I:\MEPC\54\2-3.doc For reasons of economy, this document is pr inted in a limited number. Delegates are kindly asked to bring their copies to mee tings and not to request additional copies. INTERNATIONAL MARITIME ORGANIZATION

IMO 

# E

MARINE ENVIRONMENT PROTECTION

COMMITTEE

54th session Agenda item 2 MEPC 54/2/3

16 December 2005 Original: ENGLISH

HARMFUL AQUATIC ORGANI SMS IN BALLAST WATER

Application for Basic Approval of Active Substa nces used by Electro-Clean (Electrolytic Disinfection) Ballast Water Management System

Submitted by the Republic of Korea

SUMMARY

Executive summary: This document provides an application for Basic Approval of Active Substances used by Electro-Clean (e lectrolytic disinfection) Ballast Water Management System in acc ordance with the Procedure for approval of Ballast Water Management Systems that make use of Active Substance (G9) adopted by resolution MEPC.126(53). The

relevant documents and dossiers have been submitted to Marine

Environment Division of the Organization for review by the GESAMP-Ballast Water Working Group.

Action to be taken: Paragraph 5

Related documents: MEPC 53/24, MEPC 53/24/Add.1

Introduction

1 This document provides an application for Basic Approval of Active Substances in accordance with the Procedure for approval of Ba llast Water Management Systems that make use of Active Substance (G9) adopt ed by resolution MEPC.126(53).

2 The relevant documents and dossiers have been submitted to Marine Environment Division of the Organization for review by the GESAMP-Ballast Water Working Group.

3 The applicant is proposing a ballast water ma nagement with Electro-Clean (electrolytic disinfection) system. This system produces low concentration of Active Substances by electrolytic treatment. Due to a synergy effect of various Active Substances, it has been shown to effectively kill all of the organisms in ballast water.

4 Annexed to this document is a proposal for approval of Active Substances used by Electro-Clean (electrolytic disinfection) system which is prepared by Techcross Ltd. and Korea Ocean Research and Development Institute (KORDI).MEPC 54/2/3 - 2 -

I:\MEPC\54\2-3.doc Action requested of the Committee

5 The Committee is invited to consider the pr oposal for approval of the Active Substances used by Electro-Clean (electro lytic disinfection) system for ballast water management.

***MEPC 54/2/3

I:\MEPC\54\2-3.doc ANNEX

Information for Basic Approval of Active Substances used by Electro-Clean (Electrolytic-Disinfection) Ba llast Water Management System

1 INTRODUCTION

In the Electro-Clean (electro lytic disinfection) technology, Ac tive Substances including Cl 2 , HOCl, OCl - and OH radical are produced during electrolys is of seawater (1). Due to synergy effect of these Active Substances, the system e ffectively kills bacteria, yeasts, virus, moulds, spores, algae, protozoa, zooplan kton, phytoplankton, larval stages and fish eggs in ballast water (2). This technology is effective at high c oncentration of sediment and/or organic matter at pH values between 5 and 9 in the temperature higher than 5 o C.

The level of Active Substances produced during electrolysis of seawater can be closely controlled by applying an appr opriate current density (3). The Active S ubstances produced do not persist in seawater a nd do not create any persistent byproduct at their level.

2 SPECIFIC CHARACTER OF ELECTRO-CLEAN (ELECTROLYTIC DISINFECTION) TECHNOLOGY

Safety

The equipment employs the electrod es to supply electrons which are clean reagent, so there is no need for storage or transportation of chemicals which ensures the operational safety and no risk of exposure. The Active Substances in Elec tro-Clean system are hypochlorite, chlorine and

ozone which are used to disinfect drinking water (4). The levels of Active Substances produced during the electrolysis of seawater are be low the standards for dangerous substances (United Statesí standards).

Economy

The Electro-Clean system is composed of el ectrochemical reactor employing electrode and rectifiers which makes the system compact. Because there is no need for chemical storage tanks, the system is also economical.

Environmental hazard

The Active Substances that are produced dur ing disinfection are radicals and oxidative substances including chlorine and hypochlorite which have s hort life span. The Active Substances can be reduced by reductive substances or organisms in seawater. They are also degraded in nature to lower concentration. In case of natural disasters such as typhoons and earthquakes, cutting-off electricity alone will ensure the safety.MEPC 54/2/3

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I:\MEPC\54\2-3.doc 3 EFFICIENCY OF THE ELECTRO-CLE AN (ELECTROLYTIC DISINFECTION)

SYSTEM

3.1 Principle of disinfection

.1 Disinfection by electric potential

Electric potential is the driving force wh ich makes oxidation reaction occur at the anode (positive) and reduction occur at th e cathode (negative) in the electrolytic cell. In simple terms, from a microbial perspective, an oxid izing chemical pulls electrons away from the cell membrane, causing it to become destabilized and leaky. Destroying the integrity of cell memb rane leads to rapid death of organism in a few seconds (5).

.2 Disinfection by free chlorine

Hypochlorite can be formed during electroly sis of saline water. Natural seawater contains chloride ion which is about 19.5gL -1 . The presence of 0.53mol/L of

chloride in seawater serves as an abu ndant source for electrochemical generation of chlorine and hypochlorite (6).

At the Anode:

2Cl - Cl 2 + 2 e In the Bulk:

Cl 2 + 2H 2 O HClO + Cl - + H 3 O +

HClO +H 2 O C lO - + H 3 O +

These two reversible reactions have the equilibrium constants of 4 x 10 -4 mol/L

and 3 x 10 -8 mol/L, respectively, at 25°C (7). Hypochlorous acid is a weak acid and will undergo partial dissociation as follows:

HOCl H + + OCl In waters of pH between 6 and 9, both hypochlorous acid and hypochlorite ion will be present. The proportion of each species depends on pH and temperature. Hypochlorous acid is significantly more effective as a biocide than the hypochlorite ion as hypochlorous acid de stroys organisms within two seconds, whereas hypochlorite ion takes 25-30 minutes to do the same (8).

.3 Disinfection by radicals

Seawater with its various salts is broke n down into components according to the

electrochemical reactions that occur on the surface of the electr odes. OH radical produced during electrolysis is very unstabl e substances and exists for only a few billionths of second. This radical, thr ough the exchange of ions, instantaneously disinfect bacteria and aquatic micro-organisms.MEPC 54/2/3

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I:\MEPC\54\2-3.doc .4 Electrochemical oxidation

Electrochemical oxidation i nvolves direct disinfection through the exchange of

electron with the surface of electrodes and indirect disinfection through the

creation of oxidants such as O 3 and Hydrogen peroxide. Ozone has been limitedly

used as an alternative to chlorine because it decreases the formation of THMs in the water, while hydrogen peroxide is used as a disinfectant in medical application and as an oxidant for industrial purposes . These substances do have a little stability, so they will help in redu cing the development and reproduction of micro-organisms and bacteria in ballast water (9).

When ozone decomposes in water, the free radicals of hydrogen peroxy (HO 2 ) and hydroxyl (OH) that are formed have great oxidizing capacity and play an active role in the disinfection process. It is ge nerally believed that b acteria are destroyed because of protoplasmic oxidation resulting in cell wall disintegration (cell lysis).

At low pH levels, ozone itself becomes the target of ozon ization, resulting in oxidation processes with the surface layers of micro-organisms that easily react to ozone. At low pH levels, ozone breaks down the parts that are unsaturated bonds, as well parts that have a high concentration of electrode s. Therefore, ozone is effective in breaking down unsaturated bonds and the oxidization of molecules that possess nucleophilic atoms such as ami no acids. At high pH levels, ozone has even greater oxidization capability becau se it becomes a reactant with the OH radicals that are produced wh en ozone reacts with water.

3.2 Biological efficacy test of Electro-Clean system

3.2.1 Results of marine organisms

Land-based test has been conducted to assess wh ether the Electrochemical Disinfection System meets with Regulation D-2 as a suitable Balla st Water Management System (BWMS). For

approval of testing process, test organisms smaller than 50 μm and larger than or equal to 10 μm

were included with 1.37×10 7 cells/L in the influent water.

Species of organisms were mainly diatoms, si licoflagellates, eugle noids, dinoflagellates,

microflagellates in terms of phytoplankton. Te st organisms larger than or equal to 50 μm in the

test water were 4× 105 inds./m 3 comprised of copepods, cladoceran s, harpacticoids and larvae of natural organisms, including Artemia as incubated larvae. Operating cond itions of electrolytic disinfection system were at voltages 3.6(9.8 ampere; condition 1) and 5.2(15.2 ampere, condition 2).

Biological efficacy of Electro-Clean system was es timated in terms of concentration of viable organisms in the influent and effluent water in two different conditions. Viable organisms were

less than 10 cells/ml in the size group smaller than 50 μm and larger than or equal to 10 μm , and

less than 10 inds./m 3 in the size group larger than or equal to 50 μm . Viable microbes in terms of

E. coli and coliforms were not obs erved after 48-hr incubation period.MEPC 54/2/3

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I:\MEPC\54\2-3.doc Effluent water being passed through the system was maintained under dark conditions to simulate the inside of shipís ballast tank durin g twenty days. Since no viable organisms were observed at the time of daily ch eck-up during the experimental pe riod, it can be concluded that the two experimental conditions of Electro-Clean system were in compliance with the regulation D-2.

3.2.2 Results of fresh water organisms

Land-based test was conducted to assess the di sinfection efficacy of the Electro-Clean system (10). Operating condition was 6V/15A a nd without the addition of electrolyte. Total residual chlorine was 2.5mg/L after 5 minutes. Surviving algal cells were counted based on fluorescence intensity with N.A binding DYE.

No viable microbes were observed after 0.5-hour incubation period. The removal efficacy of testing algal species was above 90%, except for Senedesmus quadricaud , in 5 minutes. A test to assess the removal efficiency of plankton presen t in water of Dae-Chung Reservoir, a source of drinking water for local residents in Korea, by electrochemical disinfection system was carried out. The numbers of phytoplanktons were 5.0× 10 6 cells/L in the testing water. Operating conditions was 6V/3A and residual chlorine was 0.3 mg/L after 5 minutes. Dominant micro-organisms were Microcystis spp, Anabaena spp. and Oscillatoria spp . Algal viability was reduced by 90% in 10 minutes afte r electrochemical disinfection.

4 GENERAL REQUIREMENTS

4.1 Identification

Active Substances produced during electrolysis of seawater are Cl 2 , HOCl, OCl - and OH radical. The chlorine is hydrolyzed creating HC1 and HOCl as shown in Equation (5). HOC1 dissociates as shown in Equation (7).

Cl 2 + H 2 O HCl + HOCl -------- (1)

HOCl H + + OCl - -------- (2)

The equilibrium of this reactio n depends on the temperature a nd pH of the water, and the

chlorine takes on three forms: molecular chlo rine, hypochlorous acid a nd hypochlorite ion. All of these are residual chlorine (11).

In water above pH 4, the concentration of molecular chlorine is less than 1~2% while almost all the rest is HOCl. At pH 7, about 75% is HOCl and 25% OCl - . At pH 8 and pH 9, 75% and 95%

exists as OCl - respectively. Because HOCl and OCl - share similar properties, Cl 2 , OCl -

, OH radicals and ORP potential which have significant influe nce on disinfection will be

discussed.MEPC 54/2/3

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I:\MEPC\54\2-3.doc 4.2 Data on Active Substances

4.2.1 Data on hypochlorite

4.2.1.1 Data on effects of hypochlorite on aquatic organisms:

4.2.1.1.1 Lethal concentrations (LC99, IC99) of hypochlorite for freshwater and saltwater

Biota:

Table 1: Lethal concentration range of hy pochlorite for fresh water and salt water

Lethal

Concentration Range (mg/L) Fresh water Salt water

<1 Alga S. capricornutum (48 hr) Alga ñ Nanochloris sp . (48 hr) Alga ñ S. obliquus (48 hr)

Invertebrate ñ D. magna (neonate) (48 hr) Bacteria ñ V.fischeri (15 min) Alga ñ S.costatum (48 hr)

1 to 10 Bacteria ñ Bacillus subtilis (spore) (48 hr)

Mollusc ñ D.polymorpha (veliger) (24 hr)

Benthic invertebrate ñ L.variegates (48 hr)

Fish ñ C.caprio (48 hr) Amphipod ñ E.estuaris (48 hr)

Fish ñ C.variegatus (48 hr)

10 to 100 Invertebrate ñ D.magna(ephippia) (48hr)

100 to 1,000 Invertebrate ñ A. salina (cyst) (24 hr)

For the fresh water species, algae (including S. capricornutum, S. ob liquus, and Nanochloris sp. ) exhibited the lowest tolerance to hypoc hlorite (IC99s 0.1 mg/L), followed by D. magna (LC99 = 0.2 mg/L based on exposure of neonates (< 24 -h old)). The most tolerant species, based on exposure of the resting egg or ìephippiaî, was D. magna (IC99 = 76.3 mg/L). Lethal effect levels for all other species were in betw een this range with LC99s below 10 mg/L.

For the salt water species, the bacterium ( Vibrio fischeri ) and the alga ( S. costatum ) exhibited the lowest tolerance to hypochlorite with IC99 esti mated to be 0.15 and 0.20 mg/L, respectively. The most tolerant species was the brine shrimp ( A. salina ), based on exposure of the cyst (IC99 486 mg/L). All other species were in this range with IC/LC 99s below 10 mg/L.

Toxicity tests using selected organisms were c onducted to assess the relative toxicity of sodium hypochlorite in dilution water versus ballast water. The results of the toxicity tests are presented in the table given below.

Table 2: Comparison of hypochlorite toxicity to Lumbriculus variegatus and Eohaustorius

estuarius in dilution waters versus ballast waters

Species Fresh water (48 hr) Salt water (48 hr)
Laboratory Water LC99 (TRC mg/L) Ballast Water LC99 (TRC mg/L) Laboratory Water LC99 (TRC mg/L) Ballast Water LC99 (TRC mg/L)

L. variegatus 1.485 (1.410-1.508) 0.743(0.743-0.743) --- ---

E. estuarius --- --- 6.998 (3.728-7.245) 7.448 (7.448-7.448)MEPC 54/2/3

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I:\MEPC\54\2-3.doc The tests conducted with the L. variegatus suggested that hypochlorite was more toxic in ballast water (LC99 = 0.743 mg/L) relative to the dilution water (LC99 = 1.485 mg/L). But in the tests

with E. estuaries , results indicate hypochlorite is slightly more toxic in the dilution water than

ballast water.

4.2.1.1.2 Reproduction of sodium hypo chlorite for aquatic organisms

Acute toxicity (after 24 hrs) of sodium hypochl orite (NaClO) to newborn individuals of daphnia is reported in the literature. On the base of these results, NOEC has been determined as the concentrations causing death rate lower than 20%, showing no significant differences with control NOEC for NaClO is 0.031 mg/l. NaCl O at NOEC concentrati on (0.031 mg/l) caused decrease in females survival (to 63%), decrea se in young survival (t o 0%) and decrease in reproduction rate (from 36.9 to 28.4 young/female) (12). NOEC of sodi um hypochlorite for opossum shrimp was reported as 0.087mg/L (13, 14).

4.2.1.2 Data on effect of hypochlorite on mammalian

4.2.1.2.1 Toxic effect on human

4.2.1.2.1.1 Short-term (acute) exposure

Inhalation

Hypochlorite does not easily form into vapour. Th e amount of chlorine released from dilute solution of hypochlorite solutions (less than 5.25%) under normal condition therefore is not significant. However, with more concentrated solutions and if the pH is powered, or if the solution is heated or if mixed with acids, high er amount of chlorine may be released. Mists

formed from solutions can cause mild to severe irritation of the nose and throat, depending mainly upon the airborne concentration and the st rength of the solution. There is no information about the short-term inhalation exposure to mists from hypochlorite solutions for human

or animal.

Skin contact

Hypochlorite solutions can cause mild irritation to corrosive injury depending on the duration of contact, the concentration and pH of the solu tion, based on human and animal information. No irritation was experienced by 20 volunteers following the application of 1% hypochlorite solution (pH unspecified) for 48 hour s in the form of a covered patch. When 2% solution (pH unspecified) was used, weak or modera te irritation was experienced by 15 out of 69 volunteers (15). No skin reaction was observed in 3 volunteers following a 48-hour application of 0.252% solutions in the form of a covered patch (16). Severe irritation was experienced by volunteer s after 4-hour application of 5.25% hypochlorite solution (pH 10.7) to unbroken skin in the form of a covered patch (17) . Slight redness and small wheals (hives) were

observed in 4 out of 10 volunteers within 20 minutes of applic ation of 0.1 ml of 6% sodium hypochlorite solution (pH 11.2) to the forehead (17).

Eye contact

Hypochlorite solutions can cause mild irritation to corrosive injury, depending on the concentration and pH of the solution, and the duration of the contact, based on human and animal information. There are several reports of pain, a nd in some cases, slight damage to the surface ofMEPC 54/2/3

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I:\MEPC\54\2-3.doc the eye and/or cornea, being experienced af ter direct contact with commercial products containing sodium hypochlorite (approximately 5%). The eyes were washed with water or a salt solution (saline) and the injury cleared within 1-2 days (18, 19, 20). There are 3 reports of burning to the eyes with slow recovery fo llowing exposure to concentrated solutions (concentration unspecified) (21). Sodium hypochlo rite solutions decompos e into chlorine gas slowly on contact with ai r. If mixed with acids or warmed to higher temperatures, significant concentrations of the gas are re leased. Chlorine gas is severe eye irritant. Stinging, burning sensation, rapid blinkin g, redness and watering of the eyes have been observed at chlorine

concentrations of 1mg/L and higher.

Ingestion

Swallowing hypochlorite solutions can cause irritation, pain and inflammation of the mouth, throat and stomach, as well as vomiting. In seve re cases, serious effect s including ulceration and perforation of the gastrointestin al tract and death can result (21, 22, 23). The effects depend on several factors, e.g., the amount ingested, the concentration and pH of the solution (21).

About 29.5ml of a solution with 15% available ch lorine may be lethal (21). For sodium hypochlorite solution with 3-6% of available chlo rine, a lethal dose for humans of 200 ml has been reported (18). Severe injury has been obser ved in a person who ingested approximately 1 litre of 5.25% sodium hypochlorite having pH of 10.8( 24). A woman who inte ntionally swallowed approximately 700ml of 5.25% sodium hypochlorite having pH of 11.5, showed falling mental status, perforation of the stomach, and died of cardiac arrest 4.5 hours after ingestion (23). Deaths have also resulted from aspiration of sodium hypochlorite solution into the lungs (18).

4.2.1.2.1.2 Long-term (chronic) exposure

Skin

Prolonged or repeated contact wi th hypochlorite may cause dry, re d, cracked skin (dermatitis). In a 5-year survey, 17/130 (13.1%) of first-tim e attacks of dermatitis reported among chemical factory workers were attributed to the misuse of hypochlorite to the clear skin (frequency of use and concentration not reported) (25).

Skin sensitization

It is not possible to conclude hypoc hlorite as an occupational skin se nsitizer. A few cases of skin sensitization have been reported, in all but one case, the individuals were predisposed to this type of reaction (reacting to other common allergens as well) (15, 16, 17). Two non-occupational cases of sensitization to sodium hypochlorite have been confirmed by patch tests. Both individuals reported a history of skin reactions following e xposures to products containing sodium hypochlorite or chlorine. Other family or personal hist ory of allergies has not been reported (26, 27). Negative results (0/86 and 0/ 90 individuals sensitized) have been obtained in two unpublished sensitization test s on human volunteers (human re peated insult patch test) using 4% sodium hypochlorite solution (18).

Carcinogenicity

The International Agency for Research on Cancer (IARC) has concluded that hypochlorite is not

classifiable as to its ca rcinogenicity to humans.MEPC 54/2/3

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I:\MEPC\54\2-3.doc Teratogenicity and embryo toxicity

No specific conclusions can be drawn about the potential devel opmental toxicity of sodium hypochlorite from a human population study that exam ined the potential effects of chlorinating drinking water with sodium hypochlorite. Exposu re in this study was based on the chlorination method, and not the measured amount of sodium hypochlorite or its byproducts in the water (28).

Reproductive toxicity

There is no human information available for repr oductive toxicity. No firm conclusion can be

drawn based on the limited animal information available.

Mutagenicity

There is no information available for human. The available information for animal suggests that sodium hypochlorite is not mutagenic. A positive result (sperm-head abnormalities) was obtained in one test using live mice. This te st did not directly measure genetic damage. Negative results have been obtaine d in other tests with live mice.

Potential for accumulation

Hypochlorite does not accumulate in the body. It reacts with tissues (21). A rat study using radiolabelled hypochlorous acid ha s shown that it is absorbed fairly rapidly in serum and eliminated from plasma with a half-life of 44 hours.

4.2.1.2.2 Toxicological information on other mammals

4.2.1.2.2.1 Short-term (acute) exposure

Ingestion

Vomiting has been observed in dogs following inge stion of 5 ml of 5.25 % sodium hypochlorite (18). Extensive damage to the stomach, esophagus and small intestine we re observed in a dog, which died after ingestin g 100 ml of a 5.25% solution, having pH of 10.8 (29).

Eye irritation

No irritation was observed in rabbits followi ng application of a 0.005% or 0.005% solution. Application of a 0.5% solution produced swolle n and bloodshot eyelid at 2 and 6 hours. The

animals returned to normal c ondition within 4 hours (18). In another study, ap plication of a 5% solution produced moderate to severe irritation in rabbits. Immediate pain was experienced by rabbits by application of a 5% solution (pH 11.1-11.6). When eyes were rinsed with water within 30 seconds, effects were not severe (sligh t effects on the cornea and swelling of the inner eyelids) and the effect lasted for less than one day. When the solution was not rinsed away, the injury was more severe (swollen and bloodshot eyes), but cured within a week (19). Severe irritation (scored 61.3/110) was observed in rabb its following application of undiluted sodium hypochlorite (30).

Skin irritation

Very dilute solution has caused negligible irrita tion, while more concentrat ed solutions can cause corrosive injury. Negligible and slight irrita tion was observed in rabbits by application of 0.6MEPC 54/2/3

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I:\MEPC\54\2-3.doc and 0.8% solutions (18). Moderate tissue change was observed in mice by application of a 0.525% solution by spraying or wiping 8 times/day for two consecutive days (31). Slight

irritation has been observed in rabbits and guinea pigs by application of a 5.25% solution (pH 10.7) using a patch (17). Mode rate irritation (Primary Irritati on Indices of 1.4-1.6) has been observed following 4-hour application of hyp ochlorite bleach (5.25% solution) using two different application techniques (cha mber and patch)(18, 32). In a nother test, moderate irritation has been observed in rabbits by application of an approximately 5.5% solution (18). Severe irritation (scored 5.08/8.00) and co rrosive injury were observed following application of 0.5ml of undiluted sodium hypochlorite for an unsp ecified duration to rabbit skin (30).

4.2.1.2.2.2 Long-term (chronic) exposure

Ingestion

Slight liver damage (biochemical changes) has been observed in rats, when water containing 0.2 and 0.4% sodium hypochlorite has been given to them for 13 weeks. Approximate doses were 200 or 400 mg/kg/day. These effects were not observed in rats which had received 25-100 mg/kg/day (cited as 0.025%-0.1%). Some absolute weights, e.g., lungs, liver and spleen in males; salivary gland, lungs, heart and brain in females, we re significantly lower at 400 mg/kg/day (0.4%). But no microscopic changes were observe d in any organs (33). Rats were given drinking water with 0, 0.05% or 0.01% (males) or 0, 0.1% or 0.2% (females) sodium hypochlorite for 2 years. Approximate doses we re 0, 50 or 100 mg/kg/day for males or 0, 100 or 200 mg/kg/day for females. A dose-related in mean body weight has been observed, from the

sixteenth week on. No other si gnificant changes have been obs erved (33). In another study, effects on the immune system (reduced spleen weight and impaired macrophage functions) were observed in rats given dr inking water containing 15 or 30 mg/L sodium hypochlorite (approximately equivalent to 1.5 or 3 mg/kg/day) for 9 weeks. Where as no harmful effects were observed on the immune system at the appli cation of 0.5 mg/kg/day (5 mg/L) of sodium hypochlorite (34). No harmful effect s were observed in male guinea pigs or male rats, when they were exposed to sodium hypochlorite in wate r (8.1 mg/kg/day sodium hypochlorite; cited as 50 mg/L available chlorine for male gui nea pigs and up to 16.5 mg/kg/day sodium hypochlorite; cited as 50 mg/L available chlorine fo r male rats) for 5 or 6 weeks, respectively (35).

Skin sensitization

Negative results (0/20 guinea pigs sensitized) have been obtain ed for 8% sodium hypochlorite solution in a skin sensitization test (18). Insuffici ent details are available to evaluate a report of a positive result (positive reactions in 2/10 anim als) obtained using 6% sodium hypochlorite (pH 11.2) with the guinea pig ear swelling test for non-immunological contact urticaria (17).

Carcinogenicity

The International Agency for Research on Cancer (IARC) has concluded that there is inadequate evidence for the carcinogenicity of sodium hypochl orite in animals. A significant increase in

cancer cases was not seen in animals when drinking water containi ng sodium hypochlorite for 2 years at concentrations up to 2,000 mg/L (rats) or 1,000 mg /L (mice) was given (36). Similarly, in another study, no-dose related increase in tumour cases were observed in rats, which were given drinking water containi ng 0.05, 0.1 and 0.2% sodium hypochlorite (approximately 125 mg/kg/day) for 104 weeks (33). Negative results have been also obtained in a 6-generation study in which rats have been gi ven drinking water containing 100 mg/L chlorine (approximately 7 mg/kg/day for adults). From a more recent study in which increase in stomachMEPC 54/2/3

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I:\MEPC\54\2-3.doc tumour cases (3 different types) have been obser ved in male rats and increase in lymphomas and

leukaemia cases have been observed in female rats after receiving 100 mg/L and 750 mg/L sodium hypochlorite in drinking wa ter, respectively. But no firm conclusions can be drawn from this study, as the study has been limited by factor s, e.g., lack of statis tical evaluation of the results and lack of a dose response relationshi p (37). Another applic ation of a 1% solution (10g/L) to mice for 51 weeks, no significant increase in skin tumour cases has been observed (38). Whereas, application of a more than 10.5% so lution for 45 times over a period of 245 days promoted the development of skin tumours in mice following skin application of a known carcinogen. This study is limited by a l ack of statistical evaluation (39).

Teratogenicity, embryotoxi city and/or fetotoxicity

There is insufficient information available to draw any conclusions. No harmful effects on growth or survival have been observed in seven generations of rats when they have been given chlorinated drinking water cont aining 100 mg/L available chlorine (approximately equivalent to 7 mg/kg/day sodium hypoc hlorite for adults) (40).

Reproductive toxicity

There is insufficient information available to draw conclusions. An increase in abnormal sperm (shape) has been observed in mice after receiv ing 1.6 to 4.0 mg/kg/day hypochlorite in drinking water. But effect on reproductive outcome has not been assessed in this study (41). In another study no effects on fertility have been observed, where a 6-generation study has been performed on rats after giving them drinking water containing 100 mg/L chlori ne (approximately equivalent to 7 mg/kg/day sodium hypoc hlorite for adults) (40).

Mutagenicity

Sodium hypochlorite has not been suggested as mutagenic according to the available information. A positive result was obtained in a sperm morphology test using live mice. But this test can not measure genetic damage directly, as negative results have also been obtained in other in vivo tests. Abnormal sperm shape was observ ed in mice following oral administration of 1.6-4 mg/kg/day hypochlorite having pH 8.5 for 5 consecutive days. But no other toxic effect has been observed (41). Sodium hypochlorite was not mutagenic in other tests (chromosomal aberrations, aneuploidy and micronucleus test ) also with live mice using similar doses (40, 41, 42), whereas positive results have been obtai ned in a number of te sts using bacteria and cultured mammalian cells (27, 28-unconfirmed, 34, 35). A negative result (unscheduled DNA synthesis) has been obtained in hamster embryo cells (43).

4.2.1.3 Data on environmental fate and eff ect under aerobic and anaerobic conditions

4.2.1.3.1 Abiotic degradation of hypochlorite

By direct photolysis, significant degradation alwa ys happens. Under the a pplication of sunlight, the half-life of 10-15% available hypochlorite solu tion can be reduced by 3-4 times. It is very unstable at pH under 11. The stability is increased by dilution of the product. It is very unstable at 25% w/w and loose at 15 degree C in 3 months at 12.5% w/w. With the oxidation reactions with different inorganic and organic materials in solutions, chloramines, peroxy radicals and oxidized metals have been produced as degradation products.MEPC 54/2/3

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I:\MEPC\54\2-3.doc Biotic degradation

Not applicable as hypochlorit e is an inorganic compound.

Potential for bioaccumulation

Not applicable as hypochlorite is an ionizing inorganic compound.

4.2.1.4 Physical and chemical properties of hypochlorite

Property Value Melting point -6 deg C (5% solution) (44) Boiling point Reported to slow ly decompose above 40 deg C

Relative density (specific gravity) About 1.1 (5-10% solution); 1.2 (15% solution) (water = 1) (44) Solubility in water So luble in all proportions

Coefficient of oil/water distribution (parti tion coefficient) Log P(oct) = -3.42 (estimated) (45)

pH value 9-10 (5% solution; ìneu tralî preparation; no sodium hydroxide) (21); approx. 11 (5% solutions); greater than 11 (commerc ial bleach; 15% sodium hypochlorite) (19) Vapour density 2.5 (air = 1) Vapour pressure Does not form a vapour Saturation vapour concentration Not applicable Evaporation rate Not available probably very low Critical temperature Not applicable

4.2.2 Data on chlorine

4.2.2.1 Toxic effect of chlorine on aquatic life

A release of large quantity may be harmful to an aquatic environment in specific conditions that allow the gas to settle to a body of water. The following aquatic toxicity data are available for the chlorine component.

4.2.2.1.1 Acute toxicity data

Species End point Daphnia magna /water flea LC50 = 0.097 mg/L (30 minutes) Daphnia magna /water flea LC50 = 0.063 mg/L (60 minutes) Gambusia affinis /mosquito fish LC50 = 1.59 mg/L (30 minutes) Gambusia affinis /mosquito fish LC50 = 0.84 mg/L (60 minutes) Grass shrimp TLm = 22 mg/L (96 hours) Ocean spot TLm = 0.14 mg/L (24 hours) Daphnia magna /water flea TLm = 0/017 mg/L (46 hours) Oncorhyncus kisutsh / Coho salmon LC50 = 208 g/L (60 minutes)

Keratella cochlearis TL50 = 0.019 mg/L (4 hours)MEPC 54/2/3

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I:\MEPC\54\2-3.doc 4.2.2.1.2 Chronic toxicity data

Species End point Daphnia pulex LC50 = 0.49 mg/L (96 hours) Micropterus salmoides, largemouth

bass LC50 = 0.74 mg/L (24 hours)

Salmo gardnerii, rainbow trout LC50 = 0.08 mg/L (168 hours) Carassium auratus, gold fish TLm = 0.17 mg/L (24 hours) Lepomis macrochirus, bluegill

sunfish LC50 = 0.44 mg/L (96 hours)

Pimphales promelas, fathead minnow LC50 = 0.1 mg/L (96 hours) Lepomis cyanellus, green sunfish LC50 = 3.0 mg/L (24 hours)

4.2.2.2 Toxic effect of chlorine on mammals

Large amount of chlorine gas can have toxic effect on mammals. Following are the different aspects of toxicity for the chlorine component.

4.2.2.2.1 Causes

Chlorine gas is one of the most common irritant . Possible sources of exposure are as follows:

- industrial bleaching operations;

- sewage treatment; - household accidents involving the ina ppropriate mixing of hypochlorite cleaning solutions with acidic agents; - transportation releases; - swimming pool chlorina tion tablet accidents; - storage tank failure; and

- chemical warfare.

Adverse effects of inappr opriate mixtures of household cleane rs usually are caused by prolonged exposure to an irritant gas in a poorly ventilat ed area. The most comm on mixtures of cleaning agents are sodium hypochlorite (ble ach) with acids or ammonia. Po tential irritants released from such mixtures are chlorine gas, chloramines, and ammonia gas.

4.2.2.2.2 Clinical effects

.1 Summary of exposure

Mechanism of activity

The mechanisms of the biological activity of the chlorine ar e poorly understood and the predominant anatomic site of in jury may vary, depending on the chemical species produced. Cellular injury is believed to result from the oxidation of functional groups in cell components, from reactions with tissue water to form hypochlorous and hydrochloric acid, a nd from the generation of free oxygen radicals. Although the idea that chlo rine causes direct tissue damage by generating free oxygen radicals was once accepte d, this idea is now controversial.MEPC 54/2/3

ANNEX Page 13

I:\MEPC\54\2-3.doc Solubility effects

Hydrochloric acid is highly soluble in water. The predominant targets of the acid are the epithelia of the ocular c onjunctivae and upper respiratory mucus membranes. Hypochlorous acid is also highl y water soluble with an injury pattern similar to hydrochloric acid. Hypochlorous acid may account for the toxicity of elemental chlorine and hydroc hloric acid to the human body.

Early response to chlorine gas

Chlorine gas, when mixed with ammonia, reacts to form chloramine gas. In the presence of water, chloramines decom pose to ammonia and hypochlorous acid or hydrochloric acid. The early response to chlorine exposu re depends on these

effects:

.1 concentration of chlorine gas;

.2 duration of exposure;

.3 water content of the tissues exposed; and

.4 individual susceptibility.

Immediate effects

The immediate effects of chlorine gas to xicity include acute inflammation of the conjunctive, nose, pharynx, larynx, trachea, and bronchi. Irrita tion of the airway mucosa leads to local edema secondary to active arterial and capillary hyperemia. Plasma exudation results in filling the alveoli with edema fluid, resulting in pulmonary congestion.

Pathologic findings

Pathologic findings are nonspecific. Th ey include severe pulmonary edema, pneumonia, hyaline membrane formation, multiple pulmonary thromboses, and ulcerative tracheobronchitis. The hallmark of pulmonary injury associated with chlorine toxicity is pulmonary edema, manifested as hypoxia. Noncardiogenic pulmonary edema is thought to occur when there is a loss of pulmonary capillary integrity, and subsequent tran sfusion of fluid into the al veolus is present. The

onset can occur with in minutes or hours, depending upon severity of exposure. Persistent hypoxemia is associated with a higher mortality rate.

The eye seldom is damaged severely by ch lorine gas toxicity; however, burns and

corneal abrasions have occurred. Acids formed by the chlorine gas reaction with the conjunctival mucous membranes are bu ffered, in part, by the tear film and the proteins present in tears. Consequentl y, acid burns to the eye typically cause epithelial and basement membrane damage but rarely damage deep endothelial cells. Acid burns to the periphery of the cornea and conjunctiva often heal uneventfully, while burns to the centre of the cornea may lead to corneal ulcer formation and subsequent scarring.MEPC 54/2/3

ANNEX Page 14

I:\MEPC\54\2-3.doc In animal models of chlorine gas toxici ty, immediate respirat ory arrest occurs at 2,000 mg/L, with the lethal concentra tion for 50% of exposed animals in the range of 800-1,000 mg/L. Bronchial constriction occurs in the 200 mg/L range with evidence of effects on ciliate activity at exposure levels as low as 18 mg/L. With acute exposures of 50 mg/L and s ubacute inhalation as low as 9 mg/L, chemical pneumonitis and bronchiolitis obliterans have been noted. Mild focal

irritation of the nose and trachea without lo wer respiratory effects occur at 2 mg/L.

In one study of chlorine gas toxicity conducted on human volunteers, 4 hours of exposure to chlorine at 1 mg/L produced significant decreases in forced vital capacity (FVC), forced expiratory vol ume in one second (FEV1), and peak expiratory flow rate. An increase in airway resistance was demonstrated. In a controlled volunteer study, patients with hyper reactive airways demonstrated an exaggerated airway response to exposure of 1 mg/L chlorine gas. While in another study, patients with rhinitis and advanced age demonstrated a significantly greater nasal mucosal congestive response to chlori ne gas challenge than patients who did not have rhinitis or those of younger age. However, the mechanism of response to chlorine in nasal tissue does not appear to include mast cell degranulation.

Frequency

In the United States: Chlorine gas is one of the most common single, irritant, inhalation exposures, occupationally a nd environmentally. In 1983, an estimated 191,000 United States workers were at risk of exposure to chlorine in various forms. In a recent study of 323 cas es of inhalation exposures reported to poison control centres, the largest single source of exposure (21%) was caused by mixing bleach with other products. The gr eatest numbers of victims were injured in manufacturing and the entertainment and recreation services sectors.

Internationally: Internationally, chlorine gas accounts for the largest single cause of major toxic release incidents. Use of chlorine internationally is parallel to use by the United States in chemical, paper, and te xtile industries and in sewage treatment.

Mortality/Morbidity: Five-year cumulativ e data (1988-1992) from the American Association of Poison Controls Centersí National Data Collection System revealed 27,788 exposures to chlorine. Of these exposures, the outcome was categorized in 21,437 cases; 40 resulted in a major effect, 2,091 resulted in a moderate effect, 17,024 resulted in a minor effect, and 2,099 had no effect. Three

fatalities occurred. Another case series a ssociated worse outcomes with advanced age, initial low peak expira tory flow rate (PEFR), expos ure in an enclosed space, and prolonged short- and long-term exposure.

.1 Minor effects include signs or symptoms that are minimally bothersome and quickly resolved.

.2 Moderate effects include signs or symptoms that are more pronounced or more prolonged than minor effects. These may have asystemic nature and usually require some form of treatment.

.3 Major effects include signs or symptoms that are life-threatening or result in significant residual disability or disfigurement.MEPC 54/2/3

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I:\MEPC\54\2-3.doc Symptoms of exposure to chlorine gas

It includes rhinorrhea, nausea, headache, dizziness and syncope, muscle weakness, choking (cramps in the pharyngeal muscle s), epigastric pain, a feeling of suffocation, apprehension and anxiety, de rmatitis, retrosternal burning and substernal pain, respiratory distre ss, shortness of breath, pneumonia, bronchospasm and acute lung injury. Bronchopneumonia or respiratory collapse may be lethal complications.

.2 Acute exposure

(i) Inhalation

It is the main route of chlorine gas e xposure. Chlorine gas vapours are heavy and settle in low areas; odour is not a good indicator of e xposure severity. Chlorine gas is severely irritating on contact and can be caustic to the eyes, skin, nose, throat, and mucous membranes; exposure can result in severe or permanent eye injury. Contact with the escaping comp ressed liquid can cause frostbite and/or chemical burns to the eyes and skin. Chlorine combines with tissue water to produce HCl, producing injury and r eactive oxygen species. Respiratory symptoms may be immediate or delayed up to several hours after exposure. Symptoms generally resolve within 6 hours after mild exposures, but may

continue for more than 24 hours after severe exposures. Deterioration may

continue for several hours.

(ii) Mixing household cleaning age nts (bleach with acids or ammonia)

It produces chlorine gas and other active chlorine compounds such as chloramines. For example, mixing household bleach (sodium hypochlorite) with acid toilet bowl cleaners produces chlorine gas. Ammonia mixed with bleach

results in the release of chloramine. A single acute exposure to these reaction products commonly produces coughing, la crimation, conjunctivitis, a burning sensation in the chest, pneumonitis, and tachycardia. A few patients may experience vomiting, diaphoresis and headache. Severe cases may result in acute lung injury.

(iii) Green hair, dental enamel erosion, conjunctivitis, lacrimation, nasal and throat irritation may occur. Anosmia has also been reported.

(iv) Cardiovascular effect

Tachycardia and initial hypertension followed by hypotension may occur. Cardiovascular collapse may ensue following severe exposure.

(v) Respiratory effect

.1 Feeling of burning and suffocation, coughing, choking, laryngeal edema, bronchospasm, and hypoxi a may occur. In high concentrations, syncope and almost immediate death may occur. Acute lung injury is common after severe exposure.MEPC 54/2/3

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I:\MEPC\54\2-3.doc .2 Exposures produced flu-like symptoms and high risk of developing reactive airway dysfunction syndrome.

.3 Pulmonary dysfunction has been reported in some individuals following severe inhalational effect.

(vi) Neurological effect

Headache may develop. Agitation and a nxiety may develop in patients with significant respiratory compromise.

(vii) Gastrointestinal effect

Vomiting may occur following initial exposure.

(viii) Acid base effect

Following severe exposure, metabolic acidosis secondary to hypoxemia may be

noted.

(ix) Dermatological effect

Dermal exposure may cause erythema, pain, irritation, and cutaneous burns.

(x) Reproductive hazards

Chlorine (as hypochlorite) is teratogenic in experimental animals. Evaluations of sperm morphology in murine experime nts demonstrated the presence of

mutations.

(xi) Carcinogenicity

.1 Human effect

Lymphoma has been observed in relation to water treatment with

chlorine. Associations with incr eased renal, bladder and gastric

cancers have also been found but firm conclusions cannot be drawn because of mixed exposures with caustic acids.

.2 Effect on animals

Chlorine gas was not carcinogenic in mice and rats exposed to varying concentrations. Chlorine administered in drinking water produced lymphomas and/or leuk aemia in rats, but was not carcinogenic in a third study.

(xii) Genotoxicity

Haloacetonitriles have produced DNA stra nd breaks in cultured human cells. Mutations have been detected in S typhimurium and chromosome aberrations have been detected in human lymphocytes.MEPC 54/2/3

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I:\MEPC\54\2-3.doc Acute effect of chlorine exposure

Exposure to

Chlorine Gas Acute Effect

1 to 3 mg/L Mild irritation

3 to 6 mg/L Itching, stinging and burning of the eyes, lacrimation, blepharospasm, as well as burning of the nose and throat, sneezing, coughing, and bloody nose or sputum 5 to 10 mg/L Moderate upper respiratory irritation 10 to 20 mg/L Intense irritation 30 mg/L chest pain, vomiting, dyspnea and cough

Acute toxicological effect

Species End Point Human (inhalation) LCLo = 2530/m 3 (30 minutes); Pulmonary effects Human (inhalation) LCLo = 500 mg/m 3 (5 minutes) Rat (inhalation) LC50 = 293 mg/L (1 hour) Mouse (inhalation) LC50 = 137mg/L (1 hour)

.3 Chronic exposure

Moderate or severe exposure (associate d with acute marked airflow obstruction and air-trapping) often results in resi dual pulmonary dysfunction, most notably hyperreactive airways and low residual vol umes. These long-term sequelae of acute exposure may persist for several years.

Chronic exposure to chlorine gas may cause dyspnea, palpitations, chest pain, reactive upper airways dysfunction syndrome, dental enamel erosion, and an increased prevalence of vira l syndromes. Chronic e xposure to 15 mg/L produced coughing, hemoptysis, chest pain and sore throat. Chronic exposure to chlorine gas is one of the most frequent causes of occupational asthma.

Hypoxia is common, whereas CO 2 retention and pulmonary function abnormalities are generally less comm on. Rales, hypoxemia and airway

obstruction have been found.

Chronic effect of chlorine exposure

Exposure to Chlorine Gas Chronic Effect 14 mg/L (30 minutes) Severe pulmonary damages 430 mg/L or more (30 minutes) May be fatal 34 to 51 mg/L (60 minutes) May be fatal 1,000 mg/L Can be fatal within a few breaths

Chronic toxicological effect

Species End Point Dog (inhalation) LCLo = 800 mg/L (30 minutes) Cat (inhalation) LCLo = 660 mg/L (4 hours) Rabbit (inhalation) LDLo = 660 mg/L (4 hours)MEPC 54/2/3

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I:\MEPC\54\2-3.doc History of toxicity of chlorine

- cough (52-80%); - shortness of breath (20-51%); - chest pain (33%); - burning sensation in the throat and substernal area (14%); - nausea or vomiting (8%); - ocular and nasal irritation (4-6%); - choking; - muscle weakness; - dizziness; - abdominal discomfort; and

- headache.

Physical toxic effect of chlorine

- decreased breath sounds; - tachypnea; - tachycardia; - wheezing; - nasal flaring; - intercostal and subcostal retractions; - cyanosis; - rhinorrhea; - lacrimation; - hoarseness of the voice or stridor; - rales (acute respiratory distre ss syndrome [ARDS]/noncardiogenic pulmonary edema); and - crepitus (associated wi th pneumomediastinum).

4.2.2.3 Physical and chemical properties of chlorine

Physical State Gas

Colour Yellow or green

Odour Distinct odour, irritating odour Molecular weight 70.906

Molecular formula Cl2 Boiling point -31F (-35C) Freezing point -150F (-101C) Vapour pressure 5168 mm Hg@ 21C Vapour density (air = 1) 2.49 Specific gravity Not applicable Density 3.214 g/L @ 0C Water solubility 1.46% @ 0C pH Not applicable Volatility Not applicable

Odour threshold 0.01 mg/L Evaporation rate Not applicable Viscosity 0.01327 cP @ 20C

Coefficient of water/oil distribution Not applicable Solvent solubility Soluble: alkaliMEPC 54/2/3

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I:\MEPC\54\2-3.doc 4.2.3 Hydroxyl radical

4.2.3.1 Hydroxyl radical production by electrolytic method

Hydroxyl radicals can be genera ted from the oxidation of water. Organic compounds were completely degraded by the reaction with gene rated OH radicals. But in the electrochemical reactor the radicals could not be monitored directly due to its very short life span in aqueous solution. A probe compound, p-chloro benzoate can be used which reacts very fast with

OH radicals with a second-order rate coefficient k (OH + pCBA) = 5 x 10 9 M -1 s -1 , it does not react with other reaction species. So OH radical can be measured from the decrease of p-CBA.

Here titanium and titanium coated with rutheniu m oxide and platinum oxide used as cathode and anode, respectively, in th e electrochemical reactor. There are some factors which affect the production rate of OH radicals in the reactor.

.1 Inter electrode gap: With an increase in the inter electrode gap the rate of production of OH radicals will be decreas ed, due to increase in the electrical resistance. In the considered experiment , an applied current was decreased from 1A to 0.6A when the electrode ga p increased from 10 mm to 20 mm.

.2 Temperature: With an increase in th e temperature the production rate of

OH radical will be increased due to increa se in mass transport of the electroactive species to the electrode surface.

.3 Applied voltage: In the considered e xperiment, the applied voltage has been ranged between 2V to 6V. OH radical production was significantly enhanced when applied voltage was increased from 2V to 4V. As the limiting current for OH radical production in the given condition flows at between 2V and 4V, further increase of applied voltage did not enhance the OH radical production.

.4 Electrical conductivity: The OH radical production has been increased with the

increase in the electrical conductivity. In the consid ered experiment, during the

variation of conductiv ity between 8ms cm-1 to 10ms cm-1, there was not much difference in the production. But when it is 20ms cm-1, then the production rate has been enhanced significantly.

4.2.3.2 Toxic effect of hydroxyl ions on fishes

The presence of hydroxyl ions in water is the key factor for controlling the pH of the aquatic environment. Whenever higher amount of hydroxyl i ons is present, the pH of the water will be in higher range. Therefore, the presence of hydroxyl radicals affects the aquatic life indirectly by changing the pH of the water.

Each species of fish has its own very narrow range of pH preferen ce and levels out side of this range will cause health problems. For exampl e, koi prefer a range between 7 and 8.5, while some tropical fish prefer water that is slightly acidic. There are several ways that pH can affect

fish health.

.1 High acidity or alkalinity can cause direct physical damage to skin, gills and eyes.MEPC 54/2/3

ANNEX Page 20

I:\MEPC\54\2-3.doc .2 Prolonged exposure to sub-lethal pH le vels can cause stress, increase mucus production and encourage epithelial hyperplasi a (thickening of the skin or gill epithelia) with sometimes fatal consequences.

.3 Fish also have to maintain their ow n constant internal pH. Even small fluctuations of blood pH can prove fatal. Extreme external or water pH can influence and affect blood pH, resulting in either acidosis or alkalosis of the blood.

.4 The other consideration is diurnal shif ts in pH, mainly as a consequence of photosynthesis as explained above. Large, fluctuations even though they may still be within the preferred range are likely to be stressful and damaging to health.

.5 Changes in pH will affect the t oxicity of many dissolved compounds. For example, ammonia becomes more toxic as pH increases.

4.2.3.3 Toxic effect of hydroxyl radicals in mammals

The systemic toxicity of hydroxyl ions confounds with an elevated blood pH. The normal pH of blood is 7.35. Alkalosis causes hyperactivity to the central nervous system with above pH 7.8, tetanus, extreme excitability, c onvulsions and respiratory stop. The blood pH is regulated by

three distinct mechanisms. An immediate mech anism is the buffering capacity of bicarbonate (1.5 g/L). A short-term mechanism is the respir ation compensation. Alkalosis will be decreased by a slow and superficial respiration, a low CO 2 expiration and an accumulation of HClO 3 - (higher than 1.7 g/L). A long-term m echanism is the renal compensation.

4.2.4 Data on the effluent of el ectrolytic disinfection system

The data on the toxicity of elect ric disinfection of water has its limits because the evaluation technology required has yet to be implemented. B ecause the micro-organisms are affected by not just the residual Active Substances, but also di fferences in potential, radicals and electrical oxidization during electric disinfect ion, it is difficult to measure the role these residual Active Substances have in the toxicity of the water. The Active Subs tances in disinfected water are types of residual chlorides so that the data give n in the above paragraph can also be applied to electrochemically disinfected water.

5 RISK CHARACTERIZATION

5.1 Screening for persistency, bioaccumulation and toxicity

.1 Persistence (P)

By direct photolysis, significant degradat ion always happens. In the oxidation reactions with different inorganic and organic materials in solutions, peroxy

radicals and oxidized metals have been produced as degradation products. Due to its degradation, total residual chlorine is not persistent in the environment. In nature, half-life is in the order of hours or a few days at maximum.

.2 Bioaccumulation (B)

Due to the high water solubility and the low octanol water partition coefficients of the hypochlorite, there is no concern for a possible bio-accumulation potentialMEPC 54/2/3

ANNEX Page 21

I:\MEPC\54\2-3.doc (log Kow below 0). A rat study using ra diolabelled hypochlorous acid has shown that it is absorbed fairly rapidly in seru m and eliminated from plasma with a halflife of 44 hours. Hypochlorite is an i onizing inorganic com pound so that it does not accumulate in the body.

.3 Toxicity (T)

There are no indications for relevant effects concerning carcinogenicity, mutagenicity or reproductive toxicit y. The active component, hypochlorite does not fulfil the PBT criteria as outlined in document MEPC 53/2/1, annex, paragraph 6.4.1.

Table 3: Criteria for identification of PBT substances

Criterion PBT criteria

Persistence half-life: > 60 days in marine water, or > 40 days in freshwater, or > 180 days in marine sediment, or 120 days in freshwater sediment

Bioaccumulation CF > 2,000 or LogPoctanol/water ≥ 3 Toxicity Chronic NOEC < 0.01 mg/l

5.2 Testing toxicity of the treated ballast water

The toxicity of the treated ballast water can be evaluated by the concentr ation of residual Active Substances in it. Because the concentration of Active Substances created during electrolytic disinfection, excluding total residua l chlorine, is very low, we can test the toxicity of treated ballast water by the concentration of total residua l chlorine in it. In the United States, they produce and supply the drinking wate r using the electrolytic disinfect ion process. Because total residual chlorine is mainly used in the disinf ection of drinking water, their toxicity in low

concentrations has alrea dy been assessed thoroughly.

When the system is operating for disinfection, the c oncentration of total resi dual chlorine that is produced is about 30mg/L. It is degraded in the ballast tank and thus th e final concentration of total residual chlorine that is discharged is less than a few mg/L. In acute toxicity tests, hypochlorite solution of 10,000 mg/L was placed on the skin for 48 hours. There was no

irritation or discoloration of the skin. Total residual chlorine used for ballast water treatment is too low to show any toxicity it may differ ac cording to the amount of microorganisms in the

water. The half-life of residual chlorine was ha lf a day in light conditio ns. After a day it was almost completely decomposed to the level belo w detection limit. Wit hout light, the half-life was about three days. The lower the amount of organisms is, the longer it took for the residual chlorine to completely decompose. The degrada tion rate of residual chlorine is dependent on the amount of reducing agents in seawater.

Taking into consideration that the NOEC of sodi um hypochlorite is 0.087mg/ L, and that the total

residual chlorine at the concentr ation of 10-30 mg/L recommended for Ballast water treatment is completely degraded already afte r 1.1 days under light condition, it can be a ssumed that there are no biological effects of treated ballast water.MEPC 54/2/3

ANNEX Page 22

I:\MEPC\54\2-3.doc 5.3 Risk characterization and analysis

In order to calculate the half-life of Active Substa nces in treated water, total residual chlorine in electrochemically disinfected water was monitored, and the results are shown below. The experiment was conducted with seawater cont aining 6,837 cells/ml of phytoplankton, 337 inds./ l of zooplankton at 5.2 volts (14.5 ampere).

Under in situ light condition, total residual chlo rine (TRC) decreased to below detection limit after about one day. The half-life under the dark condition reached before the two days.

5.4 Effect of TRC discharged to seawater on aquatic organisms

TRC discharged to seawater is readily degraded to below dete ction limit under sunlight. In addition to that, as shown in table 6, when dilution effect (about 5,000 times dilution) is considered, TRC goes down to a level in nature . Therefore, there is no effect on aquatic organisms.

Table 4: Treated ballast water discharge Scenario for hypochlorite

Initial dose 30 mg/l Retention (degradation) time [h] zero
Predicted environmental

concentration zero

No observed effect concentration 0.014 mg/l

PEC/NOEC ratio 0.087 mg/l

Port statistics 0.17 Selected port Rotterdam

Water volume 840,000,000 t Number of incoming ships 29,450/a; 80/d
Total gross tonnage 489,222,000 GT/a; 1,323,074 GT/d Average amount of ballast water 144,876,600 t/a; 396,922t/d

5.5 Bioaccumulation, octanol/water partition coefficients

Log P(oct) of hypochlorite is reported to be -3.42. Low octanol water partition coefficient indicates low potential for bioaccumulation. Hydrochl oric acid is highly soluble in water and an ionizing inorganic compound so that this can not be accumulated in biota.

5.6 Sediment toxicity

From the physical and chemical properties, the high water solubility, the low log kow and the instability in water, it is not expected th at the hypochlorite will reach the sediment to a

considerable extent and accumulate in sediment.

6 EVALUATION CRITERIA

6.1 Ship and personnel safety

Total residual chlorine produced typically ranges from 10 to 30 mg/L in the Electro-Clean system operating with an applied voltage lower than 7 volts. No skin irritation was experienced by 20 volunteers after application of a 1% hypochl orite solution (pH unspecified) for 48 hours underMEPC 54/2/3

ANNEX Page 23

I:\MEPC\54\2-3.doc a patch. The possibility of risk from the electrochemically treated water to personnel does not exist. The system is also sealed tightly. Th is makes human exposure to treated water impossible under normal operational conditions. Since the Electro-Clean system is fully automated, cutting-off electricity to the system alone can ensure the safety of the ship and personnel at the time of emergency.

6.2 Environment protection

The concentration levels of total residual chlorine in treated water discharged from the Electro-Clean system is extremely low. TRC is easily decomposed by su nlight, micro-organisms and other reductants. Thus, residual chlorine will not be accumulated in harbors or ports. Octanol/water partition coefficien t of TRC is calculate d to be log P(oct) = -3.42. TRC is not persistent and bio-accumulative. In reality, chlori ne is used for the disinfection of drinking water not only in the United Kingdom and the United St ates, but also in most other countries.

7 REGULATION OF THE USE OF AC TIVE SUBSTANCES AND PREPARATIONS

7.1 Handling of Active Substances and preparations

Electro-Clean for ballast water treatment system uses the strainer already installed on the ship to remove the large pieces of suspended solids. Th e Electro-Clean system mainly uses radicals, electric voltage, etc. to disinfect . These Active Substances disappear in seconds after they are produced.

The concentration levels of total residual ch lorine (TRC) formed during operation varies according to water temperature, conductivity, organi c and inorganic substances in the water. TRC is typically in the ranges of 10 and 30 mg/L. The operator or ship crew does not have to take special precautions when dealing with the balla st water. The system automatically controls the amount of voltage and current in order to maintain the concentr ation level of active chlorides to less than 30 mg/L.

7.2 Hazard documentation and labelling

The reactivity of the total residual chlorine in electrolytically disinf ected ballast water is extremely high so that it is rapidly decomposed in seawater. The concentration level of total

residual chloride in the ballast water is below 30 mg/L. There is no possi bility of explosion. Although there are only few precautions to be taken for management, there may be need to ventilate hydrogen generated during the elect rolytic disinfection in order to prevent

accumulation.

A document that deals with th e harmful substances produced during electrolysi s including the MSDS (IMDG code entry) data has b een summarized and provided below.

MSDS

The Material Safety Data of 2~3% w/w sodium hypochlorite solu tion have been reported to be hazardous in case of eye and skin contact. For the carcinogenic effects, this material is not

known to cause cancer in animals or humans. Ther e is no available Material Safety Data sheet for the 0.003% w/w sodium hypochlorite solution which is generated in the Electro-Clean

system.MEPC 54/2/3

ANNEX Page 24

I:\MEPC\54\2-3.doc IMDG

IMDG Code 8186, UN No.1791, Class 8, Packaging Group II/III, EmS No.8-08, MFAG table No.741 covers the hypochlorite solu tions with more than 5% available chlorine. However, it does not cover the 0.003% sodium hypochlorite solution wh ich is generated in the Electro-Clean system.

Conclusion

.1 It was found that total residual chlori ne at the concentration of 10~30mg/L recommended for ballast water treatment is completely degraded already after 1.1 days under light condition.

.2 The hydrogen peroxide and ozone concentra tion of the electrolytic solution is very low in comparison with the free chlorine . The maximum concentration produced during electrolysis of seawater is belo w 0.1 mg/L for both hydrogen peroxide and

ozone.

.3 From the acute toxicity test, no skin irritation was experienced by 20 volunteers after application of a 1% hypochlorite solution (pH unspecified) for 48 hours under a patch. The possibility of danger to personnel from the electrolytically

treated water does not exist.

.4 Since chlorine is being used to disi nfect drinking water not only in the United Kingdom and the United States, but also in most other c ountries, there is almost

no concern over PBT levels.

.5 The half-life of total residual chlorine was 0.58 day under light condition and 2.0 days under dark condition. No danger to humans a nd environment is expected.

References

1 P. Drogui, S. E l m a leh, M. Ru m eau, C. B e rnard and A. R a m baud. Oxidi s ing and disinfecting by hydrogen peroxide produced in a two-electrode cell. Water Research, Volume 35, Issue 13, September 2001, pages 3,235-3,241.

2 Milko A. Jorquera, Gustavo Valencia, Mitsuru Eguchi, Masahiko Katayose and Carlos Riquelme. Disinfection of seawater for hatchery aquaculture systems using electrolytic water treatment. Aquaculture, Volume 207, Issues 3-4, 24 May 2002, pages 213-224.

3 S. Yu. Bashtan, V.V. Goncharuk, R.D. Chebotareva, V.N. Belyakov and V.M. Linkov. Production of sodium hypochlorite in an electro lyser equipped with a ceramic membrane. Desalination, Volume 126, Issues 1-3, 1 November 1999, pages 77-82.

4 Chizuko Morita, Kouichi Sano, Shinichi Mori matsu, Hiromasa Kiura, Toshiyuki Goto, Takehiro Kohno, Wu Hong, Hiro fumi Miyoshi, Atsuo Iwasawa, Yoshiko Nakamura et al

. Disinfection potential of electrolyzed solu tions containing sodium chloride at low concentrations. Journal of Virological Methods, Volume 85, Issues 1-2, March 2000, pages 163-174.MEPC 54/2/3

ANNEX Page 25

I:\MEPC\54\2-3.doc 5 Bearman G. Ocean Chemistry and d eep-sea sediments. Pergamon, Sydney, 1989.

6 Norihito Nakajima, Takashi Nakano, Fumiue Harada, Hiromasa Taniguchi, Isao Yokoyama, Jun Hirose, Eriko Daikoku and Kouichi Sano. Evaluation of disinfective potential of reactivated free chlorine in pooled tap water by electrolysis. Journal of Microbiological Methods, Volume 57, Issue 2, May 2004, pages 163-173.

7 Chumilall V., Govender M., Jonnalagadda S.B. Journal of Environmental Science Health, Volume 7 (2002), page 1,523, and references therein.

8 Toxic Substances profile: Biocides used in Cooling Water Disinfection: United Kingdom marine special areas conservations.

9 E. Joyce, T.J. Mason, S.S. Phull and J.P. Lorimer. The development and evaluation of electrolysis in conjunction with power u ltrasound for the disinfection of bacterial suspensions. Ultrasonics Sonochemist ry, Volume 10, Issues 4-5, July 2003, pages 231-234.

10 Hong-Xing Shi, Jiu-Hui Qu, Ai-Min Wang and Jian-Tuan Ge. Degradation of microcystins in aqueous solution with in situ electrogenerated active chlorine. Chemosphere, Volume 60, Issue 3, July 2005, pages 326-333.

11 K. Vijayaraghavan, T.K. Ramanujam and N. Ba lasubramanian. In si tu hypochlorous acid generation for the treatment of syntan wastewater. Waste Management, Volume 19, Issue 5, August 1999, pages 319-323.

12 L. Migliore, L. Tancioni, et al . Ecotoxicity testing of Tibe r River water as compared to

CLO 2 , NaCLO & PAA.

13 Fisher D.J., D.T. Burton, L.T. Yonkos, S.D. Turley, B.S. Turley, G.P. Ziegler and

E.J. Zillioux. Acute and Short-Term Chr onic Effects of Continuous and Intermittent Chlorination on Mysidopsis bahia and Menidi a beryllina. Envi ron. Toxicol. Chem. 13(9):1,525-1,534.

14 Habets J.M.W. et al . Sensitization to sodium hypochl orite causing hand dermatitis. Contact Dermatitis, Volume 15 (1986), pages 140-142.

15 Eun H.C. et al . Sodium hypochlorite dermatitis. Contact Dermatitis, Volume 11, no. 1 (July 1984), page 45.

16 Nixon G.A. et al . Interspecies comparisons of skin irritancy. Toxicology and Applied pharmacology, Volume 31 (1975), pages 481-490.

17 Hostynek I.J. et al . Hypochlorite sensitivity in man. Contact Dermatitis, Volume 20, no. 1 (January 1989), pages 32-37.

18 Racioppi F. et al . Household bleaches based on sodi um hypochlorite: review of acute toxicology and poison control center expe rience. Food and Chemical Toxicology, Volume 32, no. 9 (September 1994), pages 845-861.MEPC 54/2/3

ANNEX Page 26

I:\MEPC\54\2-3.doc 19 Grant W.M. et al . Sodium hypochlorite, In : Toxicology of the eye, 4 th edition, Charles C. Thomas, 1993, pages 791-799.

20 Ingram III T.A.. Response of the human eye to accidental exposure to sodium hypochlorite. Journal of Endodontics, Volume 16, no. 5 (May 1990), pages 235-238.

21 Gosselin R.E. et al . Hypochlorite, In: C linical toxicolo gy of commercial products.

5 th edition, William and Willkins, 1984, pages III 202-III 205.

22 Ward M.J. et al . Hypernatraemia and hypochloraemic acidosis after bleach ingestion. Human Toxicology, Volume 7 (1988), pages 37-38.

23 Ross M.P. et al . Fatal ingestion of sodium hypoc hlorite bleach with associated hypernatremia and hypochloraemic metabol ic acidosis. Veterinary and Human Toxicology, Volume 41, no. 2 (Apr. 1999), pages 82-86.

24 Strange D.C. et al . Corrosive injury of the stomach: report of a case caused by ingestion

of Clorox Æ and experimental study of injurious injuries. Archives of Surgery, Volume 62, no. 3 (March 1951), pages 350-357.

25 Williamson K.S. A prognostic study of occ upational dermatitis cases in a chemical

works. British Journal of Industria l Medicine, Volume 24 (1967), pages 103-113.

26 Ng S.K. et al . Contact allergy to sodium hypochlor ite in Eusol. Contact Dermatitis, Volume 21 (1989), page 281.

27 Kaufman A.Y. et al . Hypersensitivity to sodium hypochlorite. Journal of Endodontics, Volume 15, no. 5 (May 1989), pages 224-226.

28 Nixon G.A. et al . Evaluation of modifi ed methods for determining skin irritation. Regulatory Toxicology and Pharmaco logy, Volume 12 (1990), pages 127-136.

29 Kallen B.A. et al . Drinking water chlorination and delivery outcome a registry based study in Sweden. Reproductive Toxicology, Volume 14, no. 4 (Jul y 2000), pages 303-309.

30 Anonymous. Sodium hypochlorite, Data sheet no. 18 4 / 70. In dustrial Bio Test Laboratories, Inc., Northbrook, Illinoi s, 1970 (NIOSHTIC Control No. 00066084).

31 Momma J. et al . Acute oral toxicity and ocular irri tation of chemicals in bleaching agents (English abstract). Food Hygiene Jo urnal, Volume 27 (1986), page 553.

32 Hasegawa R. et al . Carcinogenicity study of sodium hypochlorite in F344 rats. Food and Chemical Toxicology, Volume 24. no. 12 (1986), pages 1,295-1,302.

33 Exon J.H. et al . Immunotoxicologic evaluation of chlorine based drinking water disinfectants, sodium hypochlorite and monoc hloramine. Toxicology, Volume 44 (1987), pages 257-269.

34 Cunninghum H.M., et al . Effect of sodium hypoclorite on the growth of rats and guinea pigs. American Journal of Veterinary Research, Volume 41. no. 2 (February 1980), pages 295-297.MEPC 54/2/3

ANNEX Page 27

I:\MEPC\54\2-3.doc 35 Kurokawa Y., et al . Long-term in vivo carcinogenicity tests of potassium bromate, sodium hypochlorite, and sodium chlorite conducted in Japan. Environmental health Perspectives, Volume 69 (November 1986), pages 221-235.

36 Soffritti M., et al . Results of long-term carcinogenicity studies of chlorine in rats. Annals of the New York Academy of Sciences, Volume 837 (December 1997), pages 189-208.

37 Kurokawa Y., et al . Studies on the promoting and comp lete carcinogenic activities of some oxidizing chemicals in skin carcinogenesis. Cancer Letters, Volume 24. no. 3 (1984), pages 299-304.

38 Hayatsu H., et al . Potential cocarcinog enicity of sodium hypo chlorite. Nature, Volume 233 (October 15, 1971), page 495.

39 International Agency for Research on Can cer (IARC). Hypochlorite salts. In: IARC monographs on the evaluation of carcinogenic risks to humans, Volume 52. Chlorinated drinking-water; chlorination by -products; some other halogenated compounds; cobalt and cobalt compounds. World Health Organization, 1991, pages 159-176.

40 Meier J.R., et al . Evaluation of chemicals used for drinking water disinfection for production of chromosal damage and sperm-h ead abnormalities in mice. Environmental Mutagenesis, Volume 7 (1985), pages 201-211.

41 Hayashi M., et al . Micronucleus tests in mice on 39 food additives and eight miscellaneous chemicals. Food and Chemical Toxicology, Volume 26, no. 6 (1988) pages 487-500.

42 Hamaguchi F., et al . Assessment of genotoxicity of dent al antiseptics: ability of phenol, guaiacol, p-phenolsulfonic acid, sodium hypoc hlorite, p-chlorophenol, m-cresol or formaldehyde to induce unscheduled DNA synthe sis in cultured Syrian hamster embryo cells. Japanese Journal of Pharmacol ogy, Volume 83, no. 3 (July 2000), pages 273-276.

43 Sodium hypochlorite (solu tion with 150g/l active chlori ne); and Sodium hypochlorite (solution). In: Chemical safety sheets: work ing safely with hazardous chemicals. Kluwer Academic Publishers, 1991, pages 806-807.

44 Syracuse Research Corporation. Intera ctive LofKow (KowWin) Database demo.

Available from World Wide Web: <h ttp://syrres.com/esc/kowdemo.htm>.

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