I:\MEPC\61\2-12.doc 

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE 

61st session 

Agenda item 2 

MEPC 61/2/12

31 March 2010

 Original: ENGLISH

HARMFUL AQUATIC ORGANISMS IN BALLAST WATER 

Application for Basic Approval of the BlueSeas Ballast Water 

Management System 

Submitted by Singapore 

SUMMARY 

Executive summary: This document contains the non-confidential information for 

Basic Approval of the BlueSeas Ballast Water Management 

System in accordance with the "Procedure for approval of ballast 

water management systems that make use of Active Substances (G9)" 

adopted by resolution MEPC.169(57). The relevant documents 

and application dossier will be provided to the Marine Environment 

Division of the Organization for review by the GESAMP-Ballast 

Water Working Group. 

Strategic direction: 7.1 

High-level action: 7.1.2 

Planned output: 7.1.2.5 

Action to be taken: Paragraph 6 

Related documents: BWM.2/Circ.13 and BWM.2/Circ.24 

Introduction 

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

ships' Ballast Water and Sediments stipulates that ballast water management systems which 

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

Organization, based on a procedure developed by the Organization. 

2 The "Procedure for approval of ballast water management systems that make use of 

Active Substances (G9)" was adopted by resolution MEPC.169(57). Procedure (G9) defines 

the principal aspects to be documented by data or testing (MEPC 57/21, annex 1, 

paragraph 4.2.1) and some basic principles for risk evaluation (MEPC 57/21, annex 1, 

paragraph 5.3). According to section 6 of Procedure (G9), the Organization should evaluate 

the information provided in the application. 
MEPC 61/2/12 

Page 2 

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3 According to BWM.2/Circ.13 and BWM.2/Circ.24, proposals for approval of ballast 

water management systems that make use of Active Substances need to be submitted to the 

Marine Environment Division of the Organization to be reviewed by the GESAMP-BWWG. 

4 The competent authority in Singapore has verified the application dossier prepared 

by Envirotech and Consultancy Pte. Ltd., and believes that it satisfies the data requirements 

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

5 Singapore therefore submits the non-confidential part of the applicant's dossier in 

the annex of this document to the Organization for evaluation according to Procedure (G9). 

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

Action requested of the Committee 

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

appropriate. 

***
MEPC 61/2/12 

Annex, page 1 

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ANNEX 

NON-CONFIDENTIAL INFORMATION ON THE

BLUESEAS BALLAST WATER MANAGEMENT SYSTEM 

Contents 

1 INTRODUCTION 

1.1 Overview 

1.2 System (G9: 7) 

1.3 Working mechanism 

1.4 Purpose of application 

2 IDENTIFICATION (G9: 4.1) 

2.1 Active Substances (G9: 2.1.1) 

2.2 Preparations (G9: 2.1.3) 

2.3 Relevant Chemicals (G9: 2.1.4) 

3 DATA-SET FOR SUBSTANCES (G9: 4.2, 5.3) 

3.1 Free active chlorine (G9: 4.2.1) 

3.2 Hypobromous acid/Hypobromite ion (G9: 4.2.1) 

3.3 Hydroxyl radical (G9: 4.2.1) 

3.4 Ozone (G9: 4.2.1) 

3.5 Sodium thiosulfate

4 TOXICITY ANALYSIS ON DISINFECTION BY-PRODUCTS (G9: 5.2) 

4.1 Trihalomethane (THM) 

4.2 Haloacetic acids (HAA) 

4.3 Bromate 

5 TOXICITY TESTING OF THE TREATED BALLAST WATER (G9: 5.2) 

5.1 pH 

5.2 Total residual oxidant 

5.3 Disinfection by-products 

5.4 Eco-toxicity testing 

6 RISK ASSESSMENT 

6.1 Safety of ship (G9: 6.3) 

6.2 Human and environment (G9: 6.4) 

7 ASSESSMENT REPORT (G9: 4.3, 4.2.3) 

7.1 Experimental data 

7.2 Literatures for toxicity analysis 

REFERENCES 
MEPC 61/2/12 

Annex, page 2 

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1 INTRODUCTION 

1.1 Overview 

Ballast water is an essential component for the stability of vessels during the voyage. During 

the ballasting process, living organisms enter the ballast tanks together with ballast water 

and sediments. Some of these organisms are able to survive during the journey and may be 

able to grow in the receiving environment upon deballasting. The ballast water mediated 

invasions have been observed and reported. Some of these invaders can greatly affect the 

native living organisms and thus the local economic activities, such as fishing, recreation and 

hydro-power generation. Moreover, there is a risk of spreading diseases such as "cholera" 

through ballast water (Hallegraeff and Bolch., 1991). Inappropriate ballast water 

management system (BWMS) may lead to environmental pollution, economical loss and 

spread of diseases in our coastal areas. 

The ballast water exchange at mid ocean has been widely practiced. Ballast water collected 

from a coastal area is exchanged with deep seawater during the voyage. It is hypothesized 

that the organisms which are in the deep seawater will not be easily adapted to the coastal 

environment. In addition, the organisms in coastal seawater may not be able to survive in 

the low-nutrient environment in deep seawater. However, the efficiency of ballast water 

exchange in removing living organisms is questionable (Taylor et al., 2007). Moreover, the 

operation of ballast water exchange is unsafe to the ship structure and the crew. Therefore, 

the need for a safe and cost-effective alternative treatment technology is increasing. 

1.2 System (G9: 7) 

BlueSeas Ballast Water Management System of Envirotech and Consultancy Pte. Ltd., 

Singapore, has been developed and tested since 2007. The system is designed for 

treatment of ballast water (seawater) in order to better prevent the marine environment. The 

BWMS consists of three key components as follows: 

.1 a micro-sized strainer (50 μm) in order to remove bigger organisms and 

particles before entering the electrochemical reactor / ballast water tank; 

.2 an electrochemical reactor (also called as electrochemical disinfector or 

electro-disinfection reactor) for generation of disinfectant (total residual 

oxidant (TRO) less than 12 mg/L), which are used in the inactivation of 

organisms in the ballast water. The modular design can be scaled-up 

according to ballast water capacity; and 

.3 a neutralization system to remove residual chlorine prior to its discharge to 

ensure that the water is safe to the marine environment. 

In addition to the above three components, the BWMS has supporting devices; they include 

sensors and transmitters (TRO, and optional: flow rate, conductivity, pressure and 

temperature), computer control system, and auxiliary devices. 

At the electrochemical reactor, Active Substances including free active chlorine and hydroxyl 

radical (OHï) are produced. The TRO (mainly hypochlorite and hypochlorous acid) with 

concentration of less than 12 mg/L is generated in reactor; the concentration is measured by 

an online analyzer, which provides information for the operation of the electrolysis device 

controlled through a computer system. 
MEPC 61/2/12 

Annex, page 3 

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Hydrogen gas (H2) and chlorine gas (Cl2) are generated. A ventilation system is used to 

remove the gases to prevent fire/explosion and spread of toxicant to crew (e.g., inhalation); 

it is optional as concentrations of both gaseous species are with extremely low concentration 

levels (confidential supporting information "SI-list of experiment details"). 

The system diagrams for operations in both ballasting and deballasting are given in the 

confidential supporting information "SI-Description for the BWMS". 

Operation of system during ballasting 

During the ballasting, the seawater is first pumped through the strainer, goes through the 

electrochemical reactor, and finally flows to the ballast water tank. 

Operation of system during deballasting 

The ballast water from each tank is pumped out through a pipe, in which neutralizing agent 

(Na2S2O3) is injected. This is to ensure that the water will have no Active Substances 

released to the sea and thus have no adverse effects on the environment. The details in the 

application and handling of the chemical are addressed in the confidential supporting 

information "SI-application of Na2S2O3". 

The electro-disinfection system in this application treats the safety of the receiving 

environment, the ship, and the crew as the top priority. No hazardous chemical is needed to 

be handled by the crew or stored. In addition, the lower foot-print design ensures ease in 

integration of the system in newly built and existing ships. Lower operation and maintenance 

costs make the system more affordable than many commercially available technologies. 

1.3 Working mechanism 

Electrochemical generation of Active Substances is the major working mechanism in the 

ballast water treatment technology in this application. HOCl/OCl-

 and hydroxyl radical are 

two major Active Substances that are produced in the reactor. 

1.3.1 Total residual oxidants 

1.3.1.1 Free active chlorine 

The combination of HOCl, OCl-

 and Cl2(aq) is referred to as free active chlorine. Free active 

chlorine is generated due to the production of chlorine gas at the anodes of the 

electrochemical reactor as a result of oxidation of Cl-

 ions. See below: 

2 2 2 () Cl e Cl g − − − → (1-1)

The produced chlorine gas immediately dissolves and reacts with the water to form 

hypochlorous acid (HOCl), which is a weak acid. The dissociation of HOCl forms the 

hypochlorite ion (OCl-

). The reactions are as follows (Metcalf and Eddy, 2003; 

Chen et al., 2005): 

Cl H O HOCl Cl H 2 2

− + + ⇔ ++ KH = 4.5x10-4 M2

, T= 25oC (1-2)

HOCl ClO H ⇔ + − + Ki = 3x10-8 M, T= 25o

C (1-3)

Because of the magnitude of reaction constant of Equation (1-2) shown above is high, large 

quantities of chlorine can be dissolved in water. 
MEPC 61/2/12 

Annex, page 4 

I:\MEPC\61\2-12.doc 

Figure 1-1: Species distribution of active chlorine at different pH values 

Figure 1-1 shows the speciation of free active chlorine at different pH values (Deborde and 

von Gunten, 2008). At pH > 4, the aqueous-phase chlorine does not exist (White, 1992). 

In the ballast water, the pH of seawater is around 8 (7.5 to 8.5). Thus, no Cl2(aq) exists. 

Approximately 80% of active chlorine is OCl- and 20% is HOCl. 

Free active chlorine is a very powerful disinfectant due to its higher oxidation capability. 

It stays in water (as residual chlorine) for a period of time ranging from several hours 

to 1-2 days dependent upon the characteristics of seawater. Hence, a variety of living 

organisms and micro-organisms originally existing in the ballast water intake (seawater from 

contaminated coastal area) are disinfected. In addition, the organisms/micro-organisms 

originally existing in the ballast water tank will be killed and the reactivation of disinfected 

organisms/micro-organisms does not occur after disinfection because of the presence of the 

free active chlorine. On the other hand, free active chlorine decays with time, leaving no 

hazardous concentration after 1-2 days from the point of generation to a lower level (almost 

zero when the initial chlorine concentration is 3-4 mg/L) (please refer to the confidential 

supporting information "SI-Chlorine decay in the ballast water"). Therefore, the corrosion due 

to using the free active chlorine in this technology should not be concerned. 

1.3.1.2 Hypobromous acid/Hypobromite ion 

It should be noted that, normally, natural seawater contains bromide (Br-

) ions with a 

concentration of 35 to 70 mg/L. The produced free active chlorine in seawater will oxidize 

bromide ions into hypobromous acid according to the following equation: 

HOCl + Br- → HOBr + Cl-

 (1-4) 

Hypobromous acid can also dissociate in water depending upon pH, temperature and ionic 

strength, which is similar to hypochlorous acid. Hence, trace of HOBr and OBr-

 may exist in 

the treated seawater. 

HOBr → H+

 + OBr- (1-5) 

Hypobromous acid is also an effective disinfectant. 

1.3.1.3 Total residual oxidants 

Chlorine may react with ammonia (NH3) to form chloramines (NH2Cl, NHCl2 and NCl3). 

Similarly, bromamines can be formed according to the reactions between HOBr and NH3. 
MEPC 61/2/12 

Annex, page 5 

I:\MEPC\61\2-12.doc 

The chloramines and bromamines can also act as disinfectants. The overall of free active 

chlorine, HOBr/OBr-

, chloramines and bromamines are called as total residual oxidants 

(TRO). In the ballast water treatment in this application, due to the high concentration of Cland lower concentration of ammonium and Br-

 in seawater, the TRO mainly results from the 

free active chlorine (i.e. TRO ≈ [HOCl] + [OCl-

]). 

1.3.2 Hydroxyl radical 

In the electro-disinfection system in this application, the electro-chlorination is the most 

important mechanism. However, the effect of hydroxyl radical (OHï) generated at the anode 

also plays a certain role in the killing of organisms/micro-organisms. Equation (1-6) shows 

the reaction in the generation of OH as follows: 

H O OH e H 2 → ⋅+ +− +

 (1-6)

OHï is a strong oxidant and therefore can disinfect living organisms/micro-organisms. 

However, the lifespan of OHï is in the scale of nanoseconds, which results in no residuals for 

further disinfection in the ballast tanks. As a result, the disinfection due to OHï has only 

occurred in the electro-disinfection reactor. 

1.3.3 Ozone and oxygen 

Apart from TRO and OH, there is a possibility of generation of O2 and O3 at the anode. The 

following equations show the reactions at anodes on the generation of oxygen and ozone: 

2H2O = O2(g) + 4H+

 + 4e- (1-7) 

O2(g) + H2O = O3(g) + 2H+

 + 2e- (1-8) 

Because of the higher overpotential of anode (used in the technology in this application), the 

oxygen generation is limited. The ozone generation is therefore expected to be very small 

according to the reaction. In addition, our laboratory analysis revealed that the concentration 

of ozone in the effluent from the reactor was negligible ("SI-list of experiment details"). 

1.3.4 Others 

Besides, such factors as direct electrical field (electric shock) may disinfect a certain portion 

of living organisms/micro-organisms, without involving any Active Substance. However, this 

is not considered a major mechanism of disinfection because of the low strength of electrical 

field used in the reactor. 

Sodium thiosulfate is used to remove TRO from the ballast water prior to the discharge. The 

main reaction involved in the neutralization is as follows: 

Na2S2O3 + 4OCl-

 + H2O = 2NaCl + 2SO4

2- + 2HCl (1-9) 

Na2S2O3 + 4OBr-

 + H2O = 2NaCl + 2SO4

2- + 2HBr (1-10) 

The toxicity of sodium thiosulfate at lower concentration in water solution is insignificant as 

demonstrated in section 3. As the dosage needed is quite low as stated in the confidential 

supporting information "SI-Description for the BWMS", its effect on marine environment may 

be neglected. It can consume dissolved oxygen (DO) according to the below reaction: 

2Na2S2O3 + O2 = 2Na2SO4 + 2S (1-11) 
MEPC 61/2/12 

Annex, page 6 

I:\MEPC\61\2-12.doc 

As such, a slightly higher dosage of sodium thiosulfate will be added so that the chlorine can 

fully be neutralized; the left sodium thiosulfate can be removed by DO in the seawater. The 

confidential support information "SI-application of Na2S2O3" is included in this application on 

various issues associated with the chemical. 

1.4 Purpose of application 

Since our electro-disinfection technology makes use of Active Substances in the ballast 

water treatment, we are seeking for the Basic Approval of Active Substances according to 

Procedure (G9) (resolution MEPC.169(57), document MEPC 57/21, annex 1, "Procedures for 

approval of ballast water management systems that make use of Active Substances"). This 

document is prepared to provide the non-confidential information on safety and environmental 

related issues of our electro-disinfection technology according to Procedure (G9). The complete 

application dossier inclusive of this document together with two confidential documents 

("Laboratory reports" and "Supporting information") is submitted to the GESAMP-BWWG for 

the evaluation of technology for Basic Approval. 

2 IDENTIFICATION (G9: 4.1) 

2.1 Active Substances (G9: 2.1.1) 

The electro-disinfection treatment technology in this application produces Active Substances 

on board. No chemical is added to produce any other Active Substances. The following 

substances are identified as Active Substances according to the definitions in Procedure (G9). 

2.1.1 Total residual oxidants 

The maximum TRO concentration generated on board is less than 12 mg/L. TRO is divided 

into two major groups: free active chlorine and hypobromous acid/hypobromite ion. 

2.1.1.1 Free active chlorine 

In the BWMS, the free active chlorine with a maximum allowable concentration of 12 mg/L 

(i.e. TRO of 12 mg/L as Cl2) is to ensure the complete disinfection of living organisms/ 

micro-organisms in ballast water. This is particularly important as it can further ensure complete 

killing of the sediment-bound living organisms/micro-organisms, which originally exist in the 

ballast tanks previously containing ballast water for many years. In addition, the residual free 

active chlorine can disinfect the "tougher" living organisms and prevents re-growth of 

disinfected organisms. The concentration of free active chlorine drops to a very low level in a 

period of time (few days) when the ballast water intake is from a contaminated coastal area. 

2.1.1.2 Hypobromous acid/Hypobromite ion 

As discussed in section 1.3.1.2, Hypobromous acid/hypobromite ion (HOBr/OBr-

) can be 

generated on board. HOBr/OBr-

 is a disinfectant and thus is considered as an Active Substance. 

2.1.2 Hydroxyl radical 

Another Active Substance is hydroxyl radical (OHï). The process of OHï generation is 

previously explained. Due to the extremely short life span, it is nearly impossible to quantify 

the amount of OHï generated. However, the detection methods such as radical scavengers 

show the presence of OHï in the electro-disinfection reactor. OHï contributes to the 

disinfection of living organisms/micro-organisms in the ballast water. As OHï exists only for 

nanoseconds, the residual disinfection effects are not expected from this Active Substance. 
MEPC 61/2/12 

Annex, page 7 

I:\MEPC\61\2-12.doc 

2.1.3 Ozone 

Ozone is another Active Substance which may be generated inside the electrochemical 

reactor (concentration is insignificant). Due to the fast decomposition, ozone does not leave 

any residual disinfectant effect at the ballast tank. 

2.2 Preparations (G9: 2.1.3) 

According to Procedure (G9), paragraph 2.1.3, no preparations for Active Substances used 

in ballast water management are identified in the electro-disinfection technology in this 

application. 

2.3 Relevant Chemicals (G9: 2.1.4) 

Two major classes of Relevant Chemicals are identified due to their importance. 

2.3.1 Hydrogen gas 

Hydrogen gas (H2) is produced at the cathodes of the electro-disinfector. The following 

equation shows the reaction responsible for production of H2: 

2 2

1

2

H O e OH H − − +→ + (2-2) 

H2 is known as an explosive gas. The lower and upper flammability limit values of H2 gas are 

reportedly 4 and 75%, respectively. The content of H2 generated is low according to our 

calculation based on the energy consumption and generation of chlorine. Moreover, the 

hydrogen gas quickly escapes from the tank due to its very small density (its molecular weight is 2). 

Hence, the concentration of hydrogen gas accumulated in the ballast tank can be neglected. 

The quantification of H2 gas produced during the operation is provided in the confidential 

supporting information "SI-Calculation of hydrogen concentration". A gas ventilation system 

is optionally incorporated in the BWMS in this application. 

2.3.2 Disinfection by-products 

Disinfection by-products (DBPs) may be produced during the disinfection as a result of 

reactions between the disinfectants and the natural organic matter or inorganic substances in 

ballast water. Trihalomethanes (THM), haloacetic acids (HAAs), and bromate (BrO3

-

) are 

identified as the major DBPs produced during the operation of BWMS. The quantification of 

these DBPs in treated water is provided in a latter part of this report. 

3 DATA-SET FOR SUBSTANCES (G9: 4.2, 5.3) 

3.1 Free active chlorine (G9: 4.2.1) 

Free active chlorine is considered as an Active Substance according to the definition in 

Procedure (G9). It is generated by the electrolysis reaction previously discussed. 

3.1.1 Effects on aquatic plants, invertebrates, fish, and other biota, including 

sensitive and representative organisms (G9: 4.2.1.1) 

It consists of HOCl and OCl-

. Therefore, the following details are collected from the 

literatures based on studies conducted on the toxicity of HOCl/OCl-

 or NaOCl. 
MEPC 61/2/12 

Annex, page 8 

I:\MEPC\61\2-12.doc 

Chlorine gas is first produced through the electrolysis reaction shown early. It is well 

reported in various literatures that chlorine gas is quickly dissolved once it is generated. 

In order to confirm this, an experiment was conducted as follows, under the observation of 

American Bureau of Shipping (Singapore) (ABS). 

A gas sample was collected from a simulated ballast tank, in which the ballast water was 

treated by the proposed BWMS under laboratory conditions. The concentrations of chlorine of 

the gas samples were determined by a commercial lab. The concentration of chlorine is less 

than 0.1% (please refer to the confidential supporting information "SI-list of experiment details"). 

3.1.1.1 Acute aquatic toxicity 

The data based on the literature study related to the acute aquatic toxicity of free active 

chlorine are shown in Table 3-1. Since the technology in this application does not release any 

treated ballast water without neutralization (removal of residual free active chlorine), acute 

aquatic toxicity due to free active chlorine in discharging ballast water is unlikely to occur. 

3.1.1.2 Chronic aquatic toxicity 

The data based on the literature study related to the chronic aquatic toxicity of free active 

chlorine are shown in Table 3-2. As above-mentioned, since the BWMS in this application 

does not discharge any treated ballast water without neutralization (removal of residual free 

active chlorine), chronic aquatic toxicity due to free active chlorine in discharging ballast 

water is not possible to take place. 

3.1.1.3 Endocrine disruption 

Sodium hypochlorite is not listed as an endocrine disruptor under any of the following list 

(Pesticide Action Network (PAN), 2010). 

.1 Illinois EPA list; 

.2 Keith list; 

.3 Colborn list; 

.4 Benbrook list; 

.5 Danish Inert list; and 

.6 EU list. 

Based on the above listing, it can be concluded that the free active chlorine may not have 

any endocrine effects. 

3.1.1.4 Sediment toxicity 

The organic carbon partition coefficient, Koc, is a measure of the tendency for a substance to 

be adsorbed to organic materials in soil, in sediment, or in biological tissues. Koc and logKow

of NaOCl are 13.22 L/kg and -3.42 according to EPI Suite by USEPA (EPA, 2008). As the 

value of Koc is quite small (less than 500 L/kg), the free active chlorine will not easily adsorb 

onto the solids (e.g., soil and sediment) of the receiving environment. Secondly, the active 

chlorine exists as OCl-

 at pH of 7.5 to 8.5 (seawater or ballast water). Under such a pH, the 

particles carry negative surface charges. As a result, the adsorption of active chlorine is 

quite unlikely. It can therefore be concluded that the usage of chlorine will not cause an 

increase in the toxicity of the sediment. 
MEPC 61/2/12 

Annex, page 9 

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3.1.1.5 Bioavailability/bioaccumulation/bioconcentration 

The logPoctanol/water (logPow) and bioconcentration factor (BCF) of NaOCl are reported as -3.42 

and -2.19 L/kg, respectively. According to section 6.4.1 of Procedure (G9), the bioaccumulation 

potential needs to be analysed if the logPow is more than or equal to 3 or if BCF > 2000. 

Thus, it is clear that the potential of bioaccumulation/bioconcentration is negligible for free 

active chlorine. 

3.1.1.6 Food web/population effects 

The concentrations of Active Substances are reduced to a very low level 

(around 0.01 ñ 0.05 mg/L) due to the neutralization operation. In addition, the water chemistry 

(e.g., pH of 7.5 to 8.5 in seawater, lower Kow value, surface charge properties of solids, and 

lower Koc value) is not favourable in the sorption of the free Active Substances onto the 

solids. No bioaccumulation is expected. As such, it is impossible that they can be adsorbed 

onto sediment. Thus the adverse effects on the food web and population are negligible. 

3.1.2 Data on mammalian toxicity (G9: 4.2.1.2) 

3.1.2.1 Acute toxicity 

Inhalation 

At low pH, if heated, or mixed with acids, NaOCl may release Cl2. In case of inhalation, 

acute toxicity effects such as coughing and choking, burning sensation, laboured breathing, 

shortness of breath, severe respiratory tract irritation and pulmonary oedema may occur 

(MSDS, Siemens water technology, 2000). LC50 of rat through inhalation exposure to NaOCl 

is 10 mg/L (European Chemicals Bureau (ECB), 2000). 

It is worthy to note that the pH of target water to be treated by the proposed system is in the 

range of 7.5-8.5 under which Cl2 cannot be formed. In addition, the treated water is not 

heated or mixed with acids during operation. As a result, inhalation exposure of free active 

chlorine is not expected in the operation of system in this application. 

Oral 

Swallowing concentrated hypochlorite solutions may burn the tissues, causes severe 

abdominal pain, nausea, vomiting, circulatory collapse, confusion, delirium, coma and 

collapse. Swallowing large quantities can even cause death (MSDS, Horizon Chemical, 2004). 

LD50 of rat/mouse through oral exposure to NaOCl is given in Table 3-4. 

Table 3-4 clearly shows that the oral exposure is extremely serious if the concentration of 

free active chlorine is high. However, the concentration of free active chlorine in the 

technology in this application is less than 12 mg/L. The substance is generated and exists in 

the sealed reactor. Thus, no hazardous effect is expected through oral exposure. 

3.1.2.2 Effects on skin and eye 

Skin contact 

Skin contact of 10-12% NaOCl solution may cause irritation, redness, blisters, vesicular 

eruptions, and eczematoid dermatitis (MSDS, Siemens water technology, 2000). Acute 

dermal toxicity test on rabbits showed a LC50 of >10000 mg/kg bw. Severe injury in skin was 

resulted in 15 to 30 minutes after applying commercial 5.25% NaOCl (diluted 2:1 with water) 

on rabbits. In addition, a patch test (NaOCl, concentration is not specified) conducted 

on 225 humans, 3 showed positive reactions (ECB, 2000). 
MEPC 61/2/12 

Annex, page 10 

I:\MEPC\61\2-12.doc 

Eye Contact 

If eyes contact with NaOCl, irritation as eyes burn may occur, which is dependent upon the 

concentration. Eye irritation study using rabbits was reported (ECB, 2000). 5% NaOCl was 

used in the investigation. Volumes of 0.01, 0.03, and 0.1 ml were contacted with the central 

corneal surface of the rabbits. Twenty-one days study showed that 0.01 ml resulted in a 

moderate irritation while 0.03 ml resulted in a substantial irritation. Severe or corrosive 

reactions were observed at 0.1 ml. 

The concentrations of free active chlorine in the treated ballast water are quite low and they 

are in the sealed devices and ballast water tanks. As such, the risk associated with skin and 

eye contacts are neglected. 

3.1.2.3 Chronic and long-term toxicity 

Exon et al. (1987) reported a chronic toxicity study of NaOCl on rats. Rats were given 

chlorinated drinking water (chlorinated using 6.05% NaOCl) with 5, 15, 30 ppm of available 

chlorine for 9 weeks. A significantly smaller spleen weights were found among the rats 

exposed to 30 ppm, compared to the control. However, when consider all levels of dosages, 

no significant effects of NaOCl exposure were observed on body weight, thymus weight, 

antibody response, NKC cytotoxicity, IL2 production, or phagocytic activity. 

A two-year NaOCl toxicity study (oral exposure) was reported on rats and mice (U.S. Department 

of Health and Human Services, 1992). Chlorine with concentrations varied between 0-275 ppm 

was used. For high dose rats, the dosage was between 13-14 mg/kg. In female rats, 

an increase in mononuclear cell leukaemia was observed compared to the controls. The 

survival of rats was not varied significantly either they were exposed or not exposed to 

chlorinated drinking water. For high does mice, the dosage was between 20-23 mg/kg. 

Among high dose male mice, a body weight reduction of 5-8% compared to the controlled 

was observed. Body weight reduction of high dose female mice compared to the controlled 

was reported as 5-7%. However, the survival rate among the mice was not significantly 

differed whether they were exposed or not exposed to chlorinated water. 

Possibilities of chronic oral exposure of mammals are very low in the BWMS, especially 

because of the neutralization of treated water prior to discharge. 

3.1.2.4 Developmental and reproductive toxicity 

A series of studies on developmental/reproductive toxicity of the Active Substances was 

reported (U.S. Department of Health and Human Services, 1992). Female Sprague-Dawley rats 

were exposed to HOCl through drinking water. The concentrations were 0, 1, 10, or 100 mg/L 

and the duration was 2.5 months prior to conception and throughout gestation. On the 20th day 

of gestation, the rats were killed. The foetuses were examined for soft tissue and skeletal 

abnormalities. No increase in foetal resorptions was observed. HOCl exposure in utero 

produced some soft-tissue defects, such as improper orientation of the heart and adrenal 

agenesis, if the HOCl concentration was 100 mg/L. A slight increment in skeletal variants, 

such as incompletely ossified or missing sternebrae or rudimentary ribs was observed 

(Abdel-Rahman et al., 1982). 

Carlton et al. (1986) studied the teratogenic and reproductive toxicity of HOCl (NaOCl). Male 

Long Evans rats and female rats were investigated at doses of 0, 1, 2 or 5 mg/kg body weight 

by gavage. Male rats were exposed for 56 days prior to breeding and throughout the 10-day 

breeding cycle while the female rats were exposed for 14 days prior to breeding and 

throughout breeding, gestation, and lactation, until the pups were weaned on the 21st day. 
MEPC 61/2/12 

Annex, page 11 

I:\MEPC\61\2-12.doc 

It was reported that no changes in sperm count, sperm motility, or sperm morphology were 

found or no dose-related effects on fertility, fetal viability, litter size, day of eye opening, and 

day of vaginal patency were observed. Other studies reported in the literatures on effects of 

chlorinated drinking water on fetal development in mice found no evidence for a teratologic 

effect due to the intake of chlorinated drinking water (Chernoff et al., 1979; Kavlock et al., 1979; 

Staples et al., 1979). 

The concentration of free active chlorine in this application is controlled at < 12 mg/L and the 

chlorine is removed by neutralization prior to the discharge of ballast water. The operations 

are conducted in sealed reactor and tanks. Living animals and organisms unlikely stay in the 

ballast water environment. Thus, the developmental and reproductive toxicity can be negligible. 

3.1.2.5 Carcinogenicity 

HOCl/OCl-

 or NaOCl is not listed as a known or probable human carcinogen by the American 

Cancer Society (accessed on 07-02-2010). However, there are some studies of 

carcinogenicity on animals (e.g., mice and rats) (e.g., U.S. Department of Health and Human 

Services, 1992). In the studies by Kurokawa et al. (1986) and Hasegawa et al. (1986), 

female mice and male rats were exposed (oral) to 1000 mg/L and 200 mg/L of NaOCl, 

respectively, for 103-104 weeks. No dose-related increment in tumour was found. 

In addition, a 2-year study conducted by the NTP did not found any evidence of carcinogenic 

activity of chlorinated water (70-275 mg/L) on male or female mice. 

Due to lower concentration of the free Active Substances in the operation in this application 

and the neutralization, the carcinogenicity is not expected. 

3.1.2.6 Mutagenicity 

Mutagenic activities of HOCl/OCl-

 (NaOCl) on mammals are not well reported in the 

literatures. Hayashi et al. (1988) conducted a study on mutagenicity of NaOCl by mice. The 

mice were exposed to NaOCl (6.6%, 312.5-2,500 mg/kg) through a single intraperitoneal 

injection. No noteworthy increment in the frequency of micronucleated polychromatic 

erythrocytes in the bone marrow (sampled 24 hours after treatment) of male tidY mice was 

identified. Meier et al. (1985) conducted a study on mutagenicity of NaOCl. Chromosome 

aberrations or micronuclei in CD-1 mice or sperm-head abnormalities in B6C3F1 mice were 

investigated. The chemical was administered by gavage. Both acute (single dose) and 

subchronic (5 successive dosings at 24-hour intervals) protocols were employed. It was found 

that the treatment did not induce micronuclei or aberrations, but did produce a significant 

dose related increase in sperm-head abnormalities in samples collected 3 weeks after the 

final subchronic dose. However, no increments were found 1 or 5 weeks after final dosing. 

Due to lower concentration of the free Active Substances in the operation in this application 

and the neutralization, the mutagenicity is not expected. 

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

(G9: 4.2.1.3) 

3.1.3.1 Modes of degradation (biotic/abiotic) 

Biotic degradation is not expected since it has very high oxidation potential. Abiotic 

degradation of free active chlorine is possible and the routes are discussed as follows: 

.1 The degradation of HOCl/OCl-

 (NaOCl) is affected by several factors such as 

the initial concentration, temperature, pH, light, the presence of other substances 
MEPC 61/2/12 

Annex, page 12 

I:\MEPC\61\2-12.doc 

(mainly organic contaminants), and physical factors (e.g., mixing/stirring 

strength). The degradation rate/kinetics is higher at a higher initial 

concentration. Higher temperature will enhance the rate of degradation. 

.2 In addition, the NaOCl is unstable if the pH value is lower than 11. 

The degradation of NaOCl due to light becomes faster due to photolysis; 

it becomes much faster in UV light radiation. It is worthy to note that in 

fresh water or seawater environment, pH of the solution is around 7-8. 

Under these conditions most of the free active chlorine exists as OCl-

. 

At the maximum sunlight intensity of 330 nm, OCl-

 has a molar absorptivity 

of 15 times greater than HOCl. Thus, the degradation of free active 

chlorine due to photolysis can be extremely high. Apart from the above 

factors, the composition of the chlorinated solution affects the rate of 

degradation. For instant, high organic and inorganic content may increase 

the rate of degradation due to the oxidation reactions. Degradation of 

HOCl (NaOCl) may result in a range of by-products which may be harmful 

depending on the concentration (e.g., trihalomethanes and haloacetic acids). 

Chlorine can react with ammonium in water to form NCl3, NHCl2, and NH2Cl, 

which are also disinfectants. However, the chance of the occurrence is 

very low as the concentration of ammonium in coastal area is negligible. 

.3 The decay kinetics of chlorine in clean and contaminated seawater is given in 

the confidential supporting information "SI-Chlorine decay in the ballast water". 

The decay is faster when the seawater is contaminated (like ballast water). 

3.1.3.2 Bioaccumulation, partition coefficient, octanol/water coefficient 

The logPow and BCF of HOCl/OCl- (NaOCl) are -3.42 and -2.19 L/kg, respectively. 

As logPow < 3 and BCF < 2000, no bioaccumulation of NOCl is expected. Koc, the organic 

carbon partition coefficient is a measure of the tendency for a substance to be adsorbed to 

organic materials in soil, in sediment, or in biological tissues. Koc of HOCl (NaOCl) 

is 14.3 L/kg. The value of Koc is <500 L/kg and, thus HOCl will not readily partition in to 

soil/sediment of the receiving environment and no significant sediment toxicity is expected. 

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

(Ballast water, marine and fresh water) 

Due to the rapid degradation, free active chlorine is not considered to be persistent in ballast 

water, marine or fresh water. Furthermore, due to the low logPow, and BCF values, free 

active chlorine will not tend to be bioaccumulated in the aquatic life and metabolites. 

3.1.3.4 Reaction with organic matter 

HOCl/OCl- (NaOCl) can react with organic matter and produce secondary by-products. 

Trihalomethanes and haloacetic acids are important by-products as a result of reactions. 

They may be toxic to various living organisms in the receiving environments. Thus it is 

important to experimentally determine the concentrations of the disinfection by-products and 

study the toxicity of treated ballast water. 

3.1.3.5 Potential physical effects on wildlife and benthic habitats 

No reports are found in the literatures on the physical effects on wildlife and benthic habitat. 

However, based on the acute and chronic toxicity related data previously discussed and the 

toxicity study of our treated ballast water, the physical effects are expected to be negligible 

because the treated water is neutralized (i.e. remove HOCl (NaOCl)) prior to discharge in the 

operation of the technology in this application. 
MEPC 61/2/12 

Annex, page 13 

I:\MEPC\61\2-12.doc 

3.1.3.6 Potential residues in seafood 

According to the physical and chemical properties of the Active Substances given and 

discussed above, no residues are expected in seafood due to free active chlorine. 

3.1.3.7 Any known interactive effects 

No other interactive effects are expected. 

3.1.4 Physical/chemical properties of HOCl/OCl-

 (G9: 4.2.1.4) 

Physical/chemical properties of HOCl/OCl-

 are given in Table 3-5. 

3.1.5 Other details of the Active Substance 

Synonyms: Bleach; hypochlorous acid, sodium salt; soda bleach 

CAS No.: 7681-52-9 

Molecular Weight: 74.44 

Chemical Formula: NaOCl 

(MSDS, JT Baker, 2009) 

3.1.6 Analytical method (G9: 4.2.1.5) 

The measurement is conducted according to "Standard Method for the Examination of Water 

and Wastewater" (APHA, 2005). 

3.2 Hypobromous acid/Hypobromite ion (G9: 4.2.1) 

3.2.1 Data on effects on aquatic organisms (G9: 4.2.1.1) 

3.2.1.1 Acute aquatic toxicity 

No data were found for the acute aquatic toxicity of hypobromous acid/hypobromite. 

However, due to its oxidizing properties, acute aquatic toxicity is expected from these agents. 

3.2.1.2 Chronic aquatic toxicity 

No information on the chronic aquatic toxicity of hypobromous acid/hypobromite ion was 

found in the literature. However, due to its oxidizing properties, chronic aquatic toxicity is 

expected from these agents. 

3.2.1.3 Endocrine disruption 

No information on the endocrine disruption of hypobromous acid/hypobromite ion was found 

in the literature, indicating hypobromous acid/hypobromite ion might not have any endocrine 

effects on aquatic organisms. Their short half-lives present an extremely low risk. 

3.2.1.4 Sediment toxicity 

The organic carbon partition coefficient (Koc) of hypobromous acid/hypobromite ion is 14.3 L/kg. 

As the value of Koc is quite small (less than 500 L/kg), the hypobromous acid/hypobromite ion 

will not easily be adsorbed onto the sediment of the receiving environment. As a result, the 

adsorption of hypobromite ion is quite unlikely. It can therefore be concluded that the 

hypobromite ion will not cause an increase in the toxicity of the sediment. 
MEPC 61/2/12 

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3.2.1.5 Bioavailability/biomagnifications/bioconcentration 

The logPoctanol/water (logPow) and bioconcentration factor of hypobromous acid/hypobromite ion 

are reported as -1.03 and 1.24 L/kg, respectively. According to section 6.4.1 of Procedure (G9) 

(MEPC 57/21), the bioaccumulation potential is needed to be analysed if the logPow is larger 

than 3 or if BCF > 2000. Thus, it is clear that the potential of bioaccumulation/bioconcentration 

is negligible for hypobromous acid/hypobromite ion. 

3.2.1.6 Food web/population effects 

Hypobromous acid/hypobromite ion is not expected to be bioaccumulated in the food chain, 

since the value of Log Pow and BCF are very low. On the other hand, their short half-lives 

present an extremely low risk of such. 

3.2.2 Data on mammalian toxicity (G9: 4.2.1.2) 

3.2.2.1 Acute mammalian toxicity 

No data on the acute mammalian toxicity was found in the literature. 

3.2.2.2 Effects on skin and eye 

No information on the effects on mammalian's skin and eye was found in the literature.

3.2.2.3 Chronic and long-term toxicity 

No information on the chronic and long-term mammalian toxicity of hypobromous 

acid/hypobromite ion was found in the literature.

3.2.2.4 Developmental and reproductive toxicity 

No information on the developmental and reproductive toxicity was found in the literature. 

3.2.2.5 Carcinogenicity 

No data on the carcinogenicity was found in the literature. 

3.2.2.6 Mutagenicity/genotoxicity 

No data on the mutagenicity/genotoxicity was found in the literature. 

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

(G9: 4.2.1.3) 

3.2.3.1 Modes of degradation (biotic; abiotic) 

No data on the modes of degradation (biotic and abiotic) is found in the literature. 

3.2.3.2 Bioaccumulation, partition coefficient, octanol/water partition coefficient 

The octanol/water partition coefficient (log Pow), bioaccumulation factor, and the Koc for the 

hypobromous acid/hypobromite ion are -1.03, 1.24, and 14.3, respectively. 
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Annex, page 15 

I:\MEPC\61\2-12.doc 

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

(ballast water, marine and fresh waters) 

It is unlikely that it can be accumulated through the aquatic organisms and metabolites due 

to the low Pow and BCF values. 

3.2.3.4 Reaction with organic matter 

No available information on reaction with organic matter is available in the literature. 

3.2.3.5 Potential physical effects on wildlife and benthic habitats 

No potential effects are indicated in the literature. 

3.2.3.6 Potential residues in seafood 

No potential residues are indicated in the literature. 

3.2.3.7 Any known interactive effects 

No known interactive effects are indicated in the literature. 

3.2.4 Physical and chemical properties for the Active Substances, Relevant 

Chemicals and treated ballast water (G9: 4.2.1.4) 

Physical and chemical properties of hypobromous acid are shown in Table 3-7. 

3.2.5 Other details of the Relevant Chemical 

Synonyms: hypobromous acid 

CAS No.: 13517-11-8 

Molecular Weight: 96.911 

Chemical Formula: HOBr 

http://www.caslab.com/Hypobromous_acid_CAS_13517-11-8/

3.3 Hydroxyl radical (G9: 4.2.1) 

Hydroxyl radical is considered as an Active Substance according to the definition in 

Procedure (G9). It is generated according to the mechanisms previously discussed. 

3.3.1 Data on effects on aquatic plants, invertebrates, fish, and other biota, 

including sensitive and representative organisms (G9: 4.2.1.1) 

Toxicity tests carried out to evaluate acute toxicity, chronic toxicity, endocrine disruption, 

sediment toxicity, bioaccumulation, and food web/population effects on aquatic life due to 

OHï are not available in the literatures, due to the extremely short lifespan of the OHï. 

Although it is highly reactive (oxidation potential of 2.8 V) and able to damage aquatic life at 

the point of generation, the lifespan of nanoseconds prevents any negative effect of OHï on 

the aquatic life in discharging environment. 
MEPC 61/2/12 

Annex, page 16 

I:\MEPC\61\2-12.doc 

3.3.2 Data on Mammalian Toxicity (G9: 4.2.1.2) 

The OHï considered as the mediator of the DNA damage due to ionizing radiation 

(Balasubramanian et al., 1998; Chen et al., 2005). In addition, OHï plays an important role in 

the photolysis of human erythrocytes sensitized by the photosensitization with protoporphyrin IX 

and ketoporfen (El-Missiry and Abou-Seif, 2000). However, the electro-disinfection 

technology in this application does not allow any contact between the produced OHï (only 

inside the reactor) and human/mammalian under any circumstances. Thus, no adverse 

effect is expected on human/mammalian due to the production of OHï inside the 

electro-disinfection reactor. 

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

(G9: 4.2.1.3) 

The OHï is known as the "detergent of troposphere" due to its high reactivity with many 

pollutants. The OHï generated in the BWMS in this application does not reach the 

discharging environment due to the neutralization operation. Because of the short lifespan of 

OHï, the bioaccumulation does not occur and the substance is not persistent. The OHï does 

not cause any effect on the wildlife and benthic habitats or leaves no residues in seafood. 

OHï can react with organic and inorganic matters in ballast water. Thus, there is a possibility 

of generation of DBPs (Xie, 2004; Lui et al., 2008). It is difficult to differentiate the DPBs 

produced due to the production of free active chlorine, O3 or OHï because of the simultaneous 

generation of free active chlorine and OHï in the proposed reactor system. The analysis of 

DBPs in the discharging ballast water treated using the technology in this application is 

presented in a latter part of this application dossier ("SI-list of experimental details"). 

3.3.4 Physical/chemical properties of OHï (G9: 4.2.1.4) 

Physical properties: To the best of our knowledge, not available in literature. 

Chemical properties: Hydroxyl radical (OHï) is extremely reactive (oxidation potential of 2.8 V). 

Thus, it does not exist for more than few collisions after it forms in the electro-disinfection 

reactor. Lifespan of OHï is in the range of nanoseconds. Therefore, the OHï reacts only in 

the very close proximity to the electrode which it is produced (Bielski and Cabelli, 1995). 

3.3.5 Other details of the Active Substance 

Synonyms: OH; Hydroxy radical; Hydroxyl 

CAS No.: 3352-57-6

Molecular Weight: 17.0073 

Chemical Formula: HO 

3.3.6 Analytical method (G9: 4.2.1.5) 

The measurement is conducted by using radical scavengers such as iso-propanol. 

3.4 Ozone (G9: 4.2.1) 

3.4.1 Effects on aquatic plants, invertebrates, fish, and other biota, including 

sensitive and representative organisms (G9: 4.2.1.1) 

A zero concentration of ozone was found in ballast water, immediately after the treatment 

("SI-list of experiment details"). Ozone decomposes within a very short period of time 

(in several minutes) and thus, no ozone was found in the discharging ballast water. 
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3.4.1.1 Acute aquatic toxicity 

The data related to the acute aquatic toxicity of ozone is shown in Table 3-8. Since the 

technology proposed in this application does not discharge any ozone to the receiving 

environment, acute aquatic toxicity due to ozone is highly unlikely to occur. 

3.4.1.2 Chronic aquatic toxicity 

The data related to chronic aquatic toxicity are not found in literature. The ozone in the 

treated water is not expected as: 1. the water is neutralized; 2. the decay of ozone is rapid. 

3.4.1.3 Endocrine disruption 

Ozone is not listed as an endocrine disruptor under any of the following lists (Pesticide Action 

Network (PAN), 2010): Illinois EPA list, Keith list, Colborn list, Benbrook list, Danish Inert list, 

and EU list. Thus, ozone may not have any endocrine effects. 

3.4.1.4 Sediment toxicity 

Due to the fast decomposition of ozone in natural waters, no sediment toxicity is expected. 

Literature related to sediment toxicity of ozone was not found. 

3.4.1.5 Bioavailability/bioaccumulation/bioconcentration 

Fast decomposition of ozone in natural waters may not allow any bioaccumulation of ozone. 

3.4.1.6 Food web/population effects 

The above discussion reveals that ozone does not concentrate in organisms or in sediments. 

Therefore, ozone may not affect the food web. 

3.4.2 Data on Mammalian Toxicity (G9: 4.2.1.2) 

3.4.2.1 Acute toxicity 

Ozone is toxic to the lung. The effects such as pulmonary congestion, and edema can occur 

if exposed to ozone. Human volunteers exposed at 0.5 ppm, 3 h/d, 6 d/week, for 12 weeks 

showed changes in lung function (HSDB). However, due to the very low concentrations 

generate in the proposed technology, no gaseous ozone is expected. 

3.4.2.2 Effects on skin and eye 

Skin contact 

If liquid ozone contacts skin, severe burns may occur (HSDB). The very low concentration which 

may generate in the current system does not pose such toxicity to the skin. 

Eye Contact 

Ozone gas may create eye irritation (MSDS- BOC gases). Such toxicity is not expected due 

to the very low concentration which may generate in the current system. 
MEPC 61/2/12 

Annex, page 18 

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3.4.2.3 Chronic and long-term toxicity 

Immunosuppression occurs in mice and pigs at exposure at low levels of ozone, but not 

humans. If exposed to ozone concentration > 1 ppm (6 h/d) for 1 year, bronchiolitis and 

bronchitis in animals is reported (MSDS- BOC gases). 

3.4.2.4 Developmental and reproductive toxicity 

According to the PAN pesticide database, ozone is not listed as a developmental or 

reproductive toxin in the following list: CA Prop 65 Developmental toxin; US TRI Developmental 

toxin, CA Prop 65 Female Reproductive toxin, and CA Prop 65 Male Reproductive toxin. 

However, ozone is listed as a reproductive toxin under US TRI Reproductive Toxins list. 

3.4.2.5 Carcinogenicity 

Ozone is not classifiable as a human carcinogen (HSDB). 

3.4.2.6 Mutagenicity 

Ozone is not reported as a mutagen (MSDS- BOC gases). 

3.4.3 Data on environmental fate and effect under aerobic and anaerobic 

conditions(G9: 4.2.1.3) 

Ozone which may be generated in the BWMS in this application does not reach the 

discharging environment. Our experimental testing shows that the concentration is negligible 

(zero concentration). Ozone is highly reactive and thus may create DBPs in the ballast tank. 

Bromate is the predominant DBP produced due to ozone. However, the bromate 

concentration in discharging ballast water was found extremely low ("SI-list of experimental 

details" and "Laboratory reports"). This suggests that the amount of ozone produced at the 

reactor can be extremely low as well. Because of the short lifespan of ozone, it does not 

create bioaccumulation and is not persistent. For the same reason, produced ozone does 

not cause any effect on the wildlife and benthic habitats or leaves no residues in seafood. 

3.4.4 Physical/chemical properties of ozone (G9: 4.2.1.4) 

Physical/chemical properties of ozone are illustrated in Table 3-9. 

3.4.5 Other details of the Active Substance 

Synonyms: Triatomic oxygen 

CAS No.: 10028-15-6

Molecular Weight: 48.00 

Chemical Formula: O3

3.4.6 Analytical method (G9: 4.2.1.5) 

The measurement is conducted according to "Standard Method for the Examination of Water 

and Wastewater" (APHA, 2005). 

3.5 Sodium thiosulfate 

Sodium thiosulfate is used to remove residual oxidant when necessary during the deballasting. 

It is not considered as an Active Substance according to the definition in Procedure (G9). 
MEPC 61/2/12 

Annex, page 19 

I:\MEPC\61\2-12.doc 

3.5.1 Data on effects on aquatic organisms 

3.5.1.1 Acute aquatic toxicity 

The data related to the acute aquatic toxicity are shown in Table 3-10. 

3.5.1.2 Chronic aquatic toxicity 

The data related to the chronic aquatic toxicity o are shown in Table 3-11. 

3.5.1.3 Endocrine disruption 

No information on the endocrine disruption was found in the literature, indicating sodium 

thiosulfate might not have any endocrine effects on aquatic organisms. 

3.5.1.4 Sediment toxicity 

No information on the sediment toxicity can be found in the literatures. 

3.5.1.5 Bioavailability/biomagnifications/bioconcentration 

The logPoctanol/water (logPow) and bioconcentration factor of Na2S2O3 are reported as -4.53 

and 3.162 L/kg, respectively. According to section 6.4.1 of Procedure (G9), the 

bioaccumulation potential is needed to be analysed if the logPow is more than or equal to3 or 

if BCF > 2000. Thus, it is clear that the potential of bioaccumulation/bioconcentration is 

negligible for free active Na2S2O3. 

3.5.1.6 Food web/population effects 

Sodium thiosulfate is not expected to bioaccumulate in the food chain, since the value 

of Log Pow and BCF are very low. 

3.5.2 Data on mammalian toxicity 

3.5.2.1 Acute mammalian toxicity 

Oral LD50 of >5050 mg/kg was reported for rats (EPA Federal Register, Sodium 

thiosulfate, 2001). 

3.5.2.2 Effects on skin, eye, and sensitization effects 

Skin: May cause skin irritation 

Eye: May cause eye irritation and possible burns 

Sensitization: May cause respiratory tract irritation. 

(MSDS, Sigma-Aldrich, 2009) 

3.5.2.3 Repeated-dose toxicity 

No data on the repeated-dose toxicity of sodium thiosulfate is found in the literature 

(MSDS Sigma-Aldrich, 2009). 

3.5.2.4 Chronic toxicity 

No data on the chronic toxicity of sodium thiosulfate is found in the literature. 
MEPC 61/2/12 

Annex, page 20 

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3.5.2.5 Developmental and reproductive toxicity 

Oral exposure did not show any effect on maternal or foetal survival, or in incidences of 

visceral or skeletal abnormalities in mouse (EPA Federal Register, Sodium thiosulfate, 2001). 

3.5.2.6 Carcinogenicity 

No data on the carcinogenicity of sodium thiosulfate is found in the literature. 

3.5.2.7 Mutagenicity/genotoxicity 

Sodium thiosulfate has no mutagenic effects (EPA Federal Register, 2001). 

3.5.2.8 Toxicokinetics 

Sodium thiosulfate is poorly absorbed from bowel and thiosulfate ion distributes itself in 

extracellular fluid (HSDB, 2009). 

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

3.5.3.1 Modes of degradation (biotic; abiotic) 

No data on the modes of degradation (biotic and abiotic) is found in the literature. 

3.5.3.2 Bioaccumulation, partition coefficient, octanol/water partition coefficient 

The octanol/water partition coefficient (log Pow), bioaccumulation factor, and the Koc for the 

sodium thiosulfate are -4.53, 3.162, and 6.124, respectively. 

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

(ballast water, marine and fresh waters) 

It is unlikely that it can be accumulated through the aquatic organisms and metabolites due 

to the low Pow and BCF values. 

3.5.3.4 Reaction with organic matter 

No available information on reaction with organic matter is available in the literature. 

3.5.3.5 Potential physical effects on wildlife and benthic habitats 

No potential effects are indicated in the literature. 

3.5.3.6 Potential residues in seafood 

No potential residues are indicated in the literature. 

3.5.3.7 Any known interactive effects 

No known interactive effects are indicated in the literature. 

3.5.4 Physical and chemical properties 

The physical and chemical properties of sodium thiosulfate can be found in Table 3-12. 
MEPC 61/2/12 

Annex, page 21 

I:\MEPC\61\2-12.doc 

3.5.5 Other details of the Relevant Chemical 

Synonyms: Sodium thiosulfate, pentahydrate; thiosulfuric acid, disodium salt, 

pentahydrate 

CAS No.: 10102-17-7 (Pentahydrate) 

Molecular Weight: 248.17 

Chemical Formula: Na2S2O3.5H2O 

3.5.6 Analytical method 

The concentration is measured by an IC method (IPC-TM-650.2.3.28A). 

Table 3-1: Data related to the acute aquatic toxicity (free active chlorine) 

Species Explanation Reference 

Blackbrow bleak 

(Acanthalburnus 

microlepis De Filippi,

1863) 

96 h, LC50 = 0.6343 mg/L 

(In fresh water, Using 

Finney's method and SPSS 

software) 

Aksu et al., 2008 

Estuarine fish, Oryzias 

javanicus 96 h, LC50 = 0.19 mg/L AÒasco et al., 2008 

Fish 

Cyprinus carpio 72 h, NOEC (Genetics) 

= 50 μg/L 

PAN pesticide 

database 

Resting eggs of the 

fresh water cladoceran 

Daphnia mendotae

Acute toxicity 

LC90 = 78.3±1.6 mg/L Raikow et al., 2007 

Resting eggs of marine 

brine shrimp (Artemia sp.)

Acute toxicity 

LC90 = 86.5±3 mg/L Raikow et al., 2007 

Marine Amphipod, Hyale 

barbicornis 

96 h, LC50 = 2.2 mg/L, 

EC50 = 1.1 mg/L AÒasco et al., 2008 

Heptacarpus pictus 20 h, LC100 = 1600μg/L PAN pesticide 

database 

Invertebrate 

Asellus intermedius 96 h, LC50 = 32000μg/L PAN pesticide 

database 

Dunaliella primolecta 24 h, LC50 = 0.4 ppm Videau et al.,1979 

Pavlova Iutheri 24h, LC50 = 3.5-4.0 ppm Videau et al., 1979 

Phaeodactylum 

tricornutum 

24h, No mortality at 0.6 ppm 

but growth is stopped/slower 

down. 0.8 ppm, total mortality 

Videau et al., 1979 

Green algae 

(Dunaliella primolecta) LC50 = 400μg/L PAN pesticide 

database 

Phytoplankton 

Chaetoceros decipiens 24 h, EC50 = 140μg/L PAN pesticide 

database 
MEPC 61/2/12 

Annex, page 22 

I:\MEPC\61\2-12.doc 

Table 3-2: Data related to the chronic aquatic toxicity (free active chlorine) 

Species Explanation Reference 

Estuarine fish, 

Oryzias javanicus, 

early life stage 

Eggs exposed for14 d and the 

fish larvae hatched from 

exposed eggs again exposed 

for another 21 d, 1 mg/L. 

No major adverse effects 

AÒasco et al., 2008 

Cyprinus carpio 30 d, NOEC (Genetics) 

= 100 μg/L 

PAN pesticide 

database 

Fish 

Menidia beryllina 7 d, NOEC (Growth) = 87μg/L PAN pesticide 

database 

Marine Amphipod, 

Hyale barbicornis, 

early life stage 

12 d, 1 mg/L. 

No major adverse effects AÒasco et al., 2008 

7 mm 1 mg/L, 100% mortality in 20 d. 

(shell 

length) 5 mg/L, 100% mortality in 102 h. 

1 mg/L, 100% mortality in 24 d. 

Invertebrates 

Brachidontes 

striatulus 25 mm 

(shell 

length) 5 mg/L, 100% mortality in 156 h. 

Rajagopal et al., 

1997 

Phytoplankton 20 d, about 40-50% reduction in 

cell density at 0.001-0.25 mg/L Sanders et al., 1981

Phytoplankton 

Porphyra yezoensis 10 d, EC50 = 1400μg/L PAN pesticide 

database 

Table 3-3: Criteria for identification of persistent, bioaccumulative 

and toxic (PBT) substances 

Criterion PBT criteria 

Persistence 

Half-life: 

> 60 days in marine water, or 

> 40 days in fresh water, or 

> 180 days in marine sediments, or 

> 120 days in fresh water sediments 

Bioaccumulation Experimentally determined BCF >2000, or if no experimentally BCF 

has been determined, LogPow ≥ 3 

Toxicity Chronic NOEC < 0.01 mg/l 

Table 3-4: Values of LD50 of rat/mouse through oral exposure to NaOCl+ 

Species LD50 Remarks 

Rat >5000 mg/kg bw** Liquid bleach containing NaOCl, 4.74% available chlorine

Rat 8200 mg/kg bw NaOCl, 12.5% active chlorine 

Mouse 880 mg/kg bw NaOCl 

Mouse 5800-6800 mg/kg bw NaOCl, 50% 

** bw: body weight. + European Chemicals Bureau, 2000. 
MEPC 61/2/12 

Annex, page 23 

I:\MEPC\61\2-12.doc 

Table 3-5: Physical/chemical properties of HOCl/OClProperty Value Reference 

Melting point -6°C MSDS, JT Baker, 2009 

Boiling point 103.9°C (6% NaOCl) MSDS, Horizon Chemical Co., Inc, 2004 

Flammability NFPA rating= 0 MSDS, Siemens water technology, 2000 

Relative density 1.2 - 1.25 g/cm3 MSDS, Sigma-Aldrich, 2009 

Vapour pressure 17.5 mmHg at 20°C MSDS, Sigma-Aldrich, 2009 

Vapour density N/A 

Water solubility Miscible MSDS, Sigma-Aldrich, 2009 

Dissociation 

constant (pKa) 7.49 at 25°C Stumm and Morgan, 1994 

Oxidation-reduction 

potential 0.9 volts Stumm and Morgan, 1994 

Corrosivity to the 

materials or 

equipment of normal 

ship construction 

Corrosive MSDS, Sigma-Aldrich, 2009 

Auto-ignition 

temperature N/A 

Explosive properties 

If heated, decomposition 

products may cause 

containers to rupture or 

explode 

MSDS, Siemens water technology, 2000 

Oxidizing properties Strong oxidant MSDS, Siemens water technology, 2000 

Reactivity 

Reacts violently with 

combustible and reducing 

materials 

MSDS, Siemens water technology, 2000 

pH in solution 12.31 (6% NaOCl) MSDS, Horizon Chemical Co., Inc, 2004 

Colour Clear yellow MSDS, Horizon Chemical Co., Inc, 2004 

Odour Pungent Chlorine order MSDS, Horizon Chemical Co., Inc, 2004 

Table 3-6: Data related to the aquatic toxicity (HOBr/OBrSpecies LC50 (mg/L) Reference 

Fish No information was found in major database, but toxicity is expected. 

Invertebrate No information was found in major database, but toxicity is expected. 

Algae No information was found in major database, but toxicity is expected. 
MEPC 61/2/12 

Annex, page 24 

I:\MEPC\61\2-12.doc 

Table 3-7: Physical and chemical properties of Hypobromous acid 

Property Value Reference 

Melting point (°C) N.A 

Boiling point (°C) N.A. 

Flammability (flash point for liquids; °C) Not flammable 

Density (20°C; kg/m3) Not located 

Vapour pressure (20°C; Pa) 3.06×10-13 mmHg 

Vapour density (air = 1) N/A 

Water solubility 1×106

 mg/L (25oC) 

pH in solution Less than 7 

Dissociation constant (pKa) 8.14 Chekanov, et al., 2007 

Oxidation-reduction potential N.A. 

Corrosivity to material or equipment N.A. 

Reactivity to container material N.A. 

Auto-ignition temperature (°C) N.A. 

Explosive properties N.A. 

Oxidizing properties Oxidizing agent 

Surface tension N.A. 

Viscosity N.A. 

Thermal stability and identity of 

breakdown products 

N.A. 

Other physical or chemical properties N.A. 

Table 3-8: Data related to the acute aquatic toxicity (ozone) 

Species Explanation Reference 

Channel catfish, 

Ictalurus punctatus 96 h, LC50 = 30 μg/L PAN pesticide 

database 

White perch, 

Morone americana 

24 h, LC50 (mean) = 380 μg/L 

48 h, LC50 (mean) = 260 μg/L 

96 h, LC50 (mean) = 200 μg/L 

PAN pesticide 

database Fish 

Striped bass (Larvae),

Morone saxatilis

24 h, LC50 (mean) = 110 μg/L 

48 h, LC50 (mean) = 90 μg/L 

PAN pesticide 

database 

Invertebrates 

Zebra mussel, 

Dreissena 

polymorpha

0.25 h, LT50 (min) = 360 μg/L 

23.9 h, LT95 (min) = 530 μg/L 

PAN pesticide 

database 

Phytoplankton No record found 
MEPC 61/2/12 

Annex, page 25 

I:\MEPC\61\2-12.doc 

Table 3-9: Physical/chemical properties of ozone 

Property Value Reference 

Melting point -192.7 ± 2°C HSDB 

Boiling point -111.9 0

C HSDB 

Flammability Not flammable (NFPA hazard code= 0) MSDS- BOC gases 

Density Liquid: 1.614 g/L at -195.4°C HSDB 

Vapour pressure > 1atm at 100°F MSDS- BOC gases 

Vapour density 2.144 g/l at 0°C MSDS- BOC gases 

Water solubility 0.001% at 32°F MSDS- BOC gases 

Dissociation constant 

(pKa) Not available 

Oxidation-reduction 

potential > 2700 mV http://www.o3center.org

(Web site of O3 centre) 

Corrosivity to the 

materials or 

equipment of normal 

ship construction 

Can be corrosive due to oxidation 

properties. However, fast decomposition 

does not allow ozone to affect the ship 

structure 

- 

Auto-ignition 

temperature Not available 

Explosive properties Pure solid or liquid is highly explosive HSDB 

Oxidizing properties Strong oxidant HSDB 

Reactivity Reactive with All oxidizable materials HSDB 

pH in solution Not available 

Colour Colourless gas, dark blue liquid, blue-black 

crystals HSDB 

Odour Characteristic pungent odour in 

concentrations < 2 ppm HSDB 

Table 3-10: Data related to the acute aquatic toxicity (Sodium thiosulfate) 

Species LC50/EC50 Reference 

Gambusia affinis

(fresh water) 24000 mg/L/96hour ECB, IUCLID, 2000 

Fish 

Pimephales promelas

(fresh water) 10000 mg/L/96hour Terhaar et al., 1972 

Invertebrates Spirostomum ambiguum 

(fresh water) 1710 mg/L/24hour Nalecz-Jawecki and Sawicki, 1998 

Ankistrodesmus falcatus 

(fresh water) 64 mg/L/1hour Wodzinski R.S. et al., 1978 Algae Chlamydomonas 

reinhardtii (fresh water) 64 mg/L/1hour Wodzinski R.S. et al., 

1978 
MEPC 61/2/12 

Annex, page 26 

I:\MEPC\61\2-12.doc 

Table 3-11: Data related to the chronic aquatic toxicity (Sodium thiosulfate) 

Species LC50/EC50 Reference 

Fish Oncorhynchus 

mykiss 600 mg/L/18 month/no mortality ECB, IUCLID, 2000 

Invertebrates No data found in literature 

Algae No data found in literature 

Table 3-12: Physical and chemical properties of Sodium thiosulfate 

Property Value Reference 

Melting point (°C) 48 MSDS, Sigma-Aldrich,2009 

Boiling point (°C) 100 MSDS, Sigma-Aldrich,2009 

Flammability (flash point for 

liquids; °C) Non-flammable ECB, IUCLID, 2000 

Density (20 °C; kg/m3) 1740 kg/m3

 ECB, IUCLID, 2000 

Vapour pressure (20 °C; Pa) N/A 

Vapour density (air = 1) N/A 

Water solubility 293 g/l at 0°C 

209 g/l at 20°C 

http://www.atsdr.cdc.gov/MHMI/mmg184.html

pH in solution 7 in 1% solution MSDS, Sigma-Aldrich, 2009 

Dissociation constant (pKa) N/A 

Oxidation-reduction 

potential 

0.303 v Morgan and Stumm, 1994 

Corrosivity to material or 

equipment 

Not 

Reactivity to container 

material 

Not 

Auto-ignition temperature (°C) Not 

Explosive properties Not explosive ECB, IUCLID, 2000 

Oxidizing properties No oxidizing 

properties 

ECB, IUCLID, 2000 

Surface tension N/A 

Viscosity N/A 

Thermal stability and identity 

of breakdown products 

N/A 

Other physical or chemical 

properties 

N/A 

4 TOXICITY ANALYSIS ON DISINFECTION BY-PRODUCTS (G9: 5.2) 

Disinfection by-products (DBPs) are produced during the disinfection as a result of reactions 

between the generated disinfectants and the natural organic matters (NOMs) or inorganic 

substances in ballast water. Three major groups of DBPs are identified as potential 

compounds generated during the operation of electro-disinfection in this application: 
MEPC 61/2/12 

Annex, page 27 

I:\MEPC\61\2-12.doc 

.1 Trihalomethanes (THMs); 

.2 Haloacetic acids (HAAs); and 

.3 Bromate (BrO3

-

). 

The above compounds are regulated by various organizations (e.g., the United States 

Environmental Protection Agency (USEPA) and the World Health Organization (WHO)) for 

drinking water. The regulated values are shown in Table 4-1. 

The above compounds may pose threats to the receiving environment, especially if the 

concentrations in discharging ballast water after treatment are considerably high. This 

section reviews the reported literature to understand the toxicity. The quantification of DBPs 

in the treated water was conducted and provided in this application (confidential supporting 

information "SI-list of experiment details"). 

4.1 Trihalomethane (THM) 

Aquatic and mammalian toxicity of THMs reported in literature are summarized in Table 4-2. 

According to the table, most of the toxicity effects are related to dose levels that are relatively 

high (e.g., in the range of mg/L or mg/kg). In addition, at a low level of exposure (e.g., in the 

range of μg/L), mode of exposure such as drinking becomes important in toxicity. In the 

electro-disinfection technology in this application, it is found that the level of THMs in 

discharging ballast water is considerably low. These levels are comparable to the drinking 

water standards and thus, the expected toxicity upon discharge is very low. Moreover, the 

effect of dilution at the point of discharge may reduce the concentration available at the 

receiving environment to even a safer level. The toxicity testing of produced ballast water 

using the BWMS in this application further confirms that the water toxicity is less concerned. 

4.2 Haloacetic acids (HAA) 

Aquatic and mammalian toxicity of HAAs reported in the literatures are summarized in 

Table 4-3. 

Table 4-3 shows that HAAs do have risks to the aquatic life as well as to the mammalian life. 

However, the concentrations related to the aquatic and mammalian toxicity in these 

literatures are far above the concentrations found in discharging ballast water treated with 

the technology in this application, as shown in the risk assessment in this document. In 

addition, the effect of dilution at the point of discharge reduces the concentration available at 

the receiving environment to even a safer level. The toxicity testing of produced ballast 

water presented later further confirms the findings. 

4.3 Bromate 

Aquatic and mammalian toxicity of bromate reported in literature are summarized in the 

following table. Table 4-4 shows that bromate may create risks to the aquatic life and to the 

mammalian life. However the effect concentrations and lethal concentrations on aquatic life 

are much higher than the concentration of water from the BWMS in our application (see the 

confidential supporting information "SI-list of experiment details"). Thus, the bromated is not 

an issue in this application. 
MEPC 61/2/12 

Annex, page 28 

I:\MEPC\61\2-12.doc 

Table 4-1: Regulations for the DBPs in drinking water 

Compound 

USEPA standard for drinking 

water (Maximum Contaminant 

Level), mg/L*

WHO standard for drinking 

water, mg/L**

Trihalomethanes 

(THM) 0.08 (total THMs) 

Chloroform: 0.3 

Bromoform: 0.1 

Bromodichloromethane: 0.06 

Dibromochloromethane: 0.1 

Haloacetic acids 

(HAA) 

HAA5 (Monochloroacetic acid, 

Dichloroacetic acid, Trichloroacetic 

acid, Monobromoacetic acid, 

Dibromoacetic acid): 0.06 

Monochloroacetic acid: 0.02 

Dichloroacetic acid: 0.05 

Trichloroacetic acid: 0.2 

Bromate 

(BrO3

-

) 0.01 0.01 (provisional) 

*

 Source: Website of US EPA, http://www.epa.gov/safewater/contaminants/index.html#1, 

Accessed on 23-02-2010. ** Source: Guidelines for Drinking-water Quality, 3rd Edition, World Health Organization, Geneva, 2008. 
I:\MEPC\61\2-12.doc 

Table 4-2: Toxicity analysis of THMs 

Disinfection by-product 

Test or nature of study and species Effect 

Chloroform Leuciscus idus melanotus Carp 2 days, LC100 = 176 mg/L 

Green algae Pseudokirchneriella subcapitata 4 days, EC50 = 38 6000 μg/L Brown shrimp Penaeus aztecus Bromoform 4 days, LC50 = 26 000 μg/L 

Atlantic menhaden Brevoortia tyrannus 4 days, LC50 = 12 000 μg/L 

Chlorodibromomethane Cyprinus carpio LC50; Minimum toxic dose = 31 000 μg/L LC50; Mean toxic dose = 52 000 μg/L THM Risk assessment on swimmers in swimming pool 

Geometric mean concentration of THM in chlorinated swimstudy = 32.9±2.4 μg/L. Risk level from oral ingestion and 

(negligible risk level defined by USEPA). Risk level from 7.77×10−4 ñ 1.36×10−3. Thus, there is a risk from inhalatio

Additional NotesStandard values used in the assessment: Body weight: male = 69.2 kg, female = 56.4 kg, surface a= 1.83 m2, female = 1.58 m2, inhalation rate: 1.0 m3/h, i

swimming frequency: 120 events/year, swimming duratioexposure time: 1.3 h/ event, average life span: 70 years. 

THM 

Cancer-related deaths Species: Human (population size= 5144) 

Cancer-related deaths in Guastalla, northern Italy between drinking water with increased concentrations of THMs during Increment in cancers among males: 1.2% Increment in cancers among females: 1.1% Additional NotesThe THM concentration: (chloroform: 33.1 μg/L immediate

57.1 μg/L 24 h after chlorination. Total THM: 39.7 μg/L im

chlorination, 70.7 μg/L 24 h after chlorination). 

Lifestyle factors such as smoking were not considered. 
MEPC 61/2/12 

Annex, page 30 I:\MEPC\61\2-12.doc 

Disinfection by-product 

Test or nature of study and species Effect 

TCM* BDCM** 

Human health risk assessment Species: Based on human epidemiological data 

Possibility of bladder and colon cancer in males, as well as and asphyxia amongst infants. 

Chloroform Toxicity on mice At a dose of 300 mg/kg (in olive oil by oral gavage), severe 

sound after 24 h. 

BDCM Neurotoxicological evaluation Species used: Rats Dose: 9, 27, and 72 mg/(kg day), through drinking water fo

Outcome: Neurotoxicity may not be a concern 

CDBM*** Toxicity/Carcinogenicity Species: Rats/Mice 

Administered through gavage (in corn oil) for 13 weeks and 13 weeks study: Dose: 0, 15, 30, 60, 125, and 250 mg/kg Observations: Rats: At 250 mg/kg, hepatic and renal toxicity production amortality among both male and female (9/10 were dead) Mice: At 250 mg/kg, hepatic and renal toxicity production (2 years (chronic) study: Dose: Rats ñ 0,40, 80 mg/kg, Mice ñ 0, 100 mg/kg Observations: Rats: Male ñ Survival does not affected by treatment. Body weigdose level. Fatty change and cytoplasmic changes occurrdose levels. Female ñ Survival does not affected by treatment. Fatty chchanges occurred in the liver at both dose levels. Mice: Male ñ Low survival relative to control, Low body weights, 

lesions (nephrosis and hepatocytomegaly), nephrosis. Female ñ Low body weights Non-neoplastic hepatic lesionchange) 
I:\MEPC\61\2-12.doc 

Disinfection by-product 

Test or nature of study and species Effect 

BDCM Toxicity (acute) Species: Female Rats/mice 

Administered for 5 days by gavage. Rats: 75, 150, 300 mg/kg bw/day At 300 mg/kg bw/day, 2/6 rats were dead at day 5. Renal occurred at 300 mg/kg bw/day. BDCM is Hepatotoxic and Mice: 75, 150 mg/kg bw/day. BDCM is weakly Hepatotoxic and nephrotoxic. 

BDCM and chloroform 

Acute renal and hepatic Effects (comparison between chemicals) Species used: Rats 

Oral gavage (single dose), 0.0, 0.75, 1.0, 1.5, 2.0, 3.0 mmo

Both compounds were hepatotoxic at 24 after the administBDCM was significantly elevate the serum hepatotoxicity th

BDCM was more toxic to liver and kidney compared to CH

Notes: * TCM: Trichloromethane; ** BDCM: Bromodichloromethane; *** CDBM: Chlorodibromomethane.
MEPC 61/2/12 

Annex, page 32 I:\MEPC\61\2-12.doc 

Table 4-3: Toxicity analysis of HAAs 

Disinfection by-product 

Test or nature of study Species Effect 

Lemna gibba 7 d, EC50= 8.6 mg/L, Endpoint= plant growth rate Myriophyllum spicatum 4 d, EC50=13.3 mg/L, Endpoint= plant length MCAA1 Toxicity on aquatic life 

Myriophyllum sibiricum 4 d, EC50= 24.3 mg/L, Endpoint= plant length

MCAA: 7 d, EC50= 20.7 mg/L, Endpoint= Growth rate 

Lemna gibba DCAA: 7 d, EC50= 555.2 mg/L, Endpoint= Growth rate 

TCAA: 7 d, EC50= 864.3 mg/L, Endpoint= Growth rate 

MCAA: 14 d, EC50= 10.9 mg/L, Endpoint= Plant length DCAA: 14 d, EC50= 112.5 mg/L, Endpoint= Plant lengt

Myriophyllum spicatum 

TCAA: 14 d, EC50= 140.3 mg/L, Endpoint= Plant leng

MCAA: 14 d, EC50= 8.0 mg/L, Endpoint= Plant length 

MCAA DCAA TCAA3 

Toxicity on aquatic life 

Myriophyllum sibiricum TCAA: 14 d, EC50= 119.9 mg/L, Endpoint= Plant lengt

TCAA Toxicity on aquatic life Myriophyllum spp. 0.05, 0.5, 3, and 10 mg/l of TCAA for 35 days. No biologically significant effects were found and thus T

considerable risk on the species up to 10 mg/L 

Pseudokirchneriella subcapitata 

72 h EC50(Growth) = 16.2 mg/L; 72 h EC50 (Biomass) = 

72 h NOEC(Growth) = 3.00 mg/L; 72 h NOEC (Biomas

TCAA Toxicity to aquatic life Scenedesmus 

subspicatus

72 h EC50 (Growth) = 67.9 mg/L; 72 h EC50 (Biomass) = 

72 h NOEC (Growth) = 3.00 mg/L;72 h NOEC (Biomas

MBAA4

DBAA5 Acute toxicity/ Rats Acute toxicity (gavaged, most deaths within 48 h) MBAA: LC50=177 mg/kg; DBAA: LC50=1737 mg/kg 
I:\MEPC\61\2-12.doc 

Disinfection by-product 

Test or nature of study Species Effect 

 acute spermatotoxicity Acute spermatotoxicity MBAA 

Single dose, 100 mg/kg: No reproductive effects 14 daily doses, 25 mg/kg: No reproductive effects DBAA Single dose, 1250 mg/kg: 

• 17% drop of serum testosterone after 2 d (recover• Affected the sperm motion (post treatment day 14 • Degenerative flagellar changes in cauda sperm (d• Abnormal sperm head shapes (day 28) 

DBAA DCAA BCAA6

Mortality, dysmorphology/ growth retardation 

Rat Embryos 

48 h exposure during culturing DBAA: 400 μM, 39% mortality, decreases in somite nu

DCAA: 5000 μM, 23% mortality, malformations, and denumber, crown-rump length, head length and developmBCAA: 300 μM, 13% mortality, decreased DEVSC, som

number and head length 

DCAA TCAA 

Human health risk assessment 

Based on human epidemiological data

Possibility of bladder and colon cancer in males, as weeffects and asphyxia amongst infants. 

BCAA Reproductive toxicity in mice Mice (juvenile and adult) 

Juvenile males: 14 d, gavage 0-72 mg/kg- No significant variation in average body wdifferences in the relative testis weights 216 mg/kg- Significantly small body weight, Physically normal, No significant differences in the relative testis wafter the dosing period and 40 d mating period- No signrelative weights reproductive organs, no significant diffeparameters 648 mg/kg- Lethally toxic 
MEPC 61/2/12 

Annex, page 34 I:\MEPC\61\2-12.doc 

Disinfection by-product 

Test or nature of study Species Effect 

 Adult males: 14 d, gavage 

0-216 mg/kg- No signs of general toxicity or significanweight, No significant effect on relative testis, epididymweight. 40 d mating period after the 14 d dosing- No eadult males, For 72 and 216 mg/kg, significant reductiolitters/plug, litters/male and fetuses/male for the first 10 40 well-characterized genes differentially expressed in manner. 

DCAA DBAA BCAA

Dysmorphogenesis in mice- short term exposure 

Mice (Gestation day 8, CD-1 mouse conceptuses)

Reported increased incidences of dysmorphic (Cranial closure defect, Prosencephalic hypoplasia, Pharyngeal arch hypoplasia, Eye, Heart) embryos: DCAA: 11,000 μM, 6 or 26 h exposure DBAA: 300 μM, 26 h exposure BCAA: 300 μM, 3, 6 or 26 h exposure 

DCAA TCAA 

Subchronic toxicity (90 d) Rats 

0-5000 ppm in drinking water, 90 d. DCAA: 500 and 5000 ppm- terminal body weights were significTotal serum protein levels were significantly depressed TCAA: Decreased body weights were apparent, but not statisticNo consistent differences were seen in serum chemistr
I:\MEPC\61\2-12.doc 

Disinfection by-product 

Test or nature of study Species Effect 

DCAA Carcinogenicity Rats 

Doses administered through drinking water. Exposure period: 103 weeks Mean daily concentration and dose: 0.05 g/L (3.6 mg/k0.5 g/L (40.2 mg/kg bw/day), 1.6 g/L (139 mg/kg bw/daObservations: Toxic to nervous system, liver and myocardium while tr

neoplastic lesions were observed only in the liver. Considerable increment in carcinogenicity (hepatocelluobserved at the concentration of 1.6g/l. At 100 weeks, the concentration of 0.5g/l increased he(carcinoma and adenoma). No observed effects level = 0.05g/l (3.6mg/kg/day). 

DBAA Toxicity/ Carcinogenicity Rats/Mice 

2 weeks, Concentrations in drinking water: 0, 125, 250, 500, 100Rats: Daily dose 0-270 mg/kg. No adverse effects on survival, body weight gain, clinical signs. 12-44% increMale- If concentration > 250 mg/L, incidences of diffuse of hepatocytes were increased. For concentration > 50weights reduced by 8-15%. Female- If concentration was 2000 mg/L, incidences of alteration of hepatocytes were increased. Mice: Daily dose 0- 370 mg/kg. No adverse effects on survival, body weight gain, clinical signs. Male- Concentration of 1000 ñ 2000 mg/L increased thatrophy Female- Concentration of 2000 mg/L increased the incatrophy 
MEPC 61/2/12 

Annex, page 36 I:\MEPC\61\2-12.doc 

Disinfection by-product 

Test or nature of study Species Effect 

3 months Concentrations in drinking water - 0, 125, 250, 500, 10Rats: Daily dose 0-181 mg/kg. At concentration of 200in body weight. No effects on water consumption and sincrement in lever weight. Increases in centrilobular to hepatocellular cytoplasmic vacuolization. Male- 50% reduction in testis weight and reduction in ssperm concentrations at exposure to 2000 mg/L. Mice: Daly dose level- 0-260 mg/kg. At concentration reduction in body weight. No effects on water consum

2 years Concentrations in drinking water - 0, 50, 500, and 1000 Rats: No effect on survival. 5-15 % reduction in mean to 500-1000 mg/L. Neoplastic effects (Increased incidecell leukaemia). Male- Neoplastic effects (Induction of malignant mesotNon-neoplastic lesions (minimal to mild cystic degenerFemale- Non-neoplastic lesions (alveolar epithelial hypMice: No effect on survival. Lever neoplastic effects (ihepatocellular adenoma or carcinoma incidences). Male- Lever neoplastic effects (increased hepatoblastoIn 500 mg/L group, increment in Incidence of alveolar/ or carcinoma. 

1 MCAA: Monochloroacetic acid; 

2 DCAA: Dichloroacetic acid; 3 TCAA: Trichloroacetic acid; 4 MBAA: Monobromoacetic acid; 5 DBAA: Dibromoacetic acid; 6 BCAA: Bromochloroacetic acid. 
I:\MEPC\61\2-12.doc 

Table 4-4: Toxicity analysis of Bromate 

Disinfection by-product 

Test or nature of study Species Effect 

Glenodinium halli (Dinoflagellate), marine phytoplankton 

Chronic studies (exposure period is not spec

mg BrO3-/L 

Daphnia magna, (fresh water, invertebrate) Acute, 48-h LC50 of 179 mg BrO3-/LPolycelis nigra, (fresh water, invertebrate) 48-h LC50 of 2258 mg BrO3-/L Mysid shrimp (altwater, invertebrate) Acute, 24-h LC50 of 176 mg BrO3-/L Leiostomus xanthurus(juvenile), (Saltwater fish) 

2 days, LC50 of 518 mg BrO3-/L 

7 days, LC50 379 mg BrO3-/L

BrO3- 

Review on effect of BrO3- on aquatic 

organisms 

Morone saxatilis (pro-larvae), (Saltwater fish) 

2 days, LC50 of 605 mg BrO3-/L 

7 days, LC50 of 197 mg BrO3-/L 

BrO3- Acute toxicity Crassostrea virginica, larvae (Oyster) 1 mg/L initial dose, 48 h, > 90% mortality BrO3-

Alterations in protein and gene expression in rat kidney 

Rats 

Exposed to potassium bromate (drinking waconcentrations of 0, 1, 20 and 400 ppm. Alteration in mitochondrial function, glycolysmitochondrial gene transcripts. 
MEPC 61/2/12 

Annex, page 38 

I:\MEPC\61\2-12.doc 

5 TOXICITY TESTING OF THE TREATED BALLAST WATER (G9: 5.2) 

The objective of the development of the BWMS is to protect our marine environment. In order 

to effectively disinfect the unwanted/harmful organisms/micro-organisms, the Active Substances 

are generated by the electrochemical reactor and used. It has been demonstrated that the 

BWMS can achieve the goal; one of the evidences is shown in the confidential supporting 

information "SI-Disinfection study" on the disinfection of E. coli and Intestinal Enterococci. 

Although the working mechanism of electrolysis has being widely reported and accepted, the 

studies of treated effluent in terms of eco-toxicity and environmental impact are still very 

important, because the performance of electrolysis systems different from one to the other, 

which produces different types and amounts of toxicants. As such, a series of studies has 

been conducted by various research institutions shown in the confidential supporting 

information "SI-list of organizations in R&D of BWMS". The studies were: 1. measurements 

of concentrations of various environmental relevant compounds (e.g., THMs and HAAs); 

2. eco-toxicity testing by fish, invertebrate and alga. The results are summarized as follows. 

5.1 pH 

pH is one of the most important physicochemical parameters of the seawater. A suitable pH 

range of the discharged ballast water is essential to ensure the safety of ecosystem of 

receiving water and the safety of the ships. 

An experiment was conducted with various energy inputs applied to an electrochemical 

reactor, in which chlorine with different concentrations was generated. The pH was 

measured by a pH meter (ORION 920Aplus). Prior to the measurements, the pH meter was 

calibrated using pH standard solutions (pH = 4, 7, and 10). As shown in Figure 5-1, the pH in 

the effluent is quite similar to that in the influent. 

An experimental study on change in pH was conducted in February 2010; it was observed by 

a surveyor of the ABS. The result showed that, when the pH of the influent seawater is 7.97, 

the pH of the effluent seawater was 7.68 ("SI-list of experiment details"). 

According to the chemical reactions shown early, the pH of the seawater after the reactor 

may be lower than that of the influent. However, due to the short retention time of the 

seawater in the reactor, the decrease in pH of the seawater is less significant. In addition, 

there are some anionic substances in the solution (e.g., carbonate). They have buffering 

capacities, which can neutralize hydrogen ions. As a result, the decrease in the pH is less 

significant and no further increase in corrosion is expected. 

01234

6.5

7.0

7.5

8.0

8.5

9.0

9.5

10.0

pH

Total chlorine concentration, ppm

 Influent pH

 Effluent pH

Figure 5-1: Change in solution pH as a function of chlorine concentration 
MEPC 61/2/12 

Annex, page 39 

I:\MEPC\61\2-12.doc 

5.2 Total residual oxidant 

As the above analysis, the TRO (measured as Cl2) is mainly contributed by active chlorine, 

which plays an important role for the disinfection of the ballast water. A high concentration of 

active chlorine may be toxic to the aquatic organisms in the receiving water. Hence, the active 

chlorine in the discharged ballast water must be controlled under a very low level (0.1 mg/L). 

The initial active chlorine concentration of the seawater in ballast tanks is 12 mg/L, so that 

organisms and micro-organisms can be killed. After the disinfection, most of chlorine is 

consumed to a low value (e.g., 2-3 mg/L). Under such a level, the decay of active chlorine 

occurs in the ballast tank quickly (referred to the confidential supporting information 

"SI-Chlorine decay in the ballast water"). In addition, the active chlorine will be neutralized by 

sodium thiosulfate during deballasting. The amount of the dosed sodium thiosulfate is 

accurately controlled according to the level of total residual oxidants in ballast water, which is 

monitored by an online analyzer. 

According to the dosage given in the confidential supporting information "SI-Description for 

the BWMS", the maximum allowable concentration of active chlorine in the discharged 

ballast water after neutralization is 0.1 mg/L. Under such a low level of TRO, the safety of 

the aquatic organisms in the receiving water can be ensured. 

An experiment was conducted under the ABS observation and verified by staff from 

T‹V S‹D PSB Pte Ltd. The TRO (free chlorine concentration) was measured by T‹V S‹D 

PSB Pte Ltd; the value was 0.01 mg/L, far less than 0.1 mg/L. The risk of treated water in 

the marine environment is expected to be insignificant. 

5.3 Disinfection by-products 

Disinfection by-products may be generated during the ballast water treatment process using 

the BWMS in this application. Three major groups of DBPs, including trihalomethanes 

(THMs), haloacetic acids (HAA) and bromate (BrO3

-

), are identified as potential compounds 

generated during the proposed electro-disinfection process. 

An experiment was conducted with two types of contaminated seawater with TOC of 4.87 

and 4.88 mg/L and TSS of 134 and 120 for the water with 24 and 35 PSU, respectively. The 

water was not filtrated, in order to simulate the worse scenario. The water with the Active 

Substance (chlorine) after a period of time (e.g., after 2 hours termed as Day 0, 24 hours 

termed as Day 1, and 5 days termed as Day 5) was collected for the analysis of various 

parameters stated below (e.g., THMs, and HAAs). 

5.3.1 Trihalomethanes (THMs) 

Trihalomethanes (THMs) are chemical compounds in which three of the four hydrogen atoms 

of methane (CH4) are replaced by halogen atoms. As discussed previously, THMs are 

environmental pollutants and some of them are considered as carcinogenic. Chloroform/ 

trichloromethane (CCl3H), bromodichloromethane (CBrCl2H), chlorodibromomethane (CClBr2H) 

and bromoform/tribromomethane (CBr3H) are four THMs, which may exist and are 

concerned in the discharged ballast water treated by the BWMS. The results of THMs are 

showed in Table 5-1. 
MEPC 61/2/12 

Annex, page 40 

I:\MEPC\61\2-12.doc 

Table 5-1: Concentration of THMs in treated water 

24 PSU 35 PSU 

Parameter Day 0 

(ppb) 

Day 1 

(ppb) 

Day 5 

(ppb) 

Day 0 

(ppb) 

Day 1 

(ppb) 

Day 5 

(ppb) 

Trichloromethane N.D N.D N.D N.D N.D N.D 

Bromodichloromethane N.D N.D N.D N.D N.D N.D 

Dibromochloromethane 13.7 10.1 N.D 14.1 7.67 N.D 

Tribromomethane 128.7 114.3 10.9 153.1 112.3 23.8 

* N.D means under detection limit. +

 Measured by PUB (Singapore) according to ISO/IEC 17025; Report #CAWT 100000221. 

The THMs may have adverse health effects at high concentrations, and many governments 

set limits on the amount permissible in drinking water. In the United States, the EPA limits 

the total concentration of chloroform, bromoform, bromodichloromethane, and 

dibromochloromethane to 80 ppb in drinking water. The results, summarized in Table 5-2, 

show the total trihalomethanes in the treated ballast water after 5 days are less than 80 μg/L, 

which is lower than what is required for the drinking water. 

5.3.2 Haloacetic acids 

Haloacetic acids (HAAs) are carboxylic acids in which a hydrogen atom in acetic acid is 

replaced by a halogen. HAAs are a common undesirable disinfection by-product in water 

disinfected by chlorine. The concentrations of HAAs in the treated ballast water are shown in 

Table 5-2. 

Table 5-2: Concentration of HAAs in treated water 

24 PSU 35 PSU 

Parameter Day 0 

(ppb) 

Day 1 

(ppb) 

Day 5 

(ppb) 

Day 0 

(ppb) 

Day 1 

(ppb) 

Day 5 

(ppb) 

Monochloraacetic acid N.D N.D N.D N.D N.D N.D 

Dichloroacetic acid N.D N.D N.D N.D N.D N.D 

Trichloroacetic acid 6.48 6.66 11.2 6.68 N.D 18.7 

Monobromoacetic acid 12.5 5.09 N.D 8.31 N.D 11.4 

Dibromoacetic acid 73.0 64.4 106.1 101.4 76.3 175.8 

Tribromoacetic acid 190.8 89.9 146.4 308.8 160.6 373.1 

Bromochloroacetic acid 5.55 5.14 6.98 7.53 N.D 12.1 

Dibromochloroacetic acid 32.9 15.7 23.0 50.8 17.9 52.5 

Dichlorobromoacetic acid N.D N.D 5.83 5.18 N.D 10.6 

* N.D means under detection limit. +

 Measured by PUB; Report #CAWT 100000221.

5.3.3 Bromate (BrO3

-

) 

The bromate concentration is under detection limit (0.005 mg/L) as shown in Table 5-3. 

As bromate is formed in the presence of ozone, it can be concluded that the ozone 

production by our BWMS is negligible. 
MEPC 61/2/12 

Annex, page 41 

I:\MEPC\61\2-12.doc 

Table 5-3: Concentration of bromate (BrO3

-

) 

Water Day 0 (mg/L) Day 1 (mg/L) Day 5 (mg/L) 

24 PSU N.D* N.D N.D 

35 PSU N.D N.D N.D 

* N.D means under detection limit. + Measured by PUB; Report #CAWT 100000221. 

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

The important analytical methods at environmentally relevant concentrations are shown in 

Table 5-4. The full list of analytical methods and detection limits can be found in the 

confidential supporting information "SI-list of experiment details". 

Table 5- 4: Analytical methods at environmentally relevant concentrations 

Chemicals Methods 

Trihalomethanes (THMS) EPA 8260B 

Haloacetic acids (HAA) EPA 552 

Bromate ion EPA 300.1 

5.4 Eco-toxicity testing 

To evaluate the potential aquatic toxicity level of the treated ballast water by using the 

proposed electro-disinfection technology, the aquatic toxicity tests of marine fish, marine 

invertebrate and marine algae for ballast water treated by the BWMS have been carried out. 

The procedures follow to the requirements of the "Procedure for approval of ballast water 

management systems that make use of Active Substances (G9)", and are based on the 

Organisation for Economic Co-operation and Development (OECD) Guidelines. 

5.4.1 Aquatic toxicity test on marine fish 

 .1 Japanese Medaka (Oryzias latipes) 

It has been demonstrated that Japanese Medaka is very sensitive to toxins 

(Belanger, et al., 1990; Davis, et al., 2002; Sun et al., 2009). Hence, it was 

selected in the ecotoxicity study. Acute toxicity testing (96 hours) and 

chronic toxicity testing (30 days) of the treated ballast water by using the 

Japanese Medaka (Oryzias latipes) were conducted in a laboratory of 

Yantai Institute of Coastal Zone Research of Chinese Academy of 

Sciences, China. The institute has a group of experts in environmental 

assessment (marine). Each testing used 0, 6.25%, 12.5%, 25%, 50% and 

100% of the ballast water. It was found that the ballast water did not have 

any toxic effect on the marine fish in both acute and chronic toxicity studies. 

.2 Abudefduf saxatilis 

Acute toxicity testing (96 hours) and chronic toxicity testing (10 days) of the 

treated ballast water by using the Abudefduf saxatilis were conducted in a 

laboratory of T‹V S‹D PSB Pte Ltd. The laboratory is certified with 
MEPC 61/2/12 

Annex, page 42 

I:\MEPC\61\2-12.doc 

ISO/IEC 17025. The fish was selected as it normally lives in the coastal area 

(~20 metres depth). Each testing used 0, 6.25%, 12.5%, 25%, 50% and 

100% of the ballast water. It was found that the ballast water did not have 

any toxic effect on the marine fish in both acute and chronic toxicity studies.

5.4.2 Aquatic toxicity test on marine invertebrate 

.1 Penaeus monodon 

The Penaeus monodon was selected as it is very sensitive to toxins 

(Benzie, 1997; Chen and Lin, 2001; Tsai and Chen, 2002). Acute toxicity 

testing (96 hours) and chronic toxicity testing (30 days) of the treated ballast 

water by using the Penaeus monodon were conducted in a laboratory of 

Yantai Institute of Coastal Zone Research of Chinese Academy of 

Sciences, China. Each testing used 0, 6.25%, 12.5%, 25%, 50% and 100% 

of the ballast water. It was found that the ballast water did not have any 

toxic effect on the shrimp in both acute and chronic toxicity studies. 

.2 Stenopus hispidus 

Acute toxicity testing (96 hours) and chronic toxicity testing (10 days) of the 

treated ballast water by using the Stenopus hispidus were conducted in a 

laboratory of T‹V S‹D PSB Pte Ltd. The shrimp was selected as it is 

sensitive to toxins. Each testing used 0, 6.25%, 12.5%, 25%, 50% and 100% 

of the ballast water. It was found that the ballast water did not have any toxic 

effect on the marine shrimp in both acute and chronic toxicity studies. 

5.4.3 Algae growth inhibition testing 

Dunaliella primolecta (UTEX LB 1000), a marine micro-alga, has been used in toxicity study 

for seawater (Bentley-Mowat and Reid, 1977; Videau, et al., 1979; Pun, et al., 1995). It was 

used in the inhibition testing for the treated water from the BWMS in this application. The 

water used was 0, 6.25%, 12.5%, 25%, 50% and 100% ballast water treated by the BWMS. 

It was found the there was no difference between the controlled water (i.e. clean seawater) 

and the treated ballast water. The experimental details can be found in the confidential 

testing report "Algae growth inhibition study". It is worthy to note that the NaOCl is rated as a 

highly toxic chemical to Dunaliella primolecta (LC50 = 400μg/L) in PAN pesticide database. 

5.4.4 Ecox toxicity testing 

The Eclox toxicity testing technology is an internationally recognized analysis technique on 

toxicity of water (Scully, 1998; Ellis, 2000; Benfenati, et al., 2003). It was used to evaluate 

the level of toxicity of the treated ballast water. The obtained results illustrate there is no 

difference of the level of toxicity of the treated ballast water by the proposed BWMS and 

untreated ballast water. The study was conducted by the NUS staff in the PUB Lab, 

Singapore. Please refer to the confidential laboratory report "Eclox toxicity testing report". 

6 RISK ASSESSMENT 

6.1 Safety of ship (G9: 6.3) 

Fire/explosion can cause immediate damage a ship partially or fully. Hydrogen gas is the 

only gas that may cause fire/explosion. On the other hand, corrosion in ballast water tank 

may slowly consume the steel/metal of the tank, which may damage the tank and eventually 

the ship. As such, both hydrogen gas and corrosion due to the operation of the BWMS were 

studied with the results summarized as follows. 
MEPC 61/2/12 

Annex, page 43 

I:\MEPC\61\2-12.doc 

6.1.1 Gaseous species 

.1 Hydrogen gas 

There are three factors that can lead to the fire/explosion; they are fuel(s), 

oxidizer(s) and ignition source(s). Oxygen as an oxidizer is well 

available; 21% of air is oxygen. The ignition sources in a ship are 

available. Wiring of equipments (e.g., motor), smoking, lightning, and spark 

can act as ignition sources and they are all available when a ship is 

operated. The minimum ignition energy is 0.018 mJ for hydrogen gas 

(Crowl and Louvar, 2002). 

In the BWMS in this application, hydrogen gas is the only one that may 

cause fire/explosion. The lower flammability limit (vol. % fuel in air) of 

hydrogen is 4% and the upper flammability limit is 75% according to 

appendix B of "Chemical Process Safety, Fundamentals with Applications" 

(P. 568) (Crowl and Louvar, 2002). 

An experiment of electrolysis by our BWMS was conducted. The 

concentration of hydrogen gas from the BWMS was experimentally 

determined by T‹V S‹D PSB PTE LTD. The detection limit is 0.5% for the 

hydrogen gas. It was found the concentration of H2 was under the 

detection limit (less than 0.5%). The system is fully sealed and no gas 

leakage is expected. Thus, the possibilities of explosion can be neglected. 

The confidential supporting information "SI-Calculation of hydrogen 

concentration" and "SI-list of experiment details" provides more detailed 

analysis of the risk of hydrogen gas. 

.2 Chlorine gas 

Chlorine is produced through the electrolysis reaction shown early. It can 

rapidly dissolve in the water forming HClO and ClO-

. However, there could 

be chlorine gas left in the ballast water tank, which could create hazard 

problems even its concentration is low. An experiment of electrolysis by 

our BWMS was conducted. The concentration of chlorine gas from the 

BWMS was determined by T‹V S‹D PSB PTE LTD. The detection limit 

is 0.1% for the gas. It was found the concentration was under the detection 

limit (less than 0.1%) (the confidential supporting information "SI-list of 

experiment details"). As the whole electrochemical reactor is fully sealed, 

low risk in the inhalation of toxic gas to the crew is expected. Furthermore, 

an optional ventilation system is used for the ballast water tank. 

6.1.2 Corrosion 

The corrosion study for the ballast water treated with active chlorine was carried out to 

evaluate the effects of the BWMS on the ship safety. The testing includes uncoated steels and 

anti-corrosion coated steel supplied by the Neptune Orient Lines (Singapore). See below: 

Uncoated steel specimen 

The corrosion rates of uncoated steels were conducted using the method of mass loss 

(ASTM G1-90). Figure 6-1 shows that the corrosion morphology of the uncoated steel 

specimen subjected to the chlorinated water is the same to those subjected to nature 

seawater (no chlorine). 
MEPC 61/2/12 

Annex, page 44 

I:\MEPC\61\2-12.doc 

Figure 6-1: Comparison of corrosion morphology of uncoated steel specimens: 

experiments conducted for 1.5 months, 

initial chlorine concentration = 10 mg/L, 

chlorine concentration after 1 month = 0.

The corrosion rates measured for the two specimens (uncoated steel in seawater and 

chlorinated seawater) are listed in Table 6-1. As shown, the corrosion rate of the uncoated 

steel specimens after one month in the chlorinated seawater with an initial TRO of 9.2 mg/L 

is 0.11 mm/year, slightly higher than that in the natural seawater (not chlorinated). The 

corrosion rates of both after 4 months are very similar to each other. The results from one 

and four-month corrosion studies indicate that the seawater treated by the electrolysis device 

of the BWMS in this application have an insignificant impact on the corrosion that are similar 

to those reported by Song et al. (2005) and Dang (2005). 

Table 6-1: Corrosion rate results for uncoated steel specimens 

Duration time 1 month 4 month 

Corrosion Rate Natural Seawater 0.09 0.07 

(mm/yr) Treated Seawater 0.11 0.08 

*

 Initial chlorine concentration was 10 mg/L. The chlorine concentrations after 1 month 

and 4 months were 0.

Before corrosion After corrosion 

Chlorinated Seawater

Natural Seawater
MEPC 61/2/12 

Annex, page 45 

I:\MEPC\61\2-12.doc 

Anti-corrosion coated steel specimens 

It has been well documented that seawater used as ballast can cause corrosion. Thus, the 

ballast water tank must be painted by anti-corrosion paint before the ballast water is stored 

for balancing purpose. The corrosion is started from damaging the paint chemically before 

that of metal happens. When the BWMS in this application is used, active chlorine could 

enhance the corrosion. Two studies (morphology and FTIR) were conducted with the results 

shown as follows: 

Table 6-2: Corrosion morphology of coated steels 

Duration time Before experiment 1 month 

Not chlorinated 

seawater 

Coated steels 

Chlorinated seawater 

*

 Initial chlorine concentration was 10 mg/L. Chlorine concentration after 1 month was 0. 

An experiment on the anti-corrosion coated steel specimens has been tested for one month. 

The corrosion morphology shown in Table 6-2 indicates no corrosion on the specimens with 

the protection of anti-corrosion coating in both chlorinated and not-chlorinated seawater. 

The anti-corrosion paint is essentially organic (polymer). Corrosion will occur first on the 

paint then the steel. Any oxidation (i.e. corrosion) on the paint will change its chemistry. The 

Fourier transform infrared spectroscopy (FTIR), a highly sophisticated scientific analytical 

instrument was used to determine the changes in chemistry of the paint (organic/polymer 

compound). The peaks in the FTIR curve result from the vibration frequency of one or few 

typical functional groups on an organic substance (paint in this case). 

As shown in Figure 6-2, the vibration frequency values of all these specimens at any 

wavelength are exactly the same. This indicates that the usage of Active Substance 

generated from our BWMs in this application does not further strengthen/increase the 

corrosion. The experimental details are given in the confidential supporting information 

"SI-FTIR for corrosion study". 
MEPC 61/2/12 

Annex, page 46 

I:\MEPC\61\2-12.doc 

0 1000 2000 3000 4000 5000

Control sample

Chlorinated seawater sample

Transmittance (%)

Wavelength (nm)

Raw seawater sample

Figure 6-2: Corrosion study by FTIR 

The reasons causing insignificant differences in the corrosion of uncoated and coated steel 

specimens in the non-chlorinated seawater and chlorinated seawater is mainly due to the 

decay in the active residual chlorine. As shown in the confidential supporting information 

"SI-Chlorine decay in the ballast water", the decay of chlorine is relatively faster in the 

contaminated water. For example, the residual chlorine concentration becomes zero 

after 4 days when the initial concentration is 3.6 mg/L. Since the chlorine disappears 

after 1 to 2 weeks, the water originally chlorinated is the same as the non-chlorinated water. 

Hence, the corrosion in the treated ballast water is very similar to that in the seawater. 

The testing for both uncoated and coated specimens is being conducted according to 

Procedure (G9) of 6-month duration. The final testing results will be provided in the 

application dossier for the Final Approval. 

6.2 Human and environment (G9: 6.4) 

The concentrations of Active Substances and DBPs from the treated water were measured 

by the CAWT (PUB). They were used to evaluate the effects of treated ballast water on the 

human and the marine environment. The assessment was conducted by the DHI, an 

independent research company, which has no relationship in the development of the BWMS 

in this application. The summary of risk assessment by the DHI is given below as well as in 

the confidential supporting information "SI-DHI letter". The detailed information is available in 

the confidential information "SI-DHI risk assessment report". 
MEPC 61/2/12 

Annex, page 47 

I:\MEPC\61\2-12.doc 

6.2.1 Overall conclusion on the environmental risk assessment 

The risk assessment is performed as a conservative estimation using the estimated maximum 

concentrations of potentially released Active Substances and by-products inside the harbour. 

Based on these conservative estimations, the following conclusions are drawn: 

.1 The concentration of whole effluent in the OECD commercial harbour 

scenario amounts to 6.55 ml/L. Acute ecotoxicity tests performed on algae, 

crustaceans and fish indicate no toxic effects up to 1000 ml/L (100% 

undiluted treated ballast water). 

.2 Based on a PEC/PNEC evaluation, trichloroacetic acid (RQ = 1.1), 

monobromoacetic acid (RQ = 3.4) and hypochlorite and hypobromite 

(RQ = 1.9) poses a potential risk to the environment, which is based on the 

most conservative assumptions. 

.3 The assessment factor used for derivation of the PNEC value for 

trichloroacetic acid and monobromoacetic acid is 10,000 as only acute toxicity 

data could be found. This means that a very conservative approach has 

been provided. For the Final Approval of the Blueseas Ballast Water 

Management System more thorough toxicity data (chronic toxicity data) 

should if possible be applied for the derivation of the PNEC values. 

.4 The calculations on hypochlorite and hypobromite are very conservative 

and based on the detection limit of 0.01 mg/L. 

.5 None of the other evaluated substances show a PEC/PNEC ratio above 1. 

.6 Based on the evaluated fate of the substances, none of the substances are 

expected to accumulate in sediments. 

6.2.2 Overall conclusion on the human exposure assessment 

Exposure to humans from the TRC and its degradation products may occur due to: 

.1 Inhalation from exhaust air emitted from the ballast tanks (occupational). 

The predicted concentration in the air for inhalation is far below existing 

OEL-values. Thus, no risk to the crew on the ships is expected. 

.2 Exposure via the environment due to eating the fish from the harbour area 

and due to swimming in the harbour area. As the predicted daily uptake 

considering all uptake routes simultaneously is far below existing 

TDI values, no risk to the public from the TRC and its degradation products 

is expected. 

7 ASSESSMENT REPORT (G9: 4.3, 4.2.3) 

7.1 Experimental data 

The experimental data provided in the application were produced based on standard 

protocols which are internationally applicable. All experiments were conducted at the 

presence of a third-party surveyor from the ABS.
MEPC 61/2/12 

Annex, page 48 

I:\MEPC\61\2-12.doc 

The concentrations of various parameters were measured by the internationally recognized 

laboratories with relevant certifications (ISO/IEC 17025). The experiments and testing were 

performed according to the rigorous quality control/quality assurance programme. The reports 

of testing (e.g., by T‹V S‹D PSB Pte Ltd. and Centre for Advanced Water Technology of 

Public Utilities Board, Singapore) and environmental/risk assessment by DHI are provided with 

the application dossier to the committee for assessment (confidential supporting information). 

7.2 Literatures for toxicity analysis 

All the literatures cited in this application are from peer-reviewed journals, books, government 

reports, and databases of international organizations (e.g., ECB, EPA, and WHO). The sources 

of data are trustworthy and thus the collected information based on literatures for 

assessment and discussion in this application is reliable. 

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