not sufficient to indicate if the 

disinfection was completed successfully in ballast water, because it does not correspond 

to the actual biological effect of the disinfection. No correlation exists between the 

TRO concentration and disinfection for the great variability and diversity of marine 

organisms and water qualities worldwide; and 

- specifically for the CleanBallast system, where the EctoSys® disinfection is only 

producing hydroxyl radicals as Active Substance in fresh water. Thus, no additional 

Total Residual Oxidant (TRO) is formed and consequently the TRO concentration can not 

at all be used as a controlling parameter. 

Mainly after efficient ballast water treatment, the number of dead organisms is high and therefore 

common biomass parameters such as chlorophyll-a or the Genty-parameter, which gives also a 

response for dead cells, cannot give an indication on the success of the disinfection performance. 

A unique design characteristic of the algae monitor is that the measurement is specific only for 

living phytoplankton and therefore not affected by dead cells, sediment, etc. 

The base of the algae monitor is a flow-through fluorometer using well-established photometrical 

principles, which is installed after EctoSys® disinfection in a bypass to the effluent 

of CleanBallast system. Both inlet water to the CleanBallast system as well as the effluent after 

the EctoSys® disinfection can be supplied to and analysed by the Algae Monitor. If living 

phytoplankton remains in the sample, this light serves to drive photosynthetic reactions and the 

phytoplankton cells respond to the introduced light by emitting certain fluorescence light. 

The differentiation between viable and dead phytoplankton cells is achieved by the specific 

features of the measurement. Its output signal is forwarded to the PLC (Programmable Logic 

Controller) of the CleanBallast system. 

The Algae Monitor allows that the EctoSys® disinfection is controlled directly by its effect on 

phytoplankton and minimizes the use of disinfectants by a feedback loop to the EctoSys®. 

Importantly, during deballasting this allows to monitor and only generate the level of 

disinfectants that are necessary (if needed at all). By using this measure the TRO discharge 

concentration is minimized in marine water qualities, and use of hydroxyl radicals is minimized 

in fresh water. 
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The quality assurance is secured by a technical and a biological calibration. For each Algae 

Monitor the optical properties are checked before the first use in a technical calibration. After a 

certain operation time within regular surveys on board, it is checked by standard solutions that 

the technical calibration is still valid and no ageing of the optical properties occurred. 

For the biological calibration viable cells of the reference organisms Tetraselmis sueccica is used 

with a minimum length around 10 μm, representing the lower limit of the smaller size class 

regulated by the IMO Ballast Water Performance Standard. The biological calibration is carried 

out according to a Standard Operation Procedure (SOP) by an approved institute for handling and 

analysing phytoplankton. 

Tetraselmis sueccica was chosen as a reference organism, because from testing and operation of 

the CleanBallast system at different locations it was experienced that Tetraselmis sueccica is one 

of the last organisms that die. This is in accordance with the literature, e.g.. Gregg and 

Hallegraeff (2007), who published that the green flagellate Tetraselmis sueccica was found to be 

considerably more resistant to treatment by biocides than the vegetative dinoflagellates. 

Although the Algae Monitor is calibrated to the reference organism Tetraselmis sueccica, 

certainly also smaller and larger phytoplankton species are measured by the Algae Monitor as 

well. The special feature is that viable phytoplankton smaller than 10 μm give also in higher 

numbers a lower response to the measurement, while phytoplankton bigger than 10 μm but in 

numbers below 10 viable organisms per ml give a higher response. By this a safe monitoring is 

achieved. 

The Algae Monitor has successfully passed the requirements of the specification for 

Environmental Testing according to Part 3 of Guidelines (G8). 

Important note: 

The Algae Monitor is not a measuring device to check if the number of organisms in the effluent 

is in compliance with IMO Ballast Water Performance Standard. Due to the fact that two 

different size classes and different indicator bacteria are regulated, a marine biologist needs to 

analyse and decide on the compliance with the standard. 

The Algae Monitor is designed to give only an indication on the disinfecting effect on 

phytoplankton and allow minimizing the use of Active Substances. This is comparable to the 

oil/water monitors, which are widely used with bilge water separators on board. 

The oil/water-monitors measure the scattering of the light as an indicator for the 15 ppm oil 

discharge limit. 

__________