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\2-1.doc 

INTERNATIONAL MARITIME ORGANIZATION

IMO 

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE 

59th session 

Agenda item 2 

MEPC 59/2/1

 4 December 2008

 Original: ENGLISH

HARMFUL AQUATIC ORGANISMS IN BALLAST WATER 

Application for Final Approval of the Special Pipe Hybrid 

Ballast Water Management System (combined with Ozone treatment) 

Submitted by Japan 

SUMMARY

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

application for Final Approval of the Special Pipe Hybrid Ballast Water 

Management System (combined with Ozone treatment) under the 

ìProcedure for approval of ballast water management systems that make 

use of Active Substances (G9)î 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 55/2; MEPC 55/2/16; MEPC 57/2/10; 

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

Introduction 

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

Ballast Water and Sediments, 2004 stipulates that ballast water management systems that make 

use of Active Substances to comply with the Convention shall be approved by the Organization. 

2 Japan herewith submits an application for Final Approval according to the ìProcedure for 

approval of ballast water management systems that make use of Active Substances (G9)î 

adopted by resolution MEPC.169(57). This Procedure stipulates the required information 

(MEPC 57/21, annex 1, paragraph 4.2.1) which, according to section 6, should be evaluated by 

the Organization. In accordance with the Methodology for information gathering and conduct of 

work of the GESAMP-BWWG (BWM.2/Circ.13), the annex to this document contains the 

non-confidential part of the manufacturerís application dossier including the following: 
MEPC 59/2/1 - 2 - 

I:\MEPC\59\2-1.doc 

.1 summary of the research conducted for the Special Pipe Hybrid Ballast Water 

Management System combined with Ozone treatment version according 

to Procedure (G9); 

.2 reference list; and 

.3 statement and quality assurance statement. 

The complete dossier will be made available to the experts of the GESAMP-BWWG with the 

understanding of confidential treatment. 

3 ìSpecial Pipe Hybrid Ballast Water Management System combined with Ozone treatment 

versionî (SP-Hybrid BWMS Ozone version) is the same system as previously called the 

ìSpecial Pipe Ballast Water Management System (combined with Ozone treatment)î, which was 

reviewed for Basic Approval based on Procedure (G9) at the second meeting of the 

GESAMP-Ballast Water Working Group (GESAMP-BWWG) held in May 2006 and was 

granted Basic Approval at MEPC 55 in October 2006. The name was slightly changed for the 

purpose of future commercialization. 

4 The application for Final Approval is submitted by the manufacturer, Mitsui Engineering 

& Shipbuilding Co., Ltd., instead of the Japan Association of Marine Safety, that applied for 

Basic Approval, as a coordinator of the project development at that time. 

5 The receiving competent authority in Japan has verified the application dossier and has 

considered it in line with the data requirements of Procedure (G9). 

Action requested of the Committee 

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

*** 
MEPC 59/2/1 

I:\MEPC\59\2-1.doc 

ANNEX 

NON-CONFIDENTIAL INFORMATION ON THE SPECIAL PIPE HYBRID 

BALLAST WATER MANAGEMENT SYSTEM COMBINED 

WITH OZONE TREATMENT VERSION (JAPAN) 

Contents 

1 INTRODUCTION 

1.1 Application process with Procedure G9 for ìSpecial Pipe Hybrid Ballast Water Management 

System combined with Ozone treatment versionî (SP-Hybrid BWMS Ozone version) 

1.2 Points made by GESAMP-BWWG at time of G9 Basic Approval 

1.3 Constitution of the application for G9 Final Approval 

1.4 Conditions of system application 

1.5 Conclusion of Final Assessment Report 

2 APPLICATION DATA SET 

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

2.1.1 Preparations (G9: 4.2.2) 

2.1.2 Active Substances 

2.1.3 Relevant Chemicals (G9: 2.1.4) 

2.1.4 Other Chemicals 

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

sensitive and representative organisms (G9: 4.2.1.1) 

2.2.1 Acute aquatic toxicity 

2.2.2 Chronic aquatic toxicity 

2.2.3 Endocrine disruption 

2.2.4 Sediment toxicity 

2.2.5 Bioavailability/biomagnification/bioconcentration 

2.2.6 Food web/population effects 

2.3 Data on mammalian toxicity (G9: 4.2.1.2) 

2.4 Data on environmental fate and effect under aerobic and anaerobic conditions (G9: 4.2.1.3) 

2.4.1 Modes of degradation (biotic; abiotic) 

2.4.2 Bioaccumulation, partition coefficient, octanol/water partition coefficient 

2.4.3 Persistence and identification of the main metabolites in the relevant media (ballast 

water, sea and fresh water) 

2.4.4 Reaction with organic matter 

2.4.5 Potential physical effects on wildlife and benthic habitats 

2.4.6 Potential residues in seafood 

2.4.7 Any known interactive effects 

2.5 Physical and chemical properties of the Active Substances and preparations and treated 

ballast water, if applicable (G9: 4.2.1.4) 

2.6 Analytical methods at environmentally relevant concentration (G9: 4.2.1.5) 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

3 USE OF THE ACTIVE SUBSTANCE 

3.1 Summary of SP-Hybrid BWMS Ozone version 

3.1.1 Components and outline 

3.1.2 The characteristics 

3.1.3 Materials of major components 

3.1.4 Results of environmental tests of component units 

3.1.5 Approval of on board system by Classification Society 

3.2 The manner of application (G9: 4.2.6 and 7) 

3.2.1 The maximum dosage concentration of Ozone 

3.2.2 Holding time 

3.2.3 The maximum allowable discharge concentration of the Relevant Chemicals 

3.2.4 Handling, use, storage and transport of the chemicals 

3.2.5 Procedures and use of the system 

3.2.6 Risk management measures in case of emergency 

3.2.7 Other safety measures 

3.2.8 Control of discharge water and countermeasures 

3.2.9 Waste control and recycle 

4 MATERIAL SAFETY DATA SHEETS (G9: 4.2.7) 

5 RISK CHARACTERIZATION 

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

5.1.1 Persistence (G9: 5.1.1.1) 

5.1.2 Bioaccumulation (G9: 5.1.1.2) 

5.1.3 Toxicity test (G9: 5.1.2.3) 

5.1.4 Do the Ozone and Relevant Chemicals meet all three criteria for PBT? 

6 EVALUATION OF THE TREATED BALLAST WATER (G9: 5.2) 

6.1 Tests of the treated ballast water implemented for the purpose of Final Approval 

6.1.1 Outline of tests 

6.1.2 Test facilities 

6.1.3 Justification of test facilities 

6.1.4 Quality control of test 

6.2 Full-scale land-based acute toxicity test (G9: 5.2.2) 

6.3 Repetition of chronic toxicity test (G9: 5.2.1) 

6.4 Degradation test for generated Relevant Chemicals 

6.5 Removal test for generated Relevant Chemicals 

6.6 Long-term performance test of Discharge Water Treatment Tank 

6.7 Determination of holding time 

6.8 Risk characterization and analysis 

6.8.1 Reaction with organic matter (G9: 4.2.1.3) 

6.8.2 Characterization of degradation route and rate (G9: 5.3.5) 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

6.9 Prediction of discharge and environmental concentrations 

6.9.1 Discharge concentration of Relevant Chemicals 

6.9.2 Target port and the designated sea area for the estimation of PEC 

6.9.3 Calculation conditions of PEC 

6.9.4 Calculation results 

6.10 Assessment of potential for bioaccumulation 

6.11 Effects assessment 

6.12 Effects on aquatic organisms 

6.12.1 Estimated PNEC 

6.12.2 PEC/PNEC ratio 

6.13 Effects on sediment 

6.14 Comparison of effect assessment with discharge toxicity 

7 RISK ASSESSMENT 

7.1 Risk to safety of ship 

7.1.1 Increased corrosion 

7.1.2 Fire and explosion 

7.1.3 Storage and handling of the substances 

7.1.4 Contact with, or inhalation of, process products 

7.1.5 Noise 

7.2 Risk to human health 

7.2.1 Health effects in humans (G9: 5.3.12) 

7.2.2 Human Exposure Scenario (HES) (G9: 6.3.3) 

7.2.3 Conclusion 

7.3 Risk to the aquatic environment 

8 CONCLUSION 

REFERENCES 

STATEMENT and QUALITY ASSURANCE STATEMENT 
MEPC 59/2/1 

ANNEX 

Page 4 

I:\MEPC\59\2-1.doc 

1 INTRODUCTION 

1.1 Application process with Procedure (G9) for ìSpecial Pipe Hybrid Ballast Water 

Management System combined with Ozone treatment versionî (SP-Hybrid BWMS 

Ozone version) 

The ìSpecial Pipe Hybrid Ballast Water Management System combined with Ozone treatment 

versionî (SP-Hybrid BWMS Ozone version) used to be called the ìSpecial Pipe Ballast Water 

Management System (combined with Ozone treatment)î. The ìSpecial Pipe Ballast Water 

Management System (combined with Ozone treatment)î was reviewed for Basic Approval 

according to the Procedure for approval of ballast water management systems that make use of 

Active Substances (G9) at the second meeting of GESAMP-Ballast Water Working Group 

(GESAMP-BWWG) held from 22 to 26 May 2006 and was granted Basic Approval at MEPC 55, 

held from 9 to 13 October 2006. 

The SP-Hybrid BWMS Ozone version for which an application is made for Final Approval with 

Procedure (G9) is identical to the system granted Basic Approval except for the following 

modifications for practical use: 

.1 Name of the system 

Another application with procedure (G9) is also considered by developing a 

BWMS which will combine the main component of Special Pipe with an Active 

Substance other than Ozone. Therefore, an Active Substance combined with 

Special Pipe Hybrid Ballast Water Management System was added to its name to 

clarify the components of the system. Since the present application for Final 

Approval with G9 uses Ozone as an Active Substance, the name was changed to 

ìSpecial Pipe Hybrid Ballast Water Management System combined with Ozone 

treatment versionî with the abbreviation of SP-Hybrid BWMS Ozone version. 

.2 Operation of Discharge Water Treatment Tank (DWTT) 

An application was made for Basic Approval of the system with two alternatives. 

One was to discharge the ballast water after longer than 48 hoursí storage in the 

ballast tanks following treatment of ballast water with maximum 4 mg/L Ozone at 

the time of ballasting. The other was to discharge ballast water after the residual 

Relevant Chemicals in the ballast water were reduced to an allowable level by 

post-treatment by the DWTT regardless of the time of storage after treatment at 

the time of ballasting. 

Ozone was injected also for the Final Approval in such manner as to maintain 4 mg/L 

maximum Ozone concentration in the collected ballast water. However, this time 

the DWTT was applied to any ballast water discharge so that the safety of ballast 

water discharge to the environment could be assured. Furthermore, post-treatment 

by the DWTT without designating tank storage time was implemented in order to 

be able to discharge at any time. 

This application for Final Approval is based on Ozone injection to achieve 4 mg/L 

Ozone concentration for the intake of ballast water so that safety to the receiving 

environment of the discharged ballast water is assured. Furthermore, on the 

assumption that the holding time is zero, the system design was changed to apply 

post-treatment of the DWTT to every occasion. 
MEPC 59/2/1 

ANNEX 

Page 5 

I:\MEPC\59\2-1.doc 

.3 Change of the applicant 

The application for Basic Approval was submitted by the Japan Association of 

Marine Safety who had been acting as a coordinator of the system development. 

However, the application for Final Approval is presented by the manufacturer, 

Mitsui Engineering & Shipbuilding Co., Ltd. 

1.2 Points made by the GESAMP-BWWG at the time of G9 Basic Approval 

As stated in document MEPC 55/2/16, annex 5, GESAMP-BWWG had brought up the following 

points on the application for Basic Approval (MEPC 55/2, as well as the confidential version) 

and recommended that these should be examined during further development and testing and that 

the results should be reported at the time of submission of the application for Final Approval. 

1.2.1 Recommendations by the GESAMP-BWWG, contained in document MEPC 55/2/16, 

annex 5, paragraph 10.4 

.1 Due consideration should be given to the fact that the risk assessment currently 

performed has been based upon an incomplete data set and therefore the risk 

assessment should be considered as indicative only. A complete data set may 

result in a different conclusion.

.2 Due consideration should be given to the fact that the information on the 

substance Bromoform as a possible Relevant Chemical is considered insufficient 

for a risk assessment on this chemical on all topics, therefore, additional 

information should be provided on this substance. 

.3 The discharge from the ìwaste Ozone destruction unitî should be suitably sited 

and included in the Ozone monitoring and alarm system. 

.4 It should be confirmed that the levels of THM and free Ozone in the ballast tanks 

remain acceptable. Additional safety precautions should be put in place until such 

confirmation is obtained. 

.5 It should be confirmed that the noise levels when the system is in operation 

remain within permitted levels for machinery spaces (MEPC 55/2/16, annex 5, 

paragraph 10.4.2.5). 

.6 It should be confirmed that the initial assessment that the corrosion effect will be 

limited is correct and that there is no additional corrosion effect on ballast piping, 

ballast tanks or degradation of protective coatings resulting from the use of the 

system. 

.7 The apparent discrepancy between the measured chronic toxicity of the treated 

ballast water and the assessment of Bromate should be investigated further. 

Awaiting the results of such investigations, the discharge of ballast water treated 

with Ozone during further development and testing should only take place under 

controlled conditions and into an environment where a sufficient dilution can be 

assured for avoiding unreasonable risks to the aquatic environment. 
MEPC 59/2/1 

ANNEX 

Page 6 

I:\MEPC\59\2-1.doc 

1.2.2 Other recommendations by the GESAMP-BWWG 

GESAMP-BWWG made 17 comments in addition to those contained in document MEPC 55/2/16, 

annex 5, paragraph 10.4, so the total number of their comments and recommendations has 

reached 24. 

1.3 Constitution of the application for G9 Final Approval 

This application for Final Approval has been developed in compliance with the latest 

ìMethodology for information gathering and the conduct of work of the GESAMP-BWWG 

(updated May 23, 2008)î. The following further tests have been implemented for the application 

for Final Approval: 

.1 acute toxicity tests of treated ballast water from the land-based test facility; 

.2 repetition of chronic toxicity test; 

.3 degradation test for generated Relevant Chemicals; 

.4 removal test for generated Relevant Chemicals; 

.5 long-term performance test of DWTT; 

.6 inspection for hull corrosion in full-scale shipboard system; 

.7 analysis for volatile Bromoform from ballast tank; and 

.8 noise measurement test in full-scale shipboard system. 

Furthermore, taking into consideration the comments made previously by the GESAMP-BWWG on 

the application for Basic Approval (MEPC 55/2/16, annex 5), the requirement for Basic Approval 

as well as all the sections following section 2 ìApplication data setî, have been reproduced, and 

ultimately risk assessment (see section 7) has been conducted. 

1.4 Conditions of system application 

SP-Hybrid BWMS Ozone version should be applied under the following conditions. This 

application for Final Approval requires review and permission with reference to the use of 

BWMS under the following conditions: 

.1 Ballast water required for treatment 

Sea and brackish water containing bromide ion. Fresh water containing no 

bromide ion is not included in this application. 

.2 Times of ballast water treatment 

It is treated only once on ballasting. 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

.3 Concentration of Active Substance (Ozone) when in use 

Ozone as Active Substance is injected on ballasting in such manner to achieve the 

concentration of 3 mg/L in the ballasting water. 

.4 Holding time 

Holding time following ballast water treatment is not specified. Ballast water can 

be discharged immediately after treatment. 

.5 Use of DWTT 

At the time of ballast water discharge, the Relevant Chemicals should be removed 

by the DWTT. 

.6 The maximum allowable discharge concentration of Relevant Chemicals 

The concentration of relevant chemicals at the time of discharge following removal 

by the DWTT is less than 0.07 mg/L for Bromate ion, less than 0.19 mg/L for 

Bromoform and less than 0.2 mg/L for TRO (as O3). 

1.5 Conclusion of Final Assessment Report 

SP-Hybrid BWMS Ozone version uses Ozone, which is a powerful oxidizing agent as the Active 

Substance. Ozone reacts with ballast water to generate the Relevant Chemicals, Bromate ions, 

Bromoform and TRO in the ballast water. However, as this BWMS has thorough safety 

measures for Ozone put in place on board a vessel, safety to the vessel and crew is completely 

secured. Furthermore, as the concentration of generated Relevant Chemicals can be reduced 

through the DWTT, the potential impact to public health and environment in the ambient waters 

of ballast discharge is deemed almost negligible. Therefore, this system is considered to deserve 

Final Approval under Procedure (G9). 

2 APPLICATION DATA SET 

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

2.1.1 Preparations (G9: 4.2.2) 

SP-Hybrid BWMS Ozone version is a BWMS, which inactivates aquatic organisms in the ballast 

water by using the inactivation effect of Special Pipe and Ozone against the organisms. Ozone is 

generated by use of air as raw material. First air is converted to a gas with more than 90% oxygen 

concentration using an Oxygen Generator then Ozone is produced by a cylindrical water cooled 

silent discharge type Ozone Generator. The generated Ozone is injected into the ballasting line 

by the Ozone Injector. Various items of equipment installed on board a vessel make all these 

treatment processes available at the time of intake of ballast water. Therefore, this system does 

not require any preparation of chemical substances and does not need to store Ozone on board. 

The Ozone gas mixture, which is injected to ballasting line contains other gaseous components of 

the air. The concentration of Ozone is in the range of 6 to 12 v/v%. Table 2.1-1 showed the 

components of the gas injected to ballasting line of this system, showing concentration, CAS No. 

and classification of Active Substances, etc. As this BWMS generates all the components on 

board, the UN number and shipping name of each component do not need to be reported. 
MEPC 59/2/1 

ANNEX 

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Ozone is the only Active Substance in the injected Ozone gas mixture. As oxygen and other 

components are either components of the air or present temporarily in small amounts, they are 

not deemed to be Active Substances or Relevant Chemicals. 

Table 2.1-1: Component of Ozone gas injected to ballasting line of this system 

Composition of Ozone gas mixture

Component 

Chemical 

Name 

CAS 

Number 

Empirical 

formula 

Molar 

Mass 

Concentration 

(%) 

AS, RC or 

Other*

Ozone 10028-15-6 O3 48.00 6-12 v/v% AS 

Oxygen 7782-44-7 O2 32.00 80-88 v/v%

Nitrogen 7727-37-9 N2 28.01 2-3 v/v%

Argon 7440-37-1 Ar 39.95 4-5 v/v%

component of 

the air 

* AS: Active Substance, RC: Relevant Chemicals, Other: Any other Chemicals

2.1.2 Active Substances 

The Active Substance of SP-Hybrid BWMS Ozone version is Ozone. Information on Ozone 

follows below: 

.1 trade name: Not applied as this is generated on board a vessel; 

.2 chemical (IUPAC) name: Ozone; 

.3 CAS number: 10028-15-6; 

.4 UN number and proper shipping name: Not applied as this is generated on board 

a vessel; 

.5 Molar mass: 48.00; 

.6 empirical formula: O3;

.7 structural formula: ; 

.8 classification in accordance with the UN GHS system: Omitted; 

.9 purity of the technical material and identification of impurities (chemical name 

and CAS- number, etc.): Refer Table 2.1-1; and 

.10 identity of any stabilizer or necessary additives: No need to report. 

2.1.3 Relevant Chemicals (G9: 2.1.4) 

Natural seawater contains many dissolved substances. In particular, a maximum concentration 

of 60 mg/L (8.14×10-4 mol/L) of bromide ion (Br-

) is present and this has the potential to react 

with Ozone injected into the ballast water as illustrated in Figure 2.1-1. This reaction varies 

depending on conditions such as the concentration of organic matter in seawater and inorganic 

substances like ammoniacal nitrogen. The reaction also varies with temperature and pH. 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

When Ozone comes into contact with bromide ions, reactions (1) to (4) shown in Figure 2.1-1 

generate the oxidizing agents hypobromous acid ion (BrO-) and Bromate ions(BrO3

-

). In addition, 

some bromide ions reform. Bromate ions have the potential to be transformed to bromic acid 

(HBrO3) which is more oxidizing but it is only limited to pH < 0.8, which does not happen normally. 

A calculation of the equilibrium ratio of hypobromous acid (HBrO) and hypobromous acid 

ion under the normal circumstance of pH 6 - 8, which was performed by using the dissociation 

coefficient of pKa = 8.73, has shown that the hypobromous acid ion is stable above Ph = 10 but this 

is very rare in natural seawater. Eventually hypobromous acid dominates. When hypobromous 

acid is oxidized by Ozone, it is changed to bromous acid ions (BrO2

-

) and oxygen. Further 

bromous acid ions are transformed to bromide ions by Ozone oxidization. 

Hypobromous acid reacts with natural organic matter (NOM) to generate bromine organic 

compounds such as trihalomethanes (THM). In the presence of ammoniacal nitrogen 

hypobromous acid reacts with ammonia instantaneously and reverts to bromide. A comparison 

of reaction velocity between ammoniacal nitrogen and organic matter reveals that ammoniacal 

nitrogen reacts faster than the reaction formula (6) (see Figure 2.1-1), with the result that 

Bromoform is generated by reaction with organic matter after this reaction is finished. 

When Ozone self-degrades in water, free radicals are generated. As the free radicals disappear in 

a short period, Ozone is considered to disappear completely before it is discharged. 

On the assumption of these reactions between seawater and Ozone and also based on the results of 

experimental concentration measurements of chemical substances occurring after treatment of the 

intake ballast water by Ozone injection (to achieve the maximum 4 mg/L Ozone concentration in 

the ballast water) but before the post-treatment of the discharged water, the following substances 

were determined as Relevant Chemicals of the SP-Hybrid BWMS Ozone version: 

.1 Bromate ions as an ultimate product generated by reaction between seawater and 

Ozone; 

.2 Bromoform potentially generated by reaction between seawater and Ozone; and 

.3 TRO showing mass of all oxidants generated by reaction between seawater and 

Ozone including undetectable intermediate products. 

Table 2.1-2 showed information on the Relevant Chemicals of the SP-Hybrid BWMS Ozone 

version in addition to information on Ozone as the Active Substance. Comprehensive testing 

showed the following maximum concentrations of Relevant Chemicals in the ballast water 

discharge: Bromate ions: 0.07 mg/L, Bromoform: 0.018 mg/L and TRO 1.18 mg/L (as O3). 

The maximum generated concentration of Bromoform was found to be relatively low 

at 0.19 mg/L, which potentially resulted from the relatively low Ozone concentration of 4 mg/L 

in the ballast water and also from the rapid removal of the non-reacted Ozone in the 

Gas/Liquid Separation Tank immediately after Ozone injection. 

Since 0.21 to 1.21 mg/L TRO (as O3) was detected in the test water (natural water) prior to 

treatment by this BWMS, the whole TRO contained in ballast water discharge is not necessarily 

generated by ballast water treatment (Ozone treatment) of this BWMS. This result indicates that 

the substances constituting TRO involve unidentified oxidizing materials in addition to the toxic 

Bromate ion and the extremely short-lived hypobromous acid, which are generated by ballast 

water treatment of the BWMS. The TRO concentration in the test water prior to treatment by 

BWMS (natural water) can be deducted from the TRO value in the ballast water discharge in 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

order to derive the actual TRO value generated and ultimately discharged by this BWMS. 

Its maximum concentration is 0.69 mg/L in the repetition of the chronic toxicity test as detailed 

in section 6.3 of this document. 

The Final Approval application of this BWMS is based on the risk assessment with the maximum 

discharge concentration of 0.69 mg/L TRO (as O3). However, the maximum allowable discharge 

concentration of 0.2 mg/L was applied to this BWMS for the Final Approval application for the 

following reasons: 

.1 Application of 0.2 mg/L TRO (as O3), which is lower than the discharge concentration 

of the risk assessment, thoroughly eliminates the environmental impact. 

.2 Various tests were conducted to collect a total of 64 measurements of TRO (O3) in the 

ballast water discharge following injection of 4 mg/L Ozone and almost simultaneous 

removal of Relevant Chemicals in the DWTT. 45% of the measurements were less 

than the detectable limit of 0.15 mg/L, 6% were between 0.14 and 0.2 mg/L 

and 45% were between 0.2 and 0.3 mg/L. Data showing a TRO (O3) of less 

than 0.3 mg/L constitute 97 % and data showing more than 0.3 mg/L including the 

maximum value of 0.69 mg/L constitute only 3% (2 data points). As the data 

represent TRO concentrations corresponding to an Ozone concentration of as 

much as 1 mg/L higher than the 3 mg/L to be actually used for this BWMS and as 

it was discharged without a detention time, the concentration is presumed to be 

substantially higher than that which will occur during actual operation of this 

BWMS. It is considered that the TRO (as O3) in the ballast water discharge will 

be less than 0.2 mg/L in most cases when operating this BWMS. 

.3 From the standpoint of environmental consideration and actual operational 

circumstances of this BWMS, the maximum allowable discharge concentration is 

defined as 0.2 mg/L. 

The toxicity of TRO (as O3) generated and discharged by this BWMS is summarized as follows: 

.1 The TRO (as O3) concentration generated by this BWMS and discharged following 

post-treatment of the DWTT in the repetition of the chronic toxicity test as 

detailed in section 6.2 of this document was 0.69 mg/L at the maximum and less 

than 0.3 mg/L in most of the cases. No toxicity was observed in the chronic 

toxicity test for three kinds of marine organisms when they were exposed to the 

ballast water with these TRO concentrations. When 0.69 mg/L was observed, it 

resulted from an extremely high TRO (as O3) concentration of 0.6 mg/L in the test 

intake water (natural seawater) supplied to this BWMS. 

.2 The maximum TRO (as O3) concentration in the full-scale land-based acute 

toxicity test was 0.21 mg/L. No acute toxicity was observed, as in the chronic 

toxicity test. 

.3 The results of these toxicity tests are considered to reflect the degree of toxicity of 

oxidant generated by the reaction of Ozone with seawater. 

.4 The TRO (as O3) concentration in the ballast water discharge depends on removal 

performance of post-treatment in the DWTT. The sustainability of the removal 

performance of this BWMS was confirmed in the test for sustainable performance 

to remove Relevant Chemicals as described in 6.6 of this document. 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

The results of various tests showed the TRO (as O3) generated by this BWMS for risk assessment 

as well as the TRO (as O3) actually measured before subtracting the TRO (as O3) contained in the 

natural seawater used for the test. As previously stated, the observed maximum discharge 

concentration was 0.69 mg/L, which was higher than 0.15 mg/L, which was presented at the time 

of the Basic Approval. This resulted from the many subsequent tests and so the concentration for 

risk assessment should be revised accordingly. The method used to monitor TRO (as O3) and to 

operate the DWTT was detailed in section 3 ìUse of the Active Substanceî of this document. 

Reactions and Rate Constants for Molecular Ozone Mechanism 

No. Reaction k or pKa(20°C) Reference No. 

(Refer to APPENDIX1-1) 

(1) O3 + Br-→O2 + OBr- 50 M-1

 s-1 1 

(2) O3 + OBr-→2O2 +Br- 300 M-1

 s-1 2 

(3) O3 + OBr-→Br O2

-+ O2 100 M-1

 s-1 3 

(3a) O3 + HOBr→Br O2

-+ O2+H+ ≦0.013 M-1

 s-1 4 

(4) Br O2

-+ O3→BrO3-+O2 105

 M-1 s-1 4 

(5) HOBr ⇄ H+

 + OBr- 50M-1 s-1 5 

 5×1010 M-1

 s-1 6 

(6) HOBr + NH3→ NH2Br + H2O 8×107

 M-1 s-1 7 

(7) O3 + NH2Br→Y 40 M-1

 s-1 7 

(8) Y+ 2O3→2H+

+ NO3

-+Br-+3O2 k8≫k7 7 

Figure 2.1-1: Reactions of bromide ions with Ozone in water 

O3

NH3

CHBr3 NH2Br

BrO2

- B rO3

-

CO3

- ・, Br2-・

OBr-

HOBr

NOT

Br-

O3

Br・

O3 O3

BrO・

O3

Y*

NO3

-

H+

H2O

O3

O O3 3

CO3

- ・

BrO2 Br2O4

OH -

OH -

Br-

Br2

-・

Br3

-・

OBr-

*Y are unknown products that react in later r eactions

(1)

(2)

(3)

(4)

(5) (5)

(6)

(7)

(8) (8)

(3a)

O3

O2

-・

O3

NH3

CHBr3 NH2Br

BrO2

- B rO3

-

CO3

- ・, Br2-・

OBr-

HOBr

NOT

Br-

O3

Br・

O3 O3

BrO・

O3

Y*

NO3

-

H+

H2O

O3

O O3 3

CO3

- ・

BrO2 Br2O4

OH -

OH -

Br-

Br2

-・

Br3

-・

OBr-

*Y are unknown products that react in later r eactions

(1)

(2)

(3)

(4)

(5) (5)

(6)

(7)

(8) (8)

(3a)

O3

O2

-・
MEPC 59/2/1 

ANNEX 

Page 12 

I:\MEPC\59\2-1.doc 

2.1.4 Other Chemicals 

Ballast water treatment by this BWMS theoretically generates hypobromous acid, hypobromous 

acid ions and bromous acid ions. However, due to the reaction rate formula (3) to (5) described 

in Figure 2.2-1, these react to form Bromoform or Bromate ions within a few seconds and so they 

are unlikely to exist long in the ballast water discharge. D. Fisher and others also state these 

substances exist for an extremely short period (Fisher.D et al., 1999). Furthermore, it is 

practically impossible to detect their concentration in the ballast water after treatment. Also, 

free radicals such as the hydroxyl-radical (OH - ) are produced in the process of Ozoneís 

decomposition in water. Hydroxyl-radicals have an extremely strong oxidizing property. They 

react 106 times faster than Ozone and do not exist in the ballast water except for a very short 

period immediately after treatment. 

Some tests have shown generation of dibromochloromethane, which is a kind of trihalomethane. 

However, its generated concentration is only 0.0049 mg/L at maximum which is about 1/20 of 

the 0.1 mg/L, WHO Drinking Water Standard (WHO, 1996) Most of this small amount of 

dibromochloromethane was removed in the DWTT and its maximum concentration in the ballast 

water discharge was found to be 0.0002 mg/L, but the concentration was too low to be detected 

in most of the tests. 

From the above standpoint, hypobromous acid, hypobromous acid ion, free-radicals and 

dibromochloromethane, which are generated by ballast water treatment of this BWMS, are not 

left in the ballast water discharge. Furthermore, as they have no potential to affect the 

environment in the local sea area, they are not considered to be Relevant Chemicals. 

Table 2.1-2: Information about Relevant Chemicals of SP-Hybrid BWMS Ozone version 

Chemical 

Name 

Empirical 

Formula 

Molar 

mass 

Structural 

formula 

CAS 

Number 

The classification in 

accordance 

with the 

UN GHS 

system 

Concentration 

in discharge 

ballast water, 

after treatment 

of the DWTT 

(Bio) 

degradation rate 

or 

half-life 

AS, 

RC or 

Other 

Ozone O3 48.00 10028-15-6 

(1956) 

APPENDIX 

7-2 N/A 5.8 Sec AS 

Bromate 

ion BrO3

- 127.9 15541-45-4 N/A <0.01 - 0.07 

mg/L 

Over 

40 days RC 

Bromoform CHBr3 252.7 75-25-2 APPENDIX 

7-2 

0.0001 - 0.018 

mg/L 

32-185 

days RC 

TRO 

(as O3) N/A N/A N/A N/A N/A 

0.21 - 1.18 mg/L 

(<0.15 - 0.69 

mg/L) 

0.75-4.5 

days RC 

* N/A; Not Available 

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

sensitive and representative organisms (G9: 4.2.1.1) 

With reference to effects by Ozone as the Active Substance, Bromate ion and Bromoform as 

Relevant Chemicals, and TRO on aquatic plants, aquatic invertebrates (crustacean, mollusc) and 

fish, information was collated from ECOTOX (U.S.EPA 2007a). Regarding TRO, there are 

published data on specific oxidants, but relevant data were not found since the TRO is not a 

specific chemical. However, some data from the tests on treated ballast water are available. 
MEPC 59/2/1 

ANNEX 

Page 13 

I:\MEPC\59\2-1.doc 

2.2.1 Acute aquatic toxicity 

2.2.1.1 Active Substance 

Table 2.2-1 showed acute toxicity data(LC50)on Ozone. As Ozone degrades within a short 

period, it does not exist in the discharge ballast water and it does not affect aquatic organisms in 

the ambient seawater after discharge. 

2.2.1.2 Relevant Chemicals 

Table 2.2-2 showed acute toxicity data(LC50 and EC50)on Bromate ions. The lowest value 

among the data was 30 mg/L at 96 hour EC50 for molluscs of the type Crassostrea giga. 

Table 2.2-3 showed acute toxicity data(LC50 and EC50)on Bromoform. The lowest value 

of LC50 was 7.1 mg/L for fish of the type Cyprinodon variegates. 

Data on TRO were not available as it shows the total mass of oxidants and is not a specific chemical. 

Table 2.2-1: Acute Aquatic Toxicity Data on Ozone 

Species LC50

(mg/L/duration) 

Reference/Comments/ 

Justification for missing data 

Morone saxatilis, SW 0.08 (96-h LC50) ECOTOX database 

(U.S. EPA, 2007a) 

Morone Americana, SW 0.2 (96-h LC50) ECOTOX database 

(U.S. EPA, 2007a) 

Oncorhynchus mykiss, FW 0.0093 (96-h LC50) ECOTOX database 

(U.S. EPA, 2007a) 

Fish 

Ictalurus punctatus, FW 0.03 (96-h LC50) ECOTOX database 

(U.S. EPA, 2007a) 

Crustacea N/A N/A 

ECOTOX database 

(U.S. EPA, 2007a). Other literature 

was not available for data. 

Molluscs Dreissena polymorpha, FW 0.53 (5.8-h LC50) Harrington et al. (1997) 

Algae N/A N/A 

ECOTOX database 

(U.S. EPA, 2007a). Other literature 

was not available for data. 

N/A; Not Available 

Table 2.2-2: Acute Aquatic Toxicity Data for Bromate ion 

Species LC50 and EC50

(mg/L/duration) 

Reference/Comments/ 

Justification for missing data 

Fish Oncorhynchus keta, SW 512 (96-h LC50) ECOTOX database 

(U.S. EPA, 2007a) 

Crustacea Neomysis awatschensis, SW 176 (24-h LC50) ECOTOX database 

(U.S. EPA, 2007a) 

Crassostrea gigas ,SW 30 (96-h EC50) ECOTOX database 

(U.S. EPA, 2007a) Molluscs 

Crassostrea gigas ,SW 170 (24-h EC50) ECOTOX database 

(U.S. EPA, 2007a) 

Algae N/A N/A 

ECOTOX database 

(U.S. EPA, 2007a). Other literature 

was not available for data. 

N/A; Not Available 
MEPC 59/2/1 

ANNEX 

Page 14 

I:\MEPC\59\2-1.doc 

Table 2.2-3: Acute Aquatic Toxicity Data for Bromoform 

Species 

LC50(mg/L/duration) 

or 

EC50(mg/L/duration) 

Reference/Comments/ 

Justification for missing data 

Cyprinodon variegates, 

SW 7.1 (96-h LC50) ECOTOX database (U.S. EPA, 

2007a) 

Brevoortia tyrannus, SW 12 (96-h LC50) ECOTOX database (U.S. EPA, 

2007a) Fish 

Lepomis macrochirus, 

FW 29 (96-h LC50) ECOTOX database (U.S. EPA, 

2007a) 

Americamysis bahia, 

SW 24.4 (96-h LC50) ECOTOX database (U.S. EPA, 

2007a) 

Penaeus aztecus, SW 26 (96-h LC50) ECOTOX database (U.S. EPA, 

2007a) 

Daphnia Magana, FW 46 (48-h LC50) ECOTOX database (U.S. EPA, 

2007a) 

Crustacea 

Daphnia pulex, FW 44 (96-h LC50) ECOTOX database (U.S. EPA, 

2007a) 

Skeletonema costatum, 

SW 12.3 (96-h EC50) ECOTOX database (U.S. EPA, 

2007a) 

Pseudokircheneriella 

subcapitata, FW 42 (72-h EC50) ECOTOX database (U.S. EPA, 

2007a) Algae 

Pseudokircheneriella 

subcapitata, FW 40.1 (96-h EC50) ECOTOX database (U.S. EPA, 

2007a) 

2.2.1.3 Treated ballast water (G9: 5.2.3) 

An acute toxicity test for ballast water treated by the SP-Hybrid BWMS Ozone version was 

applied to the following test water under the G8 intake test water conditions for seawater and 

brackish water by using the full-scale system adopted for Guidelines (G8) land-based test. 

Ozone was injected into the flow to achieve an Ozone concentration at 4 mg/L in the intake 

ballast water (200 m3/h) at intake time. 

Test water: Discharged ballast water after Relevant Chemicals were removed through the DWTT 

immediately following treatment by Ozone injection (Holding time: 0 h) 

Table 2.2-4 showed the maximum concentrations of the Relevant Chemicals at exposure time 

and the results of acute toxicity tests to determine LC50 and ECr50 using diluted samples of the 

discharged ballast water. Almost all of the undiluted samples (i.e.100%) did not meet the 

toxicity criteria for LC50 or ECr50, so the entry in the table indicates that the result is >100%. The 

test with brackish water reported 0.4 mg/L as the lowest concentration of dissolved oxygen, 

which resulted from a decrease of dissolved oxygen in line with the decomposition of highly 

concentrated organic matter in the test water during the experiment. Measures to restore the 

dissolved oxygen by aeration were not taken in the acute toxicity test in order to preclude 

underestimation due to vaporization of Bromoform, etc. Such a low concentration of dissolved 

oxygen may possibly have affected the result of test and 71% (96h-LC50) represented by the 

crustacean Hyale barbicornis presumably resulted from this decrease of dissolved oxygen. 

If this effect was taken into consideration, no acute toxicity existed in the test water and the 

discharged ballast water. The maximum concentration of detectable Relevant Chemicals in the 

test water using both sea and brackish water is Bromate ions: 0.07 mg/L, 
MEPC 59/2/1 

ANNEX 

Page 15 

I:\MEPC\59\2-1.doc 

Bromoform: 0.015 mg/L, TRO (as O3): 1.18 mg/L, TRO (as O3) generated by ballast water 

treatment of this BWMS is less than 0.15 mg/L. The concentrations of Bromate ions and 

Bromoform are substantially lower than the acute toxicity values stated in the ECOTOX data 

base. Also 1.18 mg/L TRO and 0.15 mg/L TRO in terms of TRO generated by ballast water 

treatment of this BWMS resulted in showing no acute toxicity.

Table 2.2-4: Maximum concentration of discharged ballast water to meet LC50 and 

ECr50 criteria in the full-scale land-based toxicity test 

2.2.2 Chronic aquatic toxicity 

2.2.2.1 Active Substance 

Table 2.2-5 showed chronic toxicity data (NOEC) for Ozone. According to chronic toxicity data 

for fish of the type Oncorhynchus mykiss the 90 day NOEC is 0.002 mg/L. As described in the 

acute aquatic toxicity section of this dossier, Ozone dissolves in a short period. Therefore, it 

does not reside in the ballast water discharge and has no effect on aquatic organisms in the 

ambient seawater after discharge. 

Table 2.2-5: Chronic Aquatic Toxicity Data for Ozone 

Species 

NOEC 

(mg/L/duration) 

Reference/Comments/Justification 

for missing data 

Fish Oncorhynchus 

mykiss

0.002 

(90 day NOEC) Wedemeyer et al., 1979 

Crustacea N/A N/A ECOTOX database (U.S. EPA, 2007a). 

Data were not available in other literature. 

Algae N/A N/A ECOTOX database (U.S. EPA, 2007a). 

Data were not available in other literature 

N/A; Not Available 

2.2.2.2 Relevant Chemicals 

Table 2.2-6 showed chronic toxicity data (NOEC) for Bromate ions. According to chronic 

toxicity data for algae of the type Skeletonema costatum, the 7 day NOEC was >0.125 mg/L. 

Test water Max. concentration of 

Relevant Chemicals (mg/L)

Fish: 

Oryzias 

javanicus 

Crustacea: 

Hyale barbicornis 

(96h-LC50) 

Algae: 

Skeletonema 

costatum 

(72h-ECr50) 

Bromate ion 0.07 

Bromoform: 0.0023 

TRO (as O3) 0.85 Seawater Generated TRO by 

Ozone Treatment 

(mg/L as O3) 

<0.15 

>100% >100% >100% 

Bromate ion 0.04 

Bromoform: 0.015 

Brackish TRO (as O3) <1.18 

water Generated TRO by 

Ozone Treatment 

(mg/L as O3) 

<0.15 

>100% 71% >100% 
MEPC 59/2/1 

ANNEX 

Page 16 

I:\MEPC\59\2-1.doc 

Table 2.2-7 showed chronic toxicity data (NOEC or MATC) for Bromoform. The minimum 

concentration is 4.8 mg/L of 28 day MATC (Maximum Acceptable Toxicant Concentration) for 

fish of the type Cyprinodon variegates. 

As TRO represent the total mass of oxidants and is not a specific chemical, data were not available. 

Table 2.2-6: Chronic Aquatic Toxicity Data for Bromate ions 

Species NOEC 

(mg/L/duration) 

Reference/Comments/Justification for 

missing data 

Fish N/A N/A ECOTOX database U.S. EPA, 2007a). Data 

were not available in other literature. 

Crustacea N/A N/A ECOTOX database (U.S. EPA, 2007a). Data 

were not available in other literature. 

Algae Skeletonema 

costatum, SW 

>0.125 

(7 days NOEC) Erickson and Freeman, 1978 

N/A; Not Available 

Table 2.2-7: Chronic Aquatic toxicity Data for Bromoform 

Species 

MATC 

(mg/L/duration) or 

NOEC (mg/L/duration) 

Reference/Comments/ 

Justification for missing data 

Fish Cyprinodon 

variegates MATC; 4.8(28 days) Ward et al., 1981 

Crustacea N/A N/A 

ECOTOX database 

(U.S. EPA, 2007a). Data were 

not available in other literature. 

Algae Pseudokircheneriella 

subcapitata, FW NOEC;10 (96 hours) ECOTOX database (U.S. EPA, 2007a) 

N/A; Not Available 

2.2.2.3 Treated ballast water (G9: 5.2.3) 

A chronic toxicity test for the ballast water treated by SP-Hybrid BWMS Ozone version was 

conducted for Basic Approval. The NOEC in terms of TRO (as O3) generated by ballast water 

treatment of this BWMS was determined to be equal to or greater than 0.16 mg/L. With 

reference to this NOEC, it was reported that the TRO concentration in the ballast water discharge 

after removal of Relevant Chemicals by DWTT is consistently under 0.15 mg/L. 

However, GESAMP-BWWG recommended clarification of the relative toxicity of the discharge 

and Relevant Chemicals such as Bromate ions and Bromoform (MEPC 55/2/16, annex 5). 

To address this recommendation, a second chronic toxicity test was conducted including 

measurement of Relevant Chemicals in the test water. 

This repetition of the chronic toxicity test was conducted for the following test water and for the 

purpose of determining the NOEC in the ballast water discharge. A prerequisite condition for 

test water flown to BWMS applied Guidelines (G8) land-based test requirement using seawater. 

From the various test results it was confirmed that seawater contains a higher concentration of 

bromide ions than brackish water and consequently a higher concentration of Relevant Chemicals 

is generated by reaction with Ozone. This was the reason to use seawater. Ozone is injected in 

such manner to achieve an Ozone concentration of 4 mg/L in the intake ballast water (20 m3/h). 
MEPC 59/2/1 

ANNEX 

Page 17 

I:\MEPC\59\2-1.doc 

Test water: 

.1 Control water (i.e. the original water, which was also used for dilution). 

.2 Discharge ballast water after removal of Relevant Chemicals by DWTT 

immediately following treatment (Ozone injection) without holding time ñ Two 

samples were made: (a) undiluted discharge ballast water 100%, and (b) discharge 

ballast water diluted to 10% using original water. 

.3 Original water treated by Ozone injection without holding time and without 

removal of Relevant Chemicals by DWTT ñ Four samples were made: 

(a) undiluted discharge ballast water (100%) and discharge ballast water diluted to 

(b) 10%, (c) 3.125% and (d) 1% using original water. 

The maximum concentration of detectable Relevant Chemicals in the NOEC test water indicated 

by this test was Bromate ions: 0.03 mg/L, Bromoform: 0.0093 mg/L, TRO (as O3): 0.96 mg/L, 

the TRO (as O3) generated by ballast water treatment of this BWMS is 0.69 mg/L. Above all, the 

concentrations of Bromate ions and Bromoform were well below the previous NOEC and MATC 

and results in supporting both data. In terms of TRO (as O3) generated by ballast water treatment 

of this BWMS, the no effect maximum concentration in the test water was 0.69 mg/L. This 

supports the value of NOEC, which was found to be equal to or greater than 0.16 mg/L in the 

chronic toxicity test conducted for Basic Approval. 

Table 2.2-8: NOEC in repetition of chronic toxicity test and maximum concentration 

of Relevant Chemicals at time of exposure 

Test water 

Max. concentration of 

Relevant Chemicals in No 

Observed Effect Test Water 

Case (mg/L) 

Fish:Oryzias 

javanicus 

(28 dayNOEC) 

Crustacea: 

Hyale 

barbicornis 

(21 dayNOEC) 

Algae: 

Skeletonema 

costatum 

(78 h-NOEC) 

Bromate ion 0.03 

Bromoform: 0.0093 

TRO (as O3) 0.96 Seawater Generated TRO by 

Ozone Treatment 

(mg/L as O3) 

0.69 

Before PT;10% 

After PT;100% 

Before PT;10% 

After PT;100% 

Before PT;10% 

After PT;100% 

2.2.3 Endocrine disruption 

Information about endocrine disruption by Ozone and the Relevant Chemicals was not available 

presumably because from the standpoint of their structure it is unlikely to occur. Japan Ministry 

of Environment reports that these chemicals are not included in the list of chemicals expected to 

cause endocrine disruption (MOEís Perspective on Endocrine Disrupting Effects of Substances). 

As TRO represent the total mass of oxidants and is not a specific chemical, such data were not 

available. 

2.2.4 Sediment toxicity 

As Ozone is an inorganic compound and its half life is as short as 5.3 to 5.8 seconds in seawater 

and several minutes or several tens of minutes in fresh water, it is unlikely to adhere to sediment 

or to accumulate in the sediment. Therefore sediment toxicity does not need to be considered. 
MEPC 59/2/1 

ANNEX 

Page 18 

I:\MEPC\59\2-1.doc 

Information about the toxicity effect of Bromate ions on benthic organisms was not available. As 

Bromate ions are water soluble and dissolve in water as ions, sediment toxicity is not applicable. 

Information about toxicity effects of Bromoform on benthic organisms was not available. 

As logPow of Bromoform is 2.4 smaller than LogPow 3, which is applied as an indication of 

adherence or accumulation, Bromoform is considered unlikely to cause sediment toxicity. 

As the TRO represent the total mass of oxidants and is not a specific chemical, data were not 

available. The half life of TRO generated by the SP-Hybrid BWMS Ozone version is as short 

as 0.75 to 4.5 days and the TRO are considered unlikely to adhere to or accumulate in the sediment. 

2.2.5 Bioavailability/biomagnification/bioconcentration 

Table 2.2-9 showed bioavailability, biomagnification and bioconcentration for Ozone as the 

Active Substance and Bromate ions, Bromoform and TRO as Relevant Chemicals. 

Information about bioavailability/biomagnification/bioconcentration of Ozone was not available. As 

Ozone is an inorganic compound and its half life is as short as 5.3 to 5.8 seconds in water and several 

minutes to several tens of minutes in fresh water, bioavailability/biomagnification/bioconcentration 

are unlikely to occur. 

As logPow of Bromate ion is as small as -7.18 (SRC, 2007), biomagnification and 

bioconcentration are unlikely to occur. 

According to the test for carp, which is a fresh water fish, exposed to 0.1 mg/L and 0.01 mg/L of 

Bromoform for 6 weeks, BCF showed 7.1 to 21 and 7.7 to 19, respectively, (NITE, 2007). 

Therefore, biomagnification and bioconcentration is unlikely to occur. Since Bromoform shows 

a small value of logPow equal to 2.4, this corresponds well to the above BCF. 

As the TRO represent the total mass of oxidants and are not a specific chemical, data were not 

available. Since the half life of TRO generated by SP-Hybrid BWMS Ozone version is as short 

as 0.75 to 4.5 days, biomagnification and bioconcentration is unlikely to occur. 

Table 2.2-9: Bioavailability/biomagnification/bioconcentration of Ozone 

and Relevant Chemicals 

Chemical 

name logPow/BCF information 

Cause for 

concern 

(Yes/No) 

Reference/Comments/ 

Justification for missing data 

logPow N/A 

Ozone 

BCF N/A 

No 

 Due to Ozone being an inorganic 

compound and having a short half life 

in the environment, there is no need for 

it to be considered 

logPow -7.18 Bromate ion BCF N/A No SRC, 2007 

logPow 2.4 

Bromoform BCF 

0.1 mg/L: 

7.1-21 

0.01 mg/L: 

7.7-19 

No NITE, 2007 

logPow N/A TRO BCF N/A No Due to the short half life of the TRO, 

there is no need for it to be considered. 

N/A; Not Available 
MEPC 59/2/1 

ANNEX 

Page 19 

I:\MEPC\59\2-1.doc 

2.2.6 Food web/population effects 

As the half life of Ozone is as short as 5.3 to 5.8 seconds in seawater and several minutes to 

several tens of minutes in fresh water, it has little potential for bioaccumulation in organisms 

constituting the food web (algae, invertebrate and fish). Therefore, the potential impact on the 

food web and population is considered to be minimal. 

As the logPow of Bromate ions is extremely small (-7.18), its bioaccumulation potential in any 

organism constituting the food web (algae, invertebrate and fish), and its potential impact on the 

food web and population is considered to be minimal. 

As the BCF of Bromoform is below 21, its bioaccumulation in any organism constituting food 

web (algae, invertebrate and fish) is low and potential impact on the food web and population is 

considered to be minimal. 

As the half life of TRO generated by SP-Hybrid BWMS Ozone version is as short 

as 0.75 to 4.5 days, biomagnification and bioconcentration are considered to be nil. The potential 

impact on the food web and population is considered to be minimal. 

2.3 Data on mammalian toxicity (G9: 4.2.1.2) 

Literature relating to mammalian toxicity for Ozone as Active Substance and Bromate ions, 

Bromoform and TRO as Relevant Chemicals of SP-Hybrid BWMS Ozone version were 

scrutinized. The information is summarized as follows: 

.1 Active Substance 

As Ozone causes strong toxicity through inhalation exposure, stringent measures to protect 

human being from inhalation exposure of Ozone are required. Furthermore, Ozone has 

the potential to cause mutagenicity in humans. However, as no Ozone exists in the ballast 

tank and ballast water discharge of this system, the potential is considered to be nil. 

.2 Bromate ion 

Numerous studies indicate that potassium Bromate has the potential for mutagenicity and 

carcinogenicity in humans. Based on the possibility that Bromate ions may act as a 

mutative carcinogen, the United States currently regulates the maximum contaminant 

level of Bromate ion in the drinking water to 0.010 mg/L(10 μg/L)with a target of zero 

(U.S. EPA, 2007). Therefore, exposure to Bromate ion should be completely prevented. 

Considering the potential residue in the ballast tank, shipboard personnel should be 

protected with protective clothing at the time of entry to the tank. Though 0.70 mg/L of 

Bromate ions may exist in the discharge ballast water in the worst scenario, the dilution 

after discharge causes little impact to the residents in the neighborhood. 

.3 Bromoform 

In an acute toxicity test where Bromoform was given to laboratory animals by oral 

administration, the LD50 of mice was 707-1,550 mg/kg and that of rats was 933-2,440 mg/kg. 

Inhibition of the central nervous system and effects on livers and kidneys were observed. 

Inhibition of the central nervous system and hepatopathy of humans caused by accidental 

ingestion was also reported. Its irritant property on eyes was low since it disappeared 

relatively quickly. Its irritant property on human skin and eyes was also reported. 
MEPC 59/2/1 

ANNEX 

Page 20 

I:\MEPC\59\2-1.doc 

The target organs of Bromoform in a repeated dose toxicity test were found to be the liver 

and kidney. In case target is given to impact on liver (cavitation of liver cell) at one 

month oral dose (composite gavage) test using Wistar rats, LOAEL is 680 ppm 

(56.4 mg/kg/day). In a reproduction toxicity test, there was no impact up to a dose 

of 200 mg/kg/day. 

Development toxicity tests also indicate that doses up to 200 mg/kg/day have no fetotoxic 

effect and do not increase external malformation or disorders of the bone structure or 

internal organs. 

In genetic toxicity tests in vitro using CHL cells and CHO cells, there was a contradictory 

result between a DNA damage test and a chromosomal aberration test. Also, there were 

positive results in a DNA damage test using micro-organisms, a mutagenicity study, a 

chromosomal aberration test using Aspergillus nidulans and a mutagenicity study using 

mouse lymphoma cells. Furthermore, in vivo, an SCE test using mice and a micronucleus 

assay showed positive. From these results, it seems that Bromoform has genetic toxicity. 

Though incidence of malignancy for mice did not increase in the oral administration tests, 

rats dosed with a large amount (200 mg/kg/day) showed substantial difference in the rate 

of occurrence of tumors of the large intestine. IARC concluded that there were 

inadequate human data and limited animal data and assigned Bromoform to weight of 

evidence category 3, which is not classifiable as to carcinogenicity in humans. 

Considering the information on the mammalian toxicity of Bromoform, there does not 

appear to be a big risk considering that the generated amount of Bromoform concentration 

generated by this system is very low, being a maximum of 0.19 mg/L. However, since it 

potentially remains in the ballast tank, as in the case of Bromate ions, shipboard personnel 

should wear protective clothing when entering the tank. Though 0.018 mg/L Bromoform 

potentially remains in the ballast discharge in the worst scenario, it would have little 

impact on the residents in the neighborhood because of dilution after discharge. 

.4 Total Residual Oxidants (TRO) 

As TRO represent the total mass of oxidants and are not a specific chemical, data were 

not available in the literature. However, as it has a potential to remain in the ballast tank, 

for reasons of personal safety shipboard personnel should wear protective clothing when 

entering the tank. Though 0.69 mg/L of TRO generated by this BWMS potentially exists 

in the ballast water discharge in the worst scenario, it is considered to cause little impact 

on the population in the neighborhood due to dilution after discharge. 

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

(G9: 4.2.1.3) 

2.4.1 Modes of degradation (biotic; abiotic) 

As Ozone is an unstable substance, it decomposes into oxygen and water under aerobic and 

anaerobic conditions in addition to biodegradation. As Ozone degradation proceeds under 

anaerobic conditions, the generated oxygen may increase the concentration of dissolved oxygen. 

Hydrolysis does not occur. 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

Bromate ions are converted into bromide ions by microbe degradation under anaerobic 

conditions in the presence of methane bacteria, denitrification bacteria and sulfate reducers. 

Physicochemically, it reacts in the presence of ferrous ions (Siddiqui et al., 1995)or activated 

carbon(Siddiqui et al., 1996). It is also transformed to bromide ions in the presence of high 

energy electronic irradiation (Siddiqui et al., 1996). Reaction by hydrolysis does not occur. 

In an aerobic biodegradation test based on the Japanese Domestic Law ìLaw Concerning the 

Examination and Regulation of Manufacture, etc., of Chemical Substancesî, improved culture 

flasks for volatile substances were used with a concentration of the test substance of 100 mg/L, 

a concentration of activated sludge of 30 mg/L and a test period of 4 weeks. The degradation 

rate of Bromoform measured by biochemical oxygen consumption (BOD) measurement was 0%. 

Bromoform is therefore considered to be a persistent substance. 

Furthermore, the degradation rate was also 0% according to gas chromatograph (GC) measurements 

(MITI, Japanese Government, 1986). On the other hand, one of the reports shows that 

biodegradation was confirmed in a case where the test substance was of low concentration and was 

naturalized for a prolonged period. In a test where yeast extract was added to a broth for seven 

days at a test temperature of 25oC with test substance concentrations of 5 mg/L and 10 mg/L, the 

degradation rates measured by the Total Organic Carbon (TOC) concentration were 11% and 4%. 

Furthermore, in a test involving repeated cultivations every 7 days, with a test substance 

concentration of 5 mg/L, the degradation rate increased with progress of subcultures as follows: 

primary culture: 22%; secondary culture: 40%; third culture: 48% (Tabak et al., 1981). These 

results suggest that that biodegradation of Bromoform is strongly affected by its concentration 

and by the naturalization of micro-organisms, since the degree of aerobic biodegradation is high 

if its concentration is low and the start of the degradation curve is relatively late. 

A report shows that low concentrations of Bromoform (less than 100 μg/L) were biodegraded 

under anaerobic conditions. More than 99% of Bromoform in an average initial concentration 

of 34 μg/L was decomposed in a column filled with carriers to which a methane producer had 

been attached in an environment with acetate (retention time 2 days at 22 to 23oC) 

(Bouwer and McCarthy, 1983a). It is also reported that in a test where nitrite and nitrate were 

reduced to nitrogen and nitrogen monoxide by nitrate respiration of denitrifying bacteria under 

anaerobic conditions (denitrifying condition), an initial Bromoform concentration of 66 μg/L decreased 

to 59, 37, 35 and 2 μg/L after 2, 3, 4 and 6 weeks, respectively, (Bouwer and McCarty, 1983b). 

In conclusion, it is considered that Bromoform does not tend to be biodegraded under aerobic 

conditions. However, it is considered that Bromoform is biodegraded under conditions of low 

concentration, naturalization for a prolonged period, and others. It is also considered that 

Bromoform is biodegraded under anaerobic conditions if its concentration is low. Since no 

chemical bond of Bromoform is easily hydrolyzed, Bromoform itself is not hydrolyzed in water 

environment. 

As TRO are not a specific chemical and represents the total mass of oxidants, its degradation is 

difficult to determine. However, oxidants generated by reaction between seawater and Ozone are 

ultimately transformed to Bromate ions and Bromoform, which are treated as 

Relevant Chemicals of this system. The half life of TRO generated by the SP-Hybrid BWMS 

Ozone version was determined to be 0.75 to 4.5 days as a result of degradation tests. 
MEPC 59/2/1 

ANNEX 

Page 22 

I:\MEPC\59\2-1.doc 

2.4.2 Bioaccumulation, partition coefficient, octanol/water partition coefficient 

Table 2.2-9 summarized bioavailability/biomagnification/bioconcentrationon for Ozone and 

Relevant Chemicals. Information about bioaccumulation of Ozone was not available. 

However, Ozone is an inorganic substance and though its half life period depends on conditions 

of the environment, it is as short as 5.3 to 5.8 seconds in seawater and several minutes to several 

tens of minutes in fresh water. Therefore, bioaccumulation is not applicable to Ozone. 

As the logPow of Bromate ion is as low as -7.18, Bromate ions are assumed not to bioaccumulate. 

According to the test for carp the maximum BCF for Bromoform is 21 (NITE, 2007) and 

no bioaccumulation occurrence for Bromoform was determined. The small value of 2.4 for the 

logPow of Bromoform corresponds well to this result. 

As TRO are not a specific chemical and represents the total mass of oxidants, data were not 

available in the literature. However, the half life of TRO generated by SP-Hybrid BWMS Ozone 

version was determined to be 0.75 to 4.5 days through the degradation test. This degradation rate 

prevents bioaccumulation. 

2.4.3 Persistence and identification of the main metabolites in the relevant media 

(ballast water, sea and fresh water) 

Table 2.4-1 identified the main metabolites for the Active Substance and Relevant Chemicals and 

showed their persistence. Information was gathered from the test with the same components and 

structure as SP-Hybrid BWMS Ozone version as applied to Guidelines (G8) land-based test but 

using the scaled down BWMS with 20 m3/h treatment rated capacity. Ballast water treated by 

this system is usually discharged through the DWTT. However, since the intention of this test 

was to examine ìpersistence (degradation) of chemicals in the treated ballast waterî, the test was 

done by storing the treated ballast water in darkness at a temperature of 25oC for 40 days and 

without passing it through the DWTT. 

As the half life of Ozone is as short as 5.3 to 5.8 seconds in seawater and several minutes to 

several tens of minutes in fresh water, the Ozone decomposed within a short period and there was 

no Ozone in the ballast water discharge. Furthermore, this system adopts a Gas/Liquid 

Separation Tank to separate Ozone which is not dissolved in ballast water so that it does not exist 

or is not left in the ballast tank. 

Relevant Chemicals are generated in the case where bromide ions exist in seawater or intake 

ballast water but not in fresh water where bromide ion does not exist. 

As the half life of Bromate ions is longer than 40 days, it has high persistency. 

As the half life of Bromoform is 32 to 185 days, it has high persistency. 

As the half life of TRO is 1.3 to 4.5 days, it has low persistency. The half life in brackish water 

is even lower at 0.75 days. 
MEPC 59/2/1 

ANNEX 

Page 23 

I:\MEPC\59\2-1.doc 

Table 2.4-1: Persistence and Identification of Main Metabolites of Active Substance 

and Relevant Chemicals 

Chemical 

name 

Metabolites Method Results 

(halflife) 

Reference/Comments/ 

Justification for missing 

data 

N/A N/A N/A 

Due to high degradation rate, 

Ozone does not exist in 

discharge ballast water. Ozone 

N/A N/A N/A 

Due to high degradation rate, 

Ozone does not exist in 

discharge ballast water. 

N/A 

3 kinds of seawater 

(salinity: 29.7-32, pH:8.2-8.3, 

DO:10.6-12.6 mg/L, NTU: 

1.1-1.9)treated by BWMS and 

stored at 25oC under darkness 

for 40 days 

>40 day Test result in Confidential 

version, Appendix 2 

Bromate 

ions 

N/A 

Brackish water 

(salinity:20.6, pH:7.8, 

DO:12.1 mg/L, NTU: 5.5)

treated by BWMS and stored at 

25oC under darkness for 40 days 

>40 day Test result in Confidential 

version, Appendix 2 

N/A 

3 kinds of seawater 

(salinity:29.7-32, pH:8.2-8.3, 

DO:10.6-12.6 mg/L, NTU: 

1.1-1.9)treated by BWMS and 

stored at 25oC under darkness 

for 40 days 

32.0-

185 day 

Test result in Confidential 

version, Appendix 2 

Bromoform 

N/A 

Brackish water 

(salinity:20.6, pH:7.8, 

DO:12.1 mg/L, NTU: 5.5)

treated by BWMS and stored at 

25oC under darkness for 40 days 

34.7 day Test result in Confidential 

version, Appendix 2 

N/A 

3 kinds of seawater 

(salinity:29.7-32, pH:8.2-8.3, 

DO:10.6-12.6 mg/L, NTU: 

1.1-1.9)treated by BWMS and 

stored at 25oC under darkness 

for 40 days 

1.3-4.5 

day 

Test result in Confidential 

version, Appendix 2 

TRO 

N/A 

Brackish water 

(salinity:20.6, pH:7.8, 

DO:12.1 mg/L, NTU: 5.5)

treated by BWMS and stored at 

25oC under darkness for 40 days 

0.75 day Test result in Confidential 

version, Appendix 2 

* N/A; Not Available

2.4.4 Reaction with organic matter 

Table 2.4-2 showed the results of analysis for halogenated hydrocarbons in the test water 

produced for the additional chronic toxicity test. The concern is that halogenated hydrocarbons 

may be produced during the reaction with organic matter. However, according to the test result, 

the generation of halogenated hydrocarbon using the SP-Hybrid BWMS Ozone version was not 

confirmed. 

Ozone reacts with organic matter before reacting with inorganic bromide ions and Ozone is 

consumed in the process. Consequently the amount of Relevant Chemicals generated by reaction 

between Ozone and bromide ions is reduced. 
MEPC 59/2/1 

ANNEX 

Page 24 

I:\MEPC\59\2-1.doc 

Bromate ions are oxidants and they ultimately revert to bromide ions through reaction with organic 

matter (WHO, 1996) and by biodegradation (Hijnen et al., 1995). With regard to the relationship 

between the concentration of organic matter and the generated quantity of Bromate ions, the test 

result described in section 2.4.3 of this document showed that in seawater where TOC concentration 

of the source water was found to be relatively low (1.6 to 2.0 mg/L), the generation concentration 

was 0.031 to 0.081 mg/L. However in brackish water where the TOC concentration was relatively 

high (2.1 mg/L), the generated concentration was 0.027 mg/L. 

Bromoform is a THM and hypobromous acid, which is precursor and intermediate product of 

THMs, is generated by reaction with organic matter. Bromoform does not react with organic 

matter due to its stable structure. With regard to the relationship between the concentration of 

organic matter and the amount of Bromoform generation, the test result described in section 2.4.3 

of this document showed that the amount of Bromoform generated in brackish water (including 

water with a high TOC concentration) is low (0.033 mg/L) compared with seawater, where the 

concentration of Bromoform generated was 0.074 to 0.13 mg/L (the TOC concentration was 

relatively low in the intake water). 

As the TRO represent the total mass of oxidants, it is not possible to identify how much of this 

reacts with organic matter. Generally oxidants such as Bromate ions, hypobromous acid ions and 

bromous acid ions increase the degradation rate of the TRO by reaction with organic matter. 

With regard to the relationship between the concentration of organic matter and the amount of 

generated Bromoform, the test result described in section 2.4.3 of this document showed that in 

seawater, where the TOC concentration of intake water was relatively low, the generated 

concentration was 0.62 to 1.4 mg/L but in brackish water, where the TOC concentration was 

relatively high (2.1 mg/L) the generated concentration was 0.48 mg/L lower than in seawater. 

2.4.5 Potential physical effects on wildlife and benthic habitats 

Regarding the potential physical effects on wildlife and benthic habitats, the following is a 

summary based on various tests on the physical and chemical properties of the Active Substances 

and of preparations of treated ballast water (if applicable under G9: 4.2.1.4) described in 

section 2.5 of this dossier. 

As Ozone disappears with self-degradation and by transformation to Relevant Chemicals 

immediately after injection into water, it has less potential to be discharged overboard. Therefore, 

there is little potential for physical effects on wildlife and benthic habitats. 

Bromates have high solubility (70 g/L-20oC) and normally dissolve in water as ions. Even though 

ballast water after treatment may contain Bromate ions, the maximum discharge concentration is 

as low as 0.07 mg/L. If discharged, they revert to bromide ions by reaction with organic matter. 

Therefore, there is little potential for physical effects on wildlife and benthic habitats. 

Due to its high volatility Bromoform dissipates in air and may have an impact on wildlife. Its 

emission concentration, however, is low because of low generated concentration and potential 

physical effects are considered to be marginal. Since the density of Bromoform dissolved in 

water is greater than water itself, Bromoform may have potential physical effects on wildlife and 

benthic habitats by sinking to the bottom. However, the maximum discharge concentration of 

Bromoform is as low as 0.19 mg/L so its discharge is considered to cause no potential physical 

impact, taking into consideration its dilution in the environment and its half life. 
MEPC 59/2/1 

ANNEX 

Page 25 

I:\MEPC\59\2-1.doc 

2.4.6 Potential residues in seafood 

Since the half life of Ozone is as short as 5.3 to 5.8 seconds in seawater and several minutes to 

several tens of minutes in fresh water, it is considered to have no potential for accumulation in 

wildlife and benthic habitats. Therefore, potential residues in seafood are considered to be nil. 

Bromate ion can be considered to have no potential physical effects on wildlife and benthic 

habitats. 

Bromoform can be also considered to have no potential physical effects on wildlife and benthic 

habitats. 

TRO can be considered to have no potential physical effects on wildlife and benthic habitats. 

Therefore, these can be considered that there are no potential residues in seafood. 

2.4.7 Any known interactive effects 

Table 2.4-3 showed any known interactive effects of the Active Substance and Relevant 

Chemicals. 

When Ozone is decomposed in water, oxygen is generated, which results in an increase of 

concentration of dissolved oxygen in seawater. 

Bromate ions are rarely reduced in the water environment. However, they revert to bromide ions 

in the presence of ferrous ions or activated carbon. 

Bromoform is a relatively stable substance and is rarely decomposed under aerobic conditions 

but reverts to methane bacteria under anaerobic conditions or is biodegraded during 

denitrogenation. 

TRO are the mass of oxidants generated by reaction of Ozone with bromide ions in water and is 

ultimately transformed to Bromoform and bromide ions. 

Table 2.4-2: Chemical concentrations in untreated intake water and treated ballast water 

discharge in the repetition of the chronic toxicity test Seawater case 

Items Untreated 

influent water 

Treated BWT 

water 

Treated discharge 

water 

Water Temperature (°C) 

Salinity (PSU) 

pH 

Dissolved oxygen (mg/L) 

POC (mg/L) 

DOC (mg/L) 

TSS (mg/L) 

18.1 - 21.1 

3.0 - 4.0 

7.4 - 8.1 

0.3 - 12.8 

<0.1 - 1.0 

1.0 - 1.1 

7 - 9 

17.7 - 21.7 

31.0 - 33.5 

7.3 - 8.1 

11.3 - 19.9 

- 

- 

- 

17.9 - 21.7 

31.0 - 33.5 

7.5 - 8.2 

13.3 - 19.9 

- 

- 

- 

Bromate ion (mg/L) 

THMís Bromoform (mg/L) 

Chloroform (mg/L) 

Bromodichlotomethane (mg/L) 

 Dibromochloromethane (mg/L) 

TRO (mg/L as O3) 

Generated TRO by Ozone Treatment 

(mg/L as O3) 

<0.01 

<0.0001 

<0.0001 

<0.0001 

<0.0001 

0.23 - 0.90 

- 

0.022 - 0.10 

0.076 - 0.17 

<0.0001 

<0.0001 

<0.0001 - 0.0042 

0.90 - 1.25 

0.55 - 1.00 

0.017 - 0.030 

0.0001 - 0.0068 

<0.0001 

<0.0001 

<0.0001 

0.42 - 0.96 

<0.15 - 0.69 
MEPC 59/2/1 

ANNEX 

Page 26 

I:\MEPC\59\2-1.doc 

Items Untreated 

influent water 

Treated BWT 

water 

Treated discharge 

water 

AOX (mg/L) 

Chlorophenols (μg/L) 

2,3,4,5-Tetrachlorophenol 

Phenol 

Pentachlorophenol 

4-Chlorophenol 

3-Chlorophenol 

3,5-Dichlorophenol 

3,4-Dichlorophenol 

3,4,5-Trichlorophenol 

2-Chlorophenol 

2,6-Dichlorophenol 

2,4-u.2.5-Dichlorophenol 

2,4,6-Trichlorophenol 

2,4,5-Trichlorophenol 

2,3-Dichlorophenol 

2,3,6-Trichlorophenol 

2,3,5-Trichlorophenol 

2,3,5,6-Trichlorophenol 

2,3,4-Trichlorophenol 

2,3,4,6-Trichlorophenol 

0.012 - 0.16 

<0.1 

0.4 - 0.5 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

- 

0.020 - 0.37 

<0.1 

0.3 - 0.7 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

<0.1 

Table 2.4-3: Any known interactive effects of Active Substance and Relevant Chemicals 

Substance Interaction with other chemicals, 

BWMS or receiving environment 

Discussion of 

potential effects 

Reference/ 

Comments 

Ozone 

Relevant substances are generated by 

reaction of Ozone with seawater. Ozone 

does not exist in ballast water at discharge. 

Oxygen is generated 

by Ozone degradation. 

2.1 in this 

document 

Bromate ions 

(Potassium 

Bromate) 

They revert to bromide ions in presence of 

organic matter including ferrous ions and 

activated carbon. 

They revert to bromide 

ions by reaction with 

ferrous ions and 

activated carbon. 

Siddiqui (1995)

Siddiqui (1996) 

Bromoform 

It is a relatively stable substance and does 

not react with other chemicals. Anaerobic 

situation is assumed to occur in treated 

ballast water during treatment. 

Biodegradation is not likely either before 

discharge. 

Interactive effects in the environment of 

ballast discharge assume degradation by 

photolysis and bio-degradation under 

anaerobic conditions 

It is rare to be 

decomposed under 

aerobic condition and 

is biodegraded under 

anaerobic condition. 

Bouwer and 

McCarty, 1983a 

Bouwer and 

McCarty, 1983b 

TRO 

It represents the total mass of oxidants 

generated by reaction of Ozone with 

bromide ions and is ultimately transformed 

to Bromoform and bromide ions. 

N/A 

Section 2.1 of this 

document 

N/A; Not Available 

2.5 Physical and chemical properties of the Active Substances and preparations and 

treated ballast water, if applicable (G9: 4.2.1.4) 

Tables 2.5-1 to 2.5-3 showed physical and chemical properties of the Active Substance and 

Relevant Chemicals. As TRO represents the total mass of oxidants and is not a specific chemical, 

data were not available. 
MEPC 59/2/1 

ANNEX 

Page 27 

I:\MEPC\59\2-1.doc 

Table 2.5-1: Physical and chemical properties of the Active Substance (Ozone) 

Property Value Reference/Comments/ 

Justification for missing data 

CAS number 10028-15-6 Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition, 2001 

Molecule weight 48.0 ISCS 1993 

Liquid density 1358 g/L(at -112°C) Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition, 2001 

Evaporation heat 15.2kJ/moL Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition, 2001 

Melting point -193°C ISCS 1993 

Boiling point -112°C ISCS 1993 

Flammability 

Non-combustible but 

promotes burning of other 

substances. No 

inflammability to liquid. 

ISCS 1993 

Density (20°C) 2.144g/L(N.T.P) 

(at 0°C,101kPa) 

Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition, 2001 

Vapour pressure (20°C) >1 atm ISCS 1993 

Vapour density (air=1) 1.6 (air=1) ISCS 1993 

Water solubility 0.1g/100mL(at 0°C) ISCS 1993 

pH in solution N/A Exits as a gas 

Dissociation constant N/A Not applicable since Ozone is a gas. 

Oxidation reduction 

potential 2.07V 

Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition Section 2.Physical 

Properties P.39-P.40, June 2001 

Corrosivity to Material Yes 

Ozone reacts with inorganic compounds 

including metals and organic compounds. 

See section 2.1, APPENDIX 1-1 

(confidential dossier). 

Reactivity to container 

material Yes 

Ozone reacts with inorganic compounds 

including metals and organic compounds. 

See section 2.1, APPENDIX 1-1. 

Auto ignition temperature 

(°C) 

Non-combustible but 

promotes burning of other 

substances. Various 

reactions may cause a fire 

or explosion. 

Ozone reacts with inorganic compounds 

including metals and organic compounds. 

See section 2.1, APPENDIX 1-1. 

Explosive Properties 

May cause a fire or 

explosion when heated or 

coming in contact with a 

combustible material 

(alkene, ether). 

ISCS 1993 

Oxidizing properties Yes ISCS 1993 

Surface tension 3.84×10-2N/mm 

(at -183°C) 

Refer to section 2.1 and 

APPENDIX 1-1 

Viscosity 1.57×10-3Pa.s(at -183°C) Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition, 2001 

Thermal stability and 

breakdown product Oxygen Ullmannís Encyclopedia of Industrial 

Chemistry Sixth Edition, 2001 

Other physical and 

chemical properties N/A Refer to section 2.1 and 

APPENDIX 1-1 

* N/A; Not Available
MEPC 59/2/1 

ANNEX 

Page 28 

I:\MEPC\59\2-1.doc 

Table 2.5-2: Physical and chemical properties of Relevant Chemicals: 

Bromate ions (Potassium Bromate) 

Property Value Reference/Comments/ 

Justification for missing data 

CAS number 7758-01-2 WHO, 2005 

Molecule weight 167.01 WHO, 2005 

Liquid density N/A Not liquid but solid 

Evaporation heat Not considered to be a fire 

hazard MSDS (APPENDIX 7-1-2) 

Melting point 350°C WHO, 2005 

Boiling point 370°C(decomposes) WHO, 2005 

Flammability Yes ICSC, 2003 

Density (20°C) 3.27g/m3 WHO, 2005 

Vapour pressure (20°C) N/A MSDS (APPENDIX 7-1-2) 

Vapour density(air=1) N/A MSDS (APPENDIX 7-1-2) 

Water solubility 

70g/L(20°C) 

133g/L(40°C) 

498g/L(100°C) 

HydroChem Industrial 

Services, Inc. 

pH in solution Not Found MSDS (APPENDIX 7-1-2) 

Dissociation constant Not Found WHO, 2005 

Oxidation reduction potential 1.05V NTP 2008a 

Corrosivity to Material Yes NTP 2008a 

Reactivity to container material Yes MEPC 55/2 

Auto ignition temperature (°C) No MEPC 55/2 

Explosive Properties 

Risk of fire and explosion on 

contact with combustible, 

organic or other easily 

oxidizable materials. 

MEPC 55/2 

Oxidizing properties Oxidizer HydroChem Industrial 

Services, Inc. 

Surface tension Not Found Material Safety Data Sheet of 

Potassium Bromate 

Viscosity No ICSC, 2003 

Thermal stability and breakdown 

product 

No HydroChem Industrial 

Services, Inc. 

Other physical 

and chemical 

properties 

contact with combustible materials may cause fire. 

Incompatible with combustible material, organics, reducing 

agents, aluminium, finely powdered metals. 

The substance decomposes on heating or on burning 

producing toxic and corrosive fumes including bromine, and 

oxygen, which increases fire hazard. The substance is a 

strong oxidant and reacts violently with combustible and 

reducing materials, metal powder, fats, carbon, sulphur, 

phosphorus, ammonium salts, and metal sulphides causing 

fire and explosion hazard 

http://physchem.ox.ac.

uk/MSDS/PO/potassiu

m_Bromate.html 

http://www.itcilo.it/en

glish/actrav/telearn/os

h/ic/7758012.htm

* Values assuming the water viscosity coefficient at 0oC to be 100 (density, 14.02-34.64wt%). * N/A; Not Available
MEPC 59/2/1 

ANNEX 

Page 29 

I:\MEPC\59\2-1.doc 

Table 2.5-3: Physical and chemical properties of Relevant Chemicals: Bromoform 

Physical property Value 

Reference/Comments/ 

Justification for missing 

data 

CAS number 75-25-2 U.S. EPA 2005 

Molecule weight 252.77 U.S. EPA 2005 

Liquid density 2.899 g/mL(20°C) U.S. EPA 2005 

Evaporation heat 46.05 kJ/mol ATSDR 2005 

Melting point 8°C U.S. EPA 2005 

Boiling point 149-150°C U.S. EPA 2005 

Flammability No ATSDR 2005 

Density (20°C) 2.899 g/mL ATSDR 2005 

Vapour pressure (20°C) 667 Pa NTP 2008b 

Vapour density (air=1) 8.7 NTP 2008b 

Water solubility 3190 mg/L(30°C) U.S. EPA 2005 

pH in solution N/A Not hydrolyzed 

Dissociation constant N/A No dissociable group 

Oxidation-reduction potential N/A No ionization 

Corrosivity to 

Material 

Yes ATSDR 2005 

Reactivity to container 

material 

Yes ATSDR 2005 

Auto-ignition temperature (°C) - N/A 

Explosive Properties Not considered to be an 

explosion hazard MSDS (APPENDIX 7-1-2) 

Oxidizing properties N/A MSDS (APPENDIX 7-1-2) 

Surface tension 41.50mN/m(20°C) NTP 2008b 

Viscosity 1.8 cP NTP 2008b 

Thermal stability and 

breakdown product 

May form toxic fumes of 

bromides when heated to 

degradation 

MSDS (APPENDIX 7-1-2) 

Other physical and chemical 

properties 

Volatilize ATSDR 2005 

* N/A; Not Available

2.6 Analytical methods at environmentally relevant concentrations (G9: 4.2.1.5) 

Table 2.6-1 showed measurement methods for Ozone as Active Substance and analytical 

methods for Relevant Chemicals. 

Table 2.6-1: Analytical methods of Active Substance and Relevant Chemicals at 

environmentally relevant concentrations 

Substance Method Applicability Sensitivity 

Reference/ 

Comments/Justification 

for missing data 

Ozone 

・UV method 

・ KI method 

(as oxidant) 

for gas 

for liquid 

0.01 mg/L±1%FS 

(UV method)

0.15 mg/L 

(KI method)

IOA Standardization 

Committee 

Bromate ion IC+PC method for liquid 0.005 mg/L ISO 15061:2001 

Bromoform PT-GC/MS method or 

HS-GC/MS method for liquid 0.0002 mg/L or 

0.0001 mg/L 

drinking water test 

method in Japan*

TRO KI method for liquid 0.15 mg/L KI method 
MEPC 59/2/1 

ANNEX 

Page 30 

I:\MEPC\59\2-1.doc 

3 USE OF THE ACTIVE SUBSTANCE 

3.1 Summary of SP-Hybrid BWMS Ozone version 

SP-Hybrid BWMS Ozone version has been designed taking the compactness, integration, safety 

and reliability of the system fully into consideration. Well established shipbuilding and 

evironmental technologies have been utilized for this system and it is designed to be retrofitted 

easily on ballast piping of either new or existing vessels. 

3.1.1 Components and outline

Figure 3.1-1 showed the configuration of SP-Hybrid BWMS Ozone version. Table 3.1-1 

summarizes the arrangement of the main components. 

Figure 3.1-1: Configuration of SP-Hybrid BWMS Ozone version 

 

S.C.

Gas/Liquid 

Separation

Control Panel

Pre -Filter Gas/Liquid Separation Tank To ballast tank

O.B.

Waste Ozone

Destruction Unit

Special Pipe

(Slit plate )

Ballast Water Treatment 

Control Panel

Ballast Pump

Ballast Control Panel

Ozone Generator

Oxygen Generator

Discharge Water 

Treatment Tank

From 

ballast tank

InactivationUnit

Gas/Liquid Separation Unit

Flow Meter

Ozone Generator Module

Ozone Injector

Flow of Ozone

Electric Control Wire

Ballast Line

TRO Sensor

Post-TreatmentUnit

Flow of Ozone

(low concentration)

Flow of Oxygen

S.C.

Gas/Liquid 

Separation

Control Panel

Pre -Filter Gas/Liquid Separation Tank To ballast tank

O.B.

Waste Ozone

Destruction Unit

Special Pipe

(Slit plate )

Ballast Water Treatment 

Control Panel

Ballast Pump

Ballast Control Panel

Ozone Generator

Oxygen Generator

Discharge Water 

Treatment Tank

From 

ballast tank

InactivationUnit

Gas/Liquid Separation Unit

Flow Meter

Ozone Generator Module

Ozone Injector

Flow of Ozone

Electric Control Wire

Ballast Line

TRO Sensor

Post-TreatmentUnit

Flow of Ozone

(low concentration)

Flow of Oxygen
MEPC 59/2/1 

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I:\MEPC\59\2-1.doc 

Table 3.1-1: Roles of major components of SP-Hybrid BWMS Ozone version 

Major components Outline 

Ballast Water Treatment 

Control Panel 

Integrally controls the system. Allows start or stop of the system, displays 

alerts, and various operations. Operation data for more than 2 years can be 

recorded. 

Pre-Filter 

Positioned on the downstream side of the ballast water intake port to remove 

relatively large size suspended substances in the ballast water to prevent 

clogging of the Special Pipe. 

Flow Meter 

Measures the ballast water flow rate and outputs its data to Ozone Generator. 

The Ozone Generator calculates the Ozone production based on this data. 

(Accuracy of Flow Meter is ±3% of measurement range). 

Ozone Injector Positioned on the downstream side of Pre-Filter and upstream side of Ballast 

Pump. Injects Ozone into incoming ballast water. 

Ballast Pump 

High-pressure pump positioned on the downstream side of Ozone Injector and 

upstream side of the Special Pipe to cause enough shearing force and 

cavitation at the slit plates of the Special Pipe. 

Special Pipe 

(Slit plate)

Consists of 2 pairs of slit plates positioned on the downstream side of Ballast 

Pump. Inactivates aquatic organisms by shearing force and cavitation caused 

by slit plate. Also functions to dissolve the Ozone effectively. 

Ozone Generator Module 

Ozone Generator 

Oxygen Generator 

Generates oxygen with Oxygen Generator using compressed air and generates 

Ozone using such oxygen. Supplies Ozone to Ozone Injector. 

Gas/Liquid Separation 

Tank 

Positioned on the downstream side of Special Pipe to allow the injected Ozone 

to react with water and at the same time it separates gas from water. 

Waste Ozone Destruction 

Tank 

Positioned on the downstream side of the Gas/Liquid Separation Tank to 

convert the Ozone into oxygen using a catalyst and activated carbon when the 

gas from Gas/Liquid Separation Tank is discharged to the atmosphere. 

Discharge Water 

Treatment Tank 

(DWTT) 

Positioned immediately before the ballast water outlet to remove Relevant 

Chemicals from the ballast water when discharged. Uses coconut husk 

charcoal as activated carbon. 

TRO Sensor 

Installed immediately after DWTT. Measures TRO in the ballast water after 

passing through the DWTT and monitors TRO removal performance of 

DWTT. This sensor measures the TRO generated by the reaction of Ozone 

and seawater (Determination limit: 0.05 mg/L). 

3.1.2 The characteristics 

The features of the SP-Hybrid BWMS Ozone version are as follows: 

.1 This system efficiently utilizes mechanical shearing of the water and chemical 

effects of Ozone and Relevant Chemicals, which are generated by reaction of 

Ozone with bromide ions in seawater, in order to inactivate organisms in the water. 

.2 Since Ozone as the Active Substance is produced by the Ozone Generator Module 

installed on board, it is not necessary to load and store Active Substances or other 

chemical substances on board. 

.3 The inactivation treatment of ballast water is only required at the time of intake of 

ballast water. 
MEPC 59/2/1 

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.4 Most of the Relevant Chemicals generated by Ozone injection in seawater are 

degraded in the ballast water tanks. However, in the case of a short holding time 

Relevant Chemicals remain. In order to eliminate the residue of Relevant Chemicals, 

the DWTT is put in place. The discharge of ballast water is designed to go through 

the DWTT at any time. A TRO sensor is also installed right after the DWTT to 

survey its performance. This sensor measures the TRO generated by the reaction 

of Ozone with seawater. If the measured TRO concentration exceeds 0.15 mg/L, 

an alarm is raised. Should the TRO concentration exceed the maximum allowable 

discharge concentration of 0.2 mg/L, the discharge is automatically stopped. This 

measure ensures the environmental safety of the ballast water. Installation of the 

DWTT and surveillance of the removal performance by the TRO Sensor prevents 

migration of aquatic organisms through the ballast water and ensures 

environmental safety, which is the most important feature of this BWMS. 

.5 Each major component and its valves are automatically operated or remotely 

controlled (remote operation) from the Ballast Water Treatment Control Panel. The 

operating condition can be monitored on the display screen of this control panel. 

No manual operation of equipment or valves by the officers or crew is required 

except for maintenance or emergency operation, in the case of a serious failure. 

.6 All possible safety measures have been made for Ozone leakage and waste Ozone 

treatment. 

.7 All possible measures have been taken against corrosion for areas affected by Ozone. 

3.1.3 Materials of major components 

Ozone, which is an Active Substance, and all other Relevant Chemicals used with the SP-Hybrid 

BWMS Ozone version have corrosive effects. Therefore, corrosion-proof materials should be used 

where corrosive effects are expected. However, from the results of various tests (land-based and 

on board tests), it can be judged that there are no corrosive effects due to Relevant Chemicals. 

So that, in this system, either stainless steel is adopted or a corrosion-proof coating is applied only 

against the corrosive effects of Ozone. Stainless steel is used for the Ozone Generator, Ozone 

Injector, and the Waste Ozone Destruction Unit. The piping from the Ozone Generator to Ozone 

Injector, the piping from the Ozone Injector to the Gas/Liquid Separation Tank and the piping from 

the outlet of Gas/Liquid Separation Tank to the gas exhaust port are also made of stainless steel. 

Consideration shall be given to prevent galvanic corrosion between different kinds of metal. 

3.1.4 Results of environmental tests of component units 

Environmental tests for the electrical and electronic equipment of a BWMS have to be carried 

out according to the Guidelines for approval of ballast water management systems (G8) in order 

to secure its safety and reliability required for marine use. Therefore, environmental tests were 

conducted for the following components. The safety and reliability of other electronic equipment 

are secured by adopting type approved products of classification societies. 

.1 Ballast Water Treatment Control Panel. 

.2 Control Panel for Ozone Generator /Oxygen Generator. 

.3 Ozone Generator Tube. 
MEPC 59/2/1 

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.4 Power Supply Unit for Ozone Generator. 

.5 Ozone Leak Monitor. 

.6 Flow Meter. 

3.1.5 Approval of onboard system by Classification Society 

The SP-Hybrid BWMS Ozone version was installed on a 4,600 TEU container ship to conduct 

onboard tests. At the time of system installation, application drawings were submitted for 

approval to the American Bureau of Shipping (ABS), which registers this ship, and were 

approved. In the course of this application, the comments of the ABS were incorporated and the 

system safety was improved. 

3.2 The manner of application (G9: 4.2.6 and 7) 

3.2.1 The maximum dosage concentration of Ozone 

Ozone is injected to achieve 3 mg/L in the intake ballast water. As the amount of Ozone injection 

is automatically controlled , the Ozone concentration is maintained at 3 mg/L in the intake ballast 

water regardless of the flow rate. The Ozone concentration applied to the ballast water flow rate 

for Procedure (G9) application was 4 mg/L. The reason for this was to evaluate the effects on ships, 

human beings and the environment in a more severe manner than by using 3 mg/L. This ensures 

a margin of safety when the system is actually in use. Various tests required for Procedure (G9) 

application were also conducted with 4 mg/L Ozone concentration in the ballast water. 

3.2.2 Holding time 

The holding time in the ballast tanks after the treatment with the SP-Hybrid BWMS Ozone 

version is not specified. The performance of the DWTT to remove Relevant Chemicals ensures 

that the concentration of Relevant Chemicals in the discharged ballast water does not exceed the 

maximum allowable discharge concentration of the Relevant Chemicals even if the discharge 

occurs immediately after the inactivation treatment. 

3.2.3 The maximum allowable discharge concentration of the Relevant Chemicals 

In accordance with the results of various tests, the maximum discharge concentration of the Relevant 

Chemicals is 0.07 mg/L for Bromate ion, 0.018 mg/L for Bromoform and 0.69 mg/L for TRO (O3) 

generated by Ozone treatment of this BWMS. Since many subsequent tests have resulted in 

higher TRO concentration than the 0.15 mg/L (as O3) presented at the time of the Basic Approval, 

the maximum discharge TRO concentration for this system should be revised to 0.69 mg/L. Also, 

Bromoform was defined as 0.19 mg/L taking into consideration the removal performance of the 

DWTT (refer to section 3.2.5.2 of this document). Furthermore, the maximum discharge 

concentration of TRO (as O3) to be applied (i.e. the maximum allowable discharge concentration for 

actual operation of the BWMS) was defined as 0.2 mg/L TRO (as O3) generated by Ozone treatment 

of this BWMS as an independent index in order to provide better protection of the environment. 

3.2.4 Handling, use, storage and transport of the chemicals 

As Ozone, the Active Substance, is produced by the Ozone Generator Module installed on board 

a vessel, there is no need to transport, load and store either the Active Substance or other 

chemicals on board. 
MEPC 59/2/1 

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3.2.5 Procedures and use of the system 

3.2.5.1 Ballasting operation 

Operation at intake is automated by the Ballast Water Treatment Control Panel and Ozone is also 

produced automatically to achieve 3 mg/L in the loading ballast water, by measuring the flow 

rate with the Flow Meter. Even when the ballast water flow rate varies excessively, the system 

has the required Ozone injection capacity, which is based on the predicted maximum water flow 

rate. When a serious failure occurs in one of the major components such as the Ozone Generator 

or the Ballast Pump or if an abnormal value for pressure or water flow rate is shown, the system 

is automatically stopped and an alarm is activated. 

Operation at discharge is automatically executed by the Ballast Water Treatment Control Panel. 

When an instruction to discharge ballast water is given, the valves are automatically opened and 

the ballast water discharge line flowing through the DWTT is established. Arbitrary action by 

the officers and crew cannot interfere with this line. The performance of the DWTT is secured 

by using an automatic valve to discharge the effluent. Clogging of the DWTT is prevented by 

reversing the direction of water flow. The TRO Sensor is installed right after the DWTT to 

survey TRO concentration constantly. If the measured TRO concentration exceeds 0.15 mg/L, 

an alarm is raised to check the amount of activated carbon in the DWTT. Should the TRO 

concentration exceed the maximum allowable discharge concentration of 0.2 mg/L, the discharge 

is automatically stopped. The TRO concentration is automatically recorded by the Ballast Water 

Treatment Control Panel. 

3.2.5.2 Maintenance and inspection 

Maintenance and inspection involves the exchange of activated carbon used in the DWTT. 

Activated carbon is exchanged at the time of periodical surveys of the ship. 

In the case of a medium size bulk carrier (Handy Max BC) engaged in a tramp service, which 

seems to have the longest annual deballasting time among typical vessels, the annual discharge 

time amounts to 690 hours on the assumption that ballast water is discharged for 15 hours with a 

frequency of discharge of once every 8 days. Based on 3 years as the longest interval between 

periodical surveys, the total discharge time during that period is 2,070 hours. 

The results of performance tests on the removal of Relevant Chemicals, which involved 230 hours of 

continuous operation of the DWTT showed that the concentration of Bromate ions in the discharged 

ballast water was stable throughout the test. This result was obtained in spite of the low removal 

performance for Bromate and high removal performance for TRO. Therefore, the removal efficiency 

for these two substances is confirmed to stay constant for the period between periodical surveys. 

The Bromoform removal ratio, however, decreased from 99% at the beginning of the test to 85% 

after 230 hours of operation. This reduction of removal ratio presumably results from a decrease 

of adsorption capacity of the activated carbon. However, even if the removal ratio decreases in the 

case that no Bromoform removed, the PEC/PNEC ratio in the maximum discharge concentration 

of 0.19 mg/L is well below 1 and it was confirmed that there is no environmental effect. 

3.2.6 Risk management measures in case of emergency 

If there is a fire or other emergency, the whole system of SP-Hybrid BWMS Ozone version may 

be shut down by an emergency stop button located in the engine room or the area of Ozone 

Generator Module. When a fire alarm activated, the Ozone Generator Module automatically stops. 
MEPC 59/2/1 

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3.2.7 Other safety measures 

If Ozone is detected by one of the Ozone Leak Monitors located at several points, an audible and 

visible alarm is raised and the Ozone Generator Module automatically stops. Other measures are 

also put in place such as installation of the Ozone Generator Module in an enclosure with 

sufficient ventilation, a notice on the bulletin board and provision of protective clothing and 

protective masks. 

3.2.8 Control of discharge water and countermeasures 

The SP-Hybrid BWMS Ozone version is designed to discharge ballast water after all the residual 

Relevant Chemicals are removed by the DWTT. The removal performance of the DWTT is 

ensured by exchanging the activated carbon at the time of periodical surveys. If the measured 

TRO concentration exceeds 0.15 mg/L according to the sensor installed next to the DWTT, an 

alarm is raised to check the amount of activated carbon in the DWTT. Should the TRO 

concentration exceed 0.2 mg/L, the discharge is automatically brought to a standstill. These 

measures ensure that the maximum allowable discharge concentration of TRO. 

3.2.9 Waste control and recycle 

With the SP-Hybrid BWMS Ozone version, wastes are generated by pre-filter backwash. Since 

the backwash water is returned to the same water, there is no problem. Another waste is the 

removed activated carbon used in the Discharge Water Treatment Tank. The removed activated 

carbon is to be properly treated (recycled) according to the ìBasel Convention on the Control of 

Transboundary Movements of Hazardous Wastes and their Disposalî. 

4 MATERIAL SAFETY DATA SHEETS (G9: 4.2.7) 

The MSDS for Ozone, which is the Active Substance of SP-Hybrid BWMS Ozone version, and 

for Relevant Chemicals are submitted. 

5 RISK CHARACTERIZATION 

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

5.1.1 Persistence (G9: 5.1.1.1) 

There is no persistence because the half life of Ozone as the Active Substance, and of the TRO 

as Relevant Chemicals are extremely short in water. However as the half life of Bromate ions 

and Bromoform as Relevant Chemicals is not less than 40 days and 32 to 185 days, respectively, 

they have persistence. 

5.1.2 Bioaccumulation (G9: 5.1.1.2) 

As Ozone, the Active Substance, is an inorganic compound and its half life in water environment 

is short, there is no bioaccumulation. As described in section 2.2.5 of this document, Bromoform, 

Bromate ion and TRO as Relevant Chemicals do not bioaccumulate. 
MEPC 59/2/1 

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5.1.3 Toxicity test (G9: 5.1.2.3) 

Toxicity is determined by having a chronic toxicity value of less than 0.01 mg/L NOEC. 

As Ozone has an chronic toxicity NOEC of 0.002 mg/L, it is considered to be toxic. As the 

chronic toxicity NOEC for Bromate ions and chronic toxicity NOEC (MATC) for Bromoform 

are 0.125 mg/L and 4.8 mg/L, respectively, both these Relevant Chemicals are considered to be 

non-toxic. As the chronic toxicity test of TRO using treated ballast water showed 0.96 mg/L 

TRO (as O3) and the test result using sample water containing 0.69 mg/L TRO (as O3) generated 

by Ozone treatment of this BWMS showed no effect, it is also considered to be non-toxic. 

5.1.4 Do the Ozone and Relevant Chemicals meet all three criteria for PBT? 

In view of the above results, the following Table 5.1-1 summarized PBT of the Active Substance 

and Relevant Chemicals of the SP-Hybrid BWMS Ozone version. The Active Substance 

and Relevant Chemicals of this system are not considered to be PBT substances. 

Table 5.1-1: PBT of Active Substance and Relevant Chemicals 

 Persistent (y/n) Bioaccumulation (y/n) Toxic 

(y/n) 

Reference/ 

Comments/ 

Justification for 

missing data 

PBT criteria 

Half-life:> 60 days in 

seawater, or> 40 days in 

freshwater or > 180 days 

in seawater sediments, 

or> 120 days in 

freshwater sediments

Experimentally 

determined BCF > 2000, 

or if no experimentally 

BCF has been 

determined, Log Pow>3

Toxicity 

Chronic 

NOEC < 

0.01 mg/L

Ozone N N Y Sections 2.2.2, 2.2.5, 

2.4 of this document 

Bromate ion Y N N Sections 2.2.2, 2.2.5, 

2.4 of this document 

Bromoform Y N N Sections 2.2.2, 2.2.5, 

2.4 of this document 

TRO N N N Sections 2.2.2, 2.2.5, 

2.4 of this document 

6 EVALUATION OF THE TREATED BALLAST WATER (G9: 5.2) 

6.1 Tests of the treated ballast water implemented for the purpose of Final Approval 

6.1.1 Outline of tests 

.1 Acute toxicity test using full-scale land-based test facility described in 6.1.2.1 of 

this document: 

Acute toxicity test for treated ballast water (ballast water discharge) using full-scale 

(200 m3/h treatment capacity) system for Guidelines (G8) land-based test of 

SP-Hybrid BWMS Ozone version. 
MEPC 59/2/1 

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.2 Repetition of chronic toxicity test using small-scale test facility described in 

paragraph 6.1.2.2 of this document: 

Chronic toxicity test including measurement and evaluation of Relevant Chemicals 

such as Bromoform recommended by GESAMP-BWWG (MEPC 55/2/16, annex 5). 

.3 Degradation test for generated Relevant Chemicals using small-scale test facility 

described in paragraph 6.1.2.2 of this document: 

Identification of Relevant Chemicals generated when Ozone is injected to seawater 

by SP-Hybrid BWMS Ozone version, prediction of the amounts and degradation 

test on assumption that they are held in the ballast tank. 

.4 Removal test for generated Relevant Chemicals using small-scale test facility 

described in paragraph 6.1.2.2 of this document: 

Test to confirm removal performance of DWTT for Relevant Chemicals generated 

by SP-Hybrid BWMS zone version. 

.5 Long-term performance test of DWTT by using small-scale test facility described 

in paragraph 6.1.2.2 of this document: 

Test to confirm removal performance for Relevant Chemicals in case of operating 

DWTT for 24 days totalling 230 hours. 

6.1.2 Test facilities 

Various tests were conducted by using two kinds of test facility according to the purpose of tests. 

6.1.2.1 Full-scale land-based test facility 

This is a test facility with treatment capacity 200 m3/h arranged for Guidelines (G8) land-based 

test of SP-Hybrid BWMS Ozone version. 

6.1.2.2 Small-scale test facility 

This facility has 20 m3/h treatment water flow rate and has fundamentally the same structure and 

components as the full-scale land-based test facility. Since the difference from the full-scale 

land-based test facility is the water treatment rate only, the reaction with seawater, the kind and 

concentration of Relevant Chemicals generated, and the kind and concentration of 

Relevant Chemicals in the ballast water discharge can be considered to be the same as in the 

full-scale land-based test facility.

6.1.3 Justification of test facilities 

SP-Hybrid BWMS Ozone version is designed to render organisms harmless by oxidation by the 

injection of Ozone into the ballast water and by disinfection by Relevant Chemicals generated by 

the reaction of Ozone with the ballast water. Therefore, in the case of variations in time 

from Ozone injection to the evaluation for water quality and disinfection effect (reaction time), 

differences may arise in the disinfection effect or in the amount of Relevant Chemicals generated. 

In order not to create contradiction between the small-scale test facility and the full-scale 

land-based test facility, the same reaction time and treatment time have been applied to each test. 
MEPC 59/2/1 

ANNEX 

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I:\MEPC\59\2-1.doc 

Table 6.1-1: Scale of test facilities and reaction time 

TRC 

Ozone 

injection 

method 

Reaction time 

(From Ozone Injector to the exit of Gas/Liquid 

Separation Tank) 

Full-scale 

land-based 

test facility 

200 m3

/h Aeration 

tube About 61 seconds 

Small-scale 

test facility 20 m3

/h Aeration 

tube About 59 seconds 

6.1.4 Quality control of test 

Full-scale land-based acute toxicity test, the repetition of chronic toxicity test and the degradation 

test for Relevant Chemicals were conducted under the surveillance of ìIDEA Consultants, Inc.î 

in accordance with OECDís GLP standard ìOECD Principles of Good Laboratory Practiceî 

(1997). Their affidavit for confidence assurance is attached. The analysis of Relevant Chemicals 

for other tests was conducted by IDEA Consultants, Inc. 

6.2 Full-scale land-based acute toxicity test (G9: 5.2.2) 

The full-scale land-based acute toxicity test was applied to the treated ballast water discharge 

prepared in the same manner as the full-scale land-based test for SP-Hybrid BWMS Ozone 

version in accordance with Guidelines (G8). The acute toxicity test using test organisms was 

conducted in order to calculate the 50% lethal concentration (LC50 or 50% effect concentration 

rate ECr50)and No Observed Acute Effect Concentration(NOAEC)for test organisms. The 

test facility used for this test was the full-scale land-based test facility with 200 m3/h flow rate 

arranged for the G8 land-based test. 

The test organisms are all marine species consisting of Oryzias javanicus (fish), 

Hyale barbicornis (crustacea) and Skeletonema costatum (algae). 

Ozone was injected to achieve 4 mg/L concentration in the intake ballast water (200m3/h). 

The test water exposed to each test organism was the ballast water which was treated by Ozone 

injection and then immediately discharged without retention via the DWTT. 

After sampling, the test water was immediately transported in darkness to the IDEA Consultants, Inc. 

Exposure started within 8 hours from sampling. 

The test intake water to the system conformed to the conditions of sea and brackish test water 

specified in Guidelines (G8) land-based test. Though Guidelines (G8) require 5 mg/L for DOC 

for the test using brackish water, the concentration was 2.4 mg/L, which is just under half this 

value. However, since the sum of TOC and POC was 12.6 mg/L, which is higher than 

the 10 mg/L the total value of POC and DOC specified in Guidelines (G8), this DOC value 

should be of no concern for the purpose of implementing the test in an environment with highly 

concentrated organic matter. 

After the sampled test water was transported to the toxicity laboratory, it was diluted by various 

different amounts before exposure to the test organisms. There was no other treatment or 

filtration of the sampled water. The discharge water was diluted to achieve the following 

concentrations: 100%, 50%, 25%, 12.5% and 6.3% (v/v). Natural seawater was used for dilution. 
MEPC 59/2/1 

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The same untreated test intake water was also exposed to each test organism as a reference. The 

result of this reference test was not applied to calculation of LC50, ECr50 or NOAEC. 

The acute toxicity test for each test organism was conducted in accordance with the following 

guidelines: 

.1 Fish; Oryzias javanicus

OECD Chemical Test Guideline No.203 ìFish, Acute Toxicity Testî (1992) and 

U.S. EPA Guideline ìMethods for Measuring the Acute Toxicity of Effluents and 

Receiving Waters to Freshwater and Marine Organisms, Fifth Editionî (2002). 

.2 Crustacea; Hyale barbicornis 

U.S. EPA Guideline ìGammarid Acute Toxicity Testî (1996) ìMethods for 

Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater 

and Marine Organisms, Fifth Editionî (2002). 

.3 Algae; Skeletonema costatum 

ISO 10253 ìWater quality -Marine algae growth inhibition test with Skeletonema

costatum and Phaeodactylum tricornutum, Second editionî (2006) and U.S. EPA 

Guideline ìMethods for Measuring the Acute Toxicity of Effluents and Receiving 

Waters to Freshwater and Marine Organisms, Fifth Editionî (2002). 

Table 6.2-1 showed the results of the acute toxicity test water and the concentrations of Relevant 

Chemicals in the exposed water. No acute toxicity effect was observed in the test using seawater. 

An acute toxicity effect for brackish water was observed in the tests with Hyale barbicornis, 

crustacea, at 96 h LC50: 71% and 96 h NOAEC: 50%, with Skeletonema costatum, algae, at 72 h 

NOAEC: 50%. However, it is not appropriate to judge from this test result only that treated 

ballast water discharged from SP-Hybrid BWMS Ozone version possesses acute toxicity. Taking 

into consideration that the result was affected by oxygen consumption by decomposition of 

organic matter in the brackish water test, it was considered that the treated ballast water 

discharged from the SP-Hybrid BWMS Ozone version had no acute toxicity effect. 

Table 6.2-1: Result of acute toxicity test using full-scale land-based test facility 

Concentration of Relevant Chemicals in test 

solutions (mg/L) 

Test 

water 

Test 

organisms Endpoint Results Bromate 

ion 

Bromoform TRO 

(as O3) 

Generated 

TRO by 

Ozone 

Treatment 

(mg/L as O3) 

Fish: 96h - LC50 >100% 

Oryzias 

javanicus 96h NOAEC 100% 

Crustacea: 96h -LC50 >100% 

Hyale 

barbicornis 96h-NOAEC 100% 

72h -ECr50 >100% 

Seawater 

Algae: 

Skeletonema 

costatum 72h -NOAEC 100% 

0.07 0.0023 0.54 - 

0.85 

<0.15 
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Concentration of Relevant Chemicals in test 

solutions (mg/L) 

Test 

water 

Test 

organisms Endpoint Results Bromate 

ion 

Bromoform TRO 

(as O3) 

Generated 

TRO by 

Ozone 

Treatment 

(mg/L as O3) 

Fish: 96h-LC50 >100% 

Oryzias 

javanicus 96h-NOAEC 100% 

Crustacea: 96h -LC50 71% 

Hyale 

barbicornis 96h-NOAEC 50% 

72h -ECr50 >100% 

Brackish 

water 

Algae: 

Skeletonema 

costatum 

72hNOAEC 25% 

0.04 0.015 0.93 - 

1.18 

<0.15 

6.3 Repetition of chronic toxicity test (G9: 5.2.1) 

Chronic toxicity tests for the treated ballast water discharged from SP-Hybrid BWMS Ozone 

version were originally conducted at the time of application for G9 Basic Approval both for the 

case of discharge after 48-hour retention at tank without using DWTT and for the case of 

discharge through the DWTT without retention at tank (refer to document MEPC 55/2). 

It was reported that the TRO concentration in the ballast water discharge after removal of 

Relevant Chemicals by the DWTT was always under 0.15 mg/L, despite the conclusion of 

NOEC >0.16 mg/L(O3) for TRO. With regard to this report, the GESAMP-BWWG pointed out 

the need to clarify the toxicity relationship between the discharge and the Relevant Chemicals 

such as Bromate ion and Bromoform (MEPC 55/2/16, annex 5). Taking into account this 

comment, a second chronic toxicity test including measurements of Relevant Chemicals in the 

test water was conducted. 

The test facility with 20 m3/h treatment rated capacity had the same structure and components, 

and possibly the same concentrations of Relevant Chemicals in the ballast water discharge as the 

test facility used for the full-scale land-based test. 

The test organisms were all marine species consisting of Oryzias javanicus (fish), 

Hyale barbicornis (crustacea) and Skeltonema costarum (algae), which were the identical species 

to those in the full-scale land-based acute toxicity test. 

Ozone was injected to achieve 4 mg/L in the intake ballast water (20 m3/h). 

The following test water samples were exposed to test organisms: 

.1 control (original water before dilution); 

.2 test water without removal of Relevant Chemicals by the DWTT immediately 

after treatment by Ozone injection (zero holding time) ñ Four samples were 

made (a) undiluted sample (100%), diluted samples of (b) 10%, (c) 3.125% and 

(d) 1% concentration (v/v); and 
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.3 ballast water discharge with Relevant Chemicals removed in the DWTT 

immediately Ozone injection (zero holding time) ñ Two samples were made 

(a) no dilution (treated discharge water 100%) and (b) 10% concentration (v/v). 

The test water was transported to the IDEA Consultants, Inc., toxicity test laboratory under cool 

and dark conditions immediately after sampling. Exposure started within 24 hours after sampling. 

Test water flowing in the system met the seawater test conditions specified according to 

Guidelines (G8). As stated in section 6.2 of this document, in the case of Guidelines (G8) 

land-based test using brackish water, the decrease of DOC by the decomposition of highly 

concentrated organic matter may have influenced the result of the toxicity test. This is the 

reason why seawater was used for the test. A higher concentration of Relevant Chemicals is 

generated in the test water used for exposure if the concentration of the organic matter is lower. 

After sampling, the test water was transported to the toxicity laboratory and samples of various 

dilutions were prepared prior to exposure to test organisms. Transported test water was used for 

adjusting test water at each exposure area without treatment by filtration. Dilution was applied 

to natural seawater filtered through 3 μm diameter filter. Natural seawater used for dilution was 

exposed to each test organism for control. 

Chronic toxicity tests for each test organism were conducted with test methods specified in the 

following guidelines: 

.1 Fish; Oryzias javanicus

OECD Guideline for the testing of chemicals No.215: Fish, Juvenile Growth Test 

(2000); U.S. EPA: Short-term Methods for Estimating the Chronic Toxicity of 

Effluents and Receiving Waters to Marine and Estuarine Organisms, 

Third Edition (2002). 

.2 Crustacea; Hyale barbicornis 

Method with reference to Anasco et al. (2005) 

U.S. EPA: Short-term Methods for Estimating the Chronic Toxicity of Effluents 

and Receiving Waters to Marine and Estuarine Organisms, Third Edition (2002). 

.3 Algae; Skeletonema costatum 

ISO 10253: Water quality ñ Marine algae growth inhibition test with Skeletonema 

costatum and Phaeodactylum tricornutum, Second edition (2006). 

Table 6.3-1 showed the no observed effect concentration of treated ballast water in the additional 

chronic toxicity test and the maximum concentration of Relevant Chemicals at exposure time. 

The maximum concentration of detectable Relevant Chemicals in the test water which was 

considered to be the no observed effect concentration in this test was: Bromate ions: 0.03 mg/L, 

Bromoform: 0.0093 mg/L, TRO: 0.96 mg/L, and TRO (as O3) generated by ballast water 

treatment of this BWMS: 0.69 mg/L. The concentrations of Bromate ions and Bromoform fell 

far short of the aforementioned existing NOEC and MATC and resulted in supporting both data. 
MEPC 59/2/1 

ANNEX 

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Table 6.3-1: NOEC at chronic toxicity test and maximum concentration 

at time of exposure 

Test water 

Max. concentration of Relevant 

Chemicals in No Observes Effect 

Test Water Case (mg/L) 

Fish: Oryzias 

javanicus 

(28 day 

NOEC) 

Crustacea: 

Hyale 

barbicornis 

(21 day 

NOEC) 

Algae: 

Skeletonema 

costatum 

(78 h NOEC) 

Bromate ion 0.03 

Bromoform: 0.0093 

Seawater TRO (as O3) 0.96 

Generated TRO by Ozone 

Treatment (mg/L as O3) 0.69 

Before PT:10% 

After PT:100% 

Before PT:10% 

After PT:100% 

Before PT:10% 

After PT:100% 

* PT; Post Treatment 

6.4 Degradation test for generated Relevant Chemicals 

A degradation test was conducted by identifying Relevant Chemicals generated at the time of 

Ozone injection into seawater and brackish water by the SP-Hybrid BWMS Ozone version and 

by assuming the amount generated and retained in the ballast tank. The small-scale test facility 

(20 m3/h) was used, however, the DWTT was not used in the degradation tests. The test water 

consisted of four samples using three kinds of seawater and one of brackish water. 

The test showed that three substances, Bromate ions, Bromoform and TRO, which were 

identified as Relevant Chemicals, were generated when Ozone was injected into the ballast water 

in such a manner to achieve 4 mg/L Ozone. It was also found that the half life of Bromate ions 

was longer than 40 days and that the half lives of Bromoform and TRO were 32 to 185 days 

and 0.75 to 4.5 days, respectively. 

6.5 Removal test for generated Relevant Chemicals 

The intention of this test was to confirm the removal performance of Relevant Chemicals by the 

DWTT, which is the most important equipment of SP-Hybrid BWMS Ozone version for the removal 

of Relevant Chemicals from the ballast water discharge. Ozone was injected in such manner as 

to achieve 4 mg/L Ozone in the intake ballast water. The small-scale test facility was used. The 

water quality of the original test water used for the land-based test using the small-scale test 

facility was identical to the water quality for intake water specified for the land-based test in the 

Guidelines (G8). 

Table 6.5-1 showed the Bromate ion concentration at each sampling point. Bromate ions in the 

source water (A) was less than the determination limit (< 0.01 mg/L). Though 0.053 to 0.061 mg/L 

Bromate ion was generated by the Ozone treatment, it did not show much change during the 

elapsed time. Since the Bromate ion concentration remained in the range of 0.050 to 0.058 mg/L 

even after treatment by the DWTT, so it had little effect on removal. 

Table 6.5-2 showed the Bromoform concentration at each sampling point. The Bromoform 

concentration in the source water (A) was less than the determination limit (<0.0002 mg/L). 

Bromoform increased to 0.13 to 0.14 mg/L obviously by generation and its concentration during 

the retention period after treatment also increased to 0.18 to 0.19 mg/L. Bromoform post-treated 

by the DWTT decreased remarkably to near the determination limit (0.0003 to 0.0009 mg/L). 

Therefore, it was proved that the performance of the DWTT in the removal of Bromoform was 

close to 100%. 
MEPC 59/2/1 

ANNEX 

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Table 6.5-3 showed the TRO concentration at each sampling point. TRO was detected in the 

sample of test source water (A), which indicates that there exists oxidant detectable as TRO in the 

background when natural seawater is measured with the KI method. It was found that after this 

test source water had been treated with Ozone by this BWMS, the TRO increased. After passing 

through the DWTT, the TRO was reduced to the level of test source water (natural seawater). 

Therefore, the DWTT is considered to have a thorough removal effect on TRO. 

Table 6.5-1: Bromate ion concentrations in the test water collected from 

(A) raw water, (B) Gas/Liquid Separation Tank, and (C) downstream of DWTT 

-:No measurement

Table 6.5-2: Bromoform concentrations in the test water collected from 

(A) source water, (B) Gas/Liquid Separation Tank, 

and (C) downstream of discharge water treatment unit 

Ozonation at: The day after treatment (Water used for 

treatment) 

Run Sampling 

point Day-1 Day-2 Day-3 

A <0.0002 - - 

#1 B 0.14 0.19 0.18 

C 0.0006 0.0003 0.0003 

A <0.0002 - - 

B 0.13 0.13 0.18 

4.0 mg/L 

(Seawater) 

#2 

C 0.0009 0.0004 0.0003 

-:No measurement 

Table 6.5-3(1): TRO(as O3) concentrations in the test water collected from 

(A) original water, (B) Gas/Liquid Separation Tank, 

and (C) downstream of DWTT 

Ozonation at: The day after treatment 

(Water used for 

treatment) 

Run Sampling 

point Day-1 Day-2 Day-3 

A 0.29 0.40 0.38 

#1 B 1.25 1.09 0.88 

C 0.37 0.50 0.46 

A 0.32 0.36 0.32 

B 1.36 1.16 0.92 

4.0 mg/L 

(Seawater)

#2 

C 0.38 0.46 0.43 
MEPC 59/2/1 

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Table 6.5-3(2): Generated TRO( as O3) concentrations by Ozone Treatment in the 

test water collected from (A) original water, (B) Gas/Liquid Separation Tank, 

and (C) downstream of DWTT 

Ozonation at: The day after treatment 

(Water used for 

treatment) 

Run Sampling 

point Day-1 Day-2 Day-3 

A <0.15 - - 

#1 B 0.96 0.69 0.50 

C <0.15 <0.15 <0.15 

A <0.15 - - 

B 1.04 0.80 0.60 

4.0 mg/L 

(Seawater)

#2 

C <0.15 <0.15 <0.15 

-:No measurement

6.6 Long-term performance test of Discharge Water Treatment Tank 

This test was conducted in order to obtain data to consider the sustainable time of the removal 

performance of Relevant Chemicals by DWTT, namely time to exchange the activated carbon 

installed in the tank. The small-scale test facility was used. Test source water was collected 

from seawater in the bay in front of the test facility. The operation was continuous for about 10 

hours a day for 24 days and totalled 230 hours. The sampling points were at 3 locations, namely 

the original intake water, before DWTT and after discharge treatment tank (ballast water 

discharge). Ozone was injected on ballasting in such manner to achieve an Ozone concentration 

of 4 mg/L. When the DWTT runs in actual operation, the flow direction changes at the time of 

ballast water discharge but in this test run the flow was in the same direction for 230 hours. 

Table 6.6-1 showed measurement results for Relevant Chemicals. Though the removal 

performance for Bromate ions was low, the generated concentration as well as the discharge 

concentration remained stable all through the test. The removal effect of the DWTT was 

maintained even after 230 hours of operation. 

Therefore, the performance of DWTT for these two Relevant Chemicals does not appear to 

decrease even after a long and continuous operation. However the removal performance for 

Bromoform decreased as time passed since the 99% removal at the start of the test was reduced 

to 85% after 230 hours. In case of ballast water discharge, the Bromoform concentration after the 

DWTT started with 0.002 mg/L and ended up at about 10 times this figure, namely 0.018 mg/L, 

after 230 hours. It is considered that a reduction in the adsorption capacity of the activated 

carbon caused the decrease of in the removal performance. 
MEPC 59/2/1 

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Table 6.6-1: Observation result of Relevant Chemicals by long operation 

of a replicate process of DWTT 

6.7 Determination of holding time 

The holding time following ballast water treatment is not specified. The ballast water can be 

discharged immediately after treatment. 

6.8 Risk characterization and analysis 

6.8.1 Reaction with organic matter (G9: 4.2.1.3) 

With regard to the formation of halogenated hydrocarbons, which may occur in the reaction with 

organic matter, untreated intake water, which was prepared for the repetition of chronic toxicity 

test described in section 6.5 of this document, and ballast water discharge water were analysed. 

As described in section 2.4.4 of this document, this resulted in the finding that no halogenated 

hydrocarbons existed in the ballast water discharge. With regard to trihalomethanes generated by 

the reaction of Ozone with organic matter in seawater, the generation of Bromoform as a 

Relevant Chemical and small amounts of dibromochliromethane may occur. 

Bromoform generated in comparatively large amounts is treated as a Relevant Chemical and various 

risk assessments were conducted on this compound. The maximum generated dibromochloromethane 

was 0.0049 mg/L, which is about 1/20 of 0.1 mg/L, which is the WHO Drinking Water Standard 

(WHO, 1996). Most of this small amount of dibromochloromethane was removed in the DWTT 

and its maximum concentration in the ballast water discharge was 0.0002 mg/L, but the concentration 

was too small to be detected in most of the tests.Therefore, it is considered to cause no risk to the 

environment. As TRO mainly consist of oxidants, it is decomposed by reaction with organic matter. 

6.8.2 Characterization of degradation route and rate (G9: 5.3.5) 

Details about the decomposition of Active Substances and Relevant Chemicals under abiotic and 

biotic environment are described in section 2.4.1 of this document. Ozone as the Active 

Substance is completely decomposed or eliminated by Gas/Liquid Separation Tank in the 

SP-Hybrid BWMS Ozone version. 

Cumulative treatment time(h) 0 20 40 90 158 230 

Original Water (Untreated 

intake water) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 

before DWTT 0.02 0.02 0.02 <0.01 0.02 0.01 

Bromate 

ion 

(mg/L) after DWTT 0.02 0.02 0.02 <0.01 0.02 0.01 

Original Water 

(Untreated intake water) <0.0001 0.0001 0.0001 <0.0001 0.0002 <0.0001 

before DWTT 0.1700 0.1600 0.1400 0.0890 0.1300 0.1200 

Bromoform 

(mg/L) 

after DWTT 0.0020 0.0035 0.0054 0.0067 0.0110 0.0180 

Original Water 

(Untreated intake water) 0.21 0.30 0.25 0.22 0.33 0.33 

before DWTT 2.53 2.28 2.05 1.12 2.03 1.91 

Generated TRO by Ozone 

Treatment 2.33 1.98 1.80 0.90 1.70 1.58 

after DWTT 0.42 0.35 0.46 0.29 0.47 0.40 

TRO 

(mg/L as 

O3) 

Generated TRO by Ozone 

Treatment <0.15 <0.15 0.21 <0.15 <0.15 <0.15 
MEPC 59/2/1 

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The half life of Bromate ions as a Relevant Chemical is longer than 40 days and little 

decomposition occurs even in the DWTT. Though the half life of Bromoform is as long 

as 32 to 185 days, most of the Bromoform is decomposed by the DWTT. The half life of TRO 

are 0.75 to 4.5 days and the DWTT eliminates most of it. 

6.9 Prediction of discharge and environmental concentrations 

The predicted environmental concentration (PEC) of Bromate ions, Bromoform and TRO of 

Relevant Chemicals contained in the ballast water discharged from SP-Hybrid BWMS Ozone 

version was predicted by using the MAMPEC model ver. 2.0 as applied to the Port of Tokyo 

as described below. 

6.9.1 Discharge concentration of Relevant Chemicals 

The following summarizes the maximum discharge concentration of Bromate ion, Bromoform 

and TRO as Relevant Chemicals discharged from SP-Hybrid BWMS Ozone version determined 

by various tests: 

With reference to TRO (O3), 0.2 mg/L was independently defined as the maximum allowable 

discharge concentration for actual operation to provide better protection of the environment: 

.1 Bromate ion: 0.07 mg/L 

.2 Bromoform:0.19 mg/L 

.3 TRO: 0.69 mg/L. 

As TRO (as O3) are more properly evaluated by using TRO generated by this BWMS rather than 

direct values analysed by the KI method, the value based on the subtraction of the concentration 

in the ballast water (untreated intake water) from the concentration in the ballast water 

discharged from DWTT was used for the following reasons: 

.1 TRO which was analysed by the KI method specified in section 2.6 of this 

document is usually detected in natural seawater with substantial oxidants. 

For example, the full-scale land-based acute toxicity test described in section 6.2 

of this document detected 0.44 to 0.73 mg/L TRO in natural seawater prior to 

treatment (prior to Ozone injection). Many tests conducted in the past resulted in 

affirming the findings of TRO in natural seawater as well. 

.2 TRO concentration in natural seawater can be considered to cause no impact to 

aquatic organisms. 

.3 PEC and PNEC were predicted by using 0.44 to 0.73 mg/L TRO concentration in 

natural seawater. As the concentration detected as TRO in natural seawater 

resulted from dissipation and decomposition, PEC remained the same. PNEC was 

predicted by using the toxicity of Bromate ion constituting a part of TRO. PNEC 

of Bromate ion is assumed to be 30 μg/L for PNEC long and 300 μg/L for PNEC 

short as described in 6.11.1 of this document. 

.4 PEC/PNEC long and PEC/PNEC short are assumed to be 730/30=25.5 

and 730/300=2.55. PEC/PNEC of natural seawater far exceeds 1.0, which may 

lead to the conclusion that TRO in natural seawater causes a substantial 

environmental impact. 
MEPC 59/2/1 

ANNEX 

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.5 Environmental evaluation for ballast water discharge should be performed on the 

substances generated by ballast water treatment and ultimately discharged. 

.6 It is appropriate to evaluate the environmental effect of TRO generated and 

discharged by SP-Hybrid BWMS Ozone version on the assumption that the 

environmental concentration is 0 μg/L excluding TRO in natural seawater. 

6.9.2 Target port and the designated sea area for the estimation of PEC 

The Port of Tokyo was selected as a target since accurate calculation parameters such as 

geomorphology, tide, water quality and benthics necessary for prediction are available and it has 

been visited by most ships in Japan. If the mooring areas for ships engaged on international 

voyages which are covered by the International Convention for the Control and Management of 

Shipsí Ballast Water and Sediments, 2004 were selected as the designated sea area, the results 

would be underestimated for the following reasons. Therefore, the sea area was limited to the 

area around a container pier of the Port of Tokyo. 

.1 About 80% of ships engaged on international voyages calling in the Port of Tokyo 

are container ships (out of a total of 4,726 ships engaged on international voyages 

calling in the Port of Tokyo, 3,952 ships are container ships). 

.2 Container piers for international trade stand close together in certain areas. 

(equivalent to about 25% of total sea area around berthing space for ships 

engaged on international voyages). 

.3 About 85% of annual ballast water discharge at the Port of Tokyo is discharged 

from container ships. 

6.9.2.1 Scale of harbour facilities in designated sea area 

The container piers for international trade at the Port of Tokyo consists of three container piers 

and a berth allowing berthing of 15 ships with a total area of 1,504,718 m2

. 

6.9.2.2 Tidal current in designated sea area 

The tide in the designated area flows to north-northwest (or to the south-southeast on the opposite 

tide) in parallel with the fairway route with approximate speed of 0.4 to 0.9 knots (0.2 to 0.5 m/s). 

6.9.2.3 Amount of ballast water discharge in the designated sea area 

The intake and discharge of ballast water in the designated area amounts totally to 1,378,117 m3

annually. 1,888 m3

/day ballast water is estimated to be discharged. 

6.9.2.4 Number of ships calling ports in the designated sea area 

The number of visiting ships amounts to 3,952 annually. 

6.9.2.5 Ship mooring frequency in designated sea area 

Most of the container ships are in regular liner service and the time of entrance into port for each 

route has been usually evenly-assigned. As they are moored to each berth everyday 

(open 24 hours) at the Port of Tokyo, it leads to the calculated result: 3,952 ships (calling 

annually)/365 days/15 berths = 0.72 ships/day/berth. 
MEPC 59/2/1 

ANNEX 

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6.9.3 Calculation conditions of PEC 

6.9.3.1 Dimensions and properties of the environment 

The area for the predictive calculation was limited to the sea area around the berthing space of 

the container pier for international trade specified in the aforementioned section 6.9.2. The area 

is 3.5 km long x 1.4 km wide. Table 6.9-1 summarizes the environmental conditions such as tide 

and water quality which were used for the calculation. 

Table 6.9-1: Calculation and environmental conditions at the designated sea 

area of the Port of Tokyo 

Environmental conditions Layout 

Tidal period 12 hour Length x1 

 x2 

350 m 

3,500 m Silt concentration 35 mg/L Width y1 

 y2 

1,400 m 

POC concentration 140 m 

DOC concentration 

1 mgOC/L 

2 mg/L Depth 10 m 

Chlorophyll 3 mg/L 

Salinity 34 s.e. Mouth width 3,500 m 

Temperature 15°C

Latitude 35 degree NH Flow velocity(F) 0.35 m/s 

pH 8 

Depth mixed sediment layer 2.3 m 

Sediment density 2,800 kg/m3

Fraction organic 

Carbon in sediment 0.032

Net sedimentation Velocity 1.2 m/d 

Exchange volume 1.08E+7 m3

/tide 

22.04% tide 

6.9.3.2 Background concentration of the Relevant Chemicals 

As Bromate ions and Bromoform do not normally exist in the natural environment unless 

artificially introduced, their background concentration was considered to be 0 μg/L. 

The backgound concentration of TRO were also considerd to be 0 μg/L for the reasons given in 

section 6.9.1 of this document. 

6.9.3.3 Condition of the discharge ballast water 

6.9.3.3.1 Concentration of Relevant Chemicals 

The following maximum discharge concentrations are shown in section 6.9.1 of this document: 

.1 Bromate ion: 0.07 mg/L (132 g/d) 

.2 Bromoform: 0.19 mg/L (359 g/d) 

.3 TRO( as O3): 0.69 mg/L (1,303 g/d). 

6.9.3.3.2 Physical input values of Relevant Chemicals 

Physical input values of Relevant Chemicals required for prediction calculations using the 

MAMPEC model was set up in accordance with information in chapter 2 of this document. As 

TRO represent the total mass of oxidants and accurate physical data are not available, Bromate ion 

data were substituted, except for the degradation rate (expressed in terms of half life), which was 

obtained from the test. 
MEPC 59/2/1 

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6.9.4 Calculation results 

Table 6.9-2 showed computation results of MAMPEC for the Relevant Chemicals discharged 

from SP-Hybrid BWMS Ozone version based on the application to the Port of Tokyo. 

This computation indicated the following predicted environmental concentration (PEC): 

.1 PEC of Bromate ion :0.00517 μg/L 

.2 PEC of Bromoform :0.0113 μg/L 

.3 PEC of TRO( as O3) :0.0432 μg/L 

Table 6.9-2: Result of prediction using MAMPEC model ver. 2.0 for the Port of Tokyo 

6.10 Assessment of potential for bioaccumulation 

Referring to section 2.4.2 in this document, the LogPow of Relevant Chemicals discharged from 

SP-Hybrid BWMS Ozone version is -7.18 for Bromate ions and 2.4 for Bromoform. Though the 

TRO represent the total mass of oxidants and the octanol/water partition coefficient is not 

available, it is considered to run under logPow 3 which indicated to cause bioaccumulation due 

to its short half life. Therefore, bioaccumulation is not caused by the Relevant Chemicals 

discharged from the SP-Hybrid BWMS Ozone version. 

6.11 Effects assessment 

The maximum concentration of Relevant Chemicals discharged from the SP-Hybrid BWMS 

Ozone version is 0.07 mg/L for Bromate ions, 0.19 mg/L for Bromoform, 1.18 mg/L for TRO 

and no more than 0.69 mg/L for TRO (O3) generated by the Ozone treatment of this BWMS. 

With reference to TRO (O3), 0.2 mg/L was independently defined as the maximum allowable 

discharge concentration for actual operation to provide better protection of the environment. 

The acute toxicity value of Relevant Chemicals as described in section 2.2.1 of this document far 

exceeds these discharge concentrations. As shown in section 2.2.2 of this document, the chronic 

toxicity value NOEC also far exceeds those discharge concentrations. According to the acute 

toxicity test (section 6.2 of this document) and the chronic toxicity test (section 6.3 of this 

document) for ballast water discharged from this system, the results of both cases showed there is 

no potential for toxicity effect in the ballast water discharge. As summarized in section 6.9, 

bioaccumulation of the Relevant Chemicals is unlikely to occur and any effect of toxicity 

resulting from accumulation through the food web is also unlikely to take place. 

From the above standpoint, the Relevant Chemicals discharged from the SP-Hybrid BWMS 

Ozone version are considered not to cause impact on the environment either in short term or in 

the long term. 

PEC of Relevant Chemicals(μg/ L)

Bromate ion Bromoform TRO(as O3) 

Maximum concentration 0.00875 0.0195 0.0740 

95% concentration 0.00806 0.0179 0.0682 

Average concentration 0.00517 0.0113 0.0432 

Median concentration 0.00517 0.0112 0.0427 

Minimum concentration 0.00112 0.0025 0.0093 
MEPC 59/2/1 

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6.12 Effects on aquatic organisms 

6.12.1 Estimated PNEC 

The PNEC of Relevant Chemicals discharged from the SP-Hybrid BWMS Ozone version is 

determined as follows: 

.1 Bromate ion: LC50 or EC50 for three marine species are required and its minimum 

concentration for 96 h EC50 is 30 mg/L. If the assessment factor is set at 1,000 for 

long and 100 for short, PNEC long is 30 μg/L and PNEC short is 300 μg/L. 

.2 LC50 or EC50 for total five marine species and four freshwater species are required 

and its minimum concentration is 7.1 mg/L for 96h LC50. If the assessment factor 

is set at 1,000 for long and 100 for short, PNEC long is 7.1 μg/L and PNEC short 

is 71 μg/L. 

.3 TRO: As TRO represent the total mass of oxidants, toxicity data are not available. 

Therefore, the PNEC was calculated by using the result of the acute toxicity test 

and the chronic toxicity tests for 3 marine species in sections 6.2 and 6.3 of this 

document. An acute toxicity effect was not observed in the acute toxicity test with 

a maximum concentration of 0.85 mg/L and at the maximum TRO concentration 

generated by this BWMS (less than 0.15 mg/L). Therefore, if the assessment factor 

is set at 10, PNEC short is >16 μg/L (as O3). In the chronic toxicity test the NOEC 

was evaluated as 100% (no dilution) of the concentration for ballast water discharge. 

The maximum TRO concentration generated by this BWMS was 0.69 mg/L for 

this case. If the assessment factor is set at 100, PNEC long is 6.9 μg/L(as O3). 

6.12.2 PEC/PNEC ratio 

Based on the PEC calculated in section 6.9 of this document and the PNEC assumed in 

section 6.12.1, PEC/PNEC was computed and its result is shown in Table 6.12-1. 

PEC/PNEC of Relevant Chemicals discharged from SP-Hybrid BWMS Ozone version falls far 

below 1.0. 

Table 6.12-1: PEC, PNEC and ratio of PEC/PNEC 

PNEC(μg/L) PEC/PNEC Relevant Chemicals PEC(μg/L) long short long short 

Bromate ion 0.00517 30 300 0.000172 0.0000172 

Bromoform 0.0113 7.1 71 0.00159 0.000159 

TRO ( as O3) 0.0432 6.9 >16 0.00626 0.00270 

6.13 Effects on sediment 

As described in this document, section 2.2.4, any Relevant Chemical discharged from SP-Hybrid 

BWMS Ozone version is unlikely to cause adhesion or accumulation in the sediment. Therefore, 

it can be considered that there is no effect on sediment. 
MEPC 59/2/1 

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6.14 Comparison of effect assessment with discharge toxicity 

Evaluation of the treated ballast water summarized section 6 of this document is identical to the 

finding that neither acute toxicity nor chronic toxicity has been observed in the various tests on 

ballast water discharged from this system. 

7 RISK ASSESSMENT 

7.1 Risk to safety of ship 

7.1.1 Increased corrosion 

One of main concerns about safety to ships with this system is the possible corrosive effect of 

Ozone on the hull and the equipment. As Ozone is a strong oxidizing agent, corrosion-resistant 

materials should be selected. 

The area requiring corrosion protection is identified by electro-chemical measurements and 

corrosion tests (refer to document MEPC 55/2) and measures to use corrosion resistant materials 

such as stainless steel have been put in place. This section reports the results of an investigation 

of corrosion effects at the identified areas, in which corrosion resistant material is used, as well as 

in other representative areas. 

7.1.1.1 Confirmation of corrosion condition on board 

This system with 300 m3/h treatment capacity has been already installed on board a container 

vessel in order to gather various data and is actually in operation. A corrosion assessment was 

conducted after 8 monthsí operation. 

7.1.1.1.1 Ballast tank 

A visual survey of corrosion before operation and again after 8 monthsí operation of this system 

was conducted in the ballast tank where particular corrosion prevention measures were not put in 

place. The result showed no difference in corrosion between before operation and after 8 monthsí 

operation of this system, which confirmed that there was no corrosion effect. 

7.1.1.1.2 Ozone Injector 

Corrosion-resistant stainless steel was used for the Ozone Injector where Ozone is injected into 

the ballasting line. No corrosion effect was observed as a result of visual inspection including 

the connecting pipes. 

7.1.1.1.3 Special Pipe 

The Special Pipe, which is a core item of equipment of this system designed to inactivate aquatic 

organisms, comes into contact with highly concentrated Ozone. This item was also made from 

corrosion resistant stainless steel. Visual inspection after 8 months of operation showed no 

corrosion effect on the Special Pipe or on the connecting pipes. 
MEPC 59/2/1 

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7.1.1.1.4 Casing and impeller of Ballast Pump 

The Ballast Pump located in the middle of Ozone Injector and Special Pipe also comes in 

contact with highly concentrated Ozone. Bronze and stainless steel were used for the casing 

of the Ballast Pump and impeller. No corrosion effect was observed in a visual inspection 

after 8 monthsí operation. 

7.1.1.1.5 Conclusion of the result of corrosion condition inspected on board 

As described above, the SP-Hybrid BWMS Ozone version was visually inspected 8 months after 

the beginning of the operation. The absence of corrosion was confirmed both in the ballast tank, 

where the corrosion-control measures were judged not to be necessary at the application of Basic 

Approval, and in the equipment, where the corrosion-control measures were required due to contact 

with a high concentration of Ozone. Therefore, the materials described in paragraph 3.1.3 are 

considered to be unaffected by Ozone corrosion. 

7.1.2 Fire and explosion 

Generally speaking, the major risks with ships are fire and flood. Regarding fire, safety is 

enhanced by implementing the following measures: 

.1 In case of fire occurring in the engine room or in another room where the Ozone 

Generator is installed, the Ozone Generator can be stopped from outside the room; 

and 

.2 In case of a fire alarm, the electric power supply to Ozone Generator will be shut 

down immediately to halt production of Ozone which would otherwise help the fire. 

7.1.3 Storage and handling of the substances 

The SP-Hybrid BWMS Ozone version uses Ozone as the Active Substance, which is generated 

by the Ozone Generator Module installed on board. There is no need to store and handle the 

Active Substance on board, which reduces the risk. 

7.1.4 Contact with, or inhalation of, process products 

Ozone as Active Substance and the Relevant Chemicals may cause the following potential risk to 

shipboard personnel when this system operates: 

.1 hazard to respiratory organ by inhalation of Ozone; and 

.2 hazard to eye and dermis by contact with Ozone and Relevant Chemicals. 

This system applies the following measures to minimize all potential risks. As mentioned by 

the GESAMP-BWWG at the time of the Basic Approval (MEPC 55/2/16, annex 5), Bromoform 

(one of the Relevant Chemicals) is volatile and may cause exposure effects on shipboard 

personnel. The air in ballast tank was sampled immediately following operation of this system, 

and the Bromoform concentration in the sampling air was analysed. The measured concentration 

was less than the lower limit of 0.019 μg/m3, which shows that the Bromoform concentration 

would have no effect on shipboard personnel. 
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7.1.4.1 Countermeasures for Ozone leakage 

This system is equipped with Ozone Leak Monitors located at the Ozone Generator, near the 

Ozone Injector and near the Waste Ozone Destruction unit so that Ozone leakage can be always 

under surveillance. If leakage be detected, a visible and audible alarm is raised, the Ozone 

Generator is stopped and the evacuation of shipboard personnel is urged. Portable Ozone Leak 

Monitors are installed on board so that the Ozone concentration can be measured by shipboard 

personnel at appropriate locations and inhalation of air containing Ozone can be prevented. 

Goggles and protective masks are also provided on board. Caution plates are located near the 

Ozone Leak Monitors to draw attention to the hazard. 

As Ozone is a strong oxidizing substance, appropriate materials are used where Ozone is present 

so that the integrity of the system is maintained and Ozone leakage is prevented. 

7.1.4.2 Safety measures of components constituting the system 

This system sufficiently ensures safety to shipboard personnel with robust quality control of each 

component constituting the system including use of corrosion resistant materials, ventilation by 

mechanical exhaust fans, surveillance based on the working environmental standards for Ozone, 

automatic stoppage on failure, visible and audible alarms, preparation of caution plates, etc. 

7.1.5 Noise 

The noise of this system was measured when the installed on board system was operating. The 

result was below 110 dB(A) which is the noise limit for ìMachinery spaces (not continuously 

manned)î thereby ensuring safety to shipboard personnel. 

7.2 Risk to human health 

7.2.1 Health effects in humans (G9: 5.3.12) 

The health effect scenario in humans (except for shipboard personnel) is estimated by 

consideration of the seafood web and the ecosystem. As the ballast water discharge from this 

system is unlikely to cause any impact on the environment, however, this route has a little risk. 

As described in section 7.1.4, Bromoform is potentially dissipated from the ballast tank. When 

the Bromoform was measured, it was under the detectable limit 0.019 μg/m3 and was not at a 

level to affect human health. Therefore, volatile Bromoform has no risk to human health. 

Though residual Bromate ion and TRO in the ballast water are unlikely to affect human health 

during inspection of the ballast tank, protective equipment is worn during inspection to avoid 

any risk. 

Health effects in humans were summarized as follows, making reference to the method specified 

in the Methodology (MEPC 57/2/10, annex 4, appendix 2). 

7.2.2 Human Exposure Scenario (HES) (G9: 6.3.3) 

A third party organization conducted an assessment of the exposure to humans of the Active 

Substance and Relevant Chemicals of this system. A summary of results is described below. 
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7.2.2.1 Ozone 

As the half life of Ozone in water is short, the potential exposure to shipboard personnel is 

considered to be very low level and temporary. The effects on respiratory organs by inhalation 

exposure and mutation are the concerns. However, implementation of safety measures as 

described in section 7.1 of this document decrease the risk to shipboard personnel. As there is 

little potential for exposure to the general public, the risk is low. 

7.2.2.2 Bromate ion 

The maximum Bromate ion concentration in the ballast water collected from the experiment 

was 0.07 mg/L after treatment by this system. As it exists as ions in water, the exposure to 

humans through the air is unlikely to occur. Due to the low bioconcentration factor the risk of 

exposure to shipboard personnel and to the general public through consumption of seafood is 

extremely low. Since from the standpoint of toxicity it is regarded as carcinogenic, the exposure 

to humans especially chronic exposure should be avoided by all means. Therefore, protective 

equipment should be worn during inspection of the ballast tank. 

7.2.2.3 Bromoform 

7.2.2.3.1 Risk of exposure to shipboard personnel by volatility from ballast water 

Exposure of shipboard personnel to Bromoform is expected to be caused by the volatilization 

from the ballast water. 

The maximum concentration of Bromoform in the ballast water is 0.19 mg/L, and about 3.25% of it 

is expected to transfer into the atmosphere according to the environmental distribution prediction 

based on Mackey Level III, which takes into account the half-life of Bromoform in water 

(t1/2 = 185 days as the maximum) (see Table 7.2-1). For a typical ship, the volume of the ballast 

water taken on board is normally ca 15,000 m3 and the gas volume in the headspace of the ballast 

water tank is ca 5,000 m3

. According to the expected distribution patterns based on Mackey 

Level III, 3.25% of Bromoform distributes into the atmosphere, and the Bromoform concentration 

in air in the ballast tank can be calculated as 0.0185 mg/L = 0.0185 g/m3

 using the equation below: 

0.19 mg/L × 0.0325 × (15,000 m3/5,000 m3) = 0.0185 mg/L = 0.0185 g/m3

Assuming, as the worst case, that the Bromoform dissipates into the atmosphere (inboard) and stays 

in the ship without being diluted, it is possible that the shipboard personnel could be exposed to 

Bromoform vapour of about 0.0185 g/m3. When a member of shipboard personnel works in the 

ballast tank on maintenance and other activities, the work normally takes 5 hours and is performed 

once a month. Assuming that the weight of the worker is 60 kg and the volume of breath is 10 m3

for an activity lasting 5 hours, exposure of Bromoform to shipboard personnel is estimated to 

be 3.088 mg/kg for one activity of this kind. The acute toxicity value of Bromoform obtained 

from the study using rats is 1,147 mg/kg (LD50). Using the acute toxicity value of 1,147 mg/kg 

and the estimated exposure, the Margin of Safety (MOS) can be calculated as more than 370. 

Based on the obtained MOS of more than 370, the risk of acute exposure for shipboard personnel 

in the ballast tank is very low. 

On the other hand, the chronic hazard of Bromoform (NOAEL: No Observed Adverse Effect 

Level) is reported as 25 mg/kg/day based on the 13-week study of rats. As for the chronic risk 

assessment for shipboard personnel who work in the ballast water tank, the daily exposure value 

is calculated as 0.103 mg/kg/day since the activity is normally performed once a month 
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(3.088 mg/kg/30day = 0.103 mg/kg/day). Comparing the hazard data from animal studies 

(NOAEL = 25 mg/kg/day) and estimated exposure level to the shipboard personnel in the ballast 

water tank (0.103 mg/kg/day), the MOS is more than 240 and so there is no concern on the health 

risk of the shipboard personnel in the ballast water tank. 

The living space in the ship is ca 1,600 m3. Assuming that the living space is directly connected 

to the headspace of the ballast tank, the concentration of Bromoform in the living space would be 

diluted to 75% of the concentration in the ballast tank (5,000/(5,000 + 1,600) = ca 0.75; 0.0185 

× 0.75 = 0.0139 g/m3). In the living space, a continuous ventilation system is installed and the 

lowest ventilation rate is 78 m3/min when a cooling unit is working. Therefore, air in the living 

space is replaced with fresh air every 20 minutes and the Bromoform concentration should be 

diluted 72 times a day from the original concentration. Assuming that the exposure to shipboard 

personnel is 24 hours a day, the daily breathing volume is 20m3/day, the weight of personnel 

is 60 kg, the daily exposure volume is calculated as 0.064 mg/kg/day using the equation below: 

0.0139 g/m3

 × 1/72 × 20 m3 × 1/60kg = 0.064 mg/kg/day 

Comparing the estimated exposure value of 0.064 mg/kg/day and hazard data of 25 mg/kg/day 

(NOAEL from 13 weeksí study of rats), the MOS is more than 390, so no health risk for the 

shipboard personnel is expected. 

Table 7.2-1: Estimated environmental distribution of Bromoform according 

to Mackey Level III 

Mass Amount (%) Half-life (hr) Emissions (kg/hr) 

Air 3.25 17 0 

Water 96.6 4,440 (185 days) 1000 

Soil 0.0147 170 0 

Sediment 0.115 170 0 

7.2.2.3.2 Atmospheric risk from Bromoform vapor from the treated ballast water 

Bromoform may vaporize into the atmosphere during the ballast water treatment and discharge. It is 

reported that the half-life of Bromoform vaporized into the atmosphere is 66 hours (IARC, 1991). 

It is also reported that the concentration of Bromoform in the atmosphere (background level) of 

marine areas is between 6.2 and 4.8 μg/m3

 (IARC, 1991). The predicted environmental 

concentration (PEC) during the ballast water discharge was determined to be 0.0113 μg/L by the 

MAMPEC model calculation. Assuming that no dilution occurs in the atmosphere and 3.25% of 

the Bromoform vaporizes into the atmosphere based on the Mackey Level III calculation, the 

concentration in the atmosphere is determined to be 0.367 μg/m3. This concentration is much 

lower than the background level, and there should be no health risk caused by volatilization into 

the atmosphere. Furthermore, it is normally expected that vaporized Bromoform should be 

diluted into the atmosphere as much as hundreds to thousands of times, and the concentration 

should be much lower than the estimated value, therefore, no risk to the general public is expected. 

7.2.2.3.3 Risk of Bromoform exposure to public health via sea food 

The maximum generated concentration of Bromoform is 0.19 mg/L and that concentration is 

assumed to be the maximum discharging concentration in the seawater. Using the maximum 

concentration of 0.19 mg/L, the predicted environmental concentration (PEC) is determined to 
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be 0.0113 μg/L by the MAMPEC model calculation. As a worst case scenario, the intake amount 

of Bromoform to the general public can be estimated using the calculated PEC and the following 

parameters: 

- Bromoform concentration at the time of ballast water discharge: 0.19 mg/L; 

- Predicted environmental concentration of Bromoform: 0.0113 μg/L; 

- Bioconcentration factor: 14.06; 

- Human ingestion dose of marine products per day: 188 g*; 

- Average weight of adults: 60 kg; and 

- Human ingestion dose per day: 0.0113 μg/L×14.06×0.188 ̃60=0.000498 μg/kg/day. 

As to the hazard level of Bromoform on humans, the NOAEL value was determined to 

be 25 mg/kg/day by a test of 13 weeks using rats. Comparing the estimated daily intake amount 

of 0.000498 μg/kg/day and the NOAEL of 25 mg/kg/day, MOS is more than ca 50 million and 

therefore there is no health risk due to the Bromoform generated by the system. 

________________ 

* According to the statistics of FAO (1999), annual consumption of fish and shellfish in Japan is the largest 

among the 10 world major countries, which is 68.5 kg. This figure corresponds to 188 g/day. 

7.2.2.3.4 Effect of Bromoform contained in ballast water discharge to sea bathers 

According to the MAMPEC model calculation, the predicted environmental concentration (PEC) 

at the time of ballast water discharge is 0.0113 μg/L. As to the hazard level of Bromoform on 

humans, the value NOAEL was determined to be 25 mg/kg/day by a test of 13 weeks using rats. 

Comparing these values, the hazard level is equivalent to a person swallowing ca 2 million litres 

a day of seawater. Therefore this value causes no concern for health effects. 

Taking into account the above very low risk level, no effect on the health of children and elderly 

people is expected either. 

7.2.2.4 Total Residual Oxidants(TRO) 

As Total Residual Oxidants (TRO) presumably have no volatility, its exposure to shipboard 

personnel is restricted to such temporary works as inspection in the ballast tank. The Predicted 

Environmental Concentration (PEC) is 0.0432 μg/L, which is not harmful to a sea batherís health. 

7.2.3 Conclusion 

The results of the investigation into the toxicity and exposure to Ozone as the Active Substance 

and to the Relevant Chemicals shows that the risk to human health is low for all substances and 

that no effect on human health is expected. 

7.3 Risk to the aquatic environment 

As summarized in this document section 6, the ballast water discharged from this system has no 

potential effect on the environment. 
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8 CONCLUSION 

SP-Hybrid BWMS Ozone version uses the powerful oxidizing agent, Ozone, as 

the Active Substance, which generates Relevant Chemicals by reaction with the intake ballast 

water. There are some residual Bromate ions, Bromoform and TRO (Total Residual Oxidants) 

in the discharged ballast water. However, the safety of the ship and shipboard personnel is 

sufficiently secured by placing safety measures for Ozone on board. 

Also, since all the ballast water is discharged through the DWTT, the concentrations of the 

residual chemicals are considered to cause no risk to the general public or to the receiving marine 

environment. 

Therefore, this system is considered to deserve Final Approval under Procedure (G9). 

REFERENCES 

ATSDR 2005; U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, Public Health 

Service Agency for Toxic Substances and Disease Registry; TOXICOLOGICAL PROFILE FOR 

BROMOFORM AND DIBROMOCHLOROMETHANE, p139, August 2005. 

Bouwer E.J. and McCarty P.L. (1983a). Transfomations of 1- and 2-carbon halogenated aliphatic 

organic compounds under methanogenic conditions. Appl. Environ. Microbiol. 45, 1286-1294. 

Bouwer E.J. and McCarty P.L. (1983b). Transfomations of halogenated organic compounds 

under denitrification conditions. Appl. Environ. Microbiol. 45, 1295-1299. 

ECOTOX DATA BASE (U.S. EPA, 2007a). 

Erikson, S.J. and Freeman, A.E. (1978). Toxicity screening of fifteen chlorinated and brominated 

compounds, using four species of marine phytoplankton. In, Water Chlorination: Environmental 

Impact and Health Effects, Vol. 2 (Ed. R.L. Jolley) pp 307-311. Ann Arbor Science. 

Fisher D.J., Burton D.T., Yonkos L.T., Turley S.D. and Ziegler G.P., (1999). The relative acute 

toxicity of continuous and intermittent exposures of chlorine and bromine to aquatic organisms in 

the presence and absence of ammonia. WATER RESEARCH, 33, 760-768. 

Harrington, D.K., Van Benschoten, J.E., Jensen, J.N., Lewis, D.P., Neuhauser, E.F. (1997), 

Combined use of heat and oxidants for controlling adult zebra mussels Water Research 

31(11):2783-2791. 

Hayashi, M., Kishi, M., Sofuni, T. and Ishidate, M., Jr. (1988) Micronucleus tests in mice on 39 food 

additives and eight miscellaneous chemicals. Fd. Chem. Toxicol., 26, 487-500. 

Hijnen W,R Voogt, HR Veenendaal, H van der Jagt and D van der Kooij (1994), Bromate 

Reduction by Denitrifying Bacteria; Appl. Environ. Microbiol, Jan 1995, Vol 61, No. 239-244. 

ICSC 1993; International Chemical Safety Cards (ICSC). (1993) Ozone Retrieved on April 1993 

http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc00/icsc0068.pdf. 

ICSC 2003; International Chemical Safety Cards (ICSC). (2003) Potassium Bromate. Retrieved 

on November 2003, http://www.inchem.org/documents/icsc/icsc/eics1115.htm. 
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NITE 2007 ; National Institute of Technology and Evaluation, Biodegradation and 

Bioconcentration of Existing Chemical Substances under the Chemical Substances Control Law 

http://www.safe.nite.go.jp/data/hazkizon/pk_e_kizon_disp.html?k_no=0657. 

NTP 2008a; CAS Registry Number: 7758-01 Potassium Bromate. 

NTP 2008 b; CAS Registry Number: 75-25-2 Bromoform. 

Siddiqui, M.S., Amy, G.L. and Rice, R.G., 1995. Bromate ion formation: A critical review. 

Journal of American Water Works Association 87, pp. 58ñ70. 

Siddqui M S., Thai W., Amy G., Mysore C., 1996. Bromate ion removal by activated carbon 

Water Research Volume 30, Issue 7, July 1996, Pages 1651-1660. 

SRC 2007; Bromate ion. 

Tabak H.H., Quaze S.A., Mashni C.I. and Barth E.F. (1981). Biodegradability studies with 

organic priority pollutant compounds. J. Water Pollut. Control Fed. 53, 1503-1518. 

Ullmannís Encyclopaedia of Industrial Chemistry Six Edition, Section 2. Physical Properties, 

Ozone, June, 2001. 

U.S. EPA, Environmental Protection Agency (2007) Drinking water contaminants. 

Retrieved on May 10th, 2007.(http://epa.gov/safewater/contaminants/index.html#dbps). 

U.S. EPA (2005); Environmental Protection Agency, DRINKING WATER CRITERIA 

DOCUMENT FOR BROMINATED TRIHALOMETHANES. 

Ward, G.S., Parrish, P.R. and Rigby, R.A. (1981) Early life stage toxicity tests with a saltwater 

fish: Effects of eight chemicals on survival, growth, and development of Sheepshead minnows. 

J. Toxicol. Environ. Health, 8, 225-240. 

Wedemeyer, G.A., N.C. Nelson, and W.T. Yasutake. 1979. Physiological and Biochemical Aspects 

of Ozone Toxicity to Rainbow Trout (Salmo gairdneri). J. Fish. Res.Board Can. 36(6):605-614. 

WHO (1996) Guidelines for drinking- water quality, Second Edition Volume 2, pp 851. 

http://www.who.int/water_sanitation_health/dwq/en/2edvol2p1.pdf. 

WHO (2005) Bromate in Drinking-water Background document for development of WHO Guidelines 

for Drinking-water, Quality, Geneva,World Health Organization (WHO/SDE/WSH/05.08/78) (2005) 

(http://www.who.int/water_sanitation_health/dwq/chemicals/bromate030406.pdf). 
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STATEMENT and QUALITY ASSURANCE STATEMENT 

Example: Acute toxicity test for the treated water discharge (seawater, treated before discharge, 

retention time 0 Day) with Special Pipe Ballast Water Treatment System (combined with Ozone 

Treatment Version) using salt water fish Java medeka, Oryzias javanicus. 
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______________