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INTERNATIONAL MARITIME ORGANIZATION

IMO 

E

MARINE ENVIRONMENT PROTECTION 

COMMITTEE 

57th session 

Agenda item 2 

MEPC 57/2/13

 4 February 2008

 Original: ENGLISH

HARMFUL AQUATIC ORGANISMS IN BALLAST WATER 

Comments on the report of the fourth meeting of the GESAMP-BWWG 

Submitted by Germany 

SUMMARY

Executive summary: This document provides comments of Germany on the report of the 

fourth meeting of the GESAMP-BWWG (MEPC 57/2) and may be 

considered to avoid misunderstandings and to provide clarifications 

concerning the recommendation of GESAMP-BWWG that 

Final Approval should not be granted to the CleanBallast! system 

Strategic Direction: 7.1 

High-level Action: 7.1.2 

Planned output: 7.1.2.3 

Action to be taken: Paragraph 19 

Related documents: MEPC 57/2, MEPC 57/2/3; MEPC 55/2/4 and MEPC 55/2/16 

1 This document is submitted in accordance with the provisions of paragraph 4.10.5 of the 

Guidelines on the organization and method of work of the MSC and the MEPC and their 

subsidiary bodies (MSC-MEPC.1/Circ.1) and comments on ANNEX 6 of the report of the fourth 

meeting of the GESAMP-BWWG (MEPC 57/2). After carefully considering the report, it seems 

to Germany that there might be misunderstandings which need to be addressed. 

Total Residual Oxidants (TRO) concentration 

2 Paragraph 9.4.3 of annex 6 of the GESAMP-BWWG report (MEPC 57/2) states that 

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

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

were given for fresh water ...”. 

3 Germany emphasizes that it is stated in paragraph 3.2 of the non-confidential dossier 

(MEPC 57/2/3) “... in fresh water, e.g., river water harbours, hydroxyl radicals are the only 

Active Substance formed in the CleanBallast! process”. TRO were analysed also in fresh water 

during the land-based type approval tests (LBTA). TRO was measured as 0 mg/l in each of the
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freshwater LBTA cycles 6 – 10 and reported as part of the whole effluent characterization in the 

confidential part of the dossier. This was supported by the simultaneously reported, very low 

concentrations of disinfection by-products, e.g., THM close to detections limits of 0.1 μg/L. 

4 It is common knowledge that hydroxyl radicals give no response in accepted TRO 

analysis methods. Likewise, due to their short lifetime (half-life of nanoseconds) hydroxyl 

radicals react only within the EctoSys® cell. Consequently, the TRO concentrations are 

undetectable when operating the CleanBallast! system in freshwater. For these reasons, Germany 

has some concerns regarding the conclusions drawn by the GESAMP-BWWG based on 

paragraph 9.4.3 (MEPC 57/2, annex 6). 

Disinfection by-products (DBP) 

5 In annex 6 of the GESAMP-BWWG report (MEPC 57/2), it is stated in paragraph 9.4.4 

that “The Group noted that the Applicant had explained that high levels of disinfection byproducts such as THM were due to the fact that the EctoSys® system was run differently in the 

land-based tests than it will be in normal operation on board ships. The Group further 

considered that a full chemical characterization of water treated by the CleanBallast! system run 

in normal mode should be provided together with toxicity tests with the same water”. 

6 Polarity reversal is a very common method to prevent mineral hydroxide deposits in 

seawater electrolysis. During normal operation of the CleanBallast! system, the polarity of 

the electrodes in the EctoSys® cell is changed constantly between normal and reversed polarity, 

as described in paragraph 3.5.2.1.1 of document MEPC 57/2/3: “Due to relatively frequent 

polarity reversal, the treated water originates from both normal and reversed operation mode of 

the EctoSys® resulting in a mean THM concentration during common operation of the 

CleanBallast! System.” In the whole effluent characterization in seawater, the applicant provided 

data: (1) of the normal operation of the CleanBallast! system, i.e., 50 % of the time the reversed 

polarity (worst case concerning DBP-formation) and 50 % of the time the normal polarity (best 

case concerning DBP-formation) of the EctoSys® electrodes was run (confidential dossier, whole 

effluent characterization for LBTA, cycle 4); and (2) for a worst-case approach, as agreed with 

the German Administration, where the CleanBallast! system was operated while the EctoSys®

cell was intentionally pre-set to reversed polarity all the time (e.g., LBTA cycle 3, see table 1 in 

MEPC 57/2/3). 

7 Chronic toxicity tests were carried out with EctoSys® cell effluents continuously 

reversing the electrodes between normal and reversed polarity in seawater as described above. 

Since the applicant submitted data on the whole-effluent characterization and aquatic toxicity 

from the normal operation, Germany is of the opinion that the requirement of GESAMP-BWWG 

(MEPC 57/2, annex 6, paragraph 9.4.4) was fulfilled. 

Control system 

8 Paragraph 9.4.5 of annex 6 of the GESAMP-BWWG report (MEPC 57/2) states that “The 

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

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

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

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

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

and therefore not an integrated part of the system under evaluation by the Group.”
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9 After careful consideration and to enable a conservative worst-case approach for the Final 

Approval, the German Administration decided that the algae monitor should not control the EctoSys®

disinfection in the CleanBallast! system. The EctoSys® disinfection is controlled by the maximum 

current density applied to the electrodes and as stated in document MEPC 57/2/3, paragraph 3.1, the 

maximum TRO concentration producible by the EctoSys® cell is 2 mg/L. Due to this fact the algae 

monitor does not have the ability to increase the TRO concentration above 2.0 mg/L. 

Chronic aquatic toxicity studies 

10 Paragraph 9.4.8 of annex 6 of the GESAMP-BWWG report (MEPC 57/2) states that “The 

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

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

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

treated water and not the scale of the installation ...” 

11 The Active Substances produced by the EctoSys® disinfection in seawater are unstable 

TRO and in freshwater extremely reactive hydroxyl radicals. Therefore, an advanced approach 

for chronic aquatic toxicity in whole-effluent studies was chosen to evaluate the CleanBallast! 

system. The highest possible TRO level of 2 mg/L was produced in a permanent system 

operation during the test duration and directly tested on three trophic levels (algae, crustacean, 

fish) by continuous feeding of the effluent to the test tanks. This clearly represents a worst-case 

scenario as if a ballasting ship directly discharges the freshly disinfected ballast water to aquatic 

organisms over a longer time span. 

12 Since the land-based type approval procedure, defined by Guidelines (G8), is a 

discontinuous operation with 5 days tank storage, it is not possible to run any flow-through 

chronic toxicity test. Previously, it was shown that the TRO concentration is decisive for both 

acute and chronic aquatic toxicity. For these reasons the German Environment Agency (UBA) as 

the Competent Authority accepted the chronic toxicity test in the 10 m3/h scale according to 

Procedure (G9). In summary, the German Competent Authority is of the opinion from a chemical 

risk assessment point of view that the aquatic toxicity tests for CleanBallast! were undertaken in 

a worst-case scenario which fulfils the requirements for the Final Approval process after 

Procedure (G9). 

13 In general, Germany notes the need for an agreed upon approach for chronic toxicity tests 

in the specific case of unstable Active Substances and/or Relevant Chemicals. 

13.1 As described, a continuously flow-through approach with constant high concentration of 

Active Substances and Relevant Chemicals was used in document MEPC 57/2/3. 

13.2 For a parallel application, it is described in document MEPC 57/2, annex 4, 

paragraph 7.1.1.2 that “... chronic toxicity tests reported by the applicant were carried out as 

static non-replacement tests”. Here the GESAMP-BWWG concluded for the chronic toxicity 

tests in paragraph 7.1.1.8 that “The Group considers that only testing for ecotoxicity with treated 

ballast water after 3 and 5 days of storage is insufficient to cover all of the possible storage and 

discharge conditions. Should treated ballast water need to be discharged on a shorter time scale, 

then higher TRC values can be expected”. 

13.3 In a previous application of a system producing hydroxyl radicals an intermediate 

approach was used, as was stated in document MEPC 56/2/1 in appendix 4, page 21: “The fish 

was exposed continuously for 28 days with water exchange 3 times per week.” 
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13.4 Therefore, Germany would appreciate further guidance by the GESAMP-BWWG on 

chronic toxicity test with unstable Active Substances and/or Relevant Chemicals. 

Risk assessment 

14 In paragraph 9.4.12, annex 6 of document MEPC 57/2 it is stated that “... Based on this 

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

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

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

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

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

15 As already described in paragraph 10 above, using the algae monitor as a control system 

could only result in lower effluent concentrations of Active Substances and/or Relevant 

Chemicals and effluent toxicity. Therefore for a conservative worst-case approach, the operation 

of any controlling device was considered of lower relevance for the risk assessment. MAMPEC 

was not used directly because it concerns paints on ship hulls. The box model used for the 

Rotterdam case study was described in detail in the confidential part of the dossiers 

(MEPC 55/2/4 and MEPC 57/2/3), which uses the same basic principles and assumptions 

(e.g., same harbour dimensions) as MAMPEC. Thus, it can be evaluated as an equivalent version 

of MAMPEC giving a similar outcome for the risk assessment. 

Risk to the crew and the public 

16 Paragraph 9.4.9 of annex 6 of the GESAMP-BWWG report (MEPC 57/2) states 

that “... As the applicant couldn’t provide information concerning the Human Exposure Scenario 

(3.9. MEPC 57/2/3), the Group noted that an adequate conclusion as to the outcome of the 

Human Risk Assessment could not be achieved. Therefore, the Group recommended that human 

exposure when handling ballast water treatment operations should be restricted and RMM [Risk 

Mitigation Measures] put in place”.

17 Germany notes that the Human Emission Scenario was addressed by the applicant in 

document MEPC 57/2/3, paragraph 3.9, “The Active Substances produced and used by the 

CleanBallast! system are produced directly in the water without any external adding of 

chemicals. Therefore, no handling of the Active Substances, Relevant Chemicals or Preparations 

will be performed by humans during any processes or individual operations on board. ...”. The 

EctoSys® cell produces the Active Substances and Relevant Chemicals in situ within the closed 

cell housing in the ballast water piping system. During normal operation of the CleanBallast! no 

release pathway of Active Substances and Relevant Chemicals exists and consequently no oral, 

respiratory or any other risks of exposure to the crew occurs. 

18 The GESAMP-BWWG noted for the Basic Approval (MEPC 55/2/16, annex 7, 

paragraph 10.2.4) that “... the Group agreed that the only potential exposure of the crew to the 

Active Substances might be via leaking pipe work in the pump room but the levels of Free Active 

Chlorine should not present a safety hazard to the crew”. Furthermore, the GESAMP-BWWG 

clarified that “Maintenance, equipment failure and accident situations should be considered 

separately from conditions of normal operation” (MEPC 57/2, paragraph 7.1.6). Pipe leakage is 

a very rare event and cannot affect any long term exposures. Possible mitigation to address such 

an exposure was described by the applicant in document MEPC 57/2/3 in paragraph 3.9 

“... Furthermore, the CleanBallast! system is automatically shut down in case of a leakage and 

the bypass around the system is opened.” Because Active Substances and Relevant Chemicals
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are not handled and no pathway for human exposure exists during normal operation of the 

CleanBallast! system, Germany is of the opinion that no further requirements such as Risk 

Mitigation Measures are necessary. 

Action requested of the Committee 

19 The Committee is invited to take note of the information provided and decide as 

appropriate. 

 

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