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\2-9.doc 

INTERNATIONAL MARITIME ORGANIZATION

IMO

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE

59th session

Agenda item 2 

MEPC 59/2/9

 16 December 2008

 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 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 6 

Related documents: BWM/CONF/36; MEPC 57/21; MEPC 58/2/2, MEPC 58/2/8, 

MEPC 58/23; 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 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)”. 

The Procedure stipulates the required information (MEPC 57/21, annex 1, paragraph 4.2.1) and 

provisions for risk characterization and analysis (MEPC 57/21, annex 1, section 5) which, 

according to section 6 of the Procedure, should be evaluated by the Organization. 

3 In accordance with BWM.2/Circ.15, 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 59/2/9 - 2 - 

I:\MEPC\59\2-9.doc 

4 Basic Approval of the Active Substance used has been granted at MEPC 58 

(MEPC 58/23, paragraph 2.6.3). 

5 Taking into account the recommendations contained in annex 5 of the Report of the 

seventh meeting of the GESAMP-BWWG (MEPC 58/2/8), the receiving competent authority has 

verified the application dossier and believes it satisfies the requirements of Procedure (G9) 

adopted by resolution MEPC.169(57). 

Action requested of the Committee 

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

***
ANNEX

NON-CONFIDENTIAL INFORMATION ON THE Ecochlor® BALLAST WATER 

MANAGEMENT SYSTEM (GERMANY) 

PREAMBLE 

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

utilized with the Ecochlor® BWTS in accordance with the International Maritime Organization 

(IMO) Guideline 9 (Resolution MEPC.169(57)1

). This application was compiled using the 

guidance and format provided in the Methodology for Information Gathering and the Conduct of 

Work of GESAMP-BWWG (MEPC 58/2/7, Annex 42

)

Ecochlor submitted a dossier for G9 Basic Approval (MEPC 58/2/23

) and was recommended for 

approval by the GESAMP-BWWG (MEPC 58/2/8, Annex 54

). Ecochlor appreciates the 

comments received by the GESAMP-BWWG, which are summarized below. Per the request of 

the German Administration, this Final Approval dossier was developed by adding information to 

the existing Basic Approval dossier in response to the comments provided by the GESAMPBWWG in the report of its seventh meeting (MEPC 58/2/8, Annex 54

). In addition to the 

response to comments, applicable data from the land based testing according to Guideline 8, as 

well as other new information per the request of the German Administration has been added. 

Summary of the GESAMP-BWWG comments received (MEPC 58/2/8, Annex 5): 

1. Having considered the information provided, the Group agreed that: 

a. After the injection of chlorine dioxide to the ballast water, chlorite ion is produced 

as a reaction between seawater and chlorine dioxide and is considered by the 

Group to be an Active Substance in addition to the chlorine dioxide in need of full 

evaluation in the application for Final Approval. (See Sections 2.0.3.2.1, 2.2, 

2.2.5, 2.2.6, 2.2.7, 2.2.8)

b. Purate® containing 40% by weight sodium chlorate (NaClO3) and 8% by weight 

hydrogen peroxide (H2O2) is considered to be a Preparation. (No Response 

Required)

c. Sulfuric acid is considered to be a Relevant Chemical. (See Section 2.0.3.1.1)

2. The maximum allowable discharge level of the Active Substances (chlorine dioxide and 

chlorite) needs to be defined in the application for Final Approval. (See Section 5.3.3.5)

3. The Group considers the Level of Quantification (LOQ) for the THMs and HAAs used in 

the analyses of treated ballast water too high. It is common to determine these 

contaminants in surface waters at levels of 0.01 – 0.05 μg/L. It remains to be confirmed 

that the potential amount of by-products produced by the system is sufficiently low and 

meets the international standards on these substances. This uncertainty should be 

<0.1 μg/L. (See Section 2.0.3.3.1)

4. The Group noted that whole effluent ecotoxicity testing still has to be carried out for 

Final Approval. Samples should be taken during the land-based efficacy tests to meet G8 

standards (Ref. G9, 5.2.1) and should include samples taken at day 0, 2 and 5 after 

treatment to demonstrate conclusively eventual remaining ecotoxicity at discharge after 

varying holding time in ballast tanks. Chemical analyses with a sufficient low LOQ 

should be carried out on the samples in order to identify substances responsible for any 

toxic effects encountered. (See Sections 2.1, 2.1.1.6 and 2.1.2.4, Tables T2.9a and 

T2.10a; Section 5.2.2)

1

 International Maritime Organization, MEPC 57/21, Annex 1, Resolution MEPC.169(57), April 2008 

2

 International Maritime Organization, MEPC 58/2/7, GESAMP-BWWG 6/9, Annex 4, May 2008 

3

 International Maritime Organization, MEPC 58/2/2, March 2008 

4

 International Maritime Organization, MEPC 58/2/8, Annex 5, July 2008 

MEPC 59/2/9

I:\MEPC\59\2-9.doc
5. A full environmental risk assessment is required for the application for Final Approval. 

This should apply model calculations of environmental concentrations using defined 

emissions scenarios and include the use of the maximum allowable discharge level of 

both Active Substances and the relevant chemicals in the treated ballast water as well as 

the eventual toxicity of the whole effluent sample. (See Section 5.3.3)

6. For Final Approval the Group recommends additional long-term (at least three months 

duration) corrosion tests with the treated ballast water to be carried out and also to 

confirm that epoxy ballast tank coatings commonly in use will not be adversely affected 

by the use of this BWTS. (See Sections 6.1.2.4, 6.1.2.5)

7. The Group recommends the provision of appropriate chemical resistant save-all 

protection by way of the storage tanks and any other locations considered necessary to 

provide protection to the ship in the event of leakage or spillage of the chemicals used.

(See Section 3.0.7.1) 

Information in response to other comments in the GESAMP-BWWG Annex 5 report, but not 

listed in the Annex 5 summary has also been provided. For example, an updated process diagram 

(Figure F3.2a) has been included that shows the location of the optical sensor (Annex 5, 

comment 3.1.4). In Section 3.0.8.1.1, Ecochlor provides information in response to the 

GESAMP-BWWG comment regarding fire mitigation measures (Annex 5, comment 5.7). 

In addition to ecotoxicity data, Section 2.0.4 of this Final Approval dossier presents chemical 

analysis (Tables T2.8a, T2.8b, and T2.8c) and water quality data (Tables T2.8e and T2.8f) for 

treated ballast water discharge from the land based test set up. Based on this new data from the 

G8 land based testing, the German Administration requested that Ecochlor discuss and present 

information on dibromoacetic acid (DBAA) as a relevant chemical (see Section 2.0.3.3.2). Also 

based on chemical analysis of treated water discharge from land based testing, chlorate ion has 

been added to the list of relevant chemicals (Section 2.0.3.4). 

1.0 INTRODUCTION 

The Ecochlor® Ballast Water Treatment System (BWTS) applies established chlorine dioxide 

technology to oxidize and disinfect aquatic invasive species (AIS). Chlorine dioxide has a long 

history (50+ years) of being applied safely and economically for the control of micro-organisms 

in industrial and municipal waters. What is unique about chlorine dioxide is its ability to be 

effective against a wide range of troublesome organisms and in a broad range of water quality 

conditions. A second unique feature of the chlorine dioxide generated with the Ecochlor® BWTS 

compared to other oxidants (such as chlorine) is the minimization of unwanted by-products. 

1.0.1 Technology Overview 

The Ecochlor® BWTS uses a two-step treatment process. The first step is pre-treatment filtration 

with a 40 micron steel mesh filter. The second step is injection of chlorine-free chlorine dioxide 

into the incoming ballast water stream. 

A detailed discussion of the technology overview was provided in MEPC 58/2/2. 

2.0 IDENTIFICATION OF PREPARATIONS, ACTIVE SUBSTANCES AND 

RELEVANT CHEMICALS (G9: 4.1) 

Based on the definitions of Preparations, Active Substances and Relevant Chemicals in the G9 

procedure (Resolution MEPC.169(57)), Ecochlor classifies the substances involved in the 

Ecochlor® BWTS process as follows: 

MEPC 59/2/9

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Page 2

I:\MEPC\59\2-9.doc
Preparations: There are two preparation substances used with the Ecochlor® BWTS: 

1) Purate® (a proprietary formulation from Eka Chemicals containing 40% by 

weight sodium chlorate (NaCl03) and 8% by weight hydrogen peroxide 

(H2O2); and 

2) Sulfuric acid (78% by weight).

These two preparation substances are used to generate the active substance (chlorine-free 

chlorine dioxide) onboard and are not themselves active substances. 

Purate® is discussed in more detail in Section 2.0.1.1 and sulfuric acid is discussed further in 

Section 2.0.1.2 below. 

Active Substance: Chlorine-free chlorine dioxide is the active substance that is generated 

onboard and has “...specific action on or against harmful aquatic organisms and pathogens” 

(Guideline 9, 2.1.1). Additional information regarding chlorine dioxide is presented in Section 

2.0.2.1 below. 

Relevant Chemicals: Ecochlor discusses the following substances as Relevant Chemicals in 

Section 2.0.3:

1) Sulfate ion;

2) Chlorite ion (as sodium chlorite); 

3) Dibromoacetic acid; and 

4) Chlorate ion. 

Based on the G9 definition of relevant chemicals, these substances are “...transformation or 

reaction products that are produced during and after employment of the ballast water 

management system...” (Guideline 9, 2.1.4). 

Sulfate ions are discussed as a relevant chemical because a slight excess of sulfuric acid is used 

during the chlorine dioxide generation process. This is done to ensure high chlorine dioxide 

production efficiency. As such, additional sulfate ions (19 mg/L) may be added to ballast water 

treated with chlorine dioxide. Although the addition of sulfate ions to sea water as a result of 

treatment with the Ecochlor® BWTS is inconsequential, Ecochlor presents justifications to fully 

explain the chemistry associated with the treatment process. Section 2.0.3.1 of the application 

provides further information regarding sulfate ions that clearly demonstrates that sulfate ions are 

not added to treated ballast water at environmentally relevant concentrations. Additional 

clarification regarding sulfuric acid has been added in response to the GESAMP-BWWG 

comment. See Section 2.0.3.1.1. 

As the primary reaction by-product in ballast water after disinfection with chlorine-free chlorine 

dioxide, Ecochlor classifies chlorite ion (ClO2

-

), or sodium chlorite (NaClO2) as a relevant 

chemical. Detailed information on chlorite ion is presented in Section 2.0.3.2 below. Additional 

clarification regarding chlorite ion has been added in response to the GESAMP-BWWG 

comment. See Section 2.0.3.2.1. 

Chemical analysis and known chemical principles of disinfection using chlorine dioxide that is 

generated in the chlorine-free method used with the Ecochlor® BWTS indicate that no other 

reaction by-products are present at environmentally relevant concentrations. However, biocide 

treatment of water can raise questions regarding the formation of THM’s and/or HAA’s. 

Chemical data and justifications regarding these substances are located in Sections 1.0.1 (above) 

and 2.0.3.3. Additional clarification regarding THM and HAA analysis has been added in 

response to the GESAMP-BWWG comment. See Section 2.0.3.3.1. 

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Dibromoacetic acid and chlorate ions were measured at concentrations of 0.012 – 0.036 mg/L 

and 0.98 – 2.42 mg/L, respectively, in treated water discharge samples collected during land 

based testing. Because these values are higher than previously measured in treated ballast water 

samples, additional information is provided for these chemicals. See Section 2.0.3.3.2 for DBAA 

and Section 2.0.3.4 for chlorate. 

Table T2.1 below provides an overview of the chemicals involved in the Ecochlor® BWTS and 

descriptions of each chemical follow the table. 

Table T2.1 – Overview of Chemical Identification 

Ingredient 

(IUPAC Name) 

Identification 

Numbers 

Chemical 

Formula 

Structural 

Formula 

Molecular 

Weight

Percentage 

(by weight) 

Applied

Concentration

Preparation Chemicals 

1. Purate®

a. Hydrogen 

Peroxide

b. Sodium

Chlorate

a. CAS # 7722-84-1 

b. CAS # 7775-09-9 

 a. H2O2

b. NaClO3

a.

b. a. 34.01 

b. 106.44 

a. <8% 

b. 40% 

a. 0.05-2.9 M 

b. 0.5-3.2 M 

2. Sulfuric Acid CAS# 7664-93-9 H2SO4 98.08 78% 0.75-4M 

Active Substance in Ballast Water 

 Chlorine dioxide CAS# 10049-04-4 ClO2 67.45 -- < 5 mg/L 

in ballast water 

Relevant Chemicals in Ballast Water 

1. Sulfate ion 

 (as sodium 

 sulfate or 

 sulfuric acid) 

CAS # 7757-82-6 

or

CAS# 7664-93-9 

Na2SO4

or

H2SO4

or

142.04

or

98.08

By-product < 20 mg/L 

2. Sodium Chlorite 

 (present as 

 chlorite ion) 

CAS # 7758-19-2 NaClO2 90.45 By-product 

0.24 – 3.83 

mg/L

(as measured in 

treated water)

3. Dibromoacetic 

 acid (DBAA) CAS # 631-64-1 Br2CHCOOH 217.84 By-product 

.012 – .036 

mg/L

(as measured in 

treated water) 

4. Sodium Chlorate 

 (present as 

 chlorate ion) 

See above See above See above See above By-product 

0.49 – 2.42 

mg/L (as 

measured in 

treated water) 

2.0.1 Preparations

In order to generate chlorine dioxide onboard Ecochlor® is utilizing a two precursor chemical 

approach. The two preparation chemicals, Purate® and sulfuric acid, are mixed under controlled 

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Page 4
conditions to generate chlorine dioxide, which is then injected into the ballast water stream. The 

preparation chemicals are not added to the ballast water directly, and are not the active substance. 

2.0.1.1 Purate®

Detailed information regarding Purate® was provided in the Basic Approval dossier (MEPC 

58/2/2).

Hydrogen Peroxide:

Detailed information regarding hydrogen peroxide was provided in the Basic Approval dossier 

(MEPC 58/2/2). 

Sodium Chlorate: 

Detailed information regarding sodium chlorate was provided in the Basic Approval dossier 

(MEPC 58/2/2). 

Chlorate ion was measured at concentrations ranging from 0.98 – 2.42 mg/L, with a mean 

concentration of 1.39 mg/L, in samples of treated water discharge during land based testing. As 

such, chlorate ion is also discussed as a relevant chemical in Section 2.0.3.4 below. 

2.0.1.2 Sulfuric Acid 

Detailed information regarding sulfuric acid was provided in the Basic Approval dossier (MEPC 

58/2/2).

2.0.2 Active Substance 

2.0.2.1 Chlorine Dioxide 

Detailed information regarding chlorine dioxide was provided in the Basic Approval dossier 

(MEPC 58/2/2). Additional data generated since the submittal of the Basic Approval dossier is 

included below. 

To further define the rapid degradation of chlorine dioxide, additional demand studies where 

measurements were taken on the minutes time scale were performed in the laboratory using water 

collected at the NIOZ facility in the Netherlands. The data presented in Figure F2.3a and Table 

T2.4a below is consistent with previous studies performed to determine the demand/decay of 

chlorine dioxide. 

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Page 5
Figure F2.3a – Example of Chlorine Dioxide Demand Curve (NIOZ Water), 20°C 

Chlorine Dioxide Demand at Different Concentrations

Low Salinity Control Water, Texel, Netherlands (NIOZ) 

20C

0.00

0.50

1.00

1.50

2.00

2.50

3.00

0 10 20 30 40 50 60

Time (min)

Chlorine Dioxide Concentration (mg/L)

1 mg/L

2 mg/L

3 mg/L

Table T2.4a – Ecochlor Chlorine Dioxide Demand Study (NIOZ Water), 20oC

Ecochlor Ballast Water Chlorine Dioxide Decay Study 

 

Source Water Texel, The Netherlands (NIOZ) Low Salinity Water 

ClO2 Dose Nominal 1, 2, and 3 mg/L 

Water Temp 20oC 

 

Time after ClO2

treatment 

(minutes)

Remaining

ClO2

Concentration

(mg/L),

1 mg/L treatment 

Remaining

ClO2

Concentration

(mg/L),

2 mg/L treatment 

Remaining

ClO2

Concentration

(mg/L),

3 mg/L treatment 

0 1.03 2.06 2.97 

1 0.70 1.52 2.31 

2 0.64 1.45 2.19 

3 0.57 1.36 2.13 

4 0.54 1.34 2.09 

5 0.51 1.30 2.05 

6 0.48 1.27 2.00 

7 0.44 1.24 1.98 

8 0.43 1.22 1.93 

9 0.41 1.18 1.91 

10 0.40 1.17 1.88 

11 0.37 1.14 1.86 

12 0.36 1.13 1.83 

13 0.35 1.11 1.81 

14 0.34 1.09 1.79 

15 0.32 1.07 1.77 

20 0.26 1.00 1.65 

25 0.22 0.92 1.54 

30 0.18 0.86 1.42 

35 0.15 0.81 1.31 

40 0.12 0.76 1.19 

45 0.10 0.70 1.07 

50 0.08 0.65 0.93 

55 0.05 0.60 0.81 

60 0.04 0.56 0.68 

Note: Demand testing performed by NovaChem Laboratories 

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2.0.3 Relevant Chemicals 

The information provided in the Basic Approval dossier was obtained from laboratory and 

shipboard analysis of treated water. During land based testing at NIOZ additional chemical 

analysis was performed on water treated with the Ecochlor® BWTS. Chemical analysis was 

performed on eight (8) separate discharge sampling events; four during brackish water test cycles 

and four during sea water test cycles. Water samples were collected on days 0, 1, and 5 from 

both treatment and control ballast tanks for proper comparison. Tables T2.8a, T2.8b and T2.8c 

provide a summary of the chemical analysis results from discharge samples collected during land 

based testing.

Chlorate ion and dibromoacetic acid (DBAA) were measured at slightly higher concentrations 

during land based testing than had been previously measured in treated ballast water. As such, 

Section 2.0.3.3.2 provides additional information on DBAA and Section 2.0.3.4 provides 

additional information for chlorate ion. 

2.0.3.1 Sulfate Ion and Sulfuric Acid 

Detailed information regarding sulfuric acid was provided in the Basic Approval dossier (MEPC 

58/2/2). Also see Section 2.0.3.1.1 below for additional clarification. 

2.0.3.1.1 Additional Clarification on Sulfuric Acid 

In Ecochlor’s Basic Approval dossier sulfuric acid was classified as a preparation (Section 

2.0.1.2), and also discussed as a relevant chemical because of the small excess that is combined 

with Purate® to generate chlorine dioxide (Section 2.0.3.1 above). Comments from the 

GESAMP-BWWG suggest that sulfuric acid is considered a relevant chemical. Ecochlor would 

like to further emphasize that in water sulfuric acid will be completely dissociated into hydrogen 

ions (H+

) and sulfate ions (SO4

2-) as discussed above. Therefore, the slight excess of acid can 

only be present in treated ballast water as the ions, not as sulfuric acid. The interchangeable use 

of sulfuric acid and sulfate ions in the discussion of these constituents in treated ballast water 

unintentionally confused the evaluation of sulfate ion in treated ballast water.

Because sulfuric acid completely ionizes in water5

, the only potential impacts of the small 

amount of acid that may remain after the generation of chlorine dioxide are: 1) an addition of 

sulfate ions to treated ballast water, or 2) lowering the pH of treated ballast water. Section 

2.0.3.1 in the Basic Approval dossier (MEPC 58/2/2) provided sulfate ion concentration and pH 

data for treated ballast water, which demonstrated that neither are present in treated ballast water 

at levels that could present aquatic or human health concerns. Further, the GESAMP-BWWG 

agreed that sulfate ion is not considered a relevant chemical (MEPC 58/2/8, Annex 5, Section 

3.2.3). Therefore, no additional evaluation of sulfate ions is presented in this application for 

Final Approval. 

2.0.3.2 Chlorite Ion 

Detailed information regarding chlorite ion was provided in the Basic Approval dossier (MEPC 

58/2/2). Additional data generated since the submittal of the Basic Approval dossier is included 

below.

To further define the degradation of chlorite ion, additional demand studies where measurements 

where taken on the minutes time scale were performed in the laboratory using natural harbor 

water collected at the NIOZ facility in the Netherlands. The data presented in Figure F2.4a and 

Table T2.5a below is consistent with previous studies performed to determine the demand/decay 

of chlorite ion. 

5

 OECD SIDS, Sulfuric Acid, SIAM 11, January 2001, UNEP Publications 

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Figure F2.4a – Chlorite Ion Demand Curve 

Texel Harbor (NIOZ) Water, 20°C

Ecochlor Chlorite Ion Demand Study

Texel, 4HS-6 June 08-CX, 0.983 mg/L, ambient

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0 0.5 1 1.5 2 2.5 3 3.5

Time (Hr)

Concentration (mg/L)

 Note: Demand testing on raw water samples performed by NovaChem Laboratories 

Table T2.5a – Ecochlor Chlorite Ion Demand Study (NIOZ Water), 20oC

Ecochlor Ballast Water Chlorite Ion Demand Study 

Source Water Texel Harbor (NIOZ), The 

Netherlands

Chlorite Dose 0.983 mg/L 

Water Temp 20 oC (ambient) 

Time after ClO2

-

treatment (hour) 

Chlorite Ion 

ClO2

-

 (mg/L) 

0 0.983 

0.03 0.40 

0.75 0.40 

3.25 0.39 

 Note: Demand testing on raw water samples performed by NovaChem Laboratories 

2.0.3.2.1 Additional Clarification on Chlorite Ion

This section has been added in response to the GESAMP-BWWG comment indicating that 

chlorite ion is considered an active substance. In Ecochlor’s Basic Approval dossier chlorite ion 

was classified as a relevant chemical based on the definition provided in the G9 Methodology:

“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 and that may be of concern to the ship’s safety, aquatic 

environment or human health.”

This definition accurately describes chlorite ion, which is formed after employment of the 

Ecochlor® BWTS. Chlorite ion is not produced due to the reaction between seawater and 

chlorine dioxide. Rather, chlorite ion is the primary by-product when chlorine dioxide degrades, 

regardless of the matrix (fresh or sea water). Known chlorine dioxide disinfection chemistry 

clearly indicates that chlorite is the primary reaction by-product of chlorine dioxide oxidation

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6,7,8,9,10,11 rather than an active substance. 

There are methods of chlorine dioxide generation that utilize sodium chlorite as a preparation or 

active substance; however, this differs from the chlorate-based method used with the Ecochlor®

BWTS. 

Ecochlor agrees with the GESAMP-BWWG that the content of chlorite ion in treated ballast 

water must be considered in regards to potential aquatic toxicity. However, based on the G9 

definition and the authorities referenced above, evaluation of chlorite ion remains under the 

relevant chemicals section in this dossier. The Basic Approval dossier included information for 

chlorite ion in regards to chemical identification (Table T2.1), demand/dilution discussion 

(section 2.0.3.2), acute and chronic aquatic toxicity (Tables T2.9 and T2.10, Section 5.0), 

environmental fate and effect (Section 2.3), physical and chemical properties, analytical methods 

at environmentally relevant concentrations (Section 2.5), risk characterization (Section 5.0), and 

risks to the aquatic environment (Section 6.4). In response to the GESAMP-BWWG request, 

additional information to supplement the evaluation of chlorite ion has been included in Sections 

2.2, 2.2.5, 2.2.6, 2.2.7, and 2.2.8. 

During land based testing chlorite ion was measured in treated ballast water at concentrations 

ranging from 2.26 – 3.83 mg/L, with a mean concentration of 3.16 mg/L. Table T2.8a in Section 

2.0.4 provides analytical data for chlorite ion in treated water from land based testing at NIOZ. 

Chlorite ion was also evaluated in the predicted environmental concentration assessment using 

hydrodynamic modeling (Section 5.3.3) 

2.0.3.3 Trihalomethanes and Haloacetic Acid By-Products 

Detailed information regarding THMs and HAAs was provided in the Basic Approval dossier 

(MEPC 58/2/2). Also see Section 2.0.3.3.1 below for additional clarification.

2.0.3.3.1 Additional Clarification on THM and HAA Analysis 

The GESAMP-BWWG commented that the Level of Quantification (LOQ) associated with the 

analytical data provided in the Basic Approval dossier was too high to confirm that THMs and 

HAAs in treated water discharge are at sufficiently low levels to ensure that international 

discharge standards are not exceeded. 

Clarification on the LOQ comment was requested from the GESAMP-BWWG because the LOQ 

suggested was very low (0.01 – 0.05 μg/L). The response provided to the German 

Administration on 4 November 2008 explained that the detection limits noted by the GESAMPBWWG “...were taken from information provided in previous applications.” Due to the 

variation in detection limits and terminology that is discussed below, using other applications as 

“guidance documents” can lead to incorrect data comparisons. Other applicants may have used 

detection limit terms differently, produced data by varying methods or in differing matrices 

(fresh vs. sea water), or had possible errors. As noted by other applicants, and acknowledged by 

the GESAMP-BWWG, chemical analysis in sea water presents challenges due to potential 

interferences with the analytical methods. 

6

 US EPA Reregistration Eligibility Decision (RED) for Chlorine Dioxide and Sodium Chlorite (Case 4023), August 2006 

7

 US EPA Toxicological Review of Chlorine Dioxide and Chlorite, September 2000 

8

 EPA Guidance Manual, Alternative Disinfectants and Oxidants, Chlorine Dioxide, 1999 

9

 Simpson, G.D., Miller, R.F., Laxton, G.D., Clements, W.R., A Focus on Chlorine Dioxide: “The Ideal Biocide” 

10 OECD SIDS, Sodium Chlorite and Chlorine Dioxide, SIAM 23, October 2006 

11 World Health Organization, Guidelines for Drinking-Water Quality, 2006

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The information presented below demonstrates that the THM and HAA data presented has 

sufficient detection limits and shows that regulatory standards for these constituents are not 

exceeded in treated ballast discharge. 

Detection Limit Discussion: 

There are many different “detection limit” terms commonly used in analytical chemistry and 

each term can refer to different aspects of detection. A few examples of terms used to describe 

detection limits include: method detection limit (MDL), instrument detection limit (IDL), limit 

(or level) of quantitation (LOQ), or practical quantitation limit (PQL). Further, the use of similar 

terminology does not imply equal detection limits due to the inherent differences between 

methods, analytical equipment and laboratory practices.

Ecochlor contends that the THM and HAA methodologies used and the data generated are of 

similar accuracy and quality to that requested by the GESAMP-BWWG, but the detection limits 

are reported differently due to the USEPA requirements that the laboratory is required to adhere 

to. The THM and HAA results are reported as <1 μg/L, which specifies a Minimum Reporting 

Limit (MRL) rather than an LOQ. The different terms used to report an analytical method’s 

detection capability causes confusion when attempting to equate LOQs with MRLs. In recent 

years within the US, there has been movement toward MRLs in an attempt to make direct 

comparisons between data from different sources possible, and to be sure that the comparisons 

include equivalent levels of data accuracy. 

From the USEPA DPB/ICR Analytical Methods Manual12:

“A major issue for comparing results between laboratories is data quality. This 

includes both accuracy and precision targets in order to meet the data quality 

objectives required for setting regulatory limits. Maintaining data comparability 

between laboratories is a necessary requirement if the data are to be successfully 

used in sophisticated correlational analysis. 

The recommendations of an expert panel are the source of the data quality 

objectives discussed in this document. Thus, to ensure that the analytical data are 

scientifically valid and are of known and acceptable precision and accuracy, 

laboratories are required to adhere to defined quality assurance procedures. This 

quality assurance plan at a minimum incorporates the elements of the initial 

demonstration of capabilities. 

The Method Detection Limit (MDL) as defined in this document is considered 

qualitative, because they are not precise enough to meet the data needs for 

regulation. If accurate and precise data are required, concentrations are not 

reported below the level at which the necessary precision and accuracy are 

achieved. Thus, based on recommendations from a panel of technical experts, 

minimum reporting levels (MRLs) were established.”

12 USEPA, DBP/ICR Analytical Methods Manual (EPA 814-B-96-002), April 1996 

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EPA Method 524.2 was used to analyze treated ballast water samples for THMs. The method 

explains:

“Method detection limits (MDLs) are compound, instrument and especially matrix 

dependent and vary from approximately 0.02-1.6 ȝg/L. The applicable concentration 

range of this method is primarily column and matrix dependent, and is approximately 

0.02-200 ȝg/L...”

EPA Method 552.2 was used to analyze treated ballast water samples for HAAs. The method 

explains:

“Method Detection Limit (MDL) -- The minimum concentration of an analyte that can be 

identified, measured and reported with 99% confidence that the analyte concentration is 

greater than zero.” 

In a revised version of this method (EPA Method 552.3), the Minimum Reporting Level (MRL) 

is explained:

“The MRL is the threshold concentration of an analyte that a laboratory can expect to 

accurately quantitate in an unknown sample. The MRL should be established at an 

analyte concentration that is at least 3x the detection limit or at a concentration which 

would yield a signal-to-noise (S/N) ratio of greater than or equal to five. Depending 

upon the study’s data quality objectives it may be set at a higher concentration. The 

concentration of the lowest calibration standard must be at or below the MRL.” 

The Ph.D. chemist, Dr. Bubnis, involved with the analysis of Ecochlor’s samples has written an 

expert opinion on this matter13:

“The MRL incorporates a more demanding accounting of bias and accuracy than the

reporting of MDL or LOQ. Thus, the higher MRL value is not an indication of an inferior

method. It is simply a more rigorous treatment of potential error and includes both a 

bias and an accuracy function. In contrast, the MDL and LOQ do not account for the 

predicted accuracy of a method but rely on the expertise of the laboratory and laboratory 

personnel.”

In summary, an MDL is a compound-, matrix-, and instrument-specific detection level that 

provides information about the data precision for a specific analytical situation. An MRL takes 

into account both the precision and the accuracy of the data being produced by testing replicate 

samples with known concentrations. With the difference between MRLs, MDLs and LOQs 

clarified, the following information shows both the calculated MDL and the MRL for the 

methods that were used to analyze the treated water samples. 

Table T2.7a – Comparison of MDL and MRL for THM Analysis (EPA Method 524.2) 

Compound MDLa (μg/L) MRLb (μg/L) 

Bromdichloromethane (BDCM) 0.08 1.0 

Bromoform 0.12 1.0 

Chloroform 0.03 1.0 

Dibromochloromethane (DBCM) 0.05 1.0 

a

 MDL as determined by the analytical method. 

b

 MRL as determined by the laboratory according to EPA requirements. 

13 Bubnis, B., The Rationale and Transition of Regulating Agencies Specifying the Reporting of Method Reporting Limits (MRLs) In-Lieu of 

 Method Detection Limits (MDLs), October 2008

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Table T2.7b – Comparison of MDL and MRL for HAA Analysis 

(EPA Method 552.2, MTBE Extraction) 

Compound MDLa (μg/L) MRL b(μg/L) 

Monochloroacetic acid (MCAA) 0.17 1.0 

Monobromoacetic acid (MBAA) 0.027 1.0 

Dichloroacetic acid (DCAA) 0.020 1.0 

Trichloroacetic acid (TCAA) 0.019 1.0 

Bromochloroacetic acid (BCAA) 0.016 1.0 

Dibromoacetic acid (DBAA) 0.012 1.0 

a

 MDL as determined by the analytical method. 

b

 MRL as determined by the laboratory according to EPA requirements. 

The tables above show the calculated MDL values for THMs and HAAs determined by the 

analytical method. This information demonstrates that the methods are capable of the low 

detection limits suggested by the GESAMP-BWWG. The above MDL values apply to the 

previous data submitted by Ecochlor (Table T2.8), as well as the new data generated during the 

land based testing (Tables T2.8b and T2.8c).

The MRL values in the tables above are consistent with the <1.0 μg/L values reported with the 

THM and HAA data generated during analysis of water samples treated with the Ecochlor 

system, and are a result of the method detection study performed by the analytical laboratory in 

accordance with EPA requirements13.

Regulatory Standards Discussion: 

The primary goal of conducting chemical analysis on treated water discharge is to verify that 

regulatory standards are not exceeded. A search to locate published allowable limits for THMs 

and HAAs was conducted to verify that utilizing an MRL of <1 μg/L demonstrates that the 

Ecochlor system does not introduce these constituents to the environment at levels that exceed 

published standards. Table T2.7c below lists the standards that were located for THMs and 

HAAs during the search. The only published regulatory standards located are for drinking water 

and therefore, provide the only alternative to determine if treated water discharge meets the 

standards.

Table T2.7c – Summary of Published Standards for THMs and HAAs 

Agency Chemical Regulatory Limit Reference 

World Health 

Organization 

THMs:

 -Chloroform 

 -Bromoform 

 -Dibromochloromethane 

 (DBCM) 

 -Bromodichloromethane 

 (BDCM) 

HAAs:

 -chloroacetic acid 

 -dichloroacetic acid 

 -trichloracetic acid 

 -brominated acetic acids 

0.3 mg/L (300 μg/L) 

0.1 mg/L (100 μg/L) 

0.1 mg/L (100 μg/L) 

0.06 mg/L (60 μg/L) 

0.02 mg/L (20 μg/L) 

0.05 mg/L (50 μg/L) 

0.2 mg/L (200 μg/L) 

No guideline value 

established

Guidelines for 

Drinking-water Quality 

First Addendum to Third 

Edition, Volume 1 

Recommendations 

Australian GovernmentPrimary Industries 

Ministerial

Council(PMIC) and 

THMs

HAAs

 -chloroacetic acid 

0.25 mg/L (250 μg/L) 

0.15 mg/L (150 μg/L) 

Australian and New Zealand 

Guidelines for Fresh and 

Marine Water Quality 

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Agency Chemical Regulatory Limit Reference 

Natural Resource 

Management Ministerial 

Council (NRMMC) 

 -dichloroacetic acid 

 -trichloracetic acid 

 -brominated acetic acids 

0.1 mg/L (100 μg/L) 

0.1 mg/L (100 μg/L) 

No guideline value 

noted 

AUSTRALIAN DRINKING 

WATER GUIDELINES (6) 

2004 

Canada-Federal 

Provincial 

Subcommittee on 

Drinking Water 

THMs --Total 

HAAs --Total 

0.100 mg/L (100 μg/L) 

0.080 mg/L (80 μg/L) 

Guidelines for Canadian 

Drinking Water Quality - 

Summary Table 

US EPA THMs --Total 

HAAs --Total 

0.080 mg/L (80 μg/L) 

0.060 mg/L (60 μg/L) 

USEPA National Primary 

Drinking Water Regulations 

California Department 

of Public Health, 

Division of Drinking 

Water and 

Environmental 

Management 

THMs -- Total 

HAAs --Total 

0.080 mg/L (80 μg/L) 

0.060 mg/L (60 μg/L) 

California Regulations Related 

to Drinking Water (Title 22 of 

the California Code of 

Regulations)

Agency Chemical Limit Approved Reference 

IMO MEPC, GESAMPBWWG – based on 

levels in treated ballast 

water that have received 

G9 approval 

THMs

 -Tribromomethane 

 (Bromoform) 

 -Tribromomethane 

 (Bromoform) 

HAAs

 -Dibromoacetic acid 

 -Tribromoacetic acid 

0.230 mg/L (230 μg/L) 

0.373 mg/L (373 μg/L) 

0.163 mg/L (163 μg/L) 

0.183 mg/L (183 μg/L) 

MEPC 58/2/8, Annex 4 

(OceanSaver) 

MEPC 58/2/7, Annex 6, 

(Electroclean) 

MEPC 58/2/7, Annex 6, 

(Electroclean) 

In the table above, the lowest published standard located for a single THM was 60 μg/L (WHO, 

bromodichloromethane), while the lowest standard for total THMs located was 80 μg/L. Tables 

T2.8 and T2.8b provide the measured THMs in treated ballast water discharge. In Ecochlor 

treated ballast water discharge all THMs are <1 μg/L and therefore do not exceed the limits for 

THMs.

In the table above, the lowest published standard located for a single HAA was 20 μg/L (WHO, 

chloroacetic acid), while the lowest standard for total HAAs was 60 μg/L. No specific standard 

was located for DBAA which has been measured in treated ballast water. Tables T2.8 and T2.8c 

list the measured HAAs in treated ballast water discharge. Chloroacetic acid is reported at <1 

μg/L for all chemical analysis performed on treated ballast water discharge and therefore the 

WHO standard for this constituent is not exceeded. The highest total HAAs measured in a single 

sample was 36 μg/L (DBAA) and therefore the limit for total HAAs is not exceeded. 

Also in the table above Ecochlor notes that G9 Final Approval has been granted to other 

technologies who have concentrations of THMs and HAAs at least one order of magnitude 

higher than that present in Ecochlor treated water discharge. Based on the fact that higher 

concentrations have been previously approved, Ecochlor presumes that the lower concentrations 

measured in Ecochlor’s treated ballast water discharge are considered acceptable. Additionally, 

the results of the hydrodynamic modeling and environmental risk assessment indicate that the 

discharge will not cause unacceptable risk to the aquatic environment. See Section 5.3.3. 

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2.0.3.3.2 Dibromoacetic Acid (DBAA) 

This section has been added based on the levels of DBAA measured in treated water discharge 

from the land based testing at NIOZ and comments Ecochlor received from the German 

Administration. 

DBAA is a low-level disinfection by-product that has been measured in water treated with the 

Ecochlor system. Brominated acetic acids are formed during disinfection of water that contains 

bromide ions and organic matter11. In regards to drinking water, the WHO reports that 

brominated acetic acids are generally present in surface water and groundwater distribution 

systems at mean concentrations below 5 μg/L11. Data from the USEPA indicates that DBAA has 

been detected at mean concentrations of 0.82 μg/L and 1.09 μg/L in groundwater and surface 

water distribution systems, respectively14.

DBAA was previously measured at 12 μg/L in ballast water treated onboard the M/V Moku 

Pahu. During land based testing DBAA was measured at concentrations ranging from 12 - 36 

μg/L (Table T2.8c), with a mean concentration of 22.6 μg/L. These values are significantly 

lower than the DBAA concentrations reported by other ballast water treatment technologies that 

have received IMO Final Approval. Most importantly, the level of DBAA in treated ballast 

water does not exceed the regulatory standards as presented above. 

Information on DBAA is provided in the appropriate sections of this dossier to allow for a proper 

evaluation. Additionally, to further demonstrate and verify that DBAA potentially present in 

treated ballast water discharge will not cause unacceptable environmental risk, Ecochlor has 

included this constituent in the environmental concentration prediction model in Section 5.3.3. 

2.0.3.4 Chlorate Ion 

Ecochlor has added chlorate ion to the discussion of relevant chemicals because higher 

concentrations were measured during land based testing than had been previously measured 

during laboratory and shipboard testing.

During land based testing at NIOZ chlorate ion was measured at concentrations ranging from 

0.98 – 2.42 mg/L (mean concentration of 1.39 mg/L) in samples of treated water discharge. 

Sodium chlorate (as solid sodium chlorate) is highly soluble in water (802 g/L at 20oC15). This 

high solubility implies that chlorate does not bioaccumulate or easily adsorb to particulates25.

There are conflicting opinions published regarding the stability of chlorate in the environment. 

Examples include three sources that indicate chlorate is unstable and non-persistent in the aquatic 

environment17,19,25 while the USEPA indicates “...chlorate is stable in finished drinking water”8

.

However, finished drinking waters cannot be equated to natural waters where treated ballast 

effluent will be discharged. Natural waters will have physiological properties, organic matter, 

and biological components that play a role in the degradation of chlorate ion that finished 

drinking water will not.

Through controlled laboratory experiments, an observable degradation of chlorate ion over time 

in natural sea water has been demonstrated. Similar to chlorine dioxide and chlorite, natural 

seawater has an observable demand for chlorate. The measured decay rate of chlorate in natural 

seawater at 20oC is 0.03 mg/L-1 minute.

14 World Health Organization, Brominated Acetic Acids in Drinking Water, 2004 

15 OECD SIDS, Sodium Chlorate, SIAM 22, April 2006 

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Figure F2.7 – Example of Chlorate Ion Demand Curve 

Newark, NJ Water, 20°C

NJ Water Chlorate Ion Demand

1.49 mg/L, 20C

0.00

0.50

1.00

1.50

2.00

0 5 10 15 20 25

Time (hours)

Concentration (mg/L)

Table T2.7d – Chlorate Ion Demand Study, New Jersey. 20oC 

Ecochlor Ballast Water Chlorate Ion Demand Study 

Source Water New Jersey Ballast Water 

Chlorite Dose 1.49 mg/L 

Water Temp 20 oC 

Time after ClO3

-

treatment (hour) 

Chlorate Ion 

ClO3

-

 (mg/L) 

0 1.49 

0.03 1.41 

0.5 1.37 

1.0 1.35 

20 1.07 

Note: Testing performed by NovaChem Laboratories 

To further demonstrate that the measured concentration of chlorate in treated ballast water 

discharge will not present unacceptable risks to the aquatic environment, chlorate was included 

hydrodynamic modeling as part of the risk assessment. See Section 5.3.3. 

Detailed information on chlorate ion (as sodium chlorate) is evaluated and presented in this 

dossier to allow for an appropriate review.

2.0.4 Overview of Chemical Analysis and Water Quality Data for Treated Ballast Water 

The tables below present chemical analysis and water quality data for samples of ballast water 

treated with the Ecochlor® Ballast Water Treatment System. 

Table T2.8 – Chemical Analysis of Ballast Water Treated Onboard 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 

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Parameter 

Control Ballast 

Water

Ballast Water 

Treated Onboard 

+ 3 Day 

13 Feb 2008 

Ballast Water 

Treated Onboard 

+ 5 Day 

15 Feb 2008 

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

Bromdichloromethane 

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 

Note: Demand testing on raw water samples performed by NovaChem Laboratories 

 “--“ = not measured 

Tables T2.8a, T2.8b, and T2.8c summarize the chemical analysis results from treated water 

discharge samples collected during land based testing. Testing was performed by NovaChem 

Laboratories and McCoy & McCoy Laboratories16.

Table T2.8a – Chemical Analysis of Treated Ballast Water,

Land Based Testing at NIOZ 

Treated

Ballast

Water

5 mg/L 

ClO2

Days 

After

Treatment

Sample ID pHa FACa

(mg/L)

ClO2b

(mg/L)

Chloritea

(mg/L)

Chloratea

(mg/L)

Bromidea

(mg/L)

Bromatea

(mg/L)

Nitratea

(mg/L)

4HS 6 June 08 - CX 7.7 <0.05 -- <0.10 <0.10 55 <0.02 6 1

4HS 6 June 08 - TX 6.8 <0.05 0.79 3.6 1.47 52 <0.02 7 

5HS 12 June 08 - CX 7.8 <0.05 -- <0.10 <0.10 58 <0.02 5 0

5HS 12 June 08 - TX 6.8 <0.05 >2.5 3.83 2.42 53 <0.02 5 

5HS 13 June 08 - CX 7.6 <0.05 -- <0.10 <0.10 58 <0.02 6 1

5HS 13 June 08 - TX 7.0 <0.05 0.85 3.11 1.46 54 <0.02 6 

5HS 17 June 08 - CX 7.9 <0.05 -- <0.10 <0.10 57 <0.02 5 

Sea 

Water

(average 

salinity 

31.9 ± 

1.3

PSUc

)

5

5HS 17 June 08 - TX 7.0 <0.05 ND 2.26 1.27 54 <0.02 5 

1LS 21 June 08 - CX 8.0 <0.05 -- <0.10 <0.10 63 <0.02 6 1

1LS 21 June 08 - TX 7.0 <0.05 0.22 3.35 1.17 62 <0.02 6 

3LS 26 June 08 - CX 8.0 <0.05 -- <0.10 <0.10 55 <0.02 5 0

3LS 26 June 08 - TX 7.1 <0.05 >2.5 3.18 1.24 52 <0.02 5 

Brackish 

Water

(average 

salinity 

23.1 ± 

0.65

PSUc

)

1 3LS 27 June 08 - CX 8.1 <0.05 -- <0.10 <0.10 54 <0.02 5 

16 NovaChem Laboratories, A Data Summary of the Ecochlor Ballast Water Treatment System at the Land-Based Testing Facility Operated by the 

 Royal Netherlands Institute for Sea Research (NIOZ), November 2008 

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Treated

Ballast

Water

5 mg/L 

ClO2

Days 

After

Treatment

Sample ID pHa FACa

(mg/L)

ClO2b

(mg/L)

Chloritea

(mg/L)

Chloratea

(mg/L)

Bromidea

(mg/L)

Bromatea

(mg/L)

Nitratea

(mg/L)

3LS 27 June 08 - TX 7.1 <0.05 0.67 3.12 1.07 51 <0.02 6 

3LS 1 July 08 - CX 8.1 <0.05 -- <0.10 <0.10 53 <0.02 5 5

3LS 1 July 08 - TX 7.1 <0.05 ND 2.8 0.98 51 <0.02 5 

HS = High Salinity, LS = Low Salinity, CX = Control Sample, TX = Treated Sample, ND = non-detectable 

a Analysis performed by NovaChem Labs, USA 

b

 Chlorine dioxide residuals measured using the Palintest ChlorDiox-Duo 

c

 Average salinity during land-based test cycles as reported by NIOZ 

Table T2.8b – Chemical Analysis of Treated Ballast Water for THMs,

Land Based Testing at NIOZ 

Treated Trihalomethanes (THM) 

Ballast

Water

5 mg/L ClO2 

Days 

After

Treatment 

Sample ID BDCMa

(ug/L)

Bromoforma

(ug/L)

Chloroforma

(ug/L)

DBCMa

(ug/L)

4HS 6 June 08 - CX <1 <1 <1 <1 1

4HS 6 June 08 - TX <1 <1 <1 <1 

5HS 12 June 08 - CX <1 <1 <1 <1 0

5HS 12 June 08 - TX <1 <1 <1 <1 

5HS 13 June 08 - CX <1 <1 <1 <1 1

5HS 13 June 08 - TX <1 <1 <1 <1 

5HS 17 June 08 - CX <1 <1 <1 <1 

Sea Water 

(average 

salinity 31.9 ± 

1.3 PSUb

)

5

5HS 17 June 08 - TX <1 <1 <1 <1 

1LS 21 June 08 - CX <1 <1 <1 <1 1

1LS 21 June 08 - TX <1 <1 <1 <1 

3LS 26 June 08 - CX <1 <1 <1 <1 0

3LS 26 June 08 - TX <1 <1 <1 <1 

3LS 27 June 08 - CX <1 <1 <1 <1 1

3LS 27 June 08 - TX <1 <1 <1 <1 

3LS 1 July 08 - CX <1 <1 <1 <1 

Brackish

Water

(average 

salinity 

23.1 ± 0.65 

PSUb

)

5

3LS 1 July 08 - TX <1 <1 <1 <1 

 HS = High Salinity, LS = Low Salinity, CX = Control Sample, TX = Treated Sample, 

 BDCM = bromodichloromethane, DBCM = dibromochloromethane 

 a

 Analysis performed by McCoy & McCoy Labs, USA b Average salinity during land-based test cycles as reported by NIOZ 

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Table T2.8c – Chemical Analysis of Treated Ballast Water for HAAs, 

Land Based Testing at NIOZ 

Treated Haloacetic Acids (HAA) 

Ballast

Water

5 mg/L ClO2 

Days 

After

Treatment 

Sample ID DBAAa

(ug/L)

DCAAa

(ug/L)

MBAAa

(ug/L)

MCAAa

(ug/L

TCAAa

(ug/L)

4HS 6 June 08 - CX <1 <1 <1 <1 <1 1

4HS 6 June 08 - TX 20 <1 3 <1 <1 

5HS 12 June 08 - CX <1 <1 <1 <1 <1 0

5HS 12 June 08 - TX 23 <1 <1 <1 <1 

5HS 13 June 08 - CX <1 <1 <1 <1 <1 1

5HS 13 June 08 - TX 23 <1 3 <1 <1 

5HS 17 June 08 - CX <1 <1 <1 <1 <1 

Sea Water 

(average 

salinity 31.9 

± 1.3 PSUb

)

5

5HS 17 June 08 - TX 25 <1 2 <1 <1 

1LS 21 June 08 - CX <1 <1 <1 <1 <1 1

1LS 21 June 08 - TX 36 <1 <1 <1 <1 

3LS 26 June 08 - CX <1 <1 <1 <1 <1 0

3LS 26 June 08 - TX 21 <1 <1 <1 <1 

3LS 27 June 08 - CX <1 <1 <1 <1 <1 1

3LS 27 June 08 - TX 21 <1 <1 <1 <1 

3LS 1 July 08 - CX <1 <1 <1 <1 <1 

Brackish

Water

(average 

salinity 

23.1 ± 0.65 

PSUb

)

5

3LS 1 July 08 - TX 12 <1 <1 <1 <1 

HS = High Salinity, LS = Low Salinity, CX = Control Sample, TX = Treated Sample, DBAA = dibromoacetic acid, 

 DCAA = dichloroacetic acid, MBAA = monobromoacetic acid, MCAA = monochloroacetic acid, TCAA = trichloroacetic acid 

 a

 Analysis performed by McCoy & McCoy Labs, USA b Average salinity during land-based test cycles as reported by NIOZ 

The GESAMP-BWWG commented that water quality data associated with the shipboard treated 

ballast water toxicity results presented in Tables T2.9 and T2.10 of the Basic approval dossier 

was not provided. This was inadvertently left out of the dossier and the information is provided 

in Table T2.8d below.

Table T2.8d – Water Quality Data from Ship Board Testing 

Parameter 

Atlantic Compass 

Treatment, 

August 2006a

Atlantic Compass 

Treatment, 

September 2006 a Unit

Salinity – control tank 21.3 24.63 ppt

Salinity – treatment tank 21.5 23.96 ppt

Temperature – control tank 25 20.98 °C

Temperature – treatment tank 25.7 21.71 °C

DO – control tank 6.9 7.41 mg/L

DO – treatment tank 6.5 6.79 mg/L

pH – control tank 7.46 7.6 pH

pH – treatment tank 7.25 7.13 pH

POC – control tank 0.158 0.108 mg-C/L

POC – treatment tank 0.290 0.180 mg-C/L

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Parameter 

Atlantic Compass 

Treatment, 

August 2006a

Atlantic Compass 

Treatment, 

September 2006 a Unit

DOC – control tank 2.68 2.57 mg-C/L

DOC – treatment tank 2.17 2.19 mg-C/L

 a Water quality measurements 5 days after treatment. 

Tables T2.8e and T2.8f below provide the water quality data for the test water at intake and 

discharge from land based testing as reported by NIOZ. 

Table T2.8e – Water Quality Data from Land Based Testing at NIOZ, 

Brackish (Low Salinity) Test Cycles 

Average Salinity @ Intake 

[PSU] 

Average temperature @ Intake 

[°C]

6 Test cycles 23.1 ± 0.65 16.7 - 18.8 

Parameter Intake 

Standard

Deviation Discharge (day 5) 

Standard

Deviation unit

O2 reference tank 5.7-8.5a -- 3.5-5.9a -- mg/L 

O2 treatment tank 10.6-13.3a -- 9.9-12.0a -- mg/L 

DO saturation – 

reference tank 69-102b

 -- 43-70b -- % 

DO saturation – 

treatment tank 90-111b

 -- 81-99b -- % 

pH - reference tank 7.95 0.09 Not Measured -- pH 

pH-treatment tank 6.91c -- 6.92d -- pH 

TSS-reference tank 75.3 23.6 14.0 9.8 mg/L 

TSS-treatment tank 19.3 9.50 13.0 2.1 mg/L 

POC -reference tank 11.6 1.50 7.60 3.0 mg/L 

POC-treatment tank 9.0 3.90 6.60 1.4 mg/L 

DOC -reference tank 3.2 0.47 2.8 0.37 mg-C/L 

DOC-treatment tank 3.4 0.36 3.5 0.43 mg-C/L 

“Reference tank” is the experimental “control” tank. a Range of values; oxygen concentrations are corrected for the interference of the active substance or derivates. b Measured range of DO percent saturation. c Measurement taken as soon as possible after treatment. d Average of measurements throughout the 5 day holding period.

Table T2.8f – Water Quality Data from Land Based Testing at NIOZ, 

Sea Water (High Salinity) Test Cycles 

Average Salinity @ Intake 

[PSU] 

Average temperature @ Intake 

[°C]

5 Test cycles 31.9 ± 1.3 14.3 - 17.5 

Parameter Intake 

Standard

Deviation Discharge (day 5) 

Standard

Deviation unit

O2 reference tank 4.7-9.2a -- 2.6-6.1a -- mg/L 

O2 treatment tank 8.8-12.0a -- 8.0-10.9a -- mg/L 

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Parameter Intake 

Standard

Deviation Discharge (day 5) 

Standard

Deviation unit

DO saturation – 

reference tank 59-113b -- 33-73b

 -- % 

DO saturation – 

treatment tank 76-100b -- 69-93b -- % 

pH - reference tank 8.07 0.05 Not Measured -- pH 

pH-treatment tank 6.81c -- 6.89d -- pH 

TSS-reference tank 33.9 37.10 9.7 3.10 mg/L 

TSS-treatment tank 15.6 3.6 9.6 1.3 mg/L 

POC -reference tank 10.2 5.3 4.8 1.3 mg/L 

POC-treatment tank 7.8 2.1 4.8 0.5 mg/L 

DOC -reference tank 4.0 1.02 3.3 0.51 mg-C/L 

DOC-treatment tank 4.3 0.76 4.3 0.93 mg-C/L 

 “Reference tank” is the experimental “control” tank. 

 a Range of values; oxygen concentrations are corrected for the interference of the active substance or derivates. b Measured range of DO percent saturation. c Measurement taken as soon as possible after treatment. d Average of pH at day 5 discharge over all five test cycles.

2.1 DATA ON EFFECTS ON AQUATIC PLANTS, INVERTEBRATES AND FISH, 

AND OTHER BIOTA, INCLUDING SENSITIVE AND REPRESENTATIVE 

ORGANISMS (G9: 4.2.1.1) 

The toxicology data presented in this application varies by topic and is selective by design. To 

clarify, the toxicology data set required by Guideline 9 involves several categories; 1) aquatic 

toxicity, 2) mammalian toxicity and 3) environmental fate and effect. These categories relate to 

the Ecochlor process at different phases of treatment and potential exposure to the substances 

associated with the Ecochlor® BWTS is not the same for each category. As such, each 

toxicological category was evaluated to determine where a potential exposure existed and what 

chemicals were of potential concern throughout the treatment process. 

For example, the acute and chronic aquatic toxicity data submitted is intended to provide a reallife scenario of what chemicals may be present when treated ballast water is discharged. Because 

Purate® and sulfuric acid are converted into chlorine-free chlorine dioxide and are not present at 

significant concentrations in treated ballast water, aquatic toxicity data is not provided for these 

chemicals. However, because treated ballast water may contain chlorine dioxide and chlorite ion 

(the primary by-product of disinfection with chlorine dioxide), aquatic toxicity data is provided 

for these chemicals. Dibromoacetic acid (DBAA) and chlorate ion have been added to the list of 

relevant chemicals in treated ballast water and aquatic toxicity data, when available, is presented 

in the tables below. 

Similarly, because Purate® and sulfuric acid are stored onboard and a potential for human 

exposure (crew or technicians) exists, mammalian toxicity data is provided for these chemicals. 

However, because treated ballast water is not typically handled by crew or technicians, Ecochlor 

did not provide mammalian toxicity data on chlorite ion as this does not seem relevant. Even in a 

situation where human contact with treated ballast water could occur, (i.e. water sample 

collection) the chemicals that may be present have been determined analytically to be at 

concentrations that are not of concern to humans. Based on comments received by the 

GESAMP-BWWG and the German Administration data on chlorite ion, chlorate ion and DBAA 

has been added to the dossier.

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Whole effluent testing of the treated ballast water includes the sum of all substances formed in 

the treatment process. Therefore, aquatic toxicity testing on treated ballast water discharge 

reflects the most accurate information on the potential toxicological effects of the treated water a 

ship will discharge. Toxicity testing on the precursor chemicals and/or intermediate substances is 

informative, but may not reflect the most realistic toxicological evaluation of treated ballast 

water.

Toxicity tests for chlorine dioxide were performed by Nautilus Environmental and end-points are 

based on measured concentrations of chlorine dioxide at the start of the exposure periods. Acute 

toxicity tests were static and chronic tests were static renewal with a daily renewal of test 

solutions, with the exception of tests with Macrocystis pyrifera, Mytilus sp. and Skeletonema

costatum, which were static, and the 96 hr test with Clupea pallasi in which the solution was 

renewed only after 48 hr of exposure. All tests were conducted according to USEPA guidelines 

for conducting short term acute and chronic toxicity tests (USEPA 1995, 2002), with the 

exception of the tests with Skeletonema costatum, which followed ASTM (1998) methodology, 

and tests with Clupea pallasi, which were based on methodology developed by Dr. Paul Dinnel 

from the Shannon Point Marine Center. 

Toxicity tests for chlorite were static, with the exception of 7-day tests with Mysidposis bahia

and Atherinops affinis, which were static renewal with daily renewal of solutions. All tests were 

conducted according to USEPA guidelines for conducting short term acute and chronic toxicity 

tests (USEPA 1995, 2002). 

A summary of the toxicity testing methods is provided below. 

Table T2.8g – Summary of Aquatic Toxicity Testing Methods 

Methods Taxonomic Groups Tested 

Acute Testing Methods

EPA-821-R-02-012 Crustaceans (Mysids) 

EPA-600-R-95-136 Mollusk (Mytilus), Marine Algae, Echinoderm 

EPA FIFRA Guideline 72-3 Fish (Cyprinodon), Crustacean (Mysids), 

96 hr acute survival, Dr. Dinnel, 

Shannon Point Marine Center Fish (Clupea)

OECD 203 Fish (Cyprinodon)

ISO 14669 Crustacean (Acartia)

ASTM E724 Mollusk (Crassostrea)

ISO 11348-3 Microtox 

ISO 10253 Algae (Phaeodactylum)

Rotox Kit M Rotifers 

Chronic Methods

EPA-821-R-02-014 Fish (Menidia, Atherinops), Crustacean (Mysids) 

18-day Embryo Development, Dr. 

Dinnel, Shannon Point Marine Center Fish (Clupea)

ASTM E1218-97a Algae (Skeletonema)

EPA FIFRA Guideline 72-3 Mollusk Development (Crassostrea)

EPA-600-R-95-136 Mollusk Development (Mytilus)

ASTM E724 Mollusk Development (Crassostrea)

According to Section 3.3.2.2 of the G9 Methodology (MEPC 58/2/7, Annex 42), “In the case of 

whole effluent testing, US EPA or equivalent, short term methods for estimating the acute 

toxicity of substances and discharge provide acceptable alternatives.” 

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According to Section 3.3.3.2 of the G9 Methodology (MEPC 58/2/7, Annex 42

), “In the case of 

whole effluent testing, US EPA short term methods for estimating the chronic toxicity of 

substances and discharge provide acceptable alternatives, since the identification of the sensitive 

sub-lethal endpoints and vulnerable life-stages is the ultimate aim of the long-term testing.” 

Sections 2.1.1.6 and 2.1.2.4 along with Tables T2.9a and T2.10a below include results of whole 

effluent ecotoxicity testing conducted during land based testing for type approval according to 

IMO Guideline 8 (G8). The land based testing was successfully performed at the Royal 

Netherlands Institute for Sea Research (NIOZ) from April to July 2008 to demonstrate 

compliance with IMO Regulation D-2. Ecotoxicity testing for crustaceans, algae, mollusks, 

rotifers, and marine bacteria was performed by Grontmij|AquaSense in the Netherlands, and fish 

ecotoxicity testing was performed by Chemex Environmental International in the United 

Kingdom. 

Aquatic toxicity testing of treated ballast water discharge from the land based test set up was 

conducted at two different salinities (brackish and sea water) and two different time points (days 

1 and 5 after treatment). These time points were selected to demonstrate that treated ballast 

water is safe to discharge within 24 hours of treatment (day 1) and also after the holding time of 

5 days specified in G8 testing. Ecotoxicity was evaluated for six (6) different taxonomic groups 

(algae, crustacean, fish, rotifers, mollusks, and marine bacteria). 

Acute exposure testing was performed on all six taxonomic groups from brackish and sea water 

test cycles. The most sensitive taxonomic group identified was then tested again with day 5 

treated ballast water discharge. To evaluate chronic affects, short-term exposure (sub-lethal 

endpoint (growth / development)) testing was also evaluated for the most sensitive taxonomic 

group identified from the acute testing. This approach allowed for testing on a wider range of 

taxonomic groups and also avoided unnecessary testing on organisms that did not show evidence 

of toxic effects with acute exposures. This approach for ecotoxicity testing was based on 

discussions and agreements between Ecochlor and the German Administration. 

Comments received by the GESAMP-BWWG suggested that samples be taken at day 0, 2 and 5 

after treatment to demonstrate ecotoxicity at various holding times. Ecochlor would like to note 

that chlorine dioxide is a well-known biocide that is highly effective in water treatment systems. 

Because chlorine dioxide would still be present in treated ballast water at day 0 (i.e. immediately 

after treatment), conducting toxicity testing at this time point would more accurately reflect 

efficacy testing. This is due to the fact that the active substance, chlorine dioxide, is injected 

during ballast uptake and decays over time in the ballast tank(s). Therefore, sampling treated 

ballast water immediately after chlorine dioxide injection would only be expected to produce 

mortality of aquatic organisms. Testing a broader range of taxonomic groups at time points that 

represent more realistic onboard situations (days 1 and 5) demonstrates that treated water is safe 

to discharge within 24 hours of treatment and provides more useful information than confirming 

the efficacy of chlorine dioxide by toxicity testing on samples collected immediately after 

injection.

2.1.1 Acute Aquatic Toxicity 

2.1.1.1 Chlorine Dioxide 

A summary of chlorine dioxide toxicity data was presented in the Basic Approval dossier (MEPC 

58/2/2). The data is also summarized in Table T2.9. 

The GESAMP-BWWG commented that the Nautilus Environmental testing protocols with 

chlorine dioxide measured the effect concentrations of the active substance at the initiation of the 

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tests. Ecochlor accepts and understands this criticism of the test results and has applied the lower 

LC50 of 0.02 mg/L (juvenile Pimephales promelas) for chlorine dioxide as suggested by the 

GESAMP-BWWG for the environmental risk assessment. 

2.1.1.2 Chlorite Ion 

A summary of chlorite toxicity data was presented in the Basic Approval dossier (MEPC 58/2/2). 

The data is also summarized in Table T2.9. 

Nautilus Environmental performed a number toxicity studies on chlorite ion to evaluate this 

chemical in treated ballast water. Although data can be found in literature that may present lower 

end point results, Ecochlor contends that the data generated by Nautilus is the most appropriate to 

use for this assessment. Studies found in literature were often conducted long ago and there is 

difficulty in knowing how the chlorite solution was made for a particular study, or the exact 

method the study was conducted with. Therefore, Ecochlor undertook toxicity testing to ensure 

that the testing accurately represented this relevant chemical in treated ballast water. 

In any case, Ecochlor accepts the suggested use of the Mysidopsis bahia LC50 of 0.58 mg/L 

(Table T2.9) and the higher assessment factor of 1,000 for chlorite ion to derive a PNEC = 0.58 

μg/L.

2.1.1.3 Chlorate Ion 

A literature search was conducted to locate chlorate aquatic toxicity data. Data for both 

freshwater and marine organisms is presented when available. However, no suitable published 

data on the effects of chlorate on marine fish or invertebrates is available17. The data indicate 

that algae are more sensitive to chlorate than invertebrates or fish. Further, marine brown algae 

are the most sensitive to chlorate. Research indicates that algal sensitivity to chlorate is related to 

ambient nitrate levels and the nitrate reductase enzyme system18,19. Additionally, freshwater 

microalgae are generally more sensitive to chlorate than marine microalgae, at high nitrate 

levels19.

2.1.1.4 Dibromoacetic Acid (DBAA) 

A literature search was conducted to locate DBAA aquatic toxicity data; however, limited data 

was located. Four LC50 endpoints, with exposure periods of one to four days, were located for 

the fathead minnow (Pimephales promelas). The lowest LC50 (69 mg/L) was obtained from the 

four day exposure. Data for other aquatic species was not located. 

2.1.1.5 Treated Ballast Water – Shipboard Testing

A summary of treated ballast water toxicity data from shipboard testing was presented in the 

Basic Approval dossier (MEPC 58/2/2). The data is also summarized in Table T2.9. 

Water quality data of the test water from shipboard testing are presented in Section 2.0.4, Table 

T2.8d.

17 Ambient Water Quality Guidelines for Chlorate, Government of British Columbia, Environmental Protection Division, 2002 

18 van Wijk, D.J., Kroon, G.M. and Garttener-Arends, C.M., Toxicity of Chlorate and Chlorite to Selected Species of Algae, Bacteria, and Fungi,

 1998 

19 Stauber, J.L., Toxicity of Chlorate to Marine Microalgae, 1998 

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Table T2.9 – Overview of Acute Aquatic Toxicity 

Test Substance 

F

C

A

Species Test Type E(L)C50

mg/L

NOEC

mg/L

Reference/ 

comments

Preparations 

1. Purate® -- -- -- -- 

See Section 

2.0.1.1 for 

justification of 

not providing 

data

2. Sulfuric Acid -- -- -- -- 

See Section 

2.0.3.1 for 

justification of 

not providing 

data

Active Substance 

F Menidia beryllina 

96 hr survivala

(EPA-821-R02-014) 

>0.4 0.4 Nautilus Env. 

200520

F Clupea pallasi 

96 hr survival

(Method by 

Dr. Dinnel, 

Shannon Pt. 

Marine 

Center)

0.35 0.22 Nautilus Env. 

200520

F Pimephales promelas 96 hr survival 0.02 -- 

Wilde et al 

(1983) as 

reported in 

Nautilus Env. 

200733

C Mysidopsis bahia

48 hr survivala

(EPA-821-R02-014) 

~ 0.4 0.04b Nautilus Env. 

200520

Chlorine Dioxide 

A Macrocystis pyrifera 

48 hr 

germination 

(EPA-600-R95-136) 

0.20 0.14 Nautilus Env. 

200621

Relevant Chemicals 

F Cyprinidon variegatus 

96 hr survival 

(EPA FIFRA 

Guideline 72-

3)

75.0 13.9 Env. Sci. Eng. 

199422

C Mysidopsis bahia

96 hr survival 

(EPA FIFRA 

Guideline 72-

3)

0.58 NR Env. Sci. Eng. 

199423

Chlorite Ion 

(Sodium chlorite) 

A Macrocystis pyrifera 

48 hr 

germination 

(EPA-600-R95-136) 

>15.4 15.4 Nautilus Env. 

200824

20 Nautilus Environmental, Toxicological Evaluations of Chlorine Dioxide, January 2005 

21 Nautilus Environmental, Algal Toxicity Testing using Chlorine Dioxide, May 2006 

22 Environmental Science & Engineering, Acute Toxicity of Sodium Chlorite to the Sheepshead Minnow, 1994 

23 Environmental Science & Engineering, Acute Toxicity of Sodium Chlorite to Mysid Shrimp, 1994 

24 Nautilus Environmental, Supplemental Testing using Chlorite, January 2008 

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Test Substance 

F

C

A

Species Test Type E(L)C50

mg/L

NOEC

mg/L

Reference/ 

comments

F Oncorhynchus masou 

(larvae)

24 hr behavior/ 

survival 7,843 -- 

Matida et al

(1976) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25

F Oncorhynchus mykiss 

(juvenile) 48 hr survival 2,157 -- 

Environment 

Canada (1985) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25

F Pimephales promelas 

(juvenile) 96 hr survival -- >784 

Mark and 

Arends (1974) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25

F Different Fresh Water 

Species

Geometric 

Mean 3,815 -- 

van Wijk and 

Hutchinson, 

199525

C Daphnia magna 

(juvenile) 48 hr (LC50) 1,098 -- 

AQUIRE (1984) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25

C Asellus hilgendorfi 

(juvenile) 96 hr (LC50) 5,019 -- 

Matida et al

(1976) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25

C Daphnia pulex 

(juvenile) 3 hr survival -- >31 

Nishiuchi (1982) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25

C Different Fresh Water 

Species

Geometric 

Mean 2,442 -- 

van Wijk and 

Hutchinson, 

199525

A Phaeodactylum

tricornutum 72 hr biomass 289 50 

Hutchinson 

(1994) 

As reported in 

Stauber 199819

Chlorate Ion 

(ClO3

-

)

(Tested as 

sodium chlorate 

or potassium 

chlorate)

A Phaeodactylum

tricornutum

72 hr growth 

rate 444 -- 

Hutchinson 

(1994b) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25 

25 van Wijk, D.J. and Hutchinson T.H., The Ecotoxicity of Chlorate to Aquatic Organisms: A Critical Review, 1995 

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Test Substance 

F

C

A

Species Test Type E(L)C50

mg/L

NOEC

mg/L

Reference/ 

comments

A Phaeodactylum

tricornutum

72 hr growth 

rate -- 100 

Hutchinson 

(1994b) 

As reported in 

van Wijk and 

Hutchinson, 

1995)25 

A Fucus vesiculosus 

70 hr net 

photosynthetic

rate (EC66) 

4.0 -- 

Rosemarin et al

(1994) As 

reported in 

Ambient Water 

Quality

Guidelines17

A Dunaliella

terticolecta 72 hr biomass >1,000 500 Stauber (1998)19

A Nitzschia closterium 72 hr growth 1.9 -- Stauber (1998)19

A Different Marine 

Macroalgae Species 

Geometric 

Mean 0.1 0.06c

van Wijk and 

Hutchinson, 

199525

A Marine Mesocosms Biomass/ 

Growth -- 0.005c

van Wijk and 

Hutchinson, 

199525

F Pimephales promelas 24 hr survival 160 -- US EPA Ecotox 

Database26

F Pimephales promelas 48 hr survival 107 -- US EPA Ecotox 

Database26

F Pimephales promelas 72 hr survival 81 -- US EPA Ecotox 

Database26

Dibromoacetic 

Acid

F Pimephales promelas 96 hr survival 69 -- US EPA Ecotox 

Database26

Treated Ballast Water – Shipboard Testing 

C Mysidopsis bahia

48 hr survival 

(EPA-821-R02-012) 38.7% 25% Nautilus Env. 

August 200627

C Mysidopsis bahia

48 hr survival 

(EPA-821-R02-012) 37.7% 25% 

Nautilus Env. 

September 

200628

M Mytilus

galloprovencialis 

48 hr survival 

(EPA600-R95-136) 

>81.3%d 81.3%d Nautilus Env. 

August 200627

5.0 mg/L dose of 

ClO2

M Mytilus sp. 

48 hr survival 

(EPA600-R95-136) 

>84%e

 84% e

Nautilus Env. 

September 

200628

 F = Fish, C = Crustacean, M = Mollusk, A = Algae, NR = Not Reported 

 EC50 and NOEC values for treated ballast water are presented in % (vol/vol) treated ballast water sample. 

 a Calculated on the basis of data from the chronic toxicity test with this species. b Reported NOEC is highly conservative because the next concentration tested was 10-times higher (see discussion in Section 2.1.2.1). c

 See discussion regarding this data in Section 5.3.6.2 

 d 81.3% is the highest concentration tested in this Mytilus test. e

 84% is the highest concentration tested in this Mytilus test.

2.1.1.6 Treated Ballast Water – Land Based Testing at NIOZ 

Acute exposure tests were performed with fish, crustaceans, algae, mollusks, rotifers and marine 

bacteria. Testing was performed for all six (6) taxonomic groups during both brackish and sea 

26 US EPA, ECOTOX Database, Aquatic Report for Dibromoacetic Acid, 2008 

27 Nautilus Environmental, Toxicological Evaluation of Ballast Water Treated with Chlorine Dioxide, Atlantic Compass Trial, August 2006 28 Nautilus Environmental, Toxicological Evaluation of Ballast Water Treated with Chlorine Dioxide, Atlantic Compass Trial, September 2006

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water test cycles. However, although testing with algae at the higher salinity (sea water) was 

attempted multiple times, the laboratory control results did not meet quality control criteria to 

allow the data to be reported with confidence. Ultimately, two separate algae tests were 

completed successfully in brackish water. Because the G9 methodology indicates that toxicity 

data from freshwater OR saltwater species should be accepted, algae toxicity testing in brackish 

water fulfils the data requested by the methodology. 

The mollusk Crassostrea gigas was the most sensitive of the six (6) taxonomic groups tested one 

(1) day after treatment in both brackish and sea water, with EC50 values of 38.1% and 62.3%, 

respectively. Acute testing results from land based discharges are summarized in Table T2.9a 

below.

Water quality data of the test water from land based testing are presented in Section 2.0.4, Tables 

T2.8e and T2.8f. 

Table T2.9a – Overview of Acute Aquatic Toxicity Data – Land Based Testing 

Test Substance 

F

C

A

Species Test Type E(L)C50 NOEC Reference/ 

comments

Treated Ballast Water – Land Based Testing at NIOZ

BRACKISH WATER (average salinity 23.1 ± 0.65 PSUa)

F Cyprinodon variegatus 

(Sheepshead minnow) 

96 hr 

survival

(OECD 203) 

>100% 100% 

Chemex 

Environmental 

Internt’l, 200829

C Acartia tonsa 

(copepod) 

48 hr 

survival

(ISO 14669) 

>100% 100% 

Grontmij / 

AquaSense, 

200829

M Crassostrea gigas 

(Pacific oyster) 

48 hr 

develop. 

(ASTM 

E724,

modified) 

38.1% 10% 

Grontmij / 

AquaSense, 

200829

B Vibrio fisheri 

Microtox 

(ISO 11348-

3)

83.3% NR 

Grontmij / 

AquaSense, 

200829

A

Phaeodactylum

tricornutum

(diatom) 

96 hr growth 

inhibition

(ISO 10253) 

>100% 100% 

Grontmij / 

AquaSense, 

200829

5.0 mg/L dose of 

ClO2 - 1 day 

after treatment 

R Brachionus plicatilis 

(rotifer)

24 hr 

survival

(Rotox Kit 

M) 

>100% 100% 

Grontmij / 

AquaSense, 

200829

SEA WATER (average salinity 31.9 ± 1.3 PSUa)

F Cyprinodon variegatus 

(Sheepshead minnow) 

96 hr 

survival

(OECD 203) 

>100% 100% 

Chemex 

Environmental 

Internt’l, 200829

C Acartia tonsa 

(copepod) 

48 hr 

survival

(ISO 14669) 

>100% 100% 

Grontmij / 

AquaSense, 

200829

5.0 mg/L dose of 

ClO2 - 1 day after 

treatment 

M Crassostrea gigas 

(Pacific oyster) 

48 hr 

develop. 

(ASTM 

E724,

modified) 

62.3% 18% 

Grontmij / 

AquaSense, 

200829

29 Grontmij | Aquasense, Report of Ecotoxicological Studies, October 2008 

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B Vibrio fisheri 

Microtox 

(ISO 11348-

3)

70.9% NR 

Grontmij / 

AquaSense, 

200829

R Brachionus plicatilis 

(rotifer)

24 hr 

survival

(Rotox Kit 

M) 

>100% 100% 

Grontmij / 

AquaSense, 

200829

 F = Fish, C = Crustacean, A = Algae, M = Mollusk, B = Bacteria, R = Rotifer, NR = Not Reported 

 EC50 and NOEC values for treated ballast water are presented in % (vol/vol) treated ballast water sample. 

 a Average salinity during land-based test cycles as reported by NIOZ

2.1.2 Chronic Aquatic Toxicity 

The GEAMP-BWWG commented (Section 8.1.2 of MEPC 58/2/8, Annex 54

) that toxicity tests 

of 7-day exposures are not recognized as chronic methods. Although Ecochlor has accepted the 

recommendation of using a higher assessment factor of 1,000 for the environmental risk 

assessment as recommended by the GESAMP-BWWG, the following discussion is provided to 

explain the use and validity of short term exposure chronic testing methods. 

The primary reasons for using short term exposure (sub-lethal endpoint) testing methods is that 

these methods are commonly recognized by regulatory agencies as acceptable chronic methods, 

and the physical properties of the chemicals associated with the Ecochlor® BWTS indicate that 

they degrade rapidly. Therefore, long term exposure in the aquatic environment would not be 

expected. Justification is provided below.

As a result of extensive studies that compared “traditional” long term (full life cycle) chronic 

toxicity test data with the data obtained using short term chronic testing methods, the US EPA 

and independent scientific experts determined that short term methods provided essentially the 

same data. The US EPA therefore adopted and recognizes short term chronic testing methods as 

standard procedures for evaluating toxicity of substances and whole effluents30. Environment 

Canada also considers short term testing as standard methods. For example, a 7 day survival 

and growth test with fathead minnow eggs and larvae is considered a standard long term test31.

Additionally, a non-lethal endpoint test of 7 days with longer-lived crustaceans is considered a 

standard long term test method31.

Since the late 1960’s scientists have been evaluating the validity of long term chronic toxicity 

testing methods. From the US EPA Short Term Methods for Estimating Chronic Toxicity 

Manual30:

“2.1.6 Macek and Sleight (1977) found that exposure of critical life stages of fish to toxicants 

provides estimates of chronically safe concentrations remarkably similar to those derived from 

full life cycle toxicity tests. They reported that "for a great majority of toxicants, the concentration 

which will not be acutely toxic to the most sensitive life stages is the chronically safe 

concentration for fish, and that the most sensitive life stages are the embryos and fry." Critical 

life stage exposure was considered to be exposure of the embryos during most, preferably all, of 

the embryogenic (incubation) period, and exposure of the fry for 30 days post-hatch for warm 

water fish with embryogenic periods ranging from one-to-fourteen days, and for 60 days posthatch for fish with longer embryogenic periods. They concluded that in the majority of cases, the 

maximum acceptable toxicant concentration (MATC) could be estimated from the results of 

exposure of the embryos during incubation, and the larvae for 30 days post-hatch. 

30 US EPA, Short-Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to West Coast Marine and Estuarine 

 Organisms, EPA/600/R-95-136, August 1995, (Section 2) 

31 Canadian Water Quality Guidelines for the Protection of Aquatic Life, A Protocol for the Derivation of Water Quality Guidelines for the

 Protection of Aquatic Life 2007 

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2.1.7 Because of the high cost of full life-cycle fish toxicity tests and the emerging consensus that 

the ELS test data usually would be adequate for estimating chronically safe concentrations, there 

was a rapid shift by aquatic toxicologists to 30- to 90-day ELS toxicity tests for estimating 

chronically safe concentrations in the late 1970s. In 1980, USEPA adopted the policy that ELS 

test data could be used in establishing water quality criteria if data from full life-cycle tests were 

not available (USEPA, 

1980a).

2.1.8 Published reports of the results of ELS tests indicate that the relative sensitivity of growth 

and survival as endpoints may be species dependent, toxicant dependent, or both. Ward and 

Parrish (1980) examined the literature on ELS tests that used embryos and juveniles of the 

sheepshead minnow, Cyprinodon variegatus, and found that growth was not a statistically 

sensitive indicator of toxicity in 16 of 18 tests. They suggested that the ELS tests be shortened to 

14 days posthatch and that growth be eliminated as an indicator of toxic effects. 

2.1.9 In a review of the literature on 173 fish full life-cycle and ELS tests performed to determine 

the chronically safe concentrations of a wide variety of toxicants, such as metals, pesticides, 

organics, inorganics, detergents, and complex effluents, Woltering (1984) found that at the lowest 

effect concentration, significant reductions were observed in fry survival in 57%, fry growth in 

36%, and egg hatchability in 19% of the tests. He also found that fry survival and growth were 

very often equally sensitive, and concluded that the growth response could be deleted from 

routine application of the ELS tests. The net result would be a significant reduction in the 

duration and cost of screening tests with no appreciable impact on estimating MATCs for 

chemical hazard assessments. Benoit et al. (1982), however, found larval growth to be the most 

significant measure of effect and survival to be equally or less sensitive than growth in early lifestage tests with four organic chemicals. 

2.1.10 Efforts to further reduce the length of partial lifecycle toxicity tests for fish without 

compromising their predictive value have resulted in the development of an eight-day, embryolarval survival and teratogenicity test for fish and other aquatic vertebrates (USEPA, 1981; Birge 

et al.,1985), and a seven-day larval survival and growth test (Norberg and Mount, 1985). 

2.1.11 The similarity of estimates of chronically safe concentrations of toxicants derived from 

short-term, embryo-larval survival and teratogenicity tests to those derived from full life-cycle 

tests has been demonstrated by Birge et al. (1981), Birge and Cassidy (1983), and Birge et al. 

(1985).

2.1.12 Use of a seven-day, fathead minnow, Pimephales promelas, larval survival and growth test 

was first proposed by Norberg and Mount at the 1983 annual meeting of the Society for 

Environmental Toxicology and Chemistry (Norberg and Mount, 1983). This test was subsequently 

used by Mount and associates in field demonstrations at Lima, Ohio (USEPA, 1984), and at many 

other locations (USEPA, 1985c, USEPA, 1985d; USEPA, 1985e; USEPA, 1986a; USEPA, 1986b; 

USEPA, 1986c; USEPA, 1986d). Growth was frequently found to be more sensitive than survival 

in determining the effects of complex effluents. 

2.1.13 Norberg and Mount (1985) performed three single toxicant fathead minnow larval growth 

tests with zinc, copper, and DURSBAN®, using dilution water from Lake Superior. The results 

were comparable to, and had confidence intervals that overlapped with, chronic values reported 

in the literature for both ELS and full life-cycle tests. 

2.1.14 USEPA (1987b) and USEPA (1987c) adapted the fathead minnow larval growth and 

survival test for use with the sheepshead minnow and the inland silverside, respectively. When 

daily renewal 7-day sheepshead minnow larval growth and survival tests and 28-day ELS tests 

were performed with industrial and municipal effluents, growth was more sensitive than survival 

in seven out of 12 larval growth and survival tests, equally sensitive in four tests, and less 

sensitive in only one test. In four cases, the ELS test may have been three to 10 times more 

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sensitive to effluents than the larval growth and survival test. In tests using copper, the No 

Observable Effect Concentrations (NOECs) were the same for both types of test, and growth was 

themost sensitive endpoint for both. In a four laboratory comparison, six of seven tests produced 

identical NOECs for survival and growth (USEPA, 1987a). Data indicate that the inland 

silverside is at least equally sensitive or more sensitive to effluents and single compounds than the 

sheepshead minnow, and can be tested over a wider salinity range, 5-30‰ (USEPA, 1987a). 

2.1.15 Lussier et al. (1985) and USEPA (1987e) determined that survival and growth are often as 

sensitive as reproduction in 28-day life-cycle tests with the mysid, Mysidopsis bahia.”

The toxicity testing results presented in this and the Basic Approval dossier were performed in 

accordance with the short term chronic toxicity testing methods considered standard in the US, 

which are also recognized internationally. Section 3.3.3.2 of the G9 Methodology also indicates 

that short-term chronic testing methods are acceptable because identifying the sensitive sublethal endpoints and vulnerable life stages is the goal of long-term exposure testing. As such, and 

in accordance with widely accepted testing guidelines, US EPA short term chronic testing 

methods were used during testing with these chemicals as well as treated ballast water discharge. 

This is the basis for including and evaluating 7-day toxicity tests under the chronic test data 

section of the dossier.

In regard to the chemical properties, it is important to note that long term exposure chronic 

toxicity testing for both chlorine dioxide and chlorite ion is not the most practical approach due 

to the rapid degradation of these chemicals. According to the OECD “...the instability of these 

chemicals suggests that it would not be relevant to perform chronic experiments.”10 Subjecting

test organisms to 14, 21 or 28-day test protocols would not reflect realistic exposure times 

because chlorine dioxide and chlorite ion would not persist in the environment for these 

durations.

2.1.2.1 Chlorine Dioxide 

A summary of chlorine dioxide toxicity data was presented in the Basic Approval dossier (MEPC 

58/2/2). The data is also summarized in Table T2.10. 

2.1.2.2 Chlorite Ion 

A summary of chlorite toxicity data was presented in the Basic Approval dossier (MEPC 58/2/2). 

The data is also summarized in Table T2.10. 

Nautilus Environmental performed a number toxicity studies on chlorite ion to evaluate this 

chemical in treated ballast water. Although data can be found in literature that may present lower 

end point results, Ecochlor contends that the data generated by Nautilus is the most appropriate to 

use for this assessment. Studies found in literature were often conducted long ago and there is 

difficulty in knowing how the chlorite solution was made for a particular study, or the exact 

method the study was conducted with. Therefore, Ecochlor undertook toxicity testing to ensure 

that the testing accurately represented this relevant chemical in treated ballast water. 

In any case, Ecochlor accepts the suggested use of the Mysidopsis bahia LC50 of 0.58 mg/L 

(Table T2.9) and the higher assessment factor of 1,000 for chlorite ion to derive a PNEC = 0.58 

μg/L.

2.1.2.3 Treated Ballast Water – Shipboard Testing 

A summary of treated ballast water toxicity data from shipboard testing was presented in the 

Basic Approval dossier (MEPC 58/2/2). The data is also summarized in Table T2.10. 

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Water quality data of the test water from shipboard testing are presented in Section 2.0.4, Table 

T2.8d.

Table T2.10 – Overview of Chronic Aquatic Toxicity 

Test Substance 

F

C

A

M

Species Test Type EC50

mg/L

NOEC

mg/L

Reference/ 

comments

Preparations 

1. Purate® -- -- -- -- 

See Section 2.0.1.1 

for justification of 

not providing data 

2. Sulfuric Acid -- -- -- -- 

See Section 2.0.3.1 

for justification of 

not providing data 

Active Substance 

F Menidia beryllina 

7 day 

surv/growth 

(EPA-821-R02-014) 

>0.4 0.4 Nautilus Env.

200520

F Clupea pallasi 

18 day embryo 

devpt

(Method by 

Dr. Dinnel, 

Shannon Pt. 

Marine 

Center)

>0.33 0.33 Nautilus Env. 

200520

C Mysidopsis bahia 

7 day 

surv/growth 

(EPA-821-R02-014) 

~ 0.4 0.04a Nautilus Env. 

200520

A Macrocystis pyrifera 

48 hr 

germination 

(EPA-600-R95-136) 

0.20 0.14 Nautilus Env. 

200621

D Skeletonema

costatum 

96 hr growth 

(ASTM 

E1218-97a) 

3.09 2.09 Nautilus Env. 

200621

Chlorine 

Dioxide

M Mytilus edulis 

Development 

(EPA-600-R95-136) 

0.22 0.09 Nautilus Env. 

200520

Relevant Chemicals 

Sulfate Ion/ 

Sulfuric Acid 

-- -- -- -- 

See Section 2.0.3.1 

for justification of 

not providing data 

F Atherinops affinis 

7 day 

surv/growth 

(EPA-821-R02-014) 

>13.8 6.9 Nautilus Env. 

200824

C Mysidopsis bahia 

7 day 

surv/growth 

(EPA-821-R02-014) 

0.26 0.18 Nautilus Env. 

200824

Chlorite Ion 

(Sodium 

chlorite)

A Macrocystis pyrifera 

48 hr 

germination 

(EPA-600-R95-136) 

>15.4 15.4 Nautilus Env. 

200824

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Test Substance 

F

C

A

M

Species Test Type EC50

mg/L

NOEC

mg/L

Reference/ 

comments

E Strongylocentrotus 

purpuratus 

48 hr 

germination 

(EPA-600-R95-136) 

10.4 5.0 Nautilus Env. 

200824

M Crassostrea 

virginica

Development 

(EPA FIFRA 

Guideline 72-

3)

21.4 14.3 Env. Sci. Eng. 

199432

F Oncorhynchus 

mykiss 56 days -- 48 

Matida et al (1975) 

As reported in 

Ambient Water 

Quality Guidelines17

C Dasycorixa hybrida 10 days -- 100 

Dosdall et. al.

(1997) As reported 

in Ambient Water 

Quality Guidelines17

C Isoperla transmarina 10 days -- 100 

Dosdall et. al.

(1997) As reported 

in Ambient Water 

Quality

Guidelines17Fehler!

Textmarke nicht definiert.

A Zostera marina 6 month 

growth -- >0.29 Rosemarin et al

(1994)41

A Fucus serratus 1 month frond 

growth 0.13 -- Rosemarin et al

(1994)41

A Fucus vesiculosus 6 month 

growth -- 0.005b van Wijk and 

Hutchinson, 199525

Chlorate Ion 

(ClO3

-

)

(Tested as 

sodium chlorate 

or potassium 

chlorate)

A Fucus vesiculosus 6 month 

growth 0.08b

 -- Rosemarin et al

(1994)41

Dibromoacetic 

acid

No Chronic Aquatic 

Studies Located for 

DBAA

-- -- -- -- 

Treated Ballast Water – Shipboard Testing 

M Mytilus

galloprovincialis

Development 

(EPA-600-R95-136) 

>81.3

%c 81.3%c

Nautilus Env. 

August 200627

M Mytilus sp.

Development 

(EPA-600-R95-136) 

>84%d 50% 

Nautilus Env. 

September 200628

C

Mysidopsis bahia 48 hr survival 

(EPA-821-R02-012) 

-- 12%e

 Nautilus Env. 

200733

5.0 mg/L dose of 

ClO2

C

Mysidopsis bahia 48 hr survival 

(EPA-821-R02-012) 

-- 11.7%e

 Nautilus Env. 

200733

F = Fish, C = Crustacean, A = Algae, D = Diatom, M = Mollusk, E = Echinoderm, NR = Not Reported 

 EC50 and NOEC values for treated ballast water are presented in % (vol/vol) treated ballast water sample. a Reported NOEC is highly conservative because the next concentration tested was 10-times higher (see discussion in Section 2.1.2.1). b See discussion regarding this data in Section 5.3.6.2

 c 81.3% is the highest concentration tested in this Mytilus test. d 84% is the highest concentration tested in this Mytilus test. e Chronic NOEC calculated using acute-to-chronic ratio of 3.22. 

32 Environmental Science & Engineering, Effect of Sodium Chlorite on New Shell Growth in Eastern Oyster (Crassostrea virginica), 1994 

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2.1.2.4 Treated Ballast Water – Land Based Testing at NIOZ 

Short term exposure (sub-lethal endpoint (growth / development)) testing was evaluated only for 

the most sensitive taxonomic group identified from the acute testing. This approach allowed for 

testing on a wider range of six taxonomic groups and also avoided unnecessary testing on 

organisms that did not show evidence of toxic effects with acute exposures. This approach for 

ecotoxicity testing was based on discussions and agreements between Ecochlor and the German 

Administration. 

During the land based test set up samples of treated ballast water discharge were collected one 

(1) day (approx. 24 hours) and five (5) days after treatment and evaluated for chronic (short term 

exposure) aquatic toxicity. From the acute testing series, Crassostrea gigas was identified as the 

most sensitive taxonomic group and additional tests were performed with this species. Although 

the Crassostrea gigas testing method uses a short-term exposure, the test evaluates a chronic sublethal end point (development). As such, this test was determined by Grontmij|AquaSense to be 

the appropriate method to evaluate chronic effects with this species and is consistent with Section 

3.3.3.2 of the G9 Methodology. 

Crassostrea gigas tested with discharge one (1) day after treatment resulted in EC50 values of 

43.3% and 50.4% in brackish and sea water, respectively. Testing on day 5 samples with 

Crassostrea gigas resulted in EC50 values of 36.3% and 73.6% in brackish and sea water, 

respectively. 

One additional test with Phaeodactylum tricornutum was also performed with day 1 brackish 

water discharge. This test resulted in an EC50 of 75.8%. Poor growth performances of the 

laboratory controls during algae testing in sea water caused the tests to be invalid, so although 

testing was performed multiple times, the controls did not meet the criteria to be reported with 

confidence.

Chronic sub-lethal endpoint testing results are summarized in Table T2.10a below. 

Water quality data of the test water from land based testing are presented in Section 2.0.4, Tables 

T2.8e and T2.8f.

Table T2.10a – Overview of Chronic (Sub-lethal) Aquatic Toxicity – Land Based Testing 

Test Substance 

F

C

A

Species Test Type E(L)C50 NOEC Reference/ 

comments

Treated Ballast Water – Land Based Testing at NIOZ

BRACKISH WATER (average salinity 23.1 ± 0.65 PSUa)

M Crassostrea gigas 

(Pacific oyster) 

48 hr develop. 

(ASTM E724, 

modified) 

43.3% 18% Grontmij / 

5.0 mg/L dose of AquaSense, 2008 

ClO2 - 1 day 

after treatment A

Phaeodactylum

tricornutum

(diatom) 

96 hr growth 

inhibition

(ISO 10253) 

75.8% 32% Grontmij / 

AquaSense, 2008 

5.0 mg/L dose of 

ClO2 - 5 days 

after treatment 

M Crassostrea gigas 

(Pacific oyster) 

48 hr develop. 

(ASTM E724, 

modified) 

36.3% 18% Grontmij / 

AquaSense, 2008 

SEA WATER (average salinity 31.9 ± 1.3 PSUa)

5.0 mg/L dose of 

ClO2 - 1 day 

after treatment 

M Crassostrea gigas 

(Pacific oyster) 

48 hr develop. 

(ASTM E724, 

modified) 

50.4% 32% Grontmij / 

AquaSense, 2008 

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5.0 mg/L dose of 

ClO2 - 5 days 

after treatment 

M Crassostrea gigas 

(Pacific oyster) 

48 hr develop. 

(ASTM E724, 

modified) 

73.6% 56% Grontmij / 

AquaSense, 2008 

 A = Algae, M = Mollusk EC50 and NOEC values for treated ballast water are presented in % (vol/vol) treated ballast water sample. 

 a Average salinity during land-based test cycles as reported by NIOZ 

2.1.3 Endocrine Disruption 

There is no evidence to suggest that Purate® or sulfuric acid would result in endocrine disruption. 

There is no evidence to suggest that chlorine dioxide or chlorite would result in endocrine 

disruption33.

Sodium chlorate is not known to be an endocrine disrupter34,

No data on specific endocrine disruption studies for DBAA were located. However, a 

reproductive study using daily gavage doses of 10 mg/kg of body weight per day for 79 days 

showed altered spermiation in male rats14.

2.1.4 Sediment Toxicity 

2.1.4.1 Preparations 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

2.1.4.2 Active Substance 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

2.1.4.3 Relevant Chemicals 

Information for sulfuric acid and chlorite ion was provided in the Basic Approval dossier (MEPC 

58/2/2).

Sodium chlorate is discussed above in Section 2.1.4.1, Preparations. 

DBAA is “very soluble”14 and has a log Kow < 3. These chemical properties indicate that DBAA 

will not adsorb to sediments. 

2.1.4.4 Treated Ballast Water 

The potential substances present in treated ballast water at the time of discharge are chlorine 

dioxide, chlorite ion, chlorate ion, and DBAA. The capability of these constituents to accumulate 

in sediments is discussed above. 

2.1.5 Bioavailability/Biomagnification/Bioconcentration and Food Web/Population Effects 

The active substance (chlorine dioxide) and relevant chemicals (chlorite ion, chlorate ion, 

DBAA) are the constituents potentially present in treated ballast water that will be discharged to 

the environment. All substances are highly water soluble and are not organic in nature. Neither 

chlorine dioxide or chlorite ion would be expected to exhibit biomagnification or 

bioconcentration, and consequently, would not be expected to persist in the food web33. Sodium 

chlorate has a low potential to bioaccumulate15. DBAA is not lipophilic at physiological pH and 

has a low potential to accumulate in fat14.

2.2 DATA ON MAMMALIAN TOXICITY (G9: 4.2.1.2) 

Most information provided in this section has not changed from the Basic Approval dossier and 

is not presented again. However, based on comments received from the GESAMP-BWWG 

regarding chlorite ion, as well as new analytical chemistry data from land based testing, the data 

33 Review of the Environmental Fate and Effects of Chlorine Dioxide and Chlorite, Nautilus Environmental, 2007. 

34 European Union, The Footprint Pesticide Properties Database (www.eu-footprint.org/ppdb.html) 

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tables in this section were revised to include information on chlorite ion and DBAA to 

supplement the evaluation. 

There are very limited data available on the toxicity of brominated acetic acids35. Specific data 

was not always located for DBAA, but data for brominated acetic acids as a group is provided 

when available.

All data tables are contained within the complete confidential dossier for Final Approval. 

2.2.1 Acute Mammalian Toxicity 

Data table was presented in the Basic Approval dossier (MEPC 58/2/2) and is included in the 

complete confidential dossier for Final Approval. 

2.2.2 Effects on Skin and Eye 

Data table was presented in the Basic Approval dossier (MEPC 58/2/2) and is included in the 

complete confidential dossier for Final Approval. 

2.2.3 Repeated-dose Toxicity 

Data table was presented in the Basic Approval dossier (MEPC 58/2/2) and is included in the 

complete confidential dossier for Final Approval. 

2.2.4 Chronic Toxicity 

Data table was presented in the Basic Approval dossier (MEPC 58/2/2) and is included in the 

complete confidential dossier for Final Approval. 

2.2.5 Developmental and Reproductive Toxicity 

Information for sodium chlorate, hydrogen peroxide, sulfuric acid and chlorine dioxide was 

provided in the Basic Approval dossier (MEPC 58/2/2). 

A developmental study with rabbits concluded that sodium chlorite in drinking water was not 

considered teratogenic or a developmental toxicant10.

DBAA was administered via gavage to male rats for 14 daily doses at 0, 10, 30, 90, or 270 mg/kg 

of body weight per day. The LOAEL for this study was the lowest dose tested, 10 mg/kg of body 

weight per day14. DBAA did not exhibit teratogenic potential in the frog embryo (Xenopus)

assay14.

2.2.6 Carcinogenicity

Information for sodium chlorate, hydrogen peroxide, sulfuric acid and chlorine dioxide was 

provided in the Basic Approval dossier (MEPC 58/2/2). 

A carcinogenicity study of sodium chlorite in drinking water with mice concluded that sodium 

chlorite had no carcinogenic potential10.

Two-year drinking water studies for carcinogenicity with male and female rats indicate some 

evidence of carcinogenic activity for DBAA42.

2.2.7 Mutagenicity/Genotoxicity 

Information for sodium chlorate, hydrogen peroxide, sulfuric acid and chlorine dioxide was 

provided in the Basic Approval dossier (MEPC 58/2/2). 

35 International Programme on Chemical Safety, Environmental Health Criteria 216, World Health Organization, 2000 

42 NTP Technical Report on the Toxicology and Carcinogenesis of Dibromoacetic Acid, April 2007 

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Negative in vivo tests with sodium chlorite indicate a low potential for genotoxicity. There were 

no reliable in vitro mutagenicity tests for sodium chlorite10.

In the Ames fluctuation test with S. typhimurium tester strain TA100 DBAA was mutagenic, with 

and without metabolic activation, but not in S. typhimurium tester strain TA9814. In the SOS 

chromotest, DBAA induced DNA repair, with and without metabolic activation, but the number 

of erythrocyctes with micronuclei in the newt micronucleus test were not increased14.

2.2.8 Toxicokinetics 

Information for sodium chlorate, hydrogen peroxide, sulfuric acid, chlorine dioxide and chlorite 

was provided in the Basic Approval dossier (MEPC 58/2/2). 

In a gavage study with rats, the concentration of DBAA in blood peaked within 1 hour after 

dosing, suggesting rapid intestinal absorption14. Further, the metabolites of DBAA appear to be 

rapidly excreted; however, the urine and fecal excreted contributed minimally to the overall 

blood clearance of DBAA. This finding suggested that biotransformation was responsible for the 

rapid disappearance of DBAA from blood14.

2.3 DATA ON ENVIRONMENTAL FATE AND EFFECT UNDER AEROBIC AND 

ANAEROBIC CONDITIONS (G9: 4.2.1.3) 

The active substance (chlorine dioxide) and relevant chemicals (chlorite ion, chlorate ion, DBAA) 

are the constituents potentially present at environmentally relevant concentrations in treated ballast 

water that may be discharged to the environment. Therefore, environmental fate is evaluated for 

these substances only. 

2.3.1 Modes of Degradation (Biotic, Abiotic) 

Information for chlorine dioxide and chlorite ion was provided in the Basic Approval dossier 

(MEPC 58/2/2). 

Because sodium chlorate is an inorganic substance, it cannot be defined as biodegradable on the 

basis of mineralization of organic matter15. However, within anaerobic niches in the soil, biotic 

degradation occurred where anaerobic biodegradation occurred via non-obligate anaerobes which 

mineralize chlorate to chloride generally using the same pathway as for nitrate reduction15. In a 

water-sediment system the DT50s under anaerobic- and aerobic conditions were 8 days in water 

and less than 3 days in sediment15. In the water column, extensive redox reactions are expected 

to occur in the environment that will reduce the concentration of chlorate36.

Haloacetic acids such as (MCAA) monochlororoacetic acid, (DCAA) dichloroacetic acid, 

(TCAA) trichloroacetic acid, MBAA (monobromoacetic acid) and DBAA (dibromoacetic acid) 

have been reported to be decomposed by bacterial enzymes called haloacid dehydrogenases37. In 

a study of the degradation of haloacetic acids in seawater using mercury chloride to inhibit 

microbial activity, all of the haloacetic acids nearly disappeared within 9 days holding time, with 

the exception of TCAA37. The authors also concluded that brominated acetic acids are better 

substrates for the bacterial haloacid dehydrogenases than the chloroacetic acids37. This study 

indicates that “... degradation patterns of haloacetic acids with and without HgCl2 suggest that, 

with the exception of TCAA, about one half of the observed decomposition over the 9-d 

incubations was due to microbial activity37. Photolytic degradation of DBAA, particularly in the 

presence of a photocatalyst (titanium dioxide) is also an effective mode of degradation38.

36 US EPA Reregistration Eligibility Decision (RED) for Inorganic Chlorates, Case #4049, July 2006 

37 Hashimoto, S., Azuma, T., Otsuki, A., Distribution, Sources and Stability of Haloacetic Acids in Tokyo Bay, Japan, 1998

38 Lifongo, L., Bowden, D., Brimblecombe, P., Photodegradation of haloacetic acids in water, 2004 

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2.3.2 Bioaccumulation, Partition Coefficient, Octanol/Water Partition Coefficient 

Information for chlorine dioxide and chlorite ion was provided in the Basic Approval dossier 

(MEPC 58/2/2). 

Sodium chlorate has a low log n-octanol/water partition coefficient and high water solubility, 

which indicate that sodium chlorate has low potential to bioaccumulate36.

DBAA has a low log n-octanol/water partition coefficient and high water solubility, which 

indicate that sodium chlorate has low potential to bioaccumulate14.

2.3.3 Reaction with Organic Matter 

Information for chlorine dioxide and chlorite ion was provided in the Basic Approval dossier 

(MEPC 58/2/2). 

In the environment, chlorate can undergo reduction reactions with organic matter and “...the 

thermodynamically favored, end reduction product of chlorate in soil and in water is the chloride 

anion.”39

Brominated acetic acids such as DBAA are formed when bromide ion and organic matter is 

present during water disinfection processes14. Continued reaction of DBAA with organic matter 

is not expected.

2.3.4 Potential Physical Effects on Wildlife and Benthic Habitats 

The chemical and physical properties of the preparation chemicals, active substance, and relevant 

chemicals (Table T2-15) indicate that physical effects on wildlife and benthic habitats as 

described and rated in GESAMP Reports and Studies No. 64 would not be expected to occur. 

Also see Section 2.1.4. 

2.3.5 Potential Residues in Seafood 

No potential for residues in seafood are known or anticipated for the chemicals associated with 

the Ecochlor® Ballast Water Treatment System. 

2.3.6 Any Known Interactive Effects 

There are no other known or expected interactive effects related to the chemicals associated with 

the Ecochlor® Ballast Water Treatment System. 

2.4 PHYSICAL AND CHEMICAL PROPERTIES FOR THE PREPARATIONS, 

ACTIVE SUBSTANCE, AND TREATED BALLAST WATER (G9: 4.2.1.4) 

Data table was provided in the Basic Approval dossier (MEPC 58/2/2) and is also included in the 

complete confidential Final Approval dossier. 

2.5 ANALYTICAL METHODS AT ENVIRONMENTALLY RELEVANT 

CONCENTRATIONS (G9: 4.2.1.5) 

Information was provided in the Basic Approval dossier (MEPC 58/2/2) and is also included in the 

complete confidential Final Approval dossier. 

2.6 QUALITY CONTROL/QUALITY ASSURANCE (G9: 4.2.4) 

2.6.1 Chemical Quality Control 

Information was provided in the Basic Approval dossier (MEPC 58/2/2) and is also included in the 

complete confidential Final Approval dossier. 

39 US EPA Memorandum, Revised Inorganic Chlorates, HED Chapter of the Reregistration Eligibility Decision (RED) Case #4049, January 2006 

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2.6.2 Test Data Quality Control 

Information was provided in the Basic Approval dossier (MEPC 58/2/2) and is also included in the 

complete confidential Final Approval dossier. 

3.0 USE OF THE ACTIVE SUBSTANCE 

3.0.1 Manner of Application (G9: 4.2.6) 

A detailed description of the application of chlorine-free chlorine dioxide to treat ballast water 

was included in the Basic Approval dossier (MEPC 58/2/2). The description has been modified 

only by the addition of the following: 

The Ecochlor® BWTS uses a two-step treatment process. The first step is pre-treatment filtration 

with a 40 micron steel mesh filter. The second step is injection of chlorine-free chlorine dioxide 

into the incoming ballast water stream. 

3.0.2 Operational Overview & Process Description 

Incoming ballast water is pumped onboard as usual (through the sea chest/sea filter) via the 

ballast water pumps. Ballast water then passes through the pre-filtration step of Ecochlor’s 

treatment process. Immediately after the pre-filtration step, the Ecochlor® BWTS injects 

chlorine-free chlorine dioxide into the incoming ballast water as it is piped to the ballast tanks. 

See Figure F3.2 for a process flow overview. 

The Ecochlor® BWTS chlorine dioxide generation module consists of two self-contained 

chemical storage modules, two separate precursor chemical pumps, a chlorine dioxide generation 

module (housing for the reactor column), a booster pump, a programmable logic controller 

(PLC), an operator interface terminal (OIT), a system status/start-up panel, and piping to inject 

chlorine dioxide solution into the ballast water line. Ancillary equipment includes pipelines for 

chemical vents and re-supply, and in-line sampling valves. For demonstration, engineered 

drawings of a full scale Ecochlor® BWTS and the BallastSafeTM filter unit are included in 

Appendix D. Figure F3.1 provides a photograph of the Ecochlor® BWTS, Figure F3.1a is a 

photo of the BallastSafeTM filter unit, and Figures F3.2 and F3.2a outline the Ecochlor® BWTS 

process.

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Figure F3.1 – Photo of Full Scale Ecochlor® BWTS 

Figure F3.1a – Photo of Filtration Unit 

Figure F3.2 – Ecochlor® BWTS Process Flow Diagram 

BW

Tank(s

Sea

Chest

Sea

Filter

BW

Pump

Pretreatment

Filtration

Cl02 Generation 

System (See Figure F3.2a)

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Figure F3.2a – Ecochlor Chlorine Dioxide Generation Process 

Supply Water

Mixing 

Chamber

ClO2 solution to 

ballast line

Sulfuric Acid Purate

ClO2 is mixed in supply water

Venturi ClO2

Sensor

PLC

FT

PT

FT = Flow Transmitter, PT = Pressure Transmitter, PLC = Programmable Logic Controller

A detailed discussion of the chlorine dioxide generation process and treatment parameters was 

presented in the Basic Approval dossier (MEPC 58/2/2).

3.0.3 System Monitoring & Control, Crew Interaction 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.4 System Requirements 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.5 System Locations, Considerations and Limitations 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.6 BWTS Operational Safety Features and Alarms 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.7 Precursor Chemical Storage, Handling and Delivery 

Ecochlor’s team has accumulated over 100 years of industrial and municipal experience in 

storing, feeding and re-supplying these and many other chemicals. This experience is utilized in 

the design, fabrication and installation of the Ecochlor® BWTS. Ecochlor also utilizes a team of 

naval architects and marine engineers from Seaworthy Systems, Inc. to assist with the specifics 

of shipboard installation and environments. 

3.0.7.1 Chemical Storage 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). Additional 

clarification based on GESAMP-BWWG comments is provided below. 

The use of the terms “secondary containment” to describe additional measures to ensure 

protection to the ship in the unlikely event of a chemical leak is equivalent to the terminology 

“save-all protection” used by the GESAMP-BWWG. This is an engineered aspect of the BWTS 

to ensure safe installation. Preparing for BWTS installation onboard a ship requires detailed 

reviews by Ecochlor’s marine engineers, the vessel engineers, as well as the ship’s classification 

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society. Additional mitigation measures that may be identified for safe BWTS installation on a 

specific ship during these reviews will be implemented as needed. 

3.0.7.2 Chemical Handling 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.7.3 Chemical Delivery 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.8 Various Procedures and Management Measures 

3.0.8.1 Fire

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). Additional 

clarification based on GESAMP-BWWG comments is provided below. 

3.0.8.1.1 Additional Clarification on Fire Mitigation Measures 

The GESAMP-BWWG provided comments regarding the different fire fighting materials used 

for Purate® and sulfuric acid. Ecochlor agrees that this is a critical aspect for safe installation of 

the BWTS. There are two potential scenarios related to the chemicals and fire risk. These are: 1) 

a fire on the ship that is non-related to the BWTS, but within proximity of the system, or 2) a fire 

directly involving the chemicals. 

In an onboard fire situation that is not related to the BWTS or the stored chemicals, but may be 

within proximity to the chemicals, the primary risk would be that the chemicals could become 

heated inside the storage tanks. The chemical properties of each substance (non-flammable) as 

well as the mitigation measures that are engineered into the BWTS to ensure proper chemical 

storage and ventilation (Sections 3.0.8.1, 6.1.3.1, 6.1.4, and 6.1.5) greatly reduce a chemical fire 

starting from such a situation onboard. Additionally, although the fire fighting mediums for 

sulfuric acid and Purate® are different, water can be used on the exterior of both chemical tanks 

(but not allowed to enter the tanks) to keep the storage tanks cool in the event of a fire situation 

that may cause the tanks to become heated. This is a practical fire mitigation measure should 

such a situation arise onboard.

Because both chemicals are non-flammable and Ecochlor ensures proper chemical storage, the 

likelihood of sulfuric acid or Purate® being the direct cause of a fire onboard is extremely low. 

For sulfuric acid to directly cause a fire would require a combination of a substantial chemical 

leak and contact with an incompatible, combustible material. For Purate® to directly cause a fire 

would require the combination of a chemical leak, contact with an incompatible material, plus the 

addition of a heat and/or ignition source. Therefore, mitigating the risk of chemical fire is 

directly related to proper chemical storage and avoiding chemical contact with combustible 

materials. The general mitigation measures outlined in Sections 6.1.3, 6.1.4 and 6.1.5 to prevent 

chemical spills from contacting incompatible materials include: 

 Proper training for both BWTS technicians and ship’s crew; 

 Proper system engineering; 

 Proper location of the BWTS onboard;

 Use of appropriate chemical storage tanks, piping and construction materials for all 

aspects of the BWTS; 

 Use of chemical secondary containment (i.e. “save-all protection”); 

 Proper chemical tank ventilation; 

 Chemical storage tank temperature control devices, if necessary; 

 Storage of incompatible/combustible materials away from the BWTS; 

 Availability of chemical spill containment materials should they be needed; and 

 Regular system inspection and maintenance. 

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Additionally, ships typically have both water and CO2 (or other chemical fire suppressants) 

readily available and installed onboard for fire fighting. Considering the mitigation measures 

incorporated into the design of the BWTS and the typical fire fighting equipment onboard 

together with the low potential for the chemicals to be involved in a fire, the risk of fire related to 

the BWTS chemicals is almost non-existent. 

The mitigation measures above are general measures used to ensure safe installation of the 

BWTS. Preparing for BWTS installation onboard a ship requires detailed reviews by Ecochlor’s 

marine engineers, the vessel engineers, as well as the ship’s classification society. Additional 

mitigation measures that may be identified for safe BWTS installation on a specific ship during 

these reviews will be implemented as needed. 

3.0.8.2 Accidental Release Measures 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.8.3 Marine Environment Release 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.8.4 Active Substance Waste Management, Reuse, Recycling, Neutralization 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.8.5 Conditions for Controlled Discharge 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

3.0.10 Evaluation of Management Measures

Information was provided in the Basic Approval dossier (MEPC 58/2/2) and is also included in the 

complete confidential Final Approval dossier. 

4.0 HAZARD CLASSIFICATION & MATERIAL SAFETY DATA SHEETS (G9: 

4.2.7)

The hazard classifications presented reflect hazards only and do not consider actual potential for 

exposure.

4.0.1 Purate®

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

4.0.2 Sulfuric Acid 

Information not changed from that provided in Basic Approval dossier (MEPC 58/2/2). 

4.0.3 Chlorine Dioxide 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

4.0.4 Sodium Chlorite (Chlorite ion) 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

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4.0.5 Sodium Chlorate (Chlorate ion) 

Utilizing a typical MSDS sheet for sodium chlorate solution for hazard classification does not 

accurately represent the potential hazards at the concentration of chlorate ion that may be present 

in treated ballast water. Thus, hazard classification is not provided for chlorate ion, but 

toxicology data is presented in this application.

4.0.6 Dibromoacetic Acid (DBAA) 

Utilizing a typical MSDS sheet for dibromoacetic acid for hazard classification does not 

accurately represent the potential hazards at the low concentration of DBAA that may be present 

in treated ballast water. Thus, hazard classification is not provided for DBAA, but toxicology 

data is presented in this application.

5.0 RISK CHARACTERIZATION 

5.1 SCREENING FOR PERSISTENCE, BIOACCUMULATION, & TOXICITY (G9: 

5.1)

The chemicals that may be present in treated ballast water discharge 24 hours after treatment 

include the active substance (chlorine dioxide) and three relevant chemicals (chlorite ion, 

chlorate ion and DBAA). These constituents are evaluated below for persistence, 

bioaccumulation and toxicity. 

5.1.1 Persistence (G9: 5.1.1.1) 

Chlorine dioxide, chlorite ion, and chlorate ion demand/decay data presented in Section 2.0 

demonstrate that these constituents do not persist for extended periods of time in water, and 

undergo rapid degradation. These findings are supported by the physical and chemical properties 

(i.e. high solubility, non-organic) associated with these substances as well as studies conducted 

by others.

For chlorine dioxide, Cooper et al. (2007) demonstrated that chlorine dioxide degradation is 

photochemically-enhanced33. Fisher and Burton (1993) reported that at 25°C, 60% of chlorine 

dioxide decays to chlorite within 15 minutes, and decayed completely within four hours33. The 

studies of chlorine dioxide decay in natural seawater presented in Section 2.0.2 compare well 

with this data.

Chlorite is considered more stable in aqueous solution than chlorine dioxide; however, in a 

similar manner to chlorine dioxide, chlorite also degrades in aqueous solution as a result of 

oxidative reactions. Residual chlorite ion in treated ballast water will decrease through reactions 

with organic matter to form chloride, which is non-toxic at the concentrations of interest. 

Chlorite is not persistent as a result of its degradation pathway to chloride33.

Chlorate ion is an oxidant and is expected to be non-persistent in the environment when there are 

sufficient levels of organic matter present25.

DBAA is documented to degrade by microbial activity37 as well as photolysis38. A study of 

haloacetic acid decomposition in seawater demonstrated that DBAA was degraded within 9 

days37, even when microbial activity was inhibited. These studies, considered with the chemical 

properties of DBAA suggest non-persistent behavior in the environment. 

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5.1.2 Bioaccumulation (G9: 5.1.1.2) 

The estimated log Kow of chlorine dioxide is -3.22 and for sodium chlorite is -7.176

. These 

values along with the chemical properties (i.e. high solubility, non-organic) of chlorine dioxide 

and chlorite indicate that bioaccumulation is not expected. 

The reported log Kow for sodium chlorate is -2.934 and has a low potential to bioaccumulate15.

DBAA has a reported log Kow of 1.22, is not lipophilic at physiological pH and has a low 

potential to accumulate in fat14.

5.1.3 Toxicity (G9: 5.1.2.3) 

5.1.4 PBT Criteria - Active Substance (G9: Table 1) 

Table T5.1 – PBT Criteria Evaluation 

Substance 

Persistence (P) 

Half-life: 

>60 days in marine water, or 

>40 days in freshwater, or 

>180 days in marine 

 sediment 

>120 days in freshwater 

 sediment

Bioaccumulation (B) 

BCF >2,000 or Log Kow 3

Toxicity (T) 

Chronic NOEC 

<0.01mg/L

Chlorine dioxide 

3.9 minutes, clear freshwater at 

5 meters33

5 minutes in seawater at 20oC 

Criteria fulfilled - No 

-3.226

Criteria fulfilled - No 

Lowest LC50 = 0.02 

mg/L (see Table T2.9) 

Criteria fulfilled - No 

Chlorite Ion <2 minutes in seawater at 20oC 

Criteria Fulfilled – No 

-7.176

(as sodium chlorite) 

Criteria fulfilled - No 

Lowest chronic NOEC 

= 0.18 mg/L 

(See Table T2.10) 

Criteria Fulfilled - No 

Chlorate Ion ~1 day in seawater at 20oC 

Criteria fulfilled - No

-2.934

(as sodium chlorate)

Criteria fulfilled - No

NOEC = 0.06 mg/L 

Criteria Fulfilled - No

Dibromoacetic Acid 

14 days (freshwater, 15oC, in 

presence of titanium dioxide)38

Criteria fulfilled - No 

1.2214

Criteria fulfilled - No

LC50 = 69 mg/L 

Criteria Fulfilled - No

None of the chemicals meet the criteria to be classified as PBT substances.

In the GESAMP-BWWG review (MEPC 58/2/7, Annex 5) the chlorite ion persistence value 

from the table above was reported as 4 days in seawater. However, the review contained no 

information on the basis for this change nor was the reference source of this persistence value for 

chlorite ion provided. The updated half-life value of <2 minutes in seawater reported above is 

based on independent laboratory analysis and is considered accurate for this relevant chemical. 

5.2 EVALUATION OF THE TREATED BALLAST WATER 

Section 5.2.1 includes evaluation of treated ballast water toxicity from laboratory and shipboard 

testing conducted on the Ecochlor® BWTS and was included in the Basic Approval dossier. 

Section 5.2.2 provides new information for this Final Approval dossier and evaluates treated 

ballast water discharge from the land based testing conducted during 2008 at NIOZ.

5.2.1 Determination of Holding Time – Treated Water from Lab and Shipboard Testing 

5.2.1.1 Toxicity and Dilution of Treated Ballast Water - Lab and Shipboard Testing 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

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5.2.2 Determination of Holding Time – Treated Ballast Water from Land-Based Testing 

5.2.2.1 Toxicity, Dilution and Holding Time of Treated Ballast Water – Land Based Testing 

Toxicity testing of treated ballast water discharge from the land-based test unit was performed by 

Grontmij|AquaSense in the Netherlands (crustaceans, algae, mollusks, rotifers, and marine 

bacteria testing) and by Chemex Environmental International in the United Kingdom (fish 

testing).

Ecotoxicity was evaluated for six (6) different taxonomic groups (algae, crustacean, fish, rotifers, 

mollusks, and marine bacteria). Testing of treated ballast water discharge from the land based 

test unit was conducted at two different salinities (brackish and sea water) and two different time 

points (1 day and 5 days after treatment). These time points were selected to demonstrate that 

treated ballast water is safe to discharge within 24 hours (1 day) of treatment and also after the 

holding time of 5 days specified in G8 testing. 

Acute exposure testing was performed on all six taxonomic groups from brackish and sea water 

test cycles. The most sensitive taxonomic group identified was then tested again with day 5 

treated ballast water discharge. Short term exposure (sub-lethal endpoint (growth / 

development)) testing was also evaluated for the most sensitive taxonomic group identified from 

the acute testing. This approach allowed for testing on a wider range of taxonomic groups and 

also avoided unnecessary testing on organisms that did not show evidence of toxic effects with 

acute exposures. This approach for ecotoxicity testing was based on discussions and agreements 

between Ecochlor and the German Administration. 

Results of toxicity tests with treated ballast water discharge are presented on the basis of percent 

by volume (% v/v) of treated water. 

As shown in Table T2.9a no acute toxicity was observed with Cyprinodon variegatus, Acartia 

tonsa, Brachionus plicatilis, or Phaeodactylum tricornutum (brackish water only); the E(L)C50 

for each species was >100% for discharge testing performed on samples collected 1 day after 

treatment. Therefore, the NOEC was 100% sample for these four species with day 1 treated 

water discharge. The EC50 for Vibrio fisheri in day 1 discharge samples was 83.3% in brackish 

water and 70.9% in sea water. The EC50 for Crassostrea gigas with day 1 discharge samples 

was 38.1% (NOEC = 10%) in brackish water and 62.3% (NOEC = 18%) in sea water. The 

results of the testing indicate that Crassostrea gigas was the most sensitive species in day 1 

discharge samples. Therefore, based on the agreed testing approach, additional testing for this 

species was repeated with day 1 and 5 discharge samples for chronic effects using sub-lethal 

endpoints.

Although the Crassostrea gigas testing method uses a short-term exposure, the test evaluates a 

chronic sub-lethal end point (development). As such this test was determined by 

Grontmij|AquaSense to be the appropriate method to evaluate chronic effects with this species. 

Section 3.3.3.2 of the G9 Methodology also indicates that short-term chronic testing methods are 

acceptable because identifying the sensitive sub-lethal endpoints and vulnerable life stages is the 

goal of long-term exposure testing. 

Additional testing with discharge samples 1 day after treatment resulted in EC50s for 

Crassostrea gigas of 43.3% (NOEC = 18%) in brackish water and 50.4% (NOEC = 32%) in sea 

water. Additional testing with discharge samples 5 days after treatment resulted in EC50s of 

36.3% (NOEC = 18%) in brackish water and 73.6% (NOEC = 56%) in sea water. The average 

EC50 for all Crassostrea tests is 51% (average NOEC = 31%). Thus, a two-fold dilution is 

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

reach a concentration less than the NOEC value for Crassostrea.

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The data are quite consistent when comparing the toxicity results for Crassostrea with discharges 

on day 1 and day 5 in both brackish and seawater29. Therefore, the data support the conclusion 

that treated ballast water is safe to discharge within 24 hours of treatment and that a longer 

holding time is not required. 

5.3 RISK CHARACTERIZATION & ANALYSIS 

5.3.1 Reaction with Organic Matter (G9: 4.2.1.3) 

Information for chlorine dioxide and chlorite ion was provided in the Basic Approval dossier 

(MEPC 58/2/2).

In the environment, chlorate can undergo reduction reactions with organic matter and “...the 

thermodynamically favored, end reduction product of chlorate in soil and in water is the chloride 

anion.”39

Brominated acetic acids such as DBAA are formed when bromide ion and organic matter is 

present during water disinfection processes14. Continued reaction of DBAA with organic matter 

is not expected. 

5.3.2 Characterization of Degradation Route & Rate (G9: 5.3.5) 

Information for chlorine dioxide and chlorite ion was provided in the Basic Approval dossier 

(MEPC 58/2/2). 

Chlorate is degraded by both abioitc and biotic mechanisms. In the environment, chlorate can 

undergo reduction reactions with organic matter and “...the thermodynamically favored, end 

reduction product of chlorate in soil and in water is the chloride anion.”39 Although reduction 

reactions of chlorate are said to occur very fast, how fast they occur is not known (i.e., the actual 

rate constants in the environment are not known)36. Decay studies presented in Section 2.0.3.4 

indicate that in natural seawater the degradation of chlorate is on the hours-time scale. It is 

important to note that in a laboratory setting where the water sample is in a closed system the 

chlorate ion concentration becomes stable once demand of the water has been met. 

DBAA is degraded by both abiotic and biotic mechanisms, and a half-life of 14 days in 

freshwater (in the presence of the catalyst titanium dioxide) has been reported38.

5.3.3 Prediction of Discharge & Environmental Concentrations (G9: 5.3.8) 

The evaluation of predicted environmental concentrations presented in the Basic Approval 

dossier was based on direct measurements of the active substance and relevant chemicals in 

treated ballast water from laboratory and shipboard pilot testing. The evaluation did not involve 

prediction of environmental concentrations using hydrodynamic modeling technology. 

Therefore, the information provided in this section of Basic Approval dossier has been omitted 

and replaced with a more refined evaluation based on the results of land based testing and 

hydrodynamic modeling. 

5.3.3.1 Hydrodynamic Modeling Approach 

Two separate modeling programs were utilized to determine the predicted environmental 

concentrations (PECs) for the Ecochlor® BWTS; MamPec (beta release v2.5) and Delft-3D. 

Deltares (formerly Delft Hydraulics) is located in the Netherlands and is the firm that developed 

the MamPec and Delft-3D models. Deltares performed the analysis of the PECs for Ecochlor’s 

treated ballast water. 

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MamPec Model 

The MamPec model uses a generalized approach and is considered a rapid assessment tool40.

The model was developed for antifouling products from ship’s hulls and therefore evaluates 

discharges as continuous releases into the environment. This is different than the intermittent 

and non-continuous nature of ballast water discharges, and therefore MamPec simulations will 

provide a worst-case estimate of the PEC’s40. MamPec offers three different schematizations, 

and the estuarine harbor as shown in Figure F5.1 was selected for this analysis.

Figure F5.1 – Example of MamPec Estuarine Harbor Schematization 

Two separate ‘locations’ were simulated with MamPec for the Port of Rotterdam. The first 

location considered a specific part of the Nieuwe Waterweg, the Maashaven, and is shown in 

Figure F5.2 below. The circled area in the figure below shows the location of the Maashaven. 

Figure F5.2 – Port of Rotterdam and Location of Maashaven 

Source: Deltares 

This location was chosen because the detailed model (discussed below) was also available for the 

Maashaven and would allow for a comparison between the two models. Details of the 

Maashaven input values for MamPec are provided in Tables T5.2 and T5.3. Further, within the 

Maashaven location different emission scenarios (also called ‘environmental conditions’) were 

evaluated. For example, the modeling was done with and without the effect of flushing within 

the harbor to determine how this complex harbor characteristic impacts the PEC values. In the 

Deltares report, scenarios where flushing is considered are referred to as “with salt”, indicating 

the influence of tides and water density. The scenarios where flushing is not considered are 

referred to as “no salt”. Although the difference in the PEC values was not significant for the 

40 Deltares, Predicted Environmental Concentrations as a result of ballast water discharges in the Rotterdam harbor, 2008 

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simulation of the Maashaven with MamPec, the environmental condition without flushing can be 

considered the ‘worst-case’ scenario based on the PEC for DBAA. The results are presented in 

Section 5.3.3.3.

Table T5.2 – Summary of MamPec Model Input Parameters, Maashaven 

Parameter Value Unit 

Tidal period 12.41 h 

x2 300 m 

y1 2045 m 

y2 380 m 

depth 7.6 m 

Mouth width x3 200 m 

Flow velocity F 0.08 m/s 

Tidal difference 2.55 m 

Max density difference tide (avg conditions: with salt) 2.29 kg/m3 

Figure F5.3 – Detail of Maashaven Harbor 

 Source: Deltares 

Table T5.3 – Summary of MamPec Model Details, Maashaven 

Substance 

Dishcarge

Rate

Q [m3/s] 

Chemical

Concentration

c [g/m3] 

Discharge

Duration

Decay 

Rate

[1/d]

Emission

[g/d]

Chlorate 0.14 1.47 continuous 43.2 17640 

Dibromoacetic acid 0.14 0.036 continuous 0 432 

Chlorine dioxide 0.14 0.85 continuous 145.4 10200 

Chlorite 0.14 3.6 continuous 463.7 43200 

The second MamPec ‘location’ considered the Port of Rotterdam as a whole in which the release 

of ballast water due to all ships present was simulated40. As stated in the Deltares report, the total 

ballast water discharge for the whole Port of Rotterdam used in the model was derived from 

Niekerk (2008) and totaled 2.76 million m3

. For the whole Port of Rotterdam modeling, only one 

approach was utilized where the geometry and flushing characteristics were copied from the 

MamPec manual. Details of the input values for MamPec simulations for the whole Port of 

Rotterdam are provided in Tables T5.4 and T5.5. The results of this simulation are presented in 

Section 5.3.3.3

380

200

300

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Table T5.4 – Summary of MamPec Model Input Parameters, Port of Rotterdam (Whole) 

Parameter Value Unit 

Tidal period 12.41 h 

length x1 2000 m 

x2 20000 m 

y1 2000 m 

y2 500 m 

depth 20 m 

Mouth width x3 5000 m 

Flow velocity F 1.5 m/s 

Tidal difference 1.5 m 

Max density difference tide (avg conditions: with salt) 0.80 kg/m3 

Table T5.5 – Summary of MamPec Model Details, Port of Rotterdam (Whole) 

Substance 

Dishcarge

Rate

Q [m3/s] 

Chemical

Concentration

c [g/m3] 

Discharge

Duration

Decay 

Rate

[1/d]

Emission

[g/d]

Chlorate 1.1 1.47 continuous 43.2 139903 

Dibromoacetic acid 1.1 0.036 continuous 0 3426 

Chlorine dioxide 1.1 0.85 continuous 145.4 80897 

Chlorite 1.1 3.6 continuous 463.7 342621 

Delft 3D Detailed Model 

The Delft-3D model is a world-leading 2D/3D modeling suite developed by Deltares (formerly 

Delft Hydraulics). The Delft-3D detailed model was used to provide a precise simulation of 

treated water discharge within the Maashaven in addition than the general assessment that 

MamPec provided. Further, the detailed model provided an indication of the overall suitability of 

the MamPec model to accurately predict ballast water discharge concentrations. The intent is not 

to validate the MamPec model, but to indicate the suitability / accuracy of the MamPec model to 

be applied to ballast water discharges40. The detailed model is a calibrated numerical model that 

encompasses realistic geometry and complex hydrodynamic behavior in a specific harbor. For 

this evaluation, the Maashaven, part of the Nieuwe Waterweg, within the Port of Rotterdam was 

selected.

The modeling input parameters are the same as those used for the MamPec model as presented in 

Tables T5.2 and T5.3 above, with the only difference being that the discharge duration for the 

detailed model was 24 hours rather than continuous.

Several scenarios were evaluated with the Delft-3D model. Similar to the MamPec simulations, 

the modeling was done with and without the effect of flushing within the harbor to determine 

how this complex harbor characteristic impacts the PEC values. It was determined that the 

environmental condition without flushing provided the ‘worst-case’ scenario. Further, scenarios 

with one ship at different locations within the harbor, as well as three ships in the harbor 

discharging simultaneously were simulated. Of all the scenarios simulated with the detailed 

model, the ‘worst-case’ (where the PECs are the highest) occurred when three ships discharge 

simultaneously and no flushing is considered in the model. The results are presented in Section 

5.3.3.3 below.

General Parameters Used for both MamPec and Delft-3D Models 

To determine the discharge volume and duration, Ecochlor chose vessel parameters to represent a 

‘worst case’ scenario within Maashaven. The largest vessel able to enter Maashaven is the 

38,650 metric ton SS Rotterdam. Due to the size of this vessel, it can only be docked in the 

entrance, or front, of the Maashaven harbor. Since this vessel is a cruise ship (reduced ballast 

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water volume), Ecochlor chose to take a ‘worst-case’ approach and assume the vessel was a 

typical bulker of the identical tonnage. Most bulkers carry and discharge 30% of their tonnage in 

ballast water. Therefore a volume of 12,000 metric tons of ballast water was assumed for this 

vessel.

In order to incorporate multiple vessels discharging simultaneously in Maashaven, Ecochlor 

chose to use three vessels with equal (12,000 metric tons) volumes of ballast water. This was 

done with the knowledge that no vessel of this size could enter the smaller docks in middle and 

back of the harbor; however, this created an unattainable ‘worst-case’ scenario for the analysis 

and provided an added level of protection to the PEC values generated.

For discharge rate, and given the volumes discussed above, Ecochlor chose to assume a 

consistent discharge rate for the entire 12,000 metric tons over a 24 hour period for the detailed 

model. This equaled an hourly discharge of 500 metric tons per hour, for 24 hours, for each 

vessel used in the different emission scenarios. For the MamPec model the discharge duration is 

continuous.

5.3.3.2 Determination of Chemical Concentrations and Decay Rates for Modeling Input 

Due to the rapid degradation of chlorine dioxide, chlorite ion, and chlorate ion, a decay rate was 

specified for use in the modeling. This was determined as the most realistic approach for these 

substances. This approach, particularly when considered with the “no salt” flushing parameter, 

also demonstrates that extensive dilution is not depended upon to make treated ballast water 

discharge environmentally acceptable. The decay rates are so high that they almost completely 

determine the PECs40.

Prior to initiating the hydrodynamic modeling a decay rate for DBAA was not located. 

Therefore, no decay rate was specified for DBAA. 

Chlorine Dioxide 

When the Ecochlor® BWTS is utilized on a vessel as directed by Ecochlor, the concentration of 

chlorine dioxide is expected to be at undetectable levels when treated ballast water is discharged. 

However, it is also known that various water quality parameters can increase or decrease the 

demand/decay of chlorine dioxide. During land based testing, detectable levels of chlorine 

dioxide were measured within 24 hours (1 day) after treatment at concentrations ranging from 

0.22 – 0.85 mg/L (mean = 0.63 mg/L). To verify that chlorine dioxide in treated ballast water 

discharge does not present unacceptable environmental risk, the highest day 1 chlorine dioxide 

concentration of 0.85 mg/L (See Table T2.8a) was used in the modeling to determine the (PEC). 

This approach represents the ‘worst-case’ situation for chlorine dioxide in treated ballast water 

discharge 24 hours after treatment. The decay rate of 145.4 mg/L per day used in the model for 

chlorine dioxide was derived from laboratory testing results, and was the slowest rate measured. 

Therefore, the decay rate is considered conservative. 

Chlorite Ion 

During land based testing, chlorite ion was measured at concentrations ranging from 3.11 – 3.6 

mg/L (mean = 3.3 mg/L) 1 day after treatment. To verify that chlorite ion in treated ballast water 

discharge does not present unacceptable environmental risk, the highest day 1 chlorite ion 

concentration of 3.6 mg/L (See Table T2.8a) was used in the modeling to determine the predicted 

environmental concentration (PEC). This approach represents the ‘worst-case’ for chlorite ion in 

treated ballast water discharge 24 hours after treatment. The decay rate of 463.7 mg/L per day 

used in the model for chlorite ion was derived from laboratory testing results and was the slowest 

rate measured. Therefore, the decay rate is considered conservative. 

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Chlorate Ion 

During land based testing, chlorate ion was measured at concentrations ranging from 1.07 – 1.47 

mg/L (mean = 1.3 mg/L) 1 day after treatment. To verify that chlorate ion in treated ballast water 

discharge does not present unacceptable environmental risk, the highest day 1 chlorate ion 

concentration of 1.47 mg/L (See Table T2.8a) was used in the modeling to determine the 

predicted environmental concentration (PEC). This approach represents the ‘worst-case’ for 

chlorate ion in treated ballast water discharge 24 hours after treatment. The decay rate of 43.2 

mg/L per day used in the model for chlorine dioxide was derived from laboratory testing results 

and was the slowest rate measured. Therefore, the decay rate is considered conservative. 

DBAA

During land based testing, DBAA was measured at concentrations ranging from 20 – 36 μg/L 

(mean = 25 μg/L) 1 day after treatment. To verify that DBAA in treated ballast water discharge 

does not present unacceptable environmental risk, the highest day 1 DBAA concentration of 36 

μg/L (See Table T2.8c) was used in the modeling to determine the predicted environmental 

concentration (PEC). This approach represents the ‘worst-case’ for DBAA in treated ballast 

water discharge 24 hours after treatment. As noted above, no decay rate was entered into the 

model for DBAA.

5.3.3.3 Results of Modeling and Derived PEC Values 

MamPec Model 

For the first simulation using MamPec in Maashaven harbor, the results are presented in Table 

T5.6. Based on the concentration of dibromoacetic acid (DBAA), the scenario with no salt 

represents the ‘worst-case’ scenario. 

Table T5.6 – Results of MamPec, Maashaven 

Substance 

Average 

concentration 

(with salt) 

[g/m3] 

[Average 

concentration 

(with no salt) 

 [g/m3] 

Chlorate 8.74E-05 8.74E-05 

Dibromoacetic 

acid 3.85E-04 8.74E-04 

Chlorine dioxide 1.50E-05 1.50E-05 

Chlorite 1.99E-05 1.99E-05 

The MamPec simulation results for the whole Port of Rotterdam are presented in Table T5.7. 

This scenario was simulated with the standard flushing and geometry as outlined in the MamPec 

manual and therefore did not consider the alternate environmental condition of no flushing. The 

results indicate that the average concentrations of all constituents are lower in this simulation for 

the whole Port of Rotterdam than within Maashaven harbor. 

Table T5.7 – Results of MamPec, Port of Rotterdam (Whole)

Substance 

MamPec

average 

concentration 

[g/m3] 

Chlorate 5.67E-06 

Dibromacetic acid 6.94E-04 

Chlorine dioxide 9.73E-07 

Chlorite 1.29E-06 

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Delft-3D Model 

The results of the detailed model and the six different scenarios evaluated are presented in Table 

T5.8.

Table T5.8 – Results of Delft-3D Detailed Model, Maashaven 

Max average Maashaven concentrations [g/m3] 

Average 

(with salt) 

Worst case 

(no salt ) 

1 ship; located at back of harbour 

Chlorate 9.67E-05 9.67E-05 

Dibromacetic acid 8.53E-05 1.02E-04 

Chlorine dioxide 1.66E-05 1.66E-05 

Chlorite 2.21E-05 2.21E-05 

1 ship; located at front of harbour 

Chlorate 9.65E-05 9.67E-05 

Dibromacetic acid 4.71E-05 7.25E-05 

Chlorine dioxide 1.66E-05 1.66E-05 

Chlorite 2.21E-05 2.21E-05 

3 ships; 3 locations: back, middle and front 

Chlorate 2.85E-04 2.90E-04 

Dibromacetic acid 2.10E-04 2.65E-04 

Chlorine dioxide 4.90E-05 4.98E-05 

Chlorite 6.51E-05 6.62E-05 

For the substances that decay (chlorine dioxide, chlorite ion and chlorate ion), the PECs are the 

same for the simulations ‘with salt’ (flushing) and ‘without salt’ (no flushing). Additionally, the 

differing location of the discharge within the Maashaven (front or back) does not influence the 

PECs for these substances. For DBAA, flushing as well location of the discharge within the 

harbor influences the PEC.

The highest PEC for chlorine dioxide, chlorite ion and chlorate ion is generated with the detailed 

model for the ‘worst-case’ scenario of three ships discharging in the Maashaven simultaneously 

without the influence of flushing (no salt). These results are 4.98 x 10-5, 6.62 x 10-5, and 2.90 x 

10-4, respectively. For DBAA, the highest PEC (8.74 x 10-4) is generated with the MamPec 

model when one ship discharges in the back of the Maashaven without the influence of flushing 

(no salt). Therefore, since these are the highest PECs derived for all modeling scenarios for both 

the MamPec and the Delft-3D model, these are the values used for the environmental risk 

assessment for treated ballast water discharge. 

5.3.3.4 General Conclusions from Hydrodynamic Modeling and Derivation of PECs 

In general the PEC of the substances due to the release of treated ballast water is determined by 

the load, the amount of flushing, and the behavior of the substance (i.e. decay). In regards to 

chlorine dioxide, chlorite ion, and chlorate ion the decay rates almost completely determine the 

PECs40. This conclusion is valid for any type of harbor, independent of the flushing 

characteristics of the harbor and independent of the location of discharge within the harbor40.

The concentration of these three substances drops to 10% of the concentration present in treated 

ballast water discharge within 1.3 hours after the discharge40. Compared to the decay rates 

derived in the laboratory, which indicated that chlorine dioxide and chlorite ion are at nondetectable levels within minutes, the model is considered conservative in this regard. 

For substances that decay rapidly, MamPec provides realistic estimates of the PECs for ballast 

water discharge. This conclusion is based on the comparison between average concentrations 

derived with MamPec under various environmental conditions using a continuous release, which 

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were very close to the maximum concentrations over a 24 hour discharge period derived with the 

detailed model40. For DBAA, a conservative substance (i.e. no decay used in the model), the 

MamPec model overestimates the PECs from ballast water discharges. This conclusion is based 

on the concentration of DBAA with MamPec under continuous release being up to one order of 

magnitude higher than the maximum PEC derived with the detailed model with a 24 hour 

discharge40.

5.3.3.5 Allowable Discharge Levels 

The concentrations of chlorine dioxide, chlorite ion, chlorate ion and DBAA in treated ballast 

water discharge that were entered into the models for PEC derivation were the highest 

concentrations measured 24 hours after treatment during land based testing. Additionally, the 

concentrations of these substances measured during land based testing were higher than in all 

previous laboratory and shipboard studies. As such, the calculated PECs are based on ‘worst 

case’ scenarios with the highest levels of constituents 24 hours after treatment and are considered 

conservative. Therefore, the allowable discharge levels in treated ballast water are as follows: 

Chlorine dioxide – 0.85 mg/L 

 Chlorite ion – 3.6 mg/L 

 Chlorate ion – 1.47 mg/L 

 DBAA - 0.036 mg/L 

Because the modeling was done using these conservative values, the calculated PECs and 

PEC/PNEC ratios are considered protective of the aquatic environment. 

5.3.4 Assessment of Potential for Bioaccumulation (G9: 5.3.7) 

Because the substances utilized with the Ecochlor® BWTS do not have characteristics that would 

indicate a potential for bioaccumulation, no bioaccumulation effects are anticipated. 

5.3.5 Effects Assessment 

5.3.5.1 Chlorine Dioxide 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

5.3.5.2 Chlorite Ion 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

5.3.5.3 Chlorate Ion 

With respect to risk, toxicity to aquatic organisms appears to be the most significant potential 

exposure for chlorate because it is not persistent in the environment and is not expected to 

bioaccumulate or adsorb to sediments. An effects assessment of secondary poisoning is not 

relevant. Therefore, the acute and chronic aquatic toxicity results presented in Section 2.1 for 

chlorate provide the most appropriate evaluation of the potential for adverse effects to aquatic 

organisms. 

Acute toxicity data for chlorate ion is presented in Table T2.9, and varies widely across the 

taxonomic groups. For example, one test with Oncorhynchus masou reported and LC50 of 7,843 

mg/L, and another fish test (Oncorhynchus mykiss) reported an LC50 of 2,527 mg/L. Toxicity 

tests with crustaceans had E(L)C50 values ranging from 1,098 – 5,019 mg/L. Although 

responses varied greatly, algae is clearly the most sensitive group to chlorate with reported EC50 

values ranging from 0.1 - >1.000 mg/L, and NOEC values of 0.005 – 500 mg/L. Discussion 

regarding the NOEC value of 0.005 mg/L is presented in Section 5.3.6.2.

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Chronic aquatic toxicity data for chlorate is presented in Table T2.10. Overall, the NOEC values 

are lower than the acute values, with algae clearly being the most sensitive group. Discussion 

regarding the NOEC value of 0.005 mg/L is presented in Section 5.3.6.2. 

5.3.5.4 Dibromoacetic Acid (DBAA) 

The toxicity data set for dibromoacetic acid is limited for both aquatic and mammalian studies. 

However, high solubility indicates that DBAA is not expected to be persistent in the environment 

or adsorb to particles. Adverse reactions with organic matter are not expected. DBAA is not 

lipophilic and is not expected to bioaccumulate in tissues. Mammalian studies indicate that 

DBAA did not exhibit teratogenic potential, is readily absorbed and the metabolites are readily 

excreted. Some evidence suggests DBAA may have carcinogenic and mutagenic potential. 

Considering the limited data, and because the low level of dibromoacetic acid potentially in 

treated water discharge will be discharge to the aquatic compartment, the available aquatic 

toxicity data for Pimephales promelas is considered the most relevant data to use for this 

assessment. 

5.3.6 Effects on Aquatic Organisms 

5.3.6.1 Evaluation of Effects Based on Laboratory and Shipboard Toxicity Testing 

This information was provided in the Basic Approval dossier (MEPC 58/2/2, Section 5.3.6). An 

updated evaluation of effects is presented below.

5.3.6.2 Updated Evaluation of Effects on Aquatic Organisms 

The following effects assessment is based on revisions to the earlier assessment, comments 

received by the GESMAP-BWWG and new data generated since submission of the Basic 

Approval dossier. Derivation of the PNEC values in Table T5.9 below are based on the toxicity 

data presented in Tables T2.9 and T2.10. 

Assessment factors were selected based on the guidance in the G9 Methodology, Section 6.3.6.4, 

Table 22

 as well as the EU Technical Guidance Document (TGD) on Risk Assessment (2003). 

Justification for the selected assessment factor for each constituent is provided below. 

Chlorine dioxide: 

The GESAMP-BWWG commented that the Nautilus Environmental testing protocols with 

chlorine dioxide measured the effect concentrations of the active substance at the initiation of the 

tests. Ecochlor accepts and understands this criticism of the test results and has applied the lower 

LC50 of 0.02 mg/L (juvenile Pimephales promelas) for chlorine dioxide as suggested by the 

GESAMP-BWWG for the environmental risk assessment. Applying an assessment factor of 

1,000 results in a PNEC = 0.02 μg/L for chlorine dioxide.

Chlorite ion:

Nautilus Environmental performed a number toxicity studies on chlorite ion to evaluate this 

chemical in treated ballast water. Although data can be found in literature that may present lower 

end point data, Ecochlor contends that the data generated by Nautilus is appropriate to use for 

this assessment. The studies found in literature are often conducted long ago and there is 

difficulty in knowing how the chlorite solution was made for a particular study, or the exact 

method the study was conducted with. Therefore, Ecochlor undertook toxicity testing to ensure 

that the testing accurately represented this relevant chemical in treated ballast water. 

In any case, Ecochlor accepts the suggested use of the Mysidopsis bahia LC50 of 0.58 mg/L 

(Table T2.9) and the higher assessment factor of 1,000 for chlorite ion to derive a PNEC = 0.58 

μg/L.

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Chlorate ion: 

A literature search was done to locate acute and chronic aquatic toxicity data for this chemical. 

The acute toxicity data set in Table T2.9 presents three data points for fish, four data points for 

crustaceans and five data points for algae. The chronic toxicity data set in Table T2.10 presents 

one result for fish, two results for crustaceans, and four results for algae. This justifies the use of 

an assessment factor of 100. 

The data indicate that algae are more sensitive to chlorate than invertebrates or fish. Further, 

marine brown algae are the most sensitive to chlorate. Research indicates that algal sensitivity to 

chlorate is related to ambient nitrate levels and the nitrate reductase enzyme system18,19.

Additionally, freshwater microalgae are generally more sensitive to chlorate than marine 

microalgae, at high nitrate levels19.

The lowest NOEC value reported by van Wijk and Hutchinson25 was 0.005 mg/L (5 μg/L ) 

chlorate. This value was reported in the van Wijk and Hutchinson paper as both the marine 

mesocosms value and the result of a 6-month study of Fucus vesiculosus. These authors state 

that this data is from Rosemarin et al. (1994)41. However, the Rosemarin study does not report 

NOEC results but instead reports an EC50 of 80 μg/L for Fucus vesiculosus. The Rosemarin 

study states: 

“Clear negative effects begin at about 15-20 μg chlorate/L. The level where 50% effect is 

observed (so-called EC50) is about 80 μg/L.”

The lower chlorate concentrations tested in the Rosemarin study were 1, 5, and 20 μg/L. 

Therefore, it appears that van Wijk and Hutchinson inferred the NOEC for this 6-month Fucus

vesiculosus marine mesocosm study to be 5 μg/L, because Rosemarin reported that negative 

effects start to occur at 15-20 μg/L, and 5 μg/L was the next lowest concentration tested. 

However, the data presented by these authors are not sufficient to statistically calculate an NOEC 

value of 5 μg/L since there was no replication of the control, 1 or 5 μg/L exposures in the 

Rosemarin study. 

Based on the above discussion, and due to the large variability in toxicity data for chlorate, 

Ecochlor selected the lowest chronic NOEC geometric mean value of 0.06 mg/L (60 μg/L) for 

marine macroalgae reported by van Wijk and Hutchinson to derive a PNEC value. This 

geometric mean value takes into account the very low data point (5 μg/L ) that van Wijk inferred 

from the Rosemarin study, as well as other data points that are an order of magnitude higher. As 

such, the NOEC of 0.06 mg/L is more representative of the overall algal toxicity data for various 

species, yet is lower than the actual EC50 value of 0.08 mg/L for Fucus vesiculosus. This NOEC 

value for chlorate provides adequate protection for aquatic species when used to derive a PNEC 

= 0.6 μg/L.

DBAA:

The aquatic toxicity data set for dibromoacetic acid is very limited. The lowest LC50 reported 

for Pimephales promelas was 69 mg/L. Applying the highest assessment factor of 1,000 from 

Table 2 of the G9 Methodology results in a PNEC = 69.0 μg/L for DBAA.

41 Rosemarin, et.al. Effects of Pulp Mill Chlorate on Baltic Sea Algae, 1994 

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Table T5.9 – Derivation of PNEC Values and PEC/PNEC Ratios 

Chemical Name 

Lowest Observed 

Effect Concentration 

(mg/L)

Assessment

Factor PNEC (μg/L) 

PEC (μg/L) / PNEC (μg/L) 

Ratio

Chlorine dioxide 0.02 1000 0.02 0.0498/0.02 = 2.49 

Chlorite Ion 0.58 1000 0.58 0.0662/0.58 = 0.11 

Chlorate Ion 0.06 100 0.6 0.290/0.6 = 0.48 

Dibromoacetic acid 

(DBAA) 69.0 1000 69.0 0.874/69 = 0.013 

For all substances, with the exception of chlorine dioxide, the PEC/PNEC ratio is <1, thereby 

indicating that no further evaluation or testing is required for chlorite ion, chlorate ion and 

DBAA at the present time. Because the PECs were calculated based on a ‘worst-case’ scenario 

that considered the least amount of flushing (i.e. dilution) within the hydrodynamic model, this 

assessment is considered adequately protective of the aquatic compartment. 

For chlorine dioxide, the PEC/PNEC ratio = 2.49. This PEC was calculated for the Maashaven 

with the detailed model based on a ‘worst-case’ scenario. When the chlorine dioxide PEC result 

of 0.015 μg/L as calculated with the MamPec model for the Maashaven under a ‘worst-case’ 

scenario is considered, a PEC/PNEC ratio of 0.75 is achieved. Further, when the chlorine 

dioxide PEC result of 0.000973 μg/L as calculated with the MamPec model for the whole Port of 

Rotterdam is considered, a PEC/PNEC ratio of 0.049 is achieved. Therefore, the PEC/PNEC = 

2.49 for chlorine dioxide is a conservative value derived under unattainable ‘worst-case’ 

conditions.

5.3.7 Effects on Sediment 

Because the substances utilized with the Ecochlor® BWTS do not have characteristics that would 

indicate adsorption to sediment particles, no effects on sediments are anticipated. Further, none 

of the constituents potentially present in treated ballast water have log Kow values >3.

5.3.8 Comparison of Effect Assessment with Discharge Toxicity 

The original section presented in the Basic Approval dossier was based on discharge toxicity 

from shipboard pilot studies. This data is still considered valid and remains in Tables T2.9 and 

T2.10. However, the original section has been replaced with an updated evaluation to include the 

results of discharge toxicity testing from land based testing. 

5.3.8.1 Treated Ballast Water from Land Based Testing

The effects assessment for the individual constituents potentially present in treated ballast water 

indicates that aquatic toxicity rather than bioaccumulation or sediment toxicity is the primary 

environmental risk. An evaluation of the PEC from hydrodynamic modeling and calculation of a 

PNEC value from toxicity data for each chemical indicates that chlorite ion, chlorate ion and 

DBAA have PEC/PNEC ratios <1. Chlorine dioxide has a calculated PEC/PNEC = 2.49 based 

on a ‘worst-case’ scenario. When more realistic harbor scenarios are considered, the calculated 

PEC/PNEC ratio is <1.

From land based testing, treated ballast water discharge was evaluated for toxicity to six different 

taxonomic groups. The most sensitive species was Crassostrea gigas with an average EC50 of 

51% and an average NOEC of 31%. Therefore, a two-fold dilution is necessary to reach a 

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

less than the NOEC value for Crassostrea.

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The PEC/PNEC ratio of 2.49 compares very well to the three-fold dilution that would be required 

to reach a concentration less than the effect concentrations for Crassostrea gigas, which was 

determined to be the most sensitive species during testing with treated ballast water discharge.

6.0 RISK ASSESSMENT 

The risks presented by having the Ecochlor® BWTS onboard are discussed in Section 6.1, while 

risks to technicians and/or ships crew are discussed in Section 6.2. 

6.1 RISK TO SAFETY OF SHIP 

As discussed in Section 1.0.1, Ecochlor began testing the BWTS onboard ship in 2004 prior to 

the availability of land based testing facilities. The years of testing onboard have allowed 

Ecochlor to identify the risks and develop appropriate mitigations for the safe operation of the 

BWTS onboard, which are detailed in the sections below. This experience, along with the 

engineering reviews that are required during the design, approval and installation process for any 

ship will ensure that appropriate mitigation measures are implemented. 

Preparing for BWTS installation onboard a ship requires extensive reviews by Ecochlor’s marine 

engineers, the vessel engineers, as well as the ship’s classification society. Additional mitigation 

measures that may be identified for safe BWTS installation on a specific ship during these 

reviews will be implemented as needed. 

6.1.1 Ship Integrity and the BWTS 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.2 Corrosion

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.2.1 Effect of pH and Elevated Dissolved Oxygen Concentration on Corrosion 

Detailed information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.2.2 Corrosion Coupon Testing 

In response to the GESAMP-BWWG comment (Section 5.2 in 58/2/8, Annex 5), additional 

details of previous corrosion coupon tests are provided below. 

Corrosion tests have been conducted in ballast tanks treated by the Ecochlor® BWTS to verify 

the effect of chlorine dioxide treatment on ballast tank corrosion rates. Tests were conducted 

with C1010 mild steel corrosion test coupons and sent to Metal Samples Company, Inc. for 

analysis42.

In July/August of 2005, corrosion test coupons were placed in one control (untreated) tank and 

one chlorine dioxide-treated tank that received ballast water from Newark, NJ. The treatment 

tank received a 5.0 mg/L dose of chlorine dioxide. Two test coupons were placed in each tank; 

one high (approximately 1.35 m from the bottom of a 1.8 m tank) and one low (approximately 

0.9 m from the bottom of a 1.8 m tank), and hung by nylon strings. Both sets of coupons 

remained in the respective tanks for 672 hours (28 days). 

Two pre-weighed, standard corrosion coupons were inserted in double bottom ballast tank 

#DB5P as a control. Two pre-weighed, standard corrosion coupons were inserted in double 

bottom #DB6P as treated. Each of the coupons were hung in the ballast tanks from modified 

inspection hatches with non-reactive nylon string. 

42 Corrosion Analysis Data Report, Metal Samples, Co., 2005. 

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The control tank was filled at 10:00 am in NJ at the FAPS marine terminal in the Port of Newark 

on July 25, 2005. The treated tank was also filled at the FAPS marine terminal in the Port of 

Newark at 12:30 pm on July 25, 2005. The control tank was untreated and the treated tank 

received an initial dosage of 5.0 mg/L of chlorine dioxide that was confirmed thru chemical draw 

down calculations. The temperature of the incoming water for both tanks was 24°C. 

Both tanks were “pressed” (filled above 100%) allowing some water to enter the air vents. A 

pressed tank eliminates or drastically reduces the turbulence in the ballast tanks and is required 

for trans-Atlantic voyages. It is highly unlikely that the coupons were ever above the water line 

even in heavy seas. 

The Atlantic Compass had the following subsequent port calls: Halifax, Liverpool, Antwerp, 

Bremerhaven, Gothenburg, Antwerp, Liverpool, Halifax and then back to New Jersey. No 

ballasting or de-ballasting operations for either #DB5P or #DB6P took place until the return to 

New Jersey, when the coupons were removed from the tanks. 

Upon removal, the coupons were sealed in manila envelopes, as dictated by standard analytical 

procedures and sent via express mail to Metal Samples Company for analysis. 

In October/November of 2006 a similar test took place in a tank treated with approximately 4.0 

mg/L of chlorine dioxide. Two test coupons were placed in the tank; one high (approximately 

1.35 m from the bottom of a 1.8 m tank) and one low (approximately 0.9 m from the bottom of a 

1.8 m tank), and hung by nylon strings. Both coupons remained in the tank for 768 hours (32 

days).

Two pre-weighed, standard corrosion coupons were inserted in double bottom #DB5NP which 

was treated with chlorine dioxide upon ballasting. Each of the coupons was hung in the ballast 

tank from a modified inspection hatch with non-reactive nylon string. 

The Atlantic Compass could not guarantee that double bottom #DB5P or #DB6P (as used in the 

2005 study) could be filled in NJ and held as a control thru the Atlantic crossing. Only #DB5NP 

was available for this study. Therefore, no control tank was available for this test. 

The treated tank was filled at the FAPS marine terminal in the Port of Newark at 9:00 am on 

October 21, 2006. The treated tank received an initial dosage of 4.0 mg/L of chlorine dioxide 

that was confirmed thru chemical draw down calculations. The temperature of the incoming 

water was 15°C. 

The deviation from the typical dosage of 5.0 mg/L was due to experimental efficacy testing that 

was being evaluated on board the vessel during this period. Ecochlor has since abandoned the 

lower dosage but believes the corrosion data from this study is relevant. 

As done previously, the treatment tank (#DB5NP) was “pressed” (filled above 100%) allowing 

some water to enter the air vents. 

The Atlantic Compass had the following subsequent port calls: Halifax, Liverpool, Antwerp, 

Bremerhaven, Gothenburg, Antwerp, Liverpool, Halifax and then back to New Jersey. No 

ballasting or de-ballasting operations for #DB5NP took place until the return to New Jersey. The 

two coupons from #DB5NP were removed upon the vessels return to New Jersey on November 

22, 2006. 

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Upon removal, the coupons were sealed in manila envelopes, as dictated by standard analytical 

procedures and sent via express mail to Metal Samples Company for analysis. 

The results of this initial testing are presented in Table T6.1 below, and indicate no adverse effect 

on corrosion rates from chlorine dioxide treatment. Actually, when the July/Aug 2005 study 

corrosion rates of test coupons from untreated and treated tanks are compared, a slight decrease 

in the corrosion rate was observed for test coupons in the treated tanks.

Table T6.1 – Comparison of Corrosion Rates 

Sample Date ClO2 Dosage (mg/L) Exposure time (Hrs) Corrosion Rate (mpy)

Untreated tank (high) Jul/Aug 2005 0 672 9.8389

Untreated tank (low) Jul/Aug 2005 0 672 10.9133

Treated (high) Jul/Aug 2005 5 672 6.0879

Treated (low) Jul/Aug 2005 5 672 7.87

Treated (high) Oct/Nov 2006 4 768 5.0977

Treated (low) Oct/Nov 2006 4 768 5.5624

Corrosion by chlorine dioxide

Ecochlor’s statement that chlorine dioxide treatment will not adversely affect corrosion rates is 

supported by this data. Additional verification of these results with continued coupon corrosion 

studies is presented in Section 6.1.2.4 below. Additionally, visual inspections of piping close to 

the chlorine dioxide injection point was conducted on the Atlantic Compass during a dry-dock 

visit in Dunkirk, France in September 2007. Ecochlor and Atlantic Container Lines personnel 

took this opportunity to visually inspect the internal bare metal piping downstream of the 

injection point of the chlorine dioxide solution. It was the opinion of all inspectors that there was 

no appearance of metal loss of this internal piping. This inspection took place 3 years after the 

installation and commissioning of the Ecochlor system. 

It is also relevant to note the rapid degradation and the relatively low concentrations of the active 

substance and relevant chemicals present in Ecochlor’s treated ballast water, particularly when 

compared with other technologies. The degradation of the active substance in the ballast tanks is 

on the hours time scale, which further suggests that utilization of this BWTS will not have 

significant impacts on the rate of corrosion onboard.

6.1.2.3 Corrosion Coupon Analysis Procedure 

This information is included in the complete confidential Final Approval dossier. 

6.1.2.4 Additional Corrosion Coupon Testing 

As indicated in Section 6.1.2.2 above, additional corrosion coupon testing was conducted since 

the submittal of the Basic Approval dossier. The testing was done in conjunction with the land 

based testing at NIOZ. 

NIOZ Harbor on Texel Island is located between the North Sea and the Wadden Sea. As in the 

testing cycles, harbor water was pumped from the harbor into the coated concrete tanks (300 m3

volume each) that simulate ballast water tanks. One tank was filled on July 22, 2008 with 250 

metric tons of harbor water and used as a “control” (Tank #1) that received no treatment. A 

separate tank (Tank #2) was also filled on July 22, 2008 with approximately 250 metric tons of 

harbor water and “treated” with 5 mg/L of chlorine dioxide. Each tank was open to the 

atmosphere and not “pressed”. 

Three metal coupons were placed in each tank. One coupon was placed one meter below the air / 

water interface (high), one coupon was placed two (2) meters below the air / water interface 

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(mid) and one coupon was placed three (3) meters below the air / water interface (low). The low 

coupon was approximately 1⁄2 meter above the tank bottom. 

The tanks remained filled during the entire study and the total exposure time was 1680 hours. 

All coupons were removed on September 20, 2008 and were shipped for analysis on September 

21, 2008. The results are presented in Table T6.2 below.

Due to the length of the exposure period water quality was not measured for the duration of the 

study. However, water quality data that is typical for the NIOZ harbor and chlorine dioxide 

treatment cycles can be found in Section 2.0.4. 

Table T6.2 – Comparison of Corrosion Rates, Additional Corrosion Coupon Studies, NIOZ 

Sample Date

ClO2 Dosage 

(mg/L)

Exposure time 

(Hrs) 

Corrosion Rate 

(mpy) 

Untreated tank (high) Jul – Sept. 2008 0 1680 2.7246 

Untreated tank (mid) Jul – Sept. 2008 0 1680 2.5672 

Untreated tank (low) Jul – Sept. 2008 0 1680 0.9385 

Treated (high) Jul – Sept. 2008 5 1680 3.2891 

Treated (mid) Jul – Sept. 2008 5 1680 2.6375 

Treated (low) Jul – Sept. 2008 5 1680 2.4643 

The corrosion rates were reviewed and interpreted by Brad Krantz, Senior Corrosion Scientist at 

Corrosion Testing Laboratories, Inc. The report of Corrosion Testing Laboratories confirms the 

theoretical discussion above regarding the effect that dissolved oxygen can have on the corrosion 

rate of mild steel in natural seawater. The full text of Mr. Krantz’s review of the NIOZ corrosion 

study is included in the references of this dossier. Mr. Krantz concluded43:

“Although the corrosion rates for the specimens exposed in the treated tank are slightly 

higher than the untreated controls, all of the corrosion rates are within the range 

expected for carbon steels in natural seawater”. 

This additional corrosion work continues to support Ecochlor’s claim that there will be no 

adverse effects on ship metal surfaces with the use of the Ecochlor treatment methodology. 

6.1.2.5 Ballast Tank Coatings Testing 

Information contained in the complete confidential Final Approval dossier. 

6.1.3 Fire and Explosion 

The fire and explosion risks associated with the Ecochlor® BWTS relate to the precursor 

chemicals stored onboard or electrical components that are part of the system. 

6.1.3.1 Preparation Chemicals

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.3.2 Active Substance 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

43 Corrosion Testing Laboratories, Inc., Review of Corrosion Test Data, November 2008 

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6.1.3.3 Other BWTS Components 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.4 Chemical Storage 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.5 Accidental Chemical Release 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.5.1 Storage Tank Failure 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.1.5.2 Delivery Pipeline Failure 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.2 RISK TO TECHNICIANS AND/OR SHIP’S CREW 

6.2.1 System Interaction – Risks to Technicians and Crew 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.2.1.1 Normal System Operation 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.2.1.2 System Maintenance and Chemical Refill Operations 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.3 RISKS TO HUMAN HEALTH AND HUMAN EXPOSURE SCENARIOS 

Comments from the GESAMP-BWWG (MEPC 58/2/8, Annex 5, Section 4.9) indicated the 

information provided for HES and Human Health Risk Characterization were adequately 

addressed in the Basic Approval dossier. No further analysis has been added to this Final 

Approval dossier.

6.3.1 Identification of Chemicals of Potential Concern and Sources 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.3.2 Human Exposure Assessment 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.3.3 Potential Exposure Health Risks 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.3.4 Risk Characterization 

Information was provided in the Basic Approval dossier (MEPC 58/2/2). 

6.4 RISKS TO THE AQUATIC ENVIRONMENT 

Based on the discharge toxicity results from land based testing and the results of the 

hydrodynamic modeling, treated ballast water from the Ecochlor® BWTS will not present 

unacceptable risks to the aquatic environment. The calculated PEC/PNEC ratios for chlorite ion, 

chlorate ion and DBAA were <1, indicating no adverse effects from these constituents in treated 

ballast water discharge. The calculate PEC/PNEC ratio for chlorine dioxide is 2.49, which is 

considered to be a conservative value that was derived from an unattainable ‘worst-case’ 

scenario. More realistic modeling approaches yielded PEC/PNEC values <1 for chlorine dioxide.

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Further, only during the land based testing have residuals of chlorine dioxide been measurable in 

treated ballast water 24 hours after treatment. This is unlike shipboard testing where chlorine 

dioxide residuals have not been measured 24 hours after treatment. The longer residual time 

observed is likely due to the fact that simulated ballast tanks at the land based testing facility did 

not contain any sediments and/or biofilms that are present within actual ballast tanks onboard 

ship. The oxidative reactions with sediments and/or biofilms increases the decay rate for 

chlorine dioxide. Therefore, using the highest chlorine dioxide residual measured 24 hours after 

treatment during land based testing is also considered a ‘worst-case’ scenario. 

Discharge toxicity testing 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 

Crassostrea tests was 51% (average NOEC = 31%). Thus, a two-fold dilution is necessary to 

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

concentration less than the NOEC value for Crassostrea. This low level of dilution will be 

achieved immediately upon discharge of treated ballast water.

Further, the discharge toxicity testing results from land based testing compare well with previous 

conclusions regarding the dilution required to reach no-effect concentrations from shipboard 

discharge toxicity testing. For example, from shipboard discharge toxicity testing, acute toxicity 

with M. bahia resulted in EC50 values of 38.7% and 37.7% (v/v) and the NOEC for both tests 

was 25% sample. Thus, a three-fold dilution was necessary to reach a concentration less than the 

EC50 and a four-fold dilution was necessary to result in no acute toxicity with M. bahia.

Based on this assessment, although the PEC/PNEC value for chlorine dioxide is slightly >1, 

treated ballast water discharge from the Ecochlor BWTS will not present unacceptable risks to 

the aquatic environment. 

6.5 ASSESSMENT REPORT (G9: 4.3) 

6.5.1 Overview of Data and Endpoints 

As constituents potentially present in ballast water treated with the Ecochlor® BWTS, chlorine 

dioxide, chlorite ion, chlorate ion and dibromoacetic acid (DBAA) were evaluated in regards to 

persistence, bioaccumulation, and toxicity. In regards to persistence, chlorine dioxide was 

reported to have a half-life of 3.9 minutes in freshwater33 (5 minutes in seawater), chlorite ion in 

sea water had a measured half-life of <2 minutes in seawater, chlorate ion had a measured halflife of <1 day in seawater, and a half-life of 14 days was reported for DBAA in freshwater. The 

estimated log Kow values for chlorine dioxide and chlorite are -3.22 and -7.176

, respectively. The 

measured log Kow value for chlorate ion and DBAA are -2.934 and 1.2214, respectively. These 

Kow values, the physical and chemical characteristics, along with well-documented degradation 

behavior, indicate that these substances would not be expected to bioaccumulate. In regards to 

toxicity, the lowest LC50 for chlorine dioxide was 0.02 mg/L, while the lowest chronic NOEC 

for chlorite ion was 0.18 mg/L. For chlorate ion the NOEC (geometric mean) value was 0.06 

mg/L and for DBAA, the lowest LC50 was 69 mg/L. Therefore, these substances do not meet 

the criteria to be classified as PBT substances. 

Prediction of environmental concentrations (PECs) using two separate hydrodynamic modeling 

programs was performed for each substance that may be present in treated ballast water 

discharge. The predicted no-effect concentrations (PNECs) were derived by applying an 

appropriate assessment factor to the lowest toxicity data points for each substance. For all 

substances, with the exception of chlorine dioxide, the PEC/PNEC ratio is <1, thereby indicating 

that no unacceptable risks to the aquatic environment can be expected from chlorite ion, chlorate 

ion and DBAA. Further, because the PECs were calculated based on a ‘worst-case’ scenario that 

considered the least amount of flushing (i.e. dilution) within the hydrodynamic model, and the 

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highest measured value (rather than the average) for each constituent, this assessment is 

considered adequately protective of the aquatic compartment. 

For chlorine dioxide, the PEC/PNEC ratio = 2.49. This PEC was calculated for the Maashaven 

with the detailed model based on an unrealistic ‘worst-case’ scenario. When the chlorine dioxide 

PEC result of 0.015 μg/L as calculated with the MamPec model for the Maashaven under a 

‘worst-case’ scenario is considered, a PEC/PNEC ratio of 0.75 is achieved. Further, when the 

chlorine dioxide PEC result of 0.000973 μg/L as calculated with the MamPec model for the 

whole Port of Rotterdam is considered, a PEC/PNEC ratio of 0.049 is achieved. Therefore, the 

PEC/PNEC = 2.49 for chlorine dioxide is a conservative value derived under unrealistic ‘worstcase’ conditions.

Evaluation of discharge toxicity results from land based discharge demonstrated that the Pacific 

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

The average EC50 for all Crassostrea tests is 51% (average NOEC = 31%). Thus, a two-fold 

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

necessary to reach a concentration less than the NOEC value for Crassostrea. Additionally, the 

toxicity results between day 1 and day 5 discharges for Crassostrea were not significantly 

different, thereby indicating that treated water discharge will not present unacceptable risks when 

discharged within 24 of treatment and a longer holding time is not required. 

As presented in Sections 2.3.3 and 5.3.1, chlorine dioxide, chlorite ion and chlorate ion are 

oxidizing agents that do not produce harmful organic by-products. DBAA is not expected to 

have adverse reactions with organic matter. Additionally, chlorine dioxide degrades rapidly in 

marine and fresh waters, predominantly forming chlorite ion as a degradation by-product33.

Chlorite ion, chlorate ion, and DBAA are all considered non-persistent. Degradation of chlorine 

dioxide and chlorite ion both substances is by abiotic mechanisms and is predominantly a result 

of oxidative reactions. Chlorate ion and DBAA degradation by both abiotic and biotic 

mechanisms has been demonstrated. 

Land based testing at NIOZ in the Netherlands successfully demonstrated that the Ecochlor®

BWTS can safely and effectively treat ballast water for AIS to comply with the performance 

standards in Regulation D-2 of the International Convention for the Control and Management of 

Ship’s Ballast Water and Sediments, as well as standards proposed in the US Ballast Water 

Management Act of 2005 (Senate Bill S.363). Based on laboratory analysis, shipboard testing, 

and land based testing of treated ballast water, no related adverse effects from the use of the 

Ecochlor® BWTS to comply with the Convention can be reasonably anticipated. The level of 

uncertainty in the data supporting this opinion is low. Additional data continues to be collected 

on the Ecochlor® BWTS, further increasing the confidence in the results obtained through 

various analyses.

The potential risks to the safety of ships, human health and the environment are mitigated by 

engineering and constructing systems that are designed for use onboard ships, proper chemical 

production, dosing, storage and handling, as well as thorough personnel training and use of PPE. 

The automatic dosing of chlorine dioxide treatment based on the amount of ballast water being 

brought onboard limits chlorine dioxide production, ensuring safe discharge of treated water to 

the environment. The substances used with the Ecochlor® BWTS are not expected to persist in 

the environment or bioaccumulate, thereby presenting no risks to resources (i.e. beaches, 

fisheries).

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6.5.2 Test Report Data Quality 

Test reports used in this application were from a variety of sources, including, but not limited to, 

OECD SIDS, Eka Chemicals (performed by independent laboratories), independent research, 

USEPA, and the National Toxicology Program. The reports were evaluated to ensure that the 

data presented was generated by accredited laboratories using accepted standard methodologies 

and laboratory practices. The data met acceptable confidence intervals (i.e. >95%), indicating a 

low level of uncertainty associated with the data. For example, the following is quoted text from 

one mammalian toxicity study used in the risk characterization (Barrett, 1987): 

“Results of the inspections made by the Quality Assurance Unit at BIO/dynamics, Inc. 

indicate that this study was conducted in compliance with applicable United States 

Environmental Protection Agency’s Good Laboratory Practice Standards and applicable 

Standard Operating Procedures. No significant deviates were noted. Minor deviations 

may be include in the raw data” 

Proper quality assurance / quality control programs are strictly implemented at each of the 

laboratories that conducted testing on treated ballast water. These include NovaChem Labs 

(analytical chemistry), Nautilus Environmental, Chemex Environmental Limited, and 

Grontmij|AquaSense (toxicology). Documentation of the quality control that these labs adhere to 

are included in Appendix C of this dossier.

7.0 REFERENCE DOCUMENTS 

1 International Maritime Organization, MEPC57/21, Annex 1, Resolution MEPC.169(57),

Procedure for Approval of Ballast Water Management Systems That Make Use of Active 

Substances (G9), April 2008. 

2 International Maritime Organization, MEPC 58/2/7, Annex 4, GESAMP-BWWG 6/9, 

Methodology for Information Gathering and the Conduct of Work of GESAMP-BWWG, 

May 2008. 

3 International Maritime Organization, MEPC 58/2/2, Application for Basic Approval of the

Ecochlor® Ballast Water Treatment System, March 2008. 

4 International Maritime Organization, MEPC 58/2/8, Annex 5, July 2008. 

5 OECD SIDS, Sulfuric Acid, SIAM 11, January 2001, UNEP Publications. 

6 US EPA Reregistration Eligibility Decision (RED) for Chlorine Dioxide and Sodium 

 Chlorite (Case 4023), August 2006. 

7 US EPA Toxicological Review of Chlorine Dioxide and Chlorite, September 2000. 

8 EPA Guidance Manual, Alternative Disinfectants and Oxidants, Chlorine Dioxide, 1999 

 (http://www.epa.gov/safewater/mdbp/pdf/alter/chapt_4.pdf). 

9 Simpson, G.D., Miller, R.F., Laxton, G.D., Clements, W.R., A Focus on Chlorine Dioxide: 

The “Ideal” Biocide. 

10 OECD SIDS, Sodium Chlorite and Chlorine Dioxide, SIAM 23, October 2006. 

11 World Health Organization, Guidelines for Drinking-Water Quality, 2006. 

12 USEPA, Office of Ground Water and Drinking Water, DBP/ICR Analytical Methods 

Manual (EPA 814-B-96-002, April 1996. 

13 Bubnis, B., The Rationale and Transition of Regulating Agencies Specifying the Reporting 

of Method Reporting Limits (MRLs) In-Lieu of Method Detection Limits (MDLs), October 

2008.

14 World Health Organization, Brominated Acetic Acids in Drinking Water, Background 

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 Document for Development of WHO Guidelines for Drinking-water Quality, 2004. 

15 OECD SIDS, Sodium Chlorate, SIAM 22, April 2006. 

16 NovaChem Laboratories, A Data Summary of the Ecochlor Ballast Water Treatment 

 System at the Land Based Testing Facility Operated by the Royal Netherlands Institute for 

 Sea Research (NIOZ), Nov 2008.

17 Ambient Water Quality Guidelines for Chlorate, Government of British Columbia, 

 Environmental Protection Division, 2002. 

18 van Wijk, D.J. Kroon, G.M. and Garttener-Arends, C.M., Toxicity of Chlorate and Chlorite 

to Selected Species of Algae, Bacteria, and Fungi, 1998. 

19 Stauber, J.L., Toxicity of Chlorate to Marine Microalgae, 1998. 

20 Nautilus Environmental, Toxicological Evaluations of Chlorine Dioxide, January 2005. 

21 Nautilus Environmental, Algal Toxicity Testing using Chlorine Dioxide, May 2006. 

22 Environmental Science & Engineering, Acute Toxicity of Sodium Chlorite to the 

 Sheepshead innow (Cyprinodon variegatus), May 1994. 

23 Environmental Science & Engineering, Acute Toxicity of Sodium Chlorite to Mysid 

 Shrimp (Mysidopsis bahia), May 1994. 

24 Nautilus Environmental, Supplemental Toxicity Testing using Chlorite, January 2008. 

25 van Wijk, D.J and Hutchinson T.H., The Ecotoxicity of Chlorate to Aquatic Organisms: A 

 Critical Review, 1995. 

26 US EPA, ECOTOX Database, Aquatic Report for Dibromoacetic Acid, 2008. 

27 Nautilus Environmental, Toxicological Evaluation of Ballast Water Treated with Chlorine 

 Dioxide, Atlantic Compass Trial, August 2006. 

28 Nautilus Environmental, Toxicological Evaluation of Ballast Water Treated with Chlorine 

 Dioxide, Atlantic Compass Trial, September 2006. 

29 Grontmij | AquaSense, Report of Ecotoxicological Studies, October 2008. 

30 US EPA, Short-Term Methods for Estimating the Chronic Toxicity of Effluents and

 Receiving Waters to West Coast Marine and Estuarine Organisms, EPA/600/R-95-136 

 (Section 2), August 1995.

31 Canadian Water Quality Guidelines for the Protection of Aquatic Life, A Protocol for the 

 Derivation of Water Quality Guidelines for the Protection of Aquatic Life, 2007. 

32 Environmental Science & Engineering, Effect of Sodium Chlorite on New Shell Growth in 

 Eastern Oyster (Crassostrea virginica), May 1994. 

33 Review of the Environmental Fate and Effects of Chlorine Dioxide and Chlorite, Nautilus

 Environmental, 2007. 

34 European Union, The Footprint Pesticide Properties Database, 

 www.eu-footprint.org/ppdb.html 

35 International Programme on Chemical Safety, Environmental Health Criteria 216, 

 Disinfectants and Disinfectant By-Products, World Health Organization, 2000. 

36 Concise International Chemical Assessment Document (CICADS) 37, Chlorine Dioxide 

 (Gas), 2002. 

37 Barrett, D.S. (1987) A Subchronic (3 Month) Oral Toxicity Study of Sodium Chlorate in 

 the Rat via Gavage.

38 Barrett, D.S. (1987) A Subchronic (3 Month) Oral Toxicity Study in the Dog via Gavage 

 Administration with Sodium Chlorate. 

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39 Scientific Committee on Consumer Products (SCCP), Opinion on Hydrogen Peroxide in 

 Tooth Whitening Products, 2005 (SCCP/0844/04). 

40 NTP Technical Report on the Toxicology and Carcinogenesis Studies of Sodium Chlorate 

 in F344/N Rats and B6C3F1 Mice (Drinking Water Studies), 2005. NTP TR 517, NIH 

 Publication No. 06-4457. 

41 European Chemical Bureau (2003) Hydrogen Peroxide Summary Risk Assessment Report, 

 Special Publication I.03.148.

42 NTP Technical Report on the Toxicology and Carcinogenesis Studies of Dibromoacetic 

 Acid in F344/N Rats and B6C3F1 Mice (Drinking Water Studies), April 2007, NTP TR 

 537, NIH Publication No. 07-4475. 

43 Smith, D.J., Anderson, R. C., Ellig, E.A., and Larsen, G.L. (2005) Tissue Distribution, 

 Elimination, and Metabolism of Dietary Sodium [36Cl}Chlorate in Beef Cattle. 

44 Abdel-Rahman, M.S., Couri, D., and Bull, R.J. (1982) Metabolism and Pharmacokinetics of 

 Alternate Drinking Water Disinfectants. Environmental Health Perspectives, v46, pp19-23. 

45 US EPA Reregistration Eligibility Decision (RED) for Inorganic Chlorates (Case 4049),

 July 2006. 

46 Hashimoto, S., Azuma, T., Otsuki, A., Distribution, Sources, and Stability of Haloacetic

 Acids in Tokyo Bay, 1998. 

47 Lifongo, L., Bowden, D., Brimblecombe, P., Photodegradation of haloacetic acids in water,

 2004. 

48 US EPA Memorandum, Revised Inorganic Chlorates, HED Chapter of the Reregistration

 Eligibility Decision (RED) Case #4049, January 2006 

49 Mosser, Mark L., Sermatech International Inc., September 15, 2005. 

50 The Sulphur Institute Online, Glossary of Terms 

 (http://www.sulphurinstitute.org/webarticles/anmviewer.asp?a=109&z=30). 

51 Deltares, Draft Predicted Environmental Concentrations as a result of ballast water

 discharge in the Rotterdam harbor, 2008. 

52 Rosemarin, A., Lehtinen, K., Notini, M, Mattsson, J., Effects of Pulp Mill Chlorate on

 Baltic Sea Algae, 1994. 

53 Heidersbach, Bob; Dr. Rust, Inc.; Ballast Water Corrosion Rates Using the Ecochlor®

 Ballast Water Treatment System, May 2007. 

54 Corrosion Analysis Data Report, Metal Samples, Co., 2005. 

55 Corrosion Testing Laboratories, Inc., Review of Corrosion Test Data, November 2008. 

56 Physical and Chemical Characteristics of Purate®, Case Consulting Laboratories, 2000. 

57 Chlorine Dioxide and Chlorite Toxicological Profile, Agency for Toxic Substances and

 Disease Registry (http://www.atsdr.cdc.gov/toxprofiles/tp160-c4.pdf).

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