Copper dibromide

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

To date, toxicological experiments are oriented to the display of sublethal effects, obtained often with in vitro cultures of fish or mammalian cells, because it has been proven that these models correlate well with in vivo tests and that they can be used to predict the undesirable effects of various pollutants.
Among the various in vitro assays, the neutral red incorporation assay, the MTT reduction assay, and the Coomassie blue assay are among the most used; they have been selected for this study, as well as the cellular growth rate assay and the RNA synthesis rate determination assay. These assays, performed on the L-929 established cell line of murine fibroblasts, allowed the toxicological potential of 16 inorganic environmental pollutants (Ba, Cd, Co, Cr, Cu, Fe, Ge, Hg, Mn, Nb, Pb, Sb, Sn, Ti, V, and Zn) to be specified. Concurrently, the toxicity of these inorganic substances was tested on the most commonly used ecotoxicological model, Tetrahymena pyriformis GL, and the results were compared to the in vivo data mentioned in the literature.

GLP compliance:

not specified

Analytical monitoring:

yes

Test organisms (species):

Tetrahymena pyriformis

Details on inoculum:

Ciliated protozoa T. pyriformis, amicronucleated strain GL

Total exposure duration:

48 h

Details on test conditions:

Culture Conditions
The ciliated protozoa T. pyriformis, amicronucleated strain GL, was grown axenically at 28°C in the PPYS-defined medium containing 0.75% proteose-peptone (from Difco, France), 0.75% yeast extracts (from Difco, France), and inorganic salts (Plessner et al., 1964). The cultures were performed in suspension, in 100 ml of PPYS medium contained in capped 500-ml Fernach flasks.

Bioassay: Doubling Time of T. pyriformis GL Population Assay (DTP)
The toxicological potential of inorganic substances tested on T. pyriformis GL was evaluated by the doubling time of the TP population assay, as previously described (Sauvant et al., 1995).

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 3.6 - <= 3.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Conclusions:

The NOEC for the 48 hour activated sludge respiratory inhibition was 3.6-3.8 mg / L.

Executive summary:

Sauvant, M.P et al. (1997) reported the relative toxicity of 16 environmental pollutants such as inorganic elements (Ba, Cd, Co, Cr, Cu, Fe, Ge, Hg, Mn, Nb, Pb, Sb, Sn, Ti, To examine the toxicity of murine fibroblasts and ciliates (Tetrahymena pyriformis) by five bioassays such as RNA synthesis rate analysis, MTT reduction assay, NRI, Coomassie blue method, and cell growth rate assay .

Based on the results of this study, the NOEC for the 48 hour activated sludge respiratory inhibition was 3.6-3.8 mg / L for the substance copper chloride.

Reference 2

Endpoint:

toxicity to microorganisms, other

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

from the source substance copper chloride

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
A read-across based on analogue approach has been performed for that endpoint.
The read-across hypothesis, according to Read Across Assessment Framework published by ECHA, is based on the fact that different compounds which have the same type of effect(s). It corresponds to the scenario 2 described as follows:
« This scenario covers the analogue approach for which the read-across hypothesis is based on different compounds which have the same type of effect(s). For the REACH information requirement under consideration, the effects obtained in a study conducted with one source substance are used to predict the effects that would be observed in a study with the target substance if it were to be conducted. The same type of effect(s) or absence of effect is predicted. The predicted strength of the effects may be similar or based on a worst-case assumption. ».

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The read-across has been performed between copper dibromide (CAS No. 7789-45-9; target chemical) and copper chloride (CAS No. 7758-89-6; source chemical).

3. ANALOGUE APPROACH JUSTIFICATION
The registered substance will decompose into bromide ions (not bioconcentrated) and copper compound. Therefore, it is considered that the harmfulness to the environment will have a greater influence on the copper compound. Therefore, since there is no toxicity data on microorganisms available for the registered substance copper dibromide, data on copper chloride were used.
Based on these elements and to the fact that both target and source chemicals are inorganic substances having close physical-chemical properties and environmental fate, it can be assumed that copper chloride and copper dibromide may have similar ecotoxicological properties. The read-across approach between copper dibromide and copper chloride is therefore relevant for this endpoint.

Reason / purpose for cross-reference:

read-across source

GLP compliance:

not specified

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 3.6 - <= 3.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Conclusions:

Based on a read-across from the source substance copper chloride, the NOEC for the 48 hour activated sludge respiratory inhibition is considered to be 3.6-3.8 mg / L for the registered substance copper dibromide.

Executive summary:

Sauvant, M.P et al. (1997) reported the relative toxicity of 16 environmental pollutants such as inorganic elements (Ba, Cd, Co, Cr, Cu, Fe, Ge, Hg, Mn, Nb, Pb, Sb, Sn, Ti, To examine the toxicity of murine fibroblasts and ciliates (Tetrahymena pyriformis) by five bioassays such as RNA synthesis rate analysis, MTT reduction assay, NRI, Coomassie blue method, and cell growth rate assay .

Based on the results of this study, the NOEC for the 48 hour activated sludge respiratory inhibition was 3.6-3.8 mg / L for the substance copper chloride.

A read-across has been performed between copper cdibromide (CAS No. 7789 -45 -9; target chemical) and copper chloride (CAS No. 7758-89-6; source chemical).

Indeed, the registered substance will decompose into bromide ions (not bioconcentrated) and copper compound.

Therefore, it is considered that the harmfulness to the environment will have a greater influence on the copper compound. Therefore, since there is no toxicity data on microorganisms available for the registered substance copper dibromide, data on copper chloride were used.

Based on these elements and to the fact that both target and source chemicals are inorganic substances having close physical-chemical properties and environmental fate, it can be assumed that copper chloride and copper dibromide may have similar ecotoxicological properties. The read-across approach between copper dibromide and copper chloride is therefore relevant for this endpoint.

Therefore, the NOEC for the 48 hour activated sludge respiratory inhibition is considered to be 3.6-3.8 mg / L for the registered substance copper dibromide.

Reference 3

Endpoint:

activated sludge nitrification inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

ISO 9509 (Toxicity test for assessing the inhibition of nitrification of activated sludge microorganisms)

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Activated sludge from a municipal wastewater treatment plant

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

4 h

Test temperature:

20°C

pH:

6.5-7.5

Dissolved oxygen:

5-6 mg/L

Nominal and measured concentrations:

between 0-1.2 mg Zn/L.

Reference substance (positive control):

no

Duration:

4 h

Dose descriptor:

other: IC20

Effect conc.:

0.16 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

inhibition of nitrification rate

Duration:

4 h

Dose descriptor:

IC50

Effect conc.:

0.35 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

inhibition of nitrification rate

Duration:

4 h

Dose descriptor:

NOEC

Effect conc.:

0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

inhibition of nitrification rate

Validity criteria fulfilled:

yes

Conclusions:

Test done according to standard protocol.

Executive summary:

Test done according to standard protocol and considered useful for PNEC derivation for STP.

Reference 4

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study not according to standard protocol but good quality and considered relevant for microbial ecotoxicity. Culture medium, test water conditions well described and relevant for the PNEC STP.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Lab-designed batch growth system for measurement of inhibition kinetics of activated sludge process.

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

activated sludge

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 d

Test temperature:

25°C

pH:

7+/-0.2

Nominal and measured concentrations:

nominal doses: 1,5,10,20 mg Zn/l

Details on test conditions:

the sludge was shock-dosed with the nominal zinc concnetrations indicated above. Mixed liquor suspended solids measurements were done every 2 hrs.

Reference substance (positive control):

no

Duration:

3 d

Dose descriptor:

NOEC

Effect conc.:

5 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

growth inhibition

Validity criteria fulfilled:

yes

Conclusions:

Test not done according to standard protocol, but of good quality and considered useful for supporting the PNEC for STP.

Executive summary:

Study into the effect of zinc on activated sludge growth kinetics by following the rate of change of biomass production in batch growth experiments. NOEC of 5 mg Zn/l was derived.

Reference 5

Endpoint:

toxicity to microorganisms

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study not according to standard protocol but good quality and considered relevant for the setting of the PNEC-STP. Culture medium, test water conditions well described and relevant.

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Version / remarks:

for the respiration measurements

Qualifier:

equivalent or similar to guideline

Guideline:

other: Swedish EPA report Nr 4424 (1995) for the inhibition of nitrification

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

metal stock solutions were checked for correct metal concentration.

Vehicle:

no

Test organisms (species):

activated sludge

Details on inoculum:

Activated sludge samples for nitrification inhibition and respirometry bioassays were collected from the aeration tank of the Urduliz waste water treatment works (Biskaia, Spain) ("model B").

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20°C

Nominal and measured concentrations:

not indicated

Details on test conditions:

Tests were carried out in 1 L test bottles, containing 0.5 l test solution. Bottles were sealed and the sludge was monitored for 3 hrs by an electrolytic respirometer. Oxygen consumption was measured every 5 minutes for 3 hrs.

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

IC50

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

not specified

Basis for effect:

inhibition of nitrification rate

Details on results:

The following other parameters were also measured but considered of less relevancy for REACH: Vibrio fischeri toxicity test, ATP bioluminescence test (very insenssitive to zinc), enzyme inhibition .

Reported statistics and error estimates:

Error bars are graphically reported, are very small (number of tests respiration: 11; for nitrification inhibition: 10)

Validity criteria fulfilled:

yes

Conclusions:

Tests done according to standard protocol. Good quality and considered relevant for settting the PNEC STP.

Executive summary:

Five rapid direct toxicity assessment methods were used in 3 EU member states. Nitrification inhibition and respiration were measured as REACH-relevant endpoints. The IC50 for respiration was graphically derived as > 10mg Zn/l, the IC50 for nitrification inhibition was 10mg Zn/l.

Reference 6

Endpoint:

activated sludge respiration inhibition testing

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

study not according to standard protocol but good quality and considered useful for setting the reference value for acute aquatic ecotoxicity. Study used for that purpose in the EU risk assessment process on zinc (ECB 2008). Culture medium, test water conditions well described and according to the conditions set out in OECD 209.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

test is performed by adding activated sewage sludge to a series of vessels with synthetic sewage medium

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Inoculate originated from a predominantly domestic sewage treatment plant (Rungsted municipal sewage treatment plant , DK). The concentration of sludge in the final test mixture was 1.5g/l of suspended solid.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

pH:

7.5

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

5.2 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Validity criteria fulfilled:

yes

Conclusions:

Tests done under conditions similar to standard protocol. Good quality and used in the EU risk assessment for setting the PNEC for STP.

Executive summary:

Study compares the effect of different substances , e.g. zinc on different microbiological parameters. The EC50 for sludge respiration inhibition was used in the risk assessment for setting the PNEC for STP. Result: see "results " section.

Description of key information

Based on a read-across from the source substance copper chloride, the NOEC for the 48 hour activated sludge respiratory inhibition is considered to be 3.6-3.8 mg / L for the registered substance copper dibromide. 3.6 mg/L (more conservative than 3.8 mg/L) is selected as the key value for that endpoint.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

3.6 mg/L

Additional information

Sauvant, M.P et al. (1997) reported the relative toxicity of 16 environmental pollutants such as inorganic elements (Ba, Cd, Co, Cr, Cu, Fe, Ge, Hg, Mn, Nb, Pb, Sb, Sn, Ti, To examine the toxicity of murine fibroblasts and ciliates (Tetrahymena pyriformis) by five bioassays such as RNA synthesis rate analysis, MTT reduction assay, NRI, Coomassie blue method, and cell growth rate assay .

Based on the results of this study, the NOEC for the 48 hour activated sludge respiratory inhibition was 3.6-3.8 mg / L for the substance copper chloride.

A read-across has been performed between copper cdibromide (CAS No. 7789 -45 -9; target chemical) and copper chloride (CAS No. 7758-89-6; source chemical).

Indeed, the registered substance will decompose into bromide ions (not bioconcentrated) and copper compound. Therefore, it is considered that the harmfulness to the environment will have a greater influence on the copper compound. Therefore, since there is no toxicity data on microorganisms available for the registered substance copper dibromide, data on copper chloride were used.

Based on these elements and to the fact that both target and source chemicals are inorganic substances having close physical-chemical properties and environmental fate, it can be assumed that copper chloride and copper dibromide may have similar ecotoxicological properties. The read-across approach between copper dibromide and copper chloride is therefore relevant for this endpoint.

Therefore, the NOEC for the 48 hour activated sludge respiratory inhibition is considered to be 3.6-3.8 mg / L for the registered substance copper dibromide.

In addition, some data were available on another analogue substance and have been added as supporting studies.