I:\MEPC\61\2-8.doc 

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE 

61st session 

Agenda item 2 

MEPC 61/2/8

28 March 2010

 Original: ENGLISH

HARMFUL AQUATIC ORGANISMS IN BALLAST WATER 

Application for Final Approval of the Ecochlor® Ballast Water Management System 

Submitted by Germany 

SUMMARY 

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

the application for Final Approval of the Ecochlor®

 Ballast Water 

Management System under the "Procedure for approval of ballast water 

management 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 6 

Related documents: BWM/CONF/36; MEPC 57/21; MEPC 58/23; MEPC 59/2/9; 

MEPC 60/2/11; BWM.2/Circ.13 and BWM.2/Circ.24 

Introduction 

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

of Ships' Ballast Water and Sediments stipulates that ballast water management systems 

that make use of Active Substances to comply with the Convention shall be approved by 

the Organization. 

2 Germany herewith submits 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 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.24, this application 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 61/2/8 

Page 2 

I:\MEPC\61\2-8.doc 

3 Basic Approval of the Ecochlor® Ballast Water Management System was applied for 

in document MEPC 58/2/2 and was granted at MEPC 58 (MEPC 58/23, paragraph 2.6.3). 

Final Approval, as applied for in document MEPC 59/2/9, was not granted at MEPC 60. 

4 After carefully taking into account the recommendations contained in annex 5 of 

the Report of the tenth meeting of the GESAMP-BWWG (MEPC 60/2/11), the competent 

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

of Procedure (G9) adopted by resolution MEPC.169(57). In particular, a thorough 

re-evaluation of the discharge toxicity and environmental modelling has been undertaken by 

the Administration and has found no unacceptable environmental risk caused by the system. 

5 To ease the workload of the Committee, the annex to this document is limited to the 

issues raised by the GESAMP-BWWG in its tenth meeting (MEPC 60/2/11). It should be read 

in conjunction with documents MEPC 59/2/9 and MEPC 60/2/11. 

Action requested of the Committee 

6 The Committee is invited to consider the proposal for approval and decide as 

appropriate. 

***
MEPC 61/2/8 

Annex, page 1 

I:\MEPC\61\2-8.doc 

ANNEX 

NON-CONFIDENTIAL INFORMATION OF THE ECOCHLOR® 

BALLAST WATER MANAGEMENT SYSTEM 

Contents 

1 INTRODUCTION 

2 CHEMISTRY 

2.1 Overview of chlorine-based and chlorine-dioxide-based chemistry 

2.1.1 Bromide ion interaction and decomposition chemistry 

2.1.2 Disinfection by-product formation 

2.1.3 Hypochlorite ion and chlorite ion 

2.2 Oxidant measurements 

2.2.1 TRO as chlorine and DPD test method 

2.2.2 Methods for measuring chlorine dioxide, chlorite ion, chlorate ion and bromate ion 

2.3 Oxidant demand 

2.3.1 Comparison of oxidant demand for shipboard and land-based testing 

3 HYDRODYNAMIC MODELLING AND ASSESSMENT OF ENVIRONMENTAL RISK 

3.1 Re-calculation of PEC values using the MAMPEC Model 

3.2 Details of the modelling parameters for PEC re-calculation by Ecochlor®

3.3 PEC re-calculation results and PEC/PNEC ratios 

3.4 Maximum allowable discharge concentrations 

4 DISCHARGE ECOTOXICITY 

5 SHIP SAFETY AND MAINTENANCE

5.1 Corrosion and ballast tank coatings 

5.2 Fire risk mitigation 

5.3 Chemical storage 

6 SUMMARY

7 REFERENCES 

LIST OF TABLES 

 Table 1: Chemical analysis of ballast water treated on board 

 the M.V. Moku Pahu, San Francisco Bay Area (Richmond, CA) 

 Table 2: Comparison of DBP concentrations for chlorine and chlorine dioxide 

treatments 

 Table 3: Comparison of hypochlorite ion and chlorite ion 

 Table 4: Ecochlor® chlorine dioxide demand study, 4oC 

 Table 5: Ecochlor® chlorite ion demand study, 20oC 

 Table 6: Summary of chlorine dioxide and chlorite concentrations, 

land-based testing 

 Table 7: Summary of chlorine dioxide and chlorite concentrations, 

shipboard testing 

 Table 8: Chlorine dioxide decay study, shipboard testing 
MEPC 61/2/8 

Annex, page 2 

I:\MEPC\61\2-8.doc 

 Table 9: Summary of treated ballast water substance emissions 

 Table 10: Re-calculated Predicted Environmental Concentrations – MAMPEC 

 Table 11: Re-calculated PEC/PNEC ratios 

 Table 12: Summary of corrosion test methods 

LIST OF FIGURES 

 Figure 1: Chlorine species at various pH values 

 Figure 2: Bromine species at various pH values 

 Figure 3: Chlorine dioxide species at various pH values 

 Figure 4: Example of chlorine dioxide demand curve, 4oC 

 Figure 5: Example of chlorite ion demand curve, 20oC 

 Figure 6: Chlorine dioxide decay study, shipboard testing 

 Figure 7: Harbour definition information provided by the GESAMP-BWWG 

 Figure 8: Emission parameter information provided by the GESAMP-BWWG 

 Figure 9: Example of compound definition parameters 

APPENDICES CONTAINED IN THE CONFIDENTIAL DOSSIER 

APPENDIX 1 MAMPEC modelling documentation 

APPENDIX 2 Corrosion study reports 

APPENDIX 3 Example of Health and Safety Plan (HASP) 

APPENDIX 4 Chlorine dioxide analytical information 
MEPC 61/2/8 

Annex, page 3 

I:\MEPC\61\2-8.DOC 

1 INTRODUCTION 

Ecochlor® is applying for Final Approval of the Purate® chlorine dioxide generation method 

utilized with the Ecochlor® Ballast Water Management System (BWMS) in accordance with 

the International Maritime Organization's Procedure (G9) (resolution MEPC.169(57)). 

Ecochlor applied for Basic Approval (MEPC 58/2/2), which was granted at MEPC 58 

(MEPC 58/23). Ecochlor® submitted a dossier for Final Approval in December 2008 

(MEPC 59/2/9). That dossier was reviewed during the tenth meeting of the 

GESAMP-BWWG in September 2009 but Final Approval was not recommended. 

The comments received from the GESAMP-BWWG (MEPC 60/2/11) on Ecochlor®'s Final 

Approval application dossier are summarized below. Therefore, this document supports a 

re-submission for Final Approval and focuses on providing clarification to address the 

GESAMP-BWWG concerns. This document should be considered along with the original 

Final Approval dossier (MEPC 59/2/9). 

The following is the summary of the GESAMP-BWWG comments (MEPC 60/2/11, annex 5): 

.1 Having reviewed all the data and information submitted by Germany with 

the application for Final Approval and the information received from the 

applicant during the GESAMP-BWWG meeting, the Group could not 

recommend to MEPC that Final Approval be granted to the Ecochlor®

Ballast Water Management System (BWMS). 

Response: This submission addresses the concerns of the Group. 

.2 The Group recalled that Basic Approval of the BWMS was granted by 

MEPC 58 and the report is available at document MEPC 58/2/8 

(BWWG 7/9, annex 5, Review of Proposals for Approval of Ballast Water 

Management Systems that make use of Active Substances). 

No response required. 

.3 In view of the responses from the applicant to questions posed by the 

Group in the Basic Approval Report, together with the information received 

from the applicant during the GESAMP-BWWG meeting, the Group could 

accept that the information provided in the dossier supplemented by that 

provided by the applicant in response to questions was sufficient to enable 

an appropriate evaluation to be made. 

No response required. 

.4 The Group noted that the Ecochlor® BWMS uses a combination of filtration 

and oxidation. The oxidation is performed by the reaction on board ship 

between Purate® (a propriety Preparation from Eka Chemicals 

containing 40% by weight sodium chlorate (NaClO3) and 8% by weight 

hydrogen peroxide (H202) in water) and sulphuric acid (H2SO4) to generate 

chlorine dioxide as Active Substance at a maximum allowable concentration 

of 5 mg/L to treat the ballast water by oxidation and disinfection. 

No response required. 
MEPC 61/2/8 

Annex, page 4 

I:\MEPC\61\2-8.doc 

.5 The Group noted that the applicant has provided information on ecotoxicity 

testing of treated ballast water, environmental risk assessment for aquatic 

organisms, and a proposal for maximum allowable discharge 

concentrations for the Active Substances and Relevant Chemicals, together 

with a proposal for minimum holding time for treated ballast water. 

The Group noted the discharge concentrations, with a treated ballast water 

holding time of 24 h, were as follows: 

Chlorine dioxide – 0.85mL (= 0.44 mg/L TRO as Cl2); 

Chlorite ion – 3.8 mg/L (= 1.98 mg/L TRO as Cl2); 

Chlorate ion – 2.4 mg/L (= 1.01 mg/L TRO as Cl2); and 

Dibromoacetic acid (DBAA) – 0.036 mg/L. 

Response: Discussion on the applicability of TRO as Cl2 is 

presented in section 2.2. Ecochlor® would like to note 

that the highest discharge concentration values 

presented in the Final Approval dossier for chlorite ion 

and chlorate ion 24 hours (1 Day) after ballast water 

treatment are 3.6 mg/L and 1.47 mg/L, respectively. 

The values summarized in the Group's comment are 

the values immediately after treatment (Day 0) 

(see Table T2.8a; MEPC 59/2/9). 

.6 The Group noted that the applicant indicated in its dossier for 

Final Approval that all the discharge concentrations mentioned above were 

higher than had been reported in the application for Basic Approval. 

The Group recognized that the degradation half-life of chlorine dioxide in 

natural seawater is about 3 minutes. However, the chlorite and chlorate 

ion, which are primary by-products when chlorine dioxide degrades, are 

toxic to aquatic organisms. The Group considered that the discharge 

concentrations of chlorite and chlorate ions, which can be measured as part 

of the TRO, are significant in the evaluation of risks to the environment. 

Response: The higher discharge concentrations presented in the 

prior Final Approval dossier are due to the difference in 

testing environments (shipboard vs. land-based) and the 

varying effects of oxidant demand and decay in these 

scenarios. See section 2.3 for discussion. With respect 

to TRO and the applicability to chlorine dioxide, chlorite 

and chlorate, Ecochlor® presents discussion in 

section 2.2. 

.7 The Group noted that the discharged ballast water contains 3.8 mg 

chlorite/L (= 1.98 mg/L TRO as Cl2) after 24 hours holding time. The Group 

had concerns with this discharge concentration as very similar levels of 

TRO have been used as the maximum allowable dosage in other systems 

that have been evaluated. The Group previously recommended to other 

systems that a discharge concentration in the range of 0.1 mg/L to 0.2 mg/L 

TRO (as Cl2) should be set as the maximum allowable discharge 

concentration (MADC). The chlorite discharge concentration exceeds the 

above recommendations for TRO by a factor of 19 to 38 and is therefore 
MEPC 61/2/8 

Annex, page 5 

I:\MEPC\61\2-8.DOC 

unacceptable. The Group recalled that, in the evaluation of the Ecochlor® 

BWMS at Basic Approval, the local risks for aquatic organisms had been 

anticipated as a potential problem. Based on these concentrations, 

the Group is not able to recommend Final Approval for the Ecochlor® 

BWMS as presented. 

Response: Discussion on the applicability of TRO as Cl2 for chlorine 

dioxide's degradation products is presented in 

section 2.2. Ecochlor® would like to note that the 

highest discharge concentration reported in the prior 

Final Approval dossier for chlorite ion 24 hours (1 Day) 

after ballast water treatment is 3.6 mg/L, rather 

than 3.8 mg/L (Table T2.8a; MEPC 59/2/9). 

Local risks for the aquatic environment anticipated by 

the Group at Basic Approval was based on a preliminary 

risk assessment using the information available at that 

time. The full environmental risk assessment as 

documented in the prior Final Approval dossier as well 

as the whole effluent toxicity (WET) testing performed 

with the treated ballast water discharge did not support 

those initial concerns. The environmental risk 

assessment is further elaborated in section 3 below. 

.8 Based on additional calculations using chlorite as representative, the Group 

concluded that the systems proposed discharge concentrations would lead 

to concentrations in the environment that would not exclude unacceptable 

risks to the aquatic organisms in the receiving waters. 

Response: Discussion for MAMPEC modelling calculations is 

presented in section 3. 

.9 The Group noted that the results of the Whole Effluent Tests (WET) clearly 

indicated that even with a 5-day tank holding time, the discharged water 

has both acute and chronic toxicity, so that more mitigation would be 

needed for this BWMS. 

Response: This comment is addressed in section 4. 

.10 As the BWMS requires the storage of chemicals on board ship, the Group 

recognized that there will be a potential risk associated with storage safety 

problems. The submission states that as the chemicals used are ship's 

stores, then the provisions of the IMDG Code are not applicable. The Group 

recognized that this is the case, however strongly recommended that the 

provisions of the IMDG Code are followed as far as is practical and that the 

guidance provided in the IMO "Guidance to ensure safe handling and 

storage of chemicals and preparations used to treat ballast water and the 

development of safety procedures for risks to the ship and crew resulting 

from the treatment process" is also fully taken into account. 

Response: Ecochlor® agrees with this statement and the concerns 

of the Group. As recognized by the Group, the 

provisions of the IMDG Code are not applicable to the 

chemicals stored on board as consumables for use with 
MEPC 61/2/8 

Annex, page 6 

I:\MEPC\61\2-8.doc 

the Ecochlor® BWMS. The pre-installation review 

process, along with Ecochlor's® existing system 

mitigation measures, crew and technician training, and 

active maintenance of the BWMS, support the 

recommendations in IMO's guidance document for safe 

storage and handling of chemicals used to treat ballast 

water (BWM.2/Circ.20, July 2009). Section 5.3 elaborates 

further. 

.11 The Group recognized that the system utilizes an Active Substance with 

potential safety and environmental concerns and the Group has reviewed 

the hazards and risks associated with the Active Substance. 

No response required. 

.12 The Group recognized that the applicant has provided some information on 

system controls and safety considerations for installation of the BWMS on 

board ship, together with provisions for maintenance and chemical 

replenishments to the system which will be performed by the manufacturer. 

The Group considered that the applicant did not provide sufficient 

information to permit a full evaluation of these safety matters, particularly 

with regard to procedures and risk mitigation measures applying to BWMS 

maintenance or chemical replenishment operations on board the ship. 

Response: With respect, Ecochlor® is unclear what additional 

information is necessary, as the above comment 

appears to be in direct contrast to comment 0.14 below, 

as well as comments in sections 3.1.5 and 4.2 of the 

review report (MEPC 60/2/11, annex 5), which indicate 

such issues were satisfactorily addressed. 

Further, the Group's review of the Basic Approval 

dossier (MEPC 58/2/8, annex 5, section 4.10) stated, 

"... the Group considered that the unit operations where 

potential human exposure risks exist, e.g., maintenance 

and refilling operations, are limited in duration and 

frequency and risk mitigation measures were 

satisfactorily addressed by the applicant". As such, 

no further information was provided in the prior 

Final Approval dossier (MEPC 59/2/9). 

However, in a desire to provide additional information to 

the Group, Ecochlor® has included an example of 

a Health and Safety Plan (HASP) within the confidential 

appendices. The HASP is the general guiding document 

for Ecochlor® technicians and/or representatives with 

respect to safety issues. This guidance, along with 

vessel-specific safety considerations that may be 

necessary to address relevant issues associated with 

a particular system, are followed by Ecochlor®

technicians and/or representatives during system 

maintenance and chemical replenishment operations. 

An example of HASP has been provided in appendix 3 

for consideration. 
MEPC 61/2/8 

Annex, page 7 

I:\MEPC\61\2-8.DOC 

.13 The Group noted that while additional corrosion tests had been conducted, 

they were insufficient and additional testing was recommended by the 

applicant's corrosion testing laboratory. The Group concurred and 

recommended that additional testing should be conducted in accordance 

with the guidance provided in section 5.1 of MEPC 59/2/16. 

Response: Ecochlor® conducted corrosion testing according to the 

Group's recommendations for the review of 

the Basic Approval dossier (MEPC 58/2/8, annex 5) 

(see further discussion in section 5.1). 

.14 The Group noted the human health assessment provided by the applicant 

and the Group accepted the view of the applicant that there should be no 

unacceptable risks to human health posed by the use of this BWMS if 

operated correctly. 

No response required. 

.15 In conclusion, having reviewed all the information provided by the applicant, 

the Group could not recommend to the MEPC that Final Approval be 

granted to the Ecochlor® BWMS. 

Response: In summary, the following is suggested: 

- reconsideration of the "TRO as Cl2" technique for chlorine dioxide, 

chlorite and chlorate; 

- accept the new MAMPEC results which have been carried out per the 

GESAMP-BWWG harbour parameters; 

- accept the proposed MADC for ClO2 (section 3.4); and 

- consider the corrosion and ballast tank coating study that was 

performed based on the GESAMP-BWWG recommendations from 

Basic Approval (MEPC 58/2/8, section 5.4). 

In addition to the comments noted above, Ecochlor® also provides additional responses to 

specific sections within the Group's report. 

.16 In Table 1 on page 4 (MEPC 60/2/11, annex 5), there is a word omitted in 

the "Applicants Response" column for the response to the Group's question 

for Basic Approval (section 0.3.1). The sentence should read "Information 

from the applicant has been added in response to the GESAMP-BWWG 

comment indicating that chlorite ion is not considered an Active Substance" 

(omitted word added with emphasis). The classification of chlorite ion as 

a Relevant Chemical is accurately reflected in section 3.3.3 of the Group's 

report. 

.17 On page 14, the Group's reaction to the response to Question 4 indicates it 

is unclear how the shut-down procedures will be used for manually 

controlled systems. Ecochlor® would like to clarify that the Ecochlor®

BWMS is not operated manually and the response did not intend to indicate 

such. What Ecochlor® does note in the prior Final Approval dossier is that 

some ships are equipped with more manual ballast water systems where 
MEPC 61/2/8 

Annex, page 8 

I:\MEPC\61\2-8.doc 

valves within the ballast piping might be controlled manually. For example, 

this differs from other ships where the ballast system is controlled 

electronically and a crew member does not manually adjust valve positions. 

It is important to note that a distinction exists between the ships ballast 

water system and the Ecochlor® ballast water management system. 

How a ship controls its ballasting system and how the Ecochlor® system is 

programmed to operate automatically are separate matters. A ship that 

controls its ballast piping system (i.e. valve positions, pumps) in a more 

manual way does not preclude automatic operation of the Ecochlor®

BWMS. Therefore, regardless of whether the ship is conducting complete 

ballasting, or topping off tanks, the Ecochlor® BWMS (including the flushing 

aspect of the shut-down procedure) will occur automatically without 

additional action from ship's crew. 

.18 In section 3.3.8 of the report, the acronym MRL is stated as "Minimal Risk 

Level". In Ecochlor's® application MRL is defined as "Minimum Reporting 

Limit". 

2 CHEMISTRY 

Detailed information about the chlorine dioxide chemistry associated with the Ecochlor®

BWMS was presented in both the Basic Approval dossier (MEPC 58/2/2) and the earlier 

dossier for Final Approval (MEPC 59/2/9). Therefore, this re-submission for Procedure (G9) 

Final Approval should be considered in conjunction with both prior dossiers. The following 

chemistry discussion is provided for additional clarification to address comments from 

the Group, as well as to highlight important information that was presented (Bubnis, 2010a) 

at the Chlorine/Chloride Based Ballast Water Treatment Workshop hosted by the North Sea 

Ballast Water Project and the German Federal Maritime and Hydrographic Agency 

on 4 March 2010. 

2.1 Overview of chlorine-based and chlorine-dioxide-based chemistry 

There are numerous chlorine-based technologies that have received IMO Procedure (G9) 

Final Approval with more under review. Clearly, the Group has a high level of familiarity of 

chlorine chemistry. However, understanding the differences between chlorine-based and 

chlorine-dioxide-based chemistries is critical to a proper determination of environmental risk. 

Electro-chlorination of seawater/brine solution is the most widely used technique for ballast 

water treatment and generates chlorine through electrolysis of seawater or a chloride 

solution (Reaction 1). More specifically, the reaction can be defined through the anode 

(Reaction 2) to generate chlorine and the cathode (Reaction 3) to generate hydrogen. 

See below: 

Reaction 1 2Cl-

 + 2H2O + e- → 2OH- + Cl2 + H2

Reaction 2 Anode: 2Cl-

 → Cl2 + 2eReaction 3 Cathode: 2H+

 + 2OH- + 2e- → H2 + 2OH-
MEPC 61/2/8 

Annex, page 9 

I:\MEPC\61\2-8.DOC 

In water, chlorine will form hypochlorous acid (Reaction 4) and subsequent pH dependent 

equilibrium will be established between hypochlorous acid and hypochlorite ion (Reaction 5). 

At a pH of 7, there will be near equal amounts of hypochlorous acid and hypochlorite ion. 

See below: 

Reaction 4 Cl2 + H2O ↔ HOCl + H+ + Cl- 

Reaction 5 HOCl ↔ OCl-

 + H+ 

The chart below shows the relationship between pH and the chlorine species present. 

Chlorine Species

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0 2 4 6 8 10 12 14

pH

% Abundance

Cl2 HOCl OClFigure 1: Chlorine species at various pH values 

Chlorine dioxide is a completely different chemistry with unique characteristics. With the 

Ecochlor® BWMS, chlorine dioxide is generated on board ship as a dissolved gas in solution 

through the controlled mixing of Purate® and sulfuric acid (Reaction 6). Chlorine dioxide is 

maintained as a dissolved gas in the treated ballast water. Chlorine dioxide treatment of 

water does not cause the formation of multiple chlorinated and oxidant chemical species. 

As indicated in Reaction 6, chlorine dioxide will not form chlorine or its dissociation 

compounds when added to fresh water, brackish water or seawater (Reaction 6). 

See below: 

Reaction 6 2 NaClO3 + H2O2 + H2SO4 → 2 ClO2 + 2 NaHSO4 + 2 H2O + O2 

2.1.1 Bromide ion interaction and decomposition chemistry 

It is well understood that the addition of chlorine into bromide ion containing waters will form 

bromine (Reaction 7). Similar to chlorine chemistry, bromine added to water will form 

hypobromous acid (Reaction 8) and then a pH-dependent equilibrium will be established 

between hypobromous acid and hypobromite ion (Reaction 9). This is in contrast to chlorine 

dioxide, which does not react with bromide ion to form brominated oxidant species. 

See below: 

Reaction 7 Cl2 + 2Br- + 2H+ → Br2 + 2HCl 

Reaction 8 Br2 ↔ HOBr + H+

 + BrReaction 9 HOBr ↔ OBr-

 + H+ 

Source: NovaChem Laboratories, USA 
MEPC 61/2/8 

Annex, page 10 

I:\MEPC\61\2-8.doc 

The chart below shows the relationship between pH and the bromine species present.

Bromine Species

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0 2 4 6 8 10 12 14

pH

% Abundance

Br2 HOBr OBrSource: NovaChem Laboratories, 

USA

Figure 2: Bromine species at various pH values 

In order to accurately identify relevant substances, it is also important to understand the 

decomposition products of chlorine/bromine and compare that to chlorine dioxide. The 

decomposition of chlorine chemistry will form chlorate ion and chloride ion (Reaction 10) 

while bromine chemistry will form bromate ion and bromide ion (Reaction 11). See below: 

Reaction 10 2HOCl + OCl- → ClO3- + 2H+ + 2ClReaction 11 2HOBr + OBr- → BrO3- + 2H+ + 2BrThe decomposition of chlorine dioxide will form chlorite ion (ClO2-) and chlorate ion (ClO3-) 

(Reaction 12) and ultimately chloride (Reaction 13). There is no formation of bromate ion. 

See below: 

Reaction 12 ClO2 + e- → ClO2

-

 

Reaction 13 2ClO2 + 2OH- 

→ H2O + ClO3

-

 + ClO2

-

Reaction 14 ClO2

- + 4H+

 → Cl- + 2H2O 
MEPC 61/2/8 

Annex, page 11 

I:\MEPC\61\2-8.DOC 

The chart below shows the relationship between pH and the chlorine dioxide chemical species 

present. 

Figure 3: Chlorine dioxide species at various pH values 

The lack of bromate formation with chlorine dioxide treatment has been confirmed through 

data obtained during shipboard testing as well as during land-based testing at NIOZ. As an 

example from the prior application for Final Approval (MEPC 59/2/9, Table T2.8), shipboard 

testing on the M.V. Moku Pahu clearly showed that the treatment of ballast water with 

chlorine dioxide in the presence of bromide (50 mg/L) did not result in formation of bromate. 

Table T2.8a (MEPC 59/2/9) can be referenced for land-based data, which also shows no 

detection of bromate ion. 
MEPC 61/2/8 

Annex, page 12 

I:\MEPC\61\2-8.doc 

Table 1: Chemical analysis of ballast water treated on board the M.V. Moku Pahu, 

San Francisco Bay Area (Richmond, CA) 

Parameter 

Control Ballast 

Water 

Ballast Water 

Treated 

Onboard 

+ 3 Day 

13 Feb 2008 

Ballast Water 

Treated 

Onboard 

+ 5 Day 

15 Feb 2008 

pH 7.6 7.3 7.3 

FAC <0.05 mg/L <0.05 mg/L -- 

ClO2 -- <0.05 mg/L <0.05 mg/L 

ClO2

-

 <0.05 mg/L 0.91 mg/L 0.24 mg/L 

ClO3

-

 <0.10 mg/L 0.49 mg/L 0.49 mg/L 

Br - 50 mg/L -- -- 

BrO3

-

<0.02 mg/L -- <0.02 mg/L 

(+11 Day) 

SO4

-2

1902 mg/L -- 1826 mg/L 

(+ Day 8) 

THM's 

Bromodichloromethane 

Bromoform 

Chloroform 

Dibromochloromethane 

<1 μg/L 

<1 μg/L 

<1 μg/L 

<1 μg/L 

-- 

<1 μg/L 

<1 μg/L 

<1 μg/L 

<1 μg/L 

HAA's 

Dibromoacetic Acid 

Dichloroacetic Acid 

Monobromoacetic Acid 

Monochloroacetic Acid 

Trichloroacetic Acid 

<1 μg/L 

<1 μg/L 

<1 μg/L 

<1 μg/L 

<1 μg/L 

-- 

12 μg/L 

<1 μg/L 

<1 μg/L 

<1 μg/L 

<1 μg/L 

Analysis performed by NovaChem Laboratories 

"--" = not measured 

In summary, chlorine will form hypochlorous acid (HOCl), hypochlorite ion (OCl-

), chlorate ion 

(ClO3

-

) and bromine will form hypobromous acid (HOBr), hypobromite ion (OBr-), and bromate 

ion (BrO3

-

). Chlorine dioxide (ClO2)will form chlorite ion (ClO2

-

), and chlorate ion (ClO3

-

). 

2.1.2 Disinfection by-product formation 

Another significant difference between chlorine and chlorine dioxide chemistries is the 

formation of disinfection by-products (DBPs). The formation of by-products consisting of 

THMs (trihalomethanes) and HAAs (haloacetic acids) occurs when chlorine and/or bromine 

is added to water containing organic matter. This is because chlorine reacts by both oxidative 

and chlorination pathways.

Conversely, chlorine dioxide does not "chlorinate"; the mechanism for disinfection is 

oxidation. Oxidation by chlorine dioxide will not form chlorinated by-products such as THMs 

and formation of HAAs is significantly lower than that with chlorination. Ecochlor's® data from 

shipboard and land-based testing, as presented in the prior Final Approval dossier 

(MEPC 59/2/9, Tables T2.8b and T2.8c), demonstrates this important feature of water 

treatment with chlorine dioxide. The data clearly shows no formation of THMs and limited 

formation of one HAA (dibromoacetic acid, DBAA) when chlorine dioxide is used to treat 

water containing organic matter. As reflected in published chlorine-based BWMS dossiers, 

and as Table 2 below demonstrates, THM and HAA concentrations from the Ecochlor®

BWMS are in sharp contrast compared to chlorine/bromine treatment chemistries. 
MEPC 61/2/8 

Annex, page 13 

I:\MEPC\61\2-8.DOC 

Table 2: Comparison of DBP concentrations for chlorine and 

chlorine dioxide treatments 

 

Parameter 

Chlorine 

Based1 (μg/L) 

Chlorine Dioxide 

Based2 (μg/L) 

 BDCM <1 

 Bromoform <1 

 Chloroform <1 

 DBCM <1 

THM (Total) 260-410 <1 

 DBAA 12 - 36 

 DCAA <1 

 MBAA <1 

 MCAA <1 

 TCAA <1 

HAA (Total) 48.5 – 100 12 - 36 

 1 Data presented by T. Bowmer at the IMO-WMU Global R&D Forum on 

 Emerging Ballast Water Management Systems (Malmö, Sweden, January 2010) 

 2 Combined data from Ecochlor®

 shipboard and land-based testing 

While it is acknowledged that each DBP indentified as a Relevant Chemical during the 

application of a BWMS is subjected to an individual assessment of environmental and human 

health risks, these risk assessments presently have considerable uncertainties. This is due 

to the limited data available for some of the DBP substances with respect to both aquatic 

ecotoxicity (especially chronic effects), and mammal toxicity (especially carcinogenicity and 

reproductive and developmental toxicity). Limited DBP formation, as observed with the 

Ecochlor® system, therefore limits such uncertainties of the risk assessment. 

2.1.3 Hypochlorite ion and chlorite ion 

There is often confusion between hypochlorite ion (OCl-

) and chlorite ion (ClO2

-

). Although 

sounding and appearing similar, hypochlorite ion (OCl-

) is dramatically different from chlorite 

ion (ClO2

-

). Ecochlor® provides Table 3 below to allow for a direct comparison between 

hypochlorite ion and chlorite ion. As noted above, the chlorine dioxide chemistry used with 

the Ecochlor® BWMS does not produce hypochlorite ion. 

Hypochlorite ion is an active ingredient formed when chlorine is added to water (section 2.1) 

and will: form bromine when added to bromide containing waters (section 2.1.1); be 

measured through the standard DPD test (section 2.2.1); form organic byproducts like THMs 

and HAAs in waters with organics; and will decompose to form bromate (section 2.1.2). 

Conversely, chlorite ion is a Relevant Chemical formed through reaction of the active 

ingredient, chlorine dioxide. Chlorite ion does not: form bromine when added to bromide 

containing waters (section 2.1.1); is not measured by the standard DPD test (section 2.2.1) 

but rather through ion chromatography (section 2.2.2); will not form THMs or HAAs (chlorine 

dioxide does not form THMs and forms HAAs to a significantly less degree than 

hypochlorite ion) (section 2.1.2); chlorite ion will decompose to form chloride ion. See below: 

 OCl- ≠ ClO2

-

(Hypochlorite ion) (Chlorite ion) 
MEPC 61/2/8 

Annex, page 14 

I:\MEPC\61\2-8.doc 

Table 3: Comparison of hypochlorite ion and chlorite ion 

Hypochlorite Ion Chlorite Ion 

CAS # (of the sodium salts) 7681-52-9 7758-19-2 

Molecular Formula OCl- ClO2

-

Chlorine Oxidation State +1 +3 

Associated With Chlorine Chlorine Dioxide 

In Water 

Chlorine Equilibrium 

pKa = 7.5 

Cl2 ↔ HOCl + ClHOCl ↔ OCl-

 + ClIon 

pKa = 1.9 

ClO2 → ClO2

-

pH Dependence YES NO 

Reaction Mechanism 

Oxidation – very fast 

Chlorination 

Organics → chlorinated 

organics 

Oxidation – very slow 

End Product After 

Complete Reaction Typically Cl-

 Typically ClChloramine Formation YES NO 

Reacts with Bromide Ion YES 

Hypobromite formation NO 

2.2 Oxidant measurements 

2.2.1 TRO as chlorine and DPD test method 

As discussed above in section 2.1, when chlorine is used to treat water, instantaneous 

dissociation into hypochlorous acid (HOCl) and hypochlorite ion (OCl-

) takes place. As shown 

in Figure 1 above, these chemical species will be present at nearly equal concentration at 

neutral pH. When chlorinating seawater, the presence of bromide ions also causes the 

formation of hypobromous acid (HOBr) and hypobromite ion (OBr-

). Chlorination of water 

can also result in the formation of additional oxidants that can include, but are not limited to, 

chloramines and bromamines. Therefore, water that has been treated with chlorine contains 

a complex mixture of chemical oxidants. Due to the difficulty in measuring each chemical 

species individually, the method of measuring Total Residual Oxidants (TRO) in a complex 

water sample is utilized. TRO is used to describe the aggregate concentration of oxidants 

present in a complex water sample, and is frequently quantified by utilizing the DPD 

(N,N'-diethyl-p-phenylenediamine) colorimetric test (equivalent method to EPA 330.5 or 

APHA SM4500-D). Therefore, TRO is a "surrogate" measurement that provides a bulk 

concentration of various oxidant species present in complex water samples, but does not 

indicate the concentration of each chemical species individually. 

Occasionally, terms other than TRO are used for the test results from the standard DPD test. 

These include Free Available Chlorine (FAC) and Free Available Bromine (FAB), depending 

on the oxidant species present. However, for this discussion, TRO is considered to mean 

the total of FAC and FAB (TRO = FAC + FAB), and the sum of the chlorine and bromine 

species measured by the DPD test. Of importance, is that the TRO methods frequently state 

that the measurement is calculated as mg Cl2/L, or "TRO as Cl2". 

A TRO measurement will detect the various chlorine and bromine oxidant species such as 

chlorine (Cl2), hypochlorous acid (HOCl), hypochlorite ion (OCl-

), bromine (Br2), 

hypobromous acid (HOBr) and hypobromite ion (OBr-

). However, the standard DPD test, at 

the neutral pH of fresh water and seawater, will not measure chlorine dioxide (ClO2) or the 

various decomposition products discussed in section 2.1.1 (chlorite ion, chlorate ion and 
MEPC 61/2/8 

Annex, page 15 

I:\MEPC\61\2-8.DOC 

bromate ion) (Bubnis, 2010b). Therefore, although TRO implies that all residual oxidants are 

being measured, the standard DPD test has significant limitations and cannot be applied to 

all oxidative chemistries equally. 

This can be clearly seen in Table 1 above (Table T2.8 in MEPC 59/2/9). In the samples 

evaluated the standard DPD test showed a non-detect reading (FAC = <0.05 mg/L) while 

through other specific test methods (discussed in section 2.2.2 below) measurable quantities 

of chlorite (ClO2

-

 = 0.91 mg/L) and chlorate (ClO3

-

= 0.49 mg/L) were present. This finding is 

consistent for Ecochlor's® shipboard and all land-based testing (MEPC 59/2/9, Table T2.8a) 

where a TRO measurement (reported as FAC) was non-detect (less than detection limit), yet 

measurable quantities of chlorite ion and chlorate ion were present. 

2.2.2 Methods for measuring chlorine dioxide, chlorite ion, chlorate ion and bromate ion 

From section 2.2.1, it was found that the DPD test has limitations. The DPD test can be 

correctly used to quantify the primary active ingredients in chlorination/bromination 

chemistries but it clearly does not measure all possible oxidants present in a water sample. 

For chlorine and bromine chemistry, the standard DPD test does not measure the Relevant 

Chemicals chlorate ion and bromate ion. For chlorine dioxide chemistry, the standard DPD 

test does not accurately measure the active ingredient (chlorine dioxide) or the two Relevant 

Chemicals (chlorite ion and chlorate ion) (Bubnis, 2010b). Therefore, other selective and 

accurate test methodologies must be employed to measure these substances. 

The preferred field test to measure chlorine dioxide is the Lissamine Green B (LGB) method 

(US EPA 327). This test is specific to chlorine dioxide and eliminates the potential for 

interferences and false positives that are possible when attempting to utilize the DPD method 

to measure TRO in seawater treated with chlorine dioxide. As well, the concentration of 

chlorine dioxide using the LGB method can be easily measured in the field through a 

hand-held digital instrument. 

There is no accurate and accepted field test for chlorite ion, chlorate ion, and/or bromate ion. 

As such, ion chromatography is the preferred method (US EPA 300.1 for chlorite and 

chlorate ions; US EPA 300.1/317 for bromate ion) (Bubnis, 2010b). These are laboratory run 

tests where proper sample preservation, storage and transportation is required for 

meaningful and defendable results. The methods are selective for these chemical species 

and are accurate. 

In contrast to chlorine/bromine chemistry where the surrogate method of TRO as Cl2 is useful 

to quantify a majority of the oxidant species present, there are specific and accurate methods 

for measuring chlorine dioxide, chlorite ion, chlorate ion, and bromate ion (Bubnis, 2010b). 

As such, there is no scientific basis for applying a less specific surrogate method such as 

TRO. Additionally, because no chlorine is produced in the chlorine dioxide generation 

method used with the Ecochlor® system, reporting the oxidant levels as "TRO as Cl2" is not 

accurate. There is no chlorine present. 

2.3 Oxidant demand 

As presented in prior dossiers (MEPC 58/2/2 and MEPC 59/2/9), when used to treat ballast 

water, chlorine dioxide will rapidly react (oxidize/disinfect) with susceptible organisms and 

certain chemical components over time. This continuing consumption of chlorine dioxide is 

described as the chlorine dioxide demand. In practice, when chlorine dioxide is added to 

ballast water, there is a rapid decrease in the chlorine dioxide concentration followed by 

a continuing reaction of the remaining chlorine dioxide until the demand of the water is met. 

After meeting the demand, the chlorine dioxide will maintain a residual concentration and 
MEPC 61/2/8 

Annex, page 16 

I:\MEPC\61\2-8.doc 

continue to react with components in the ballast water. This results in a slower decrease in 

concentration over time until the concentration of chlorine dioxide falls to a level that is 

undetectable by available analytical methods. Much like chlorine dioxide, the chlorite ion 

formed as chlorine dioxide reacts will also decrease due to oxidant demand. Detailed graphs 

and data for chlorine dioxide (F2.1 and T2.2) and chlorite demand (F2.4 and T2.5) under 

varying conditions were presented in MEPC 59/2/9. Examples of these are also presented 

below for ease of reference (chlorine dioxide – Table 4, Figure 4; chlorite – Table 5, Figure 

5). 

Table 4: Ecochlor® chlorine dioxide demand study, 4oC 

Ecochlor® Ballast Water Chlorine Dioxide Decay Study 

 

Source Water New Jersey Ballast Water 

ClO2 Dose 5.06 mg/L 

Water Temp 4oC 

 

Time after 

ClO2

treatment 

(minutes) 

Chlorine 

Dioxide 

ClO2 (mg/L) 

Chlorite Ion 

ClO2

-

 (mg/L) 

Chlorate Ion 

ClO3

-

 (mg/L) 

0 5.06 ND ND 

5 3.50 0.742 0.001 

30 2.80 0.855 0.055 

60 1.90 1.285 0.110 

180 1.40 1.727 0.169 

300 1.10 -- -- 

480 0.21 -- -- 

660 0.00 1.796 0.282 

0.00

1.00

2.00

3.00

4.00

5.00

6.00

0 200 400 600 800

Concentration (mg/L)

Time (min)

NJ Ballast Water Chlorine Dioxide Demand

5.06 mg/L, 4oC

Chlorine Dioxide

Chlorite Ion

Chlorate Ion

 Source: Nova Chem Laboratories, USA 

Figure 4: Example of chlorine dioxide demand curve, 4oC 
MEPC 61/2/8 

Annex, page 17 

I:\MEPC\61\2-8.DOC 

Table 5: Ecochlor® Chlorite ion demand study, 20oC 

Ecochlor® Ballast Water Chlorite Ion Demand 

Study 

 

Source Water New Jersey Ballast Water 

Chlorite Dose 1.94 mg/L 

Water Temp 20oC 

 

Time after ClO2

-

treatment (hour) 

Chlorite Ion 

ClO2

-

 (mg/L) 

0 1.94 

1 0.88 

18 0.30 

42 0.36 

69 0.19 

Ballast Water Chlorite Ion Demand

1.94 mg/L, 20 C

0.00

0.50

1.00

1.50

2.00

2.50

0 10 20 30 40 50 60 70 80

Time (Hr)

Concentration (mg/L)

Figure 5: Example of chlorite ion demand curve, 20oC 

The concept of oxidant demand has significance in the discussion of the data Ecochlor® has 

gathered during shipboard and land-based testing. 

2.3.1 Comparison of oxidant demand for shipboard and land-based testing 

In the prior Final Approval dossier (MEPC 59/2/9), Ecochlor® reported that the concentration 

of chlorine dioxide and its degradation products measured during land-based testing were 

higher than reported in the Basic Approval dossier (MEPC 58/2/2). This observation can be 

explained with the concept of oxidant demand. To ensure proper inactivation of potential 

aquatic invasive species, chlorine dioxide is dosed at a concentration high enough to 

maintain a residual that will act on the biofilm and sediment that will be present in actual 

ballast tanks. These contribute significantly to the demand for chlorine dioxide within the 

ballast tank(s). In direct contrast to an actual ballast tank, the controlled environment of 

land-based testing consisted of very clean tanks. As standard protocol, the land-based tanks 

were washed with high-pressure hoses before each test cycle, allowing no biofilm or 

sediment to accumulate in the test tanks. Without these biofilms and/or sediments that are 

normally present in ballast tanks, the typical timeline for chlorine dioxide and chlorite ion 

decay were not observed. 
MEPC 61/2/8 

Annex, page 18 

I:\MEPC\61\2-8.doc 

Land-based testing conditions were also static and no mixing of the treated water occurred 

as it would on board ship. This was a contributing factor in the observed differences in 

chlorine dioxide and chlorite ion concentrations noted during land-based testing compared to 

an onboard treatment scenario. In the static water of land-based testing, once the oxidant 

demand of the water was met, chlorine dioxide and chlorite ion concentrations became 

relatively stable and decay required more time. This is directly related to the differences in 

shipboard and land-based testing conditions, and the differing oxidant demand in each case. 

This is reflected in Table T2.8a in document MEPC 59/2/9, which has been modified to 

highlight only chlorine dioxide and chlorite in treated water samples at Days 0, 1 and 5 for 

two test cycles (Table 6). 

Table 6: Summary of chlorine dioxide and chlorite concentrations, 

land-based testing 

Treated Ballast 

Water 

5 mg/L ClO2

Days After 

Treatment 

 

Sample ID 

 

 

ClO2

a

(mg/L)

 

Chloriteb

(mg/L)

Seawater 

(average salinity 

31.9 ± 1.3 PSUc

) 

0 5HS 12 June 08 - TX >2.5 3.83 

1 5HS 13 June 08 - TX 0.85 3.11 

5 5HS 17 June 08 - TX ND 2.26 

Brackish Water 

(average salinity 

23.1 ± 0.65 PSUc

) 

0 3LS 26 June 08 - TX >2.5 3.18 

1 3LS 27 June 08 - TX 0.67 3.12 

5 3LS 1 July 08 - TX ND 2.8 

 a Chlorine dioxide residual measured using the LGB method (Palintest ChlorDiox Duo instrument) b Analysis performed by NovaChem Labs, USA

The land-based testing data above indicate that chlorine dioxide and chlorite decay over 

time, but not as rapidly as has been observed on board ship. The difference in oxidant 

demand is evident when chlorine dioxide and chlorite concentrations from land-based testing 

and shipboard ballast water samples are compared. Chlorite levels from shipboard data are 

consistently lower than chlorite concentrations measured in land-based testing performed 

at NIOZ. Residual chlorine dioxide follows the same trend with higher residual 

concentrations measured in land-based testing water samples. Table 7 below provides data 

from two separate shipboard studies. 

Table 7: Summary of chlorine dioxide and chlorite concentrations, 

shipboard testing 

Test 

Substance 

Days After 

Treatment 

 

Sample ID 

 

ClO2

a

(mg/L)

Chloriteb

(mg/L)

Shipboard 

Studies 

Treated 

Ballast Water 

5 mg/L ClO2

0 Forepeak tank 0.26 NM 

3 Forepeak tank ND 0.91 

5 Forepeak tank ND 0.24 

1 AC- Tank 2 ND 0.34 

2 AC- Tank 2 ND 1.12 

3 AC- Tank 2 ND 0.64 

4 AC- Tank 2 ND 0.53 

5 AC- Tank 2 ND 0.41 a Chlorine dioxide residual measured using the LGB method (Palintest ChlorDiox Duo instrument) b Analysis performed by NovaChem Labs, USA 
MEPC 61/2/8 

Annex, page 19 

I:\MEPC\61\2-8.DOC 

When comparing the data, the Day 0 samples from NIOZ indicate >2.5 mg/L ClO2

(Table 6) while on board ship only 0.26 mg/L ClO2 was measured at Day 0 (Table 7). 

Similarly, 3.11 mg/L ClO2

-

 was measured in the land-based sample on Day 1, while 0.34 

mg/L ClO2

-

 was reported for the shipboard study. During another shipboard study the 

following ClO2 decay was observed and the data is presented in Table 8 and Figure 6 below. 

Table 8: Chlorine dioxide decay study, shipboard testing 

Ecochlor® Ballast Water Chlorine Dioxide Decay 

 

Source Water New Jersey Ballast Water 

ClO2 Dose 5 mg/L 

Water Temp 24oC 

 

Time after ClO2

treatment (mins) 

Chlorine Dioxide Residual 

ClO2 (mg/L) 

0 1.77 

45 1.67 

91 1.75 

171 0.92 

245 0.67 

576 0.19 

650 ND 

Figure 6: Chlorine dioxide decay study, shipboard testing 

The residual chlorine dioxide concentrations, as well as the concentrations of the Relevant 

Chemical chlorite ion, that were reported from land-based testing are the highest values ever 

documented by Ecochlor®. The concentrations of these substances observed during 

shipboard studies are representative of actual ballast tank conditions that are encountered 

during practical use of the Ecochlor® BWMS. 
MEPC 61/2/8 

Annex, page 20 

I:\MEPC\61\2-8.doc 

3 HYDRODYNAMIC MODELLING AND ASSESSMENT OF ENVIRONMENTAL 

RISK 

As discussed in document MEPC 59/2/9 and in section 2.3.1 above, the concentrations of 

substances observed during land-based testing were higher than those that had been 

recorded during studies of the Ecochlor® system on board ship. However, as required by the 

Methodology for information gathering and the conduct work of the GESAMP-BWWG, the 

risk assessment undertaken for the prior Final Approval dossier was based on data from 

ballast water discharge samples drawn from the land-based test set-up. The discharge 

concentrations were carried forward in hydrodynamic modelling to derive Predicted 

Environmental Concentration (PEC) values. These PEC values were then used to derive 

a ratio using the Predicted No Effect Concentration (PNEC) for each substance. 

In section 3.1 below, Ecochlor® presents additional MAMPEC modelling results based on the 

parameters provided by the GESAMP-BWWG. Additional discharge concentrations and 

resulting PEC values for chlorine dioxide are presented to support a reduced chlorine dioxide 

MADC. 

3.1 Re-calculation of PEC values using the MAMPEC model 

In section 6.3.12 of document MEPC 60/2/11, annex 5, Ecochlor® notes that the review of the 

Final Approval dossier included PEC value calculations for chlorite by the GESAMP-BWWG. 

The Group's result was greatly different (nearly 1000 times larger) than the chlorite PEC 

calculated by Deltares, who performed the modelling and PEC derivation, and which was 

subsequently used in Ecochlor's® PEC/PNEC ratios. The modelling input parameters are 

absolutely critical to the outcome of the PEC and all modelling scenarios cannot be 

considered as equivalent. More specifically, the three input parameters that are the primary 

drivers of the PEC value are 1) substance "load", 2) amount of "flushing" in the harbour, 

and 3) the behaviour of the substance(s) being modelled. 

The GESAMP-BWWG review report did not include details on the input parameters used in 

recalculating the chlorite PEC. In an effort to understand the discrepancies in PEC value 

results, Ecochlor® commissioned Deltares to perform additional hydrodynamic modelling. 

To enable modelling in the same manner as done by the GESAMP-BWWG, the German 

Administration obtained the input parameters used for the MAMPEC model directly from the 

GESAMP-BWWG. The following harbour definition (Figure 7) and emission scenario 

(Figure 8) information was provided to Ecochlor® as the scenario used during the evaluation 

of the Ecochlor® BWMS. 

(Figure 7 provided in the confidential dossier.) 

Figure 7: Harbour definition information provided by the GESAMP-BWWG 

(Figure 8 provided in the confidential dossier.) 

Figure 8: Emission parameter information provided by the GESAMP-BWWG 
MEPC 61/2/8 

Annex, page 21 

I:\MEPC\61\2-8.DOC 

The version of MAMPEC used by the GESAMP-BWWG was not specified. As such, 

Ecochlor® was asked by the German Administration to proceed with re-modelling using the 

best assumptions. Based on expert guidance from Deltares, the last publicly released 

version of MAMPEC (version 2.5.04) was used. 

The "compound definition" input parameters used in the MAMPEC model by the 

GESAMP-BWWG was not specified. Therefore, the compound definition parameters 

(e.g., decay rate) that Deltares used in the original MAMPEC modelling for Ecochlor® were 

utilized. The compound definition screen for chlorite is provided as an example below 

(Figure 9). The compound definition screens for all new modelling scenarios are included 

behind the Deltares reports in appendix 1. 

(Figure 9 provided in the confidential dossier.) 

Figure 9: Example of compound definition parameters 

Although the GESAMP-BWWG review report focused on the PEC value for chlorite, 

Ecochlor® re-modelled all four substances associated with the Ecochlor® BWMS. Detailed 

information is provided below. 

3.2 Details of the modelling parameters for PEC re-calculation by Ecochlor®

To determine the substance emission (i.e. "loading") the same discharge concentrations as 

presented in the prior Final Approval dossier were used. That is, the highest 24-hour values 

of ClO2, ClO2

-

, ClO3

-

 and DBAA measured in treated ballast water discharge as shown in 

document MEPC 59/2/9, Tables T2.8a and T2.8c were re-modelled. 

In addition, Ecochlor® re-calculated PEC values according to the GESAMP-BWWG scenario 

for three additional chlorine dioxide concentrations. The concentrations selected 

are 0.4 mg/L ClO2, 0.2 mg/L ClO2, and 0.1 mg/L ClO2. As part of the approval process in the 

United States, the Washington State Department of Ecology (DOE) has conducted an 

environmental risk assessment for the discharge of chlorine dioxide associated with the 

Ecochlor® BWMS. Ecotoxicology studies were performed according to the 

DOE requirements and based on their findings, the maximum allowable discharge 

concentration (MADC) for chlorine dioxide is 0.4 mg/L. As such, Ecochlor chose to model the 

DOEs allowed MADC using MAMPEC to derive a PEC value. Also, as Ecochlor® is 

proposing that the MADC of 0.2 mg/L ClO2 will be verified as a mitigation measure (q.v. 3.4) 

to ensure the environmental acceptability of treated water discharge, this concentration was 

modelled as well. An additional ClO2 concentration of 0.1 mg/L was also modelled. 
MEPC 61/2/8 

Annex, page 22 

I:\MEPC\61\2-8.doc 

Based on the calculation shown in the GESAMP-BWWG provided emission screen in 

Figure 8 above, the substance emissions were calculated as follows: 

Chlorine dioxide: 

Emission = [chlorine dioxide, g/m3] in BW * BW volume, m3/d 

Emission 1 = 0.85 g/m3

 chlorine dioxide * 200000 m3/d BW = 170,000 g/d 

Emission 2 = 0.4 g/m3

 chlorine dioxide * 200000 m3/d BW = 80,000 g/d 

Emission 3 = 0.2 g/m3

 chlorine dioxide * 200000 m3/d BW = 40,000 g/d 

Emission 4 = 0.1 g/m3

 chlorine dioxide * 200000 m3/d BW = 20,000 g/d 

Chlorite: 

Emission = [chlorite, g/m3] in BW * BW volume, m3/d 

Emission = 3.6 g/m3

 chlorite * 200000 m3/d BW = 720,000 g/d 

Chlorate: 

Emission = [chlorate, g/m3] in BW * BW volume, m3/d 

Emission = 1.47 g/m3 chlorate * 200000 m3/d BW = 294,000 g/d 

Dibromoacetic Acid (DBAA): 

Emission = [DBAA, g/m3] in BW * BW volume, m3/d 

Emission = 0.036 g/m3

 DBAA * 200000 m3/d BW = 7,200 g/d 

Table 9 summarizes the emissions for each substance. 

Table 9: Summary of treated ballast water substance emissions 

Substance 

Discharge 

Concentration

[g/m3

] 

BW 

Discharge 

Volume 

(m3

/d) 

Emission 

[g/d] 

Chlorine dioxide (highest 24-hr 

concentration from land-based testing) 0.85 200000 170,000 

Chlorine dioxide (WA State DOE Approved 

MADC) 0.4 200000 80,000 

Chlorine dioxide (Proposed Procedure (G9) 

Approval MADC) 0.2 200000 40,000 

Chlorine dioxide 0.1 200000 20,000 

Chlorite 3.6 200000 720,000 

Chlorate 1.47 200000 294,000 

Dibromoacetic acid (DBAA) 0.036 200000 7,200 

3.3 PEC re-calculation results and PEC/PNEC ratios 

Using the MAMPEC scenario parameters provided by the GESAMP-BWWG, the MAMPEC 

software version suggested by Deltares, and Ecochlor's® chemical input values 

(as presented in the prior Final Approval dossier) new PEC values were derived. 

The compound information, including the chemical decay rates (based on laboratory 

studies), used for PEC re-calculation are the same as used in Ecochlor's® previous PEC 

calculations (MEPC 59/2/9, Tables T5.3 and T5.5 and section 5.3.3.2). Based on the new 

PEC values, new PEC/PNEC ratios were derived. The tables below summarize the results. 
MEPC 61/2/8 

Annex, page 23 

I:\MEPC\61\2-8.DOC 

Table 10: Re-calculated Predicted Environmental Concentrations – MAMPEC 

Substance 

Discharge 

Concentration 

(g/m3) 

Mass 

Discharge 

Rate In Model 

(g/s) 

1st Order 

Decay Rate 

(1/d) 

Half-life in 

Water (days) 

PEC 

(μg/L) 

Chlorine Dioxide 0.85 1.967 145.4 4.75E-03 0.0218 

Chlorine Dioxide 0.4 0.926 145.4 4.75E-03 0.0103 

Chlorine Dioxide 0.2 0.463 145.4 4.75E-03 0.00513 

Chlorine Dioxide 0.1 0.231 145.4 4.75E-03 0.00257 

Chlorite 3.6 8.33 463.7 1.49E-03 0.0290 

Chlorate 1.47 3.402 43.2 1.60E-02 0.127 

Dibromoacetic acid 0.036 0.0833 0 ∞ 1.03 

Table 11: Re-calculated PEC/PNEC ratios 

Substance 

Lowest 

Observed Effect 

Concentration 

(mg/L) 

Assessment 

Factor 

PNEC 

(μg/L) 

PEC / PNEC 

Ratio (μg/L) 

Chlorine Dioxide 

(0.85 mg/L discharge 

concentration) 

0.02 1000 0.02 0.0218/0.02 = 1.09 

Chlorine Dioxide 

(0.4 mg/L WA State DOE 

MADC) 

0.02 1000 0.02 0.0103/0.02 = 0.515 

Chlorine Dioxide 

(0.2 mg/L proposed MADC) 0.02 1000 0.02 0.00513/0.02 = 0.267 

Chlorine Dioxide 

(0.1 mg/L) 0.02 1000 0.02 0.00257/0.02 = 0.129 

Chlorite 0.58 1000 0.58 0.0290/0.58 = 0.05 

Chlorate 0.06 100 0.60 0.127/0.60 = 0.212 

Dibromoacetic acid 69.0 1000 69.0 1.03/69.0 = 0.015 

The PEC values and PEC/PNEC ratios obtained with Ecochlor's® re-modelling effort (using 

the GESAMP-BWWG scenario) indicate that the new values are lower than presented in the 

prior Final Approval dossier. With respect to chlorite, the PEC result and PEC/PNEC ratio 

differ significantly from those presented in the GESAMP-BWWG report (MEPC 60/2/11, 

section 6.3.12). 

It should also be noted that environmental risk for chlorine dioxide, chlorite and chlorate are 

evaluated individually in EU regulatory frameworks (e.g., REACH and Biocidal Products 

Directive) (Thomas, 2010). That is, PNEC values are based on toxicity endpoints for each 

individual substance and PEC values are based on measured and modelled concentrations 

of these compounds individually (Thomas, 2010). This provides additional validity to 

Ecochlor's risk assessment for these substances, which is based on the existing risk 

assessment methodology for the individual substances, as well as whole effluent toxicity 

testing. 

3.4 Maximum allowable discharge concentrations 

Based on the additional modelling scenarios, the maximum ClO2 residual of 0.85 mg/L from 

the land-based testing resulted in a PEC/PNEC ration of 1.09 using the GESAMP-BWWG 

harbour scenario. Based on the shipboard data presented above, Ecochlor® would like to 
MEPC 61/2/8 

Annex, page 24 

I:\MEPC\61\2-8.doc 

reiterate that a chlorine dioxide residual of 0.85 mg/L 24 hours post-treatment cannot be 

reasonably anticipated. In any case, Ecochlor® accepts that a lower discharge concentration 

for ClO2 is desirable. As such, Ecochlor® performed modelling for the proposed MADC 

of 0.2 mg/L. The PEC result allows for calculation of a PEC/PNEC ratio of 0.267, which is 

well below 1. As further mitigation, Ecochlor® has discussed with the German Administration 

that part of the Type Approval process will include verifying that the ClO2 MADC of 0.2 mg/L 

(using the LGB method) is not exceeded prior to discharge of treated ballast water. 

To ensure environmental acceptability of treated ballast water discharge and verify that the 

MADC of 0.2 mg/L ClO2 is not exceeded a manual measurement of the chlorine dioxide 

residual will be taken prior to the initial discharge of a de-ballasting operation. As presented 

in the prior Final Approval dossier (section 2.5), chlorine dioxide residual in treated ballast 

water is measured using the Palintest Chlordiox-Duo instrument which employs the 

LGB method. The Chlordiox-Duo digital meter and the LGB method allows for easy 

calibration of the meter, simple addition of colorimetric reagents and direct measurement of 

the chlorine dioxide concentration. To measure low concentrations, as will be applicable in 

treated ballast water, the LGB Low Range (LR) test method is used. This method has a 

range of 0.1 mg/L to 2.5 mg/L with a detection limit of 0.1 mg/L. The LGB test for chlorine 

dioxide will verify that the MADC of 0.2 mg/L ClO2 is not exceeded. This information would 

be recorded on board the vessel and could be used for any port State control monitoring that 

might be required. Information regarding the Palintest and Ecochlor's® standard operating 

procedure (SOP) for measuring chlorine dioxide is included in appendix 4. 

With respect to chlorite and chlorate, the prior application for Final Approval indicated that 

the PEC/PNEC ratios for both substances were <1, even when using the highest discharge 

concentrations and worst-case modelling scenarios and PEC results. This result 

(PEC/PNEC ratio <1) was supported again when Ecochlor® utilized the 

draft GESAMP-BWWG harbour scenario to determine the new PEC values. Based on 

section 7.3.2 of the Methodology, PEC/PNEC ratios <1 indicate that no further assessment of 

effects to the aquatic environment would be required. 

Even though the PEC/PNEC ratio assessment clearly demonstrates that there is no 

unacceptable risk from the discharge of chlorite ion or chlorate ion, Ecochlor® has agreed 

with the German Administration (BSH) to monitor chlorite ion and chlorate ion levels from 

shipboard treated ballast water (through ion chromatography analysis). This data will allow 

BSH to verify discharge concentrations as part of the Type Approval oversight of the 

Ecochlor® BWMS. 

4 DISCHARGE ECOTOXICITY 

As presented in the prior Final Approval dossier, whole effluent toxicity (WET) testing on 

discharge samples drawn from the land-based unit resulted in Pacific oyster 

(Crassostrea gigas) being the most sensitive species of six taxonomic groups tested. 

The average EC50 for all C. gigas tests was 51% (average NOEC = 31%). Thus a two-fold 

dilution is necessary to reach a concentration less than the EC50 value and a three-fold 

dilution is necessary to reach a concentration less than the NOEC value for C. gigas. 
MEPC 61/2/8 

Annex, page 25 

I:\MEPC\61\2-8.DOC 

Based on the guidance in section 4.2.4.2 of the EU Technical Guidance Document (TGD) on 

Risk Assessment (2003), a default dilution factor of 100 for discharges to coastal zones can 

be assumed and is representative of a realistic worst-case. This is based on the differing 

dilutions in various environments that can range from a factor of 10 (minimal tidal influence) 

to a factor of 500 (larger current/tidal influence) that have been estimated. Because releases 

of ballast water can occur in a wide range of situations, the generic local exposure 

assessment approach discussed in the TGD is appropriate for this assessment. 

The 2- or 3-fold dilution that would be required to reach the EC50 or NOEC value derived from 

WET testing of Ecochlor® ballast water discharges is far below the default worst case dilution 

factor of 100 utilized in the TGD guidance. Therefore, it can be reasonably assumed that the 

low level dilution of 2 or 3-fold will be achieved immediately upon discharge of treated ballast 

water. Further, this assessment indicates no unacceptable aquatic risk. 

5 SHIP SAFETY AND MAINTENANCE 

5.1 Corrosion and ballast tank coatings 

In the application Ecochlor® submitted in December of 2008, Ecochlor® had already identified 

a suitable testing laboratory for the corrosion study and was awaiting representative samples 

of coated panels from leading ballast tank coating suppliers. This study was initiated based 

on the recommendations from GESAMP-BWWG in the review of the application for 

Basic Approval (MEPC 58/2/8, annex 5, sections 0.8 and 2.3). It was anticipated 

in December 2008 that the study would last three (3) months as requested by the Group. 

However, since the application for Final Approval was not reviewed in the first 

two GESAMP-BWWG meetings of 2009, Ecochlor® continued the study for 120 days which 

would allow completion of the study and report before the September 2009 review. 

Section 6.1.2.5 of the prior Final Approval dossier (MEPC 59/2/9) stated that the study had 

been initiated. 

The study included bare metal samples and a total of four (4) different ballast tank coatings 

from two global paint suppliers (International Paint, PPG). The coupons and panels were 

partially submerged to evaluate the air/water interface in treated and untreated simulated 

seawater for periods of 2 months, 4 months and 6 months based on standard laboratory 

practices. Water samples were replenished every two weeks to simulate a frequent vessel 

ballasting schedule, which provided conservative results. The coupons and panels were 

analysed by independent laboratories including a metal analysis group, each of the two paint 

suppliers and a team of corrosion experts. 

Although there are deviations from the GESAMP-BWWG recommendations in document 

MEPC 59/2/16, section 5.1, the study undertaken and the data gathered by Ecochlor® is 

comprehensive and demonstrates no corrosion impacts can be reasonably expected. 

The primary deviations in the Ecochlor® study are related to 7 of the 12 suggested protocols. 

Seven of the test protocols are only performed when a surface defect is observed in the 

coating. As no surface defects were noted, these test protocols were not warranted as 

summarized in Table 12 below. 
MEPC 61/2/8 

Annex, page 26 

I:\MEPC\61\2-8.doc 

Table 12: Summary of corrosion test methods 

Analytical 

Test Method 

Recommended 

by GESAMP-BWWG Test Not Warranted 

ASTM G78 √

ASTM G61-86 √ 

ISO 2812-2 √ 

ASTM G31-72 √ 

ISO 11463 √ √

ASTM G46 √ √

ISO 4624 √ 

ISO 4628-2 √ √

ISO 4628-3 √ √

ISO 4628-4 √ √

ISO 4628-5 √ √

ISO 4628-8 √ √

Of the other five recommended tests, Ecochlor performed ISO 4624, an equivalent test to 

ASTM G31-72, and also ASTM G1. Ecochlor® respectfully requests that 

the GESAMP-BWWG appreciate that the corrosion study protocol and testing was initiated 

prior to the recommendations established at MEPC 59 (April 2009), which occurred four 

months after the prior application for Final Approval was submitted (December 2008). 

The study undertaken and the data gathered are comprehensive and appropriate to 

demonstrate no corrosion impacts to vessels. Because Ecochlor tested four separate ballast 

tank coatings, which is more than recommended in document MEPC 59/2/16, there is less 

uncertainty in the data and conclusions regarding corrosion risk to ballast tank coatings. 

The corrosion study report was not submitted to the GESAMP-BWWG prior to review of the 

dossier based on document MEPC 59/2/13, section 2.3.10. This section states "If an 

Administration provides additional information regarding a proposal for approval that has 

been already submitted, a new position at the end of the waiting list will be assigned and the 

respective proposal will be evaluated according to the new chronological order". As such, 

there was concern about submitting the corrosion report prior to the GESAMP-BWWG 

meeting and it was envisaged that the GESAMP-BWWG would note the mention of the study 

(MEPC 59/2/9, section 6.1.2.5) and request the data. However, no questions concerning 

corrosion were asked during the review and there was no opportunity to submit the corrosion 

report. 

Ecochlor's® corrosion study is summarized in two reports: Laboratory Immersion Corrosion 

Testing of Ballast Panels in Chlorine Dioxide Treated Artificial Seawater (NovaChem 

Laboratories, 2009) and Corrosion Evaluation of Test Panels Exposed to ClO2 Treated and 

Untreated Seawater (Corrosion Testing Laboratories, Inc. 2009). The reports are included in 

appendix 2. 

5.2 Fire risk mitigation 

The GESAMP-BWWG indicated that it was partially satisfied with the information provided for 

fire mitigation. Ecochlor® appreciates that the Group understands that ship-specific 

measures will be identified on a case-by-case basis. However, due to the variation in 
MEPC 61/2/8 

Annex, page 27 

I:\MEPC\61\2-8.DOC 

matters such as vessel type, location where the BWMS may be installed on a particular 

vessel, the existing fire system(s) on board, and the cargo carried by the vessel, defining 

specific fire mitigation arrangements to be put in place for a hypothetical vessel is not 

feasible. Further, Ecochlor® is clearly responsible for providing the necessary information to 

identify any potential chemicals hazards associated with the BWMS system. However, 

as a BWMS vendor, it is beyond Ecochlor's® scope to engineer or specify precise 

arrangements for fire mitigation on board a vessel. 

It is important to note that an installation on board will be reviewed and approved by the 

ships' classification society, which has the ultimate decision on what will be required for safe 

BWMS installation. If the classification society deems a measure necessary for safe 

installation, that is what must be implemented. If the vendor is unwilling to comply with the 

requirements of the classification society, then the system will not be approved for 

installation. 

As an example, a major classification society recently reviewed the Ecochlor® BWMS for 

installation on a specific vessel for construction in Japan. During that review, this 

classification society specified requirements in regard to fire mitigation. These include: 

.1 portable fire extinguisher is to be installed adjacent to the Ecochlor® BWMS 

house; and 

.2 cooling water spray to cover the outside of the Ecochlor® BWMS to be 

considered by means of an existing hydrant with canvas hose or additional 

water spray nozzle like one for paint stores. 

Requirements agreed to by shipyard and Ecochlor® include: 

.1 powder foam or C02 as portable extinguisher shall be installed in the 

Ecochlor® BWMS or around the entrance of the house; and 

.2 installation of a fixed spray nozzle to cover the entire Ecochlor® BWMS 

shall be provided with water quantity of 5 litres/m2

/minute. 

5.3 Chemical storage 

Sections 3.0.8, 6.1.3, 6.1.4, 6.1.5 and 6.2 of the prior Final Approval dossier (MEPC 59/2/9) 

presented discussion pertaining to safe chemical storage and handling, as well as the 

measures (such as PPE) that mitigate the risks. Further, preparing for BWMS installation on 

board a ship requires comprehensive reviews by Ecochlor's® marine engineers, the vessel 

engineers, as well as the ships' classification society. Additional mitigation measures that 

may be deemed necessary by these competent parties to ensure safe BWMS installation on 

a specific ship will be implemented as needed. 

As recognized by the Group, the provisions of the IMDG Code are not applicable to the 

storage of the chemicals associated with the Ecochlor® BWMS. However, the IMDG Code 

will be considered by Ecochlor®, in consultation with the ship owner/master and/or 

classification society, as appropriate, in the following respects: 

- chemical packing (e.g., labelling, materials of construction, and/or special 

provisions); 

- emergency schedules for fire and spillage; and 

- stowage and segregation. 
MEPC 61/2/8 

Annex, page 28 

I:\MEPC\61\2-8.doc 

Section 3.0.8.1 of the prior Final Approval dossier provided information about chemical 

storage tanks such as tank construction materials, capacity, containment, and prior approval 

by Lloyd's and ABS classification societies. The MSDS for each chemical stored on board 

(Purate® and sulfuric acid) provided in appendix B of the prior Final Approval dossier 

indicates the container labelling requirements, which are implemented by Ecochlor. 

Section 3.0.9 of the prior Final Approval dossier includes information about fire mitigation 

measures. These include the flammability of the chemicals, fire avoidance measures 

(storage away from incompatible materials, etc.), and fire fighting methods. With respect 

to a fire situation, section 3.0.9 provides information similar to the guidance in the IMDG 

Code Emergency Schedules for fire (EmS F-H (Purate®) and EmS F-A (sulfuric acid) such as 

using water sprays to keep containers cool and prevent spread of fire. 

Section 3.0.9.2 of the prior Final Approval dossier provides information on accidental release 

(i.e. chemical spillage) measures, which is similar to the guidance in the IMDG Code 

Emergency Schedules for spillage (EmS S-Q (Purate®) and EmS S-B (sulfuric acid). 

The measures outlined in section 3.0.9.2 include use of respiratory protection, proper PPE, 

ventilation, and use of inert, non-combustible sorbent materials. 

The IMDG Code will also be consulted to ensure that Purate® and sulfuric acid storage tanks 

will be placed on board with sufficient segregation from incompatible substances. Further, 

applicable safety measures will be included during the Type Approval process with the 

German Administration. 

The IMO's "Guidance to ensure safe handling and storage of chemicals and preparations 

used to treat ballast water and the development of safety procedures for risks to the ship 

crew resulting from the treatment process" (BWM.2/Circ.20, July 2009) will be taken into 

consideration. The recommendations in "Methodology for addressing risk, section 5" for the 

role of the BWMS supplier are specifically considered by Ecochlor®, in consultation with the 

ship owner/master as appropriate, for each individual vessel as follows: 

- clear operational instructions and training for the BWMS are provided to ships' 

crew; 

- MSDSs for Purate® and sulfuric acid are provided; 

- only Ecochlor® technicians or qualified representatives will conduct chemical 

re-supply operations (this will never be performed by ships' crew); 

- Ecochlor® performs all routine maintenance of the BWMS and associated 

components (including chemical storage tanks); 

- all risks associated with the chemicals are fully disclosed and discussed during 

the Ecochlor® training program for ships' crew; and 

- Ecochlor® is directly involved with ensuring that all necessary personal 

protective equipment and/or spill response kits that may be needed during an 

emergency situation related to the BWMS are on board the vessel. These aspects 

are also included in the Ecochlor®

 training program for ships' crew. 

The pre-installation review process, along with Ecochlor's® existing system mitigation 

measures, crew and technician training, and active maintenance of the BWMS, support the 

guidance in the IMDG Code and the recommendations in IMO's guidance document for safe 

storage and handling of chemicals used to treat ballast water. 
MEPC 61/2/8 

Annex, page 29 

I:\MEPC\61\2-8.DOC 

6 SUMMARY 

The final recommendations made by the GESAMP-BWWG in section 7.4 (MEPC 60/2/11, 

annex 5) are summarized below. The sections in this re-submission where the comments are 

addressed are also listed, as follows: 

7.4.2.1 The proposed MADCs for chlorine dioxide, chlorite ion and chlorate ion 

significantly exceed the discharge concentration of 0.1 mg/L to 0.2 mg/L TRO 

(as Cl2) previously recommended by the Group. 

In sections 2 and 3 Ecochlor® discusses the applicability of TRO 

measurements to chlorine dioxide chemistry and MADCs, respectively. 

Ecochlor® is agreeable to an MADC of 0.2 mg/L for chlorine dioxide. 

However, chlorine dioxide measurements should be done using the more 

appropriate method of LGB, rather than TRO as Cl2. 

7.4.2.2 To provide certainty for environmental safety, monitoring and control of the 

discharge should be incorporated to ensure that the finally agreed MADCs for all 

Active Substances and Relevant Chemicals are not exceeded. 

The LGB method can be used to monitor the concentration of chlorine 

dioxide in treated ballast water discharge to ensure the proposed MADC 

of 0.2 mg/L of ClO2 is not exceeded (refer to the discussion in section 3.4). 

7.4.2.3 The provisions of the IMDG Code should be followed as far as practical and 

the guidance provided in the IMO "Guidance to ensure safe handling and storage of 

chemicals and preparations used to treat ballast water and the development of 

safety procedures for risks to the ship and crew resulting from the treatment 

process" should also be fully taken into account. 

Ecochlor® agrees with the recommendations of the GESAMP-BWWG in this 

regard (refer to the response in section 5.3). 

7.4.2.4 Further attention to procedures and risk mitigation measures applying to 

BWMS maintenance and chemical replenishment operations on board the ship. 

Refer to the response in section 0.12. A sample health and safety plan has 

been provided in appendix 3 to assure the Group that these safety matters 

are fully considered by Ecochlor®. 

7.4.2.5 Additional corrosion testing should be conducted in accordance with the 

guidance provided in document MEPC 59/2/16, section 5.1. 

Ecochlor® conducted the corrosion testing that was recommended by the 

Group during Basic Approval prior to the above recommendation. 

The study followed similar analytical techniques and verifies no significant 

difference between control and chlorine dioxide treated bare metal and 

ballast tank coating coupons (refer to the discussion in section 5.1, and 

appendix 2 for corrosion study reports). 
MEPC 61/2/8 

Annex, page 30 

I:\MEPC\61\2-8.doc 

7.4.2.6 A more detailed description of arrangements to be put in place for fire 

mitigation measures. 

The appropriate fire mitigation measures will be implemented by Ecochlor®

(refer to the discussion in section 5.2). 

7 REFERENCES 

Bubnis, B. 2010a, Chemistry of Oxidants in Ballast Water Treatment. (Presented at the 

Workshop on Chlorine/Chloride Based Ballast Water Treatment, 4 March 2010, Hamburg, 

Germany). 

Bubnis, B. 2010b, Total Residual Oxidant Measurements. (Presented at the Workshop on 

Chlorine/Chloride Based Ballast Water Treatment, 4 March 2010, Hamburg, Germany). 

European Chemicals Bureau, 2003. Technical Guidance Document on Risk Assessment, 

TGD Part II. 

Thomas, P., 2010. Chlorine dioxide – Current regulatory processes and techniques in the 

EU. (Presented at the Workshop on Chlorine/Chloride Based Ballast Water Treatment, 4 

March 2010, Hamburg, Germany). 

LIST OF TABLES 

 Table 1: Chemical analysis of ballast water treated on board the 

 M.V. Moku Pahu, San Francisco Bay Area (Richmond, CA) 

 Table 2: Comparison of DBP concentrations for chlorine and 

 chlorine dioxide treatments 

 Table 3: Comparison of hypochlorite ion and chlorite ion 

 Table 4: Ecochlor® chlorine dioxide demand study, 4oC 

 Table 5: Ecochlor® chlorite ion demand study, 20oC 

 Table 6: Summary of chlorine dioxide and chlorite concentrations, 

land-based testing 

 Table 7: Summary of chlorine dioxide and chlorite concentrations, 

shipboard testing 

 Table 8: Chlorine dioxide decay study, shipboard testing 

 Table 9: Summary of treated ballast water substance emissions 

 Table 10: Re-calculated Predicted Environmental Concentrations – MAMPEC 

 Table 11: Re-calculated PEC/PNEC ratios 

 Table 12: Summary of corrosion test methods 

LIST OF FIGURES 

 Figure 1: Chlorine species at various pH values 

 Figure 2: Bromine species at various pH values 

 Figure 3: Chlorine dioxide species at various pH values 

 Figure 4: Example of chlorine dioxide demand curve, 4oC 

 Figure 5: Example of chlorite ion demand curve, 20oC 

 Figure 6: Chlorine dioxide decay study, shipboard testing 
MEPC 61/2/8 

Annex, page 31 

I:\MEPC\61\2-8.DOC 

 Figure 7: Harbour definition information provided by the GESAMP-BWWG 

 Figure 8: Emission parameter information provided by the GESAMP-BWWG 

 Figure 9: Example of compound definition parameters 

APPENDICES CONTAINED IN THE CONFIDENTIAL DOSSIER 

APPENDIX 1 MAMPEC modelling documentation 

APPENDIX 2 Corrosion study reports 

APPENDIX 3 Example of Health and Safety Plan (HASP) 

APPENDIX 4 Chlorine dioxide analytical information 

____________