Ethyl 9,9-dioctyl-4,7,11-trioxo-3,8,10-trioxa-9-stannatetradeca-5,12-dien-14-oate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

The target substance is a mono-constituent organotin substance that consists of a tin as central metal element with two octyl-ligands. The source substance Dioctyltin oxide (DOTO) (EC Number 212-791-1 and CAS 870-08-6) is also an organotin compound that has the identical structure elements as the target substance in respect of the tin-alkyl moiety.
According to WHO IPCS CIRCAD (2006) organotin compounds are characterized by a tin–carbon bond and have the general formula RxSn(L)(4−x), where R is an organic alkyl or aryl group and L is an organic (or sometimes inorganic) ligand. The organotin moiety is significant toxicologically. The anionic ligand influences physicochemical properties but generally has little or no effect on the toxicology.
Since the target substance and the source substances share the identical organotin moiety, and the organotin moiety is generally recognized as the relevant toxophore of organotins and the toxicity estimates (AE) respectively toxicity limits for organotins are expressed as tin, the overall ecotoxicity/systemic toxicity of the target can be interpolated by assessing the (eco-)toxicity of the source (WHO IPCS CIRCAD, 2006, BAUA AGS TRGS 900, 2014, Summer KH, Klein D and Greim H, 2003).
The purity of the source and target substance are expected to be similar, based on the manufacturing method. The impurity profile is not expected to have strong effects on substance properties and any impurity of (eco-)toxicological relevance of the source substances is expected to be present in the target substance. Consequently, the hazard profiles of the source substances, including those of their impurities, are intrinsically covered. Differences in impurities are not expected and thus do not have an impact on the (eco-)toxic properties.

References
BAUA (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (Federal Institute for Occupational Safety and Health)) AGS (Ausschuss für Gefahrstoffe (Committee on Hazardous Substances)) TRGS (Technical Rules for Hazardous Substances) 900 (2014). Begründung zu n-Octylzinnverbindungen, April 2014.
Summer KH, Klein D, Griem H (2003). Ecological and toxicological aspects of mono- and disubstituted methyl-, butyl-, octyl-, and dodecyltin compounds - Update 2002. GSF National Research Center for Environment and Health, Neuherberg, for the Organotin Environmental Programme (ORTEP) Association.
World Health Organization (WHO) International Programme on Chemical Safety (IPCS) Concise International Chemical Assessment Document (CICAD) 73 Mono- and disubstituted methyltin, butyltin, and octyltin compounds (2006). Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization, and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals

Reason / purpose for cross-reference:

read-across source

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.001 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

0.001 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

The target substance is a mono-constituent organotin substance that consists of a tin as central metal element with two octyl-ligands. The source substance Dioctyltin oxide (DOTO) (EC Number 212-791-1 and CAS 870-08-6) is also an organotin compound that has the identical structure elements as the target substance in respect of the tin-alkyl moiety.
According to WHO IPCS CIRCAD (2006) organotin compounds are characterized by a tin–carbon bond and have the general formula RxSn(L)(4−x), where R is an organic alkyl or aryl group and L is an organic (or sometimes inorganic) ligand. The organotin moiety is significant toxicologically. The anionic ligand influences physicochemical properties but generally has little or no effect on the toxicology.
Since the target substance and the source substances share the identical organotin moiety, and the organotin moiety is generally recognized as the relevant toxophore of organotins and the toxicity estimates (AE) respectively toxicity limits for organotins are expressed as tin, the overall ecotoxicity/systemic toxicity of the target can be interpolated by assessing the (eco-)toxicity of the source (WHO IPCS CIRCAD, 2006, BAUA AGS TRGS 900, 2014, Summer KH, Klein D and Greim H, 2003).
The purity of the source and target substance are expected to be similar, based on the manufacturing method. The impurity profile is not expected to have strong effects on substance properties and any impurity of (eco-)toxicological relevance of the source substances is expected to be present in the target substance. Consequently, the hazard profiles of the source substances, including those of their impurities, are intrinsically covered. Differences in impurities are not expected and thus do not have an impact on the (eco-)toxic properties.

References
BAUA (Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (Federal Institute for Occupational Safety and Health)) AGS (Ausschuss für Gefahrstoffe (Committee on Hazardous Substances)) TRGS (Technical Rules for Hazardous Substances) 900 (2014). Begründung zu n-Octylzinnverbindungen, April 2014.
Summer KH, Klein D, Griem H (2003). Ecological and toxicological aspects of mono- and disubstituted methyl-, butyl-, octyl-, and dodecyltin compounds - Update 2002. GSF National Research Center for Environment and Health, Neuherberg, for the Organotin Environmental Programme (ORTEP) Association.
World Health Organization (WHO) International Programme on Chemical Safety (IPCS) Concise International Chemical Assessment Document (CICAD) 73 Mono- and disubstituted methyltin, butyltin, and octyltin compounds (2006). Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organization, and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.21 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: EC50 of the test material is greater than the limit of solubility of the test material. Aqueous solubility of the test material is between 0.09 and 0.54 mg/L

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

01 March 1988 to 03 March 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed to the OECD guideline 202. Some deficiencies were present in the methods and the reporting, such as limited detail, the test was only run for 24 hours and the concentrations of the test material were not maintained throughout the test. As such the study is considered to be reliable with acceptable restrictions for use as supporting information. The test material DOTO (di-n-octyltin oxide) is in the same category of substances as the registration substance, as such it is considered acceptable to use a read-across approach to address this endpoint.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

(test was only run for 24 hours)

GLP compliance:

no

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material:
PHYSICO-CHEMICAL PROPERTIES
- Melting point: melting with decomposition from approximately 282 °C
- Vapour pressure: 0.00042 Pa at 25 °C
- Water solubility (under test conditions): <0.0000152 g/L at 20 °C
- Log Pow: Calculated estimate of 9.26 (method not validated for this class of material)

OTHER PROPERTIES (if relevant for this endpoint)
- Results of test for ready biodegradability: not readily biodegradable
- Results of short-term toxicity testing on fish (Brachydanio rerio): 96 hour LC50 >water solubility under the conditions of the study (between 0.05 and 0.18 mg/L); LC50 >0.09 mg/L (geometric mean of the solubility of the test material).
- Results of growth inhibition study on algae (Desmodesmus subspicatus): 72 hours ErC50 >0.0018 mg/L; the test material exhibited little or no difference on the growth rate of the algae, the ErC50 of the test material is considered to be greater than the water solubility.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 10, 18, 32, 50 and 100 % of stock solution. Samples for analysis were taken at 0 and 24 h. Test solutions were measured for their tin content, and the concentration of the test material calculated accordingly.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 300 mg of the test material was added to 1500 mL water and stirred for 48 h then filtered first through a glass filter D4 and then through a membrane filter (Millipore Type HA 0.45 µm)
- Controls: Blank control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Straus 1820
- Age at study initiation (mean and range, SD): 0-24 hours
- Method of breeding: Parthenogenic reproduction. 24 hours prior to the start of the test, reproductive daphnia were separated from the young by sieving through a 800 micrometer sieve. This operation was repeated immediately before the start and the young daphnia (0-24 hours old) were retained for the test.
- Feeding during test: No

ACCLIMATION
- Type and amount of food: Suspension of green algae supplemented by trout chow and/or powder mild and/or yeast in such quantities that food is consumed after 24 hours.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

240 mg/L as CaCO3

Test temperature:

20 ± 1 °C

pH:

7.4-7.7

Dissolved oxygen:

96-97 % O2 saturation

Nominal and measured concentrations:

0, 10, 18, 32, 50 and 100 % (of the prepared stock solution). equivalent to <0.00019, <0.00021, 0.00031, 0.00048 and 0.00067 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Beakers (100 mL solution)
- Type (delete if not applicable): closed vessels were covered with watch glasses
- Aeration: The water was aerated with clean air for at least 24 hours before use
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water produced by dissolving:
65 mg NaHCO3
294 mg CaCL2.2H2O
123 mg MgSO4.7H2O
6 mg KCl
in 1000 mL bidistilled water

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light daily
- Light intensity: Fluorescent light, approx. 2000 lux

EFFECT PARAMETERS MEASURED : Daphnia were examined for immobilisation 24 hours after start of exposure

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.001 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

0.001 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no toxic effects were observed

Table 1: Immobilisation results

Concentration mg/L (Actual)	Immobilisation after 24 hours
	R1	R2	R3	R4	Total	%
Blank	0	0	0	0	0	0
<0.00019	0	0	0	0	0	0
<0.00021	0	0	0	0	0	0
0.00031	0	0	0	0	0	0
0.00048	0	0	0	0	0	0
0.00067	0	0	0	0	0	0

 

Table 2: Test conditions

Concentration mg/L (Actual)	0 hours			24 hours
	pH	% O2 saturation	temperature	pH	% O2 saturation	temperature
Blank	7.7	97	20	7.7	97	20
<0.00019	7.4	97	20	7.5	97	20
<0.00021	7.5	97	20	7.5	97	20
0.00031	7.6	96	20	7.6	97	20
0.00048	7.6	97	20	7.5	96	20
0.00067	7.7	97	20	7.6	97	20

 

Table 3: Measured concentrations

Concentration % of stock solution	Measured concentrations*
	0 h mg/L	24 h mg/L	Average mg/L
10	<0.00015	0.00023	<0.00019
18	<0.00015	0.00026	<0.00021
32	0.00026	0.00035	0.00031
58	0.00037	0.00059	0.00048
100	0.00053	0.00081	0.00067
* Analytically determined values multiplied by a factor of 100/32.87; Sn-content of test material 32.87 % (mean of measured concentrations of 2 samples)

Validity criteria fulfilled:

no

Conclusions:

Under the conditions of the study, no toxic effects in Daphnia magna were observed after 24 hours of exposure to the test material at a 100 % saturated solution. The EC50 of the test material in Daphnia magna is expected to be greater than the water solubility of the test material.

Executive summary:

The toxicity of the test material to freshwater crustacea was assessed in a short-term toxicity test in Daphnia magna. The study was performed in line with the OECD 202, however the test was only performed up until the 24 hour observation point with no explanation as to why the 48 hour observation was not performed. The study was performed with a range of concentrations, up to a 100 % saturated solution of the test material. Under the conditions of the study, no toxicity was observed in any of the Daphnia. The EC50 of the test material in Daphnia magna is expected to be greater than the water solubility of the test material.

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 October 2002 to 12 December 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed to GLP and in line with the standardised guidelines OECD 202 and EU method C.2 with no deficiencies thought to influence the accuracy of the presented results. The study was reported to a high standard. The test material DOTO (di-n-octyltin oxide) is in the same category of substances as the registration substance, as such it is considered acceptable to use a read-across approach to address this endpoint.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material:
PHYSICO-CHEMICAL PROPERTIES
- Melting point: melting with decomposition from approximately 282 °C
- Vapour pressure: 0.00042 Pa at 25 °C
- Water solubility (under test conditions): <0.0000152 g/L at 20 °C
- Log Pow: Calculated estimate of 9.26 (method not validated for this class of material)

OTHER PROPERTIES (if relevant for this endpoint)
- Results of test for ready biodegradability: not readily biodegradable
- Results of short-term toxicity testing on fish (Brachydanio rerio): 96 hour LC50 >water solubility under the conditions of the study (between 0.05 and 0.18 mg/L); LC50 >0.09 mg/L (geometric mean of the solubility of the test material).
- Results of growth inhibition study on algae (Desmodesmus subspicatus): 72 hours ErC50 >0.0018 mg/L; the test material exhibited little or no difference on the growth rate of the algae, the ErC50 of the test material is considered to be greater than the water solubility.

Analytical monitoring:

yes

Details on sampling:

- Sampling method: In duplicate, one sample of the newly prepared (clean) control medium and the newly prepared (clean) exposure medium were taken at t = 0 h. Thereafter, in duplicate, one sample of the control medium (24 h, spent; 24 h, clean; 48 h spent) and two samples of the exposure medium (24 h; spent, 24 h clean, 48 h, spent) were taken. 100 mL samples were collected in 125 mL Nalgene bottles. One set of samples was transferred to the analytical laboratories immediately after sampling. All other samples were stored in a freezer.
- Sample storage conditions before analysis: <-18 °C

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A saturated test solutions was prepared as a WSF. One day prior, the test solutions were prepared by adding 300 mg test material to 3 litres of DSWL-E (loading rate 100 mg/L). The contents of the flask were stirred for 16 hours followed by 6 hours standing. The aqueous phase was tapped off, the first 100 mL discarded and the aqueous phase aerated for 2 hours.
- Controls: DSWL-E was used as a control

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: Cultured in the testing laboratory
- Feeding during test: The daphnids were not fed during the test
- Method of breeding: Every week cultures were started with ca. 150 daphnids of the same age (approximately 1 day) in 4 litres of dilution water. The medium was replaced completely at least once a week at which time, all young were removed. Cultures were discarded every 4 weeks

ACCLIMATION
- Acclimation period/conditions: The Daphnia were bred under the same conditions as the test.
- Type and amount of food: approximately 4 x 10^9 cells (Chlorella) and ca. 0.13 g of yeast per 4 L.
- Feeding frequency: Daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

209 mg/L as CaCO3

Test temperature:

20 ± 1 °C

pH:

8.1-8.2

Dissolved oxygen:

8.5-9.4 mg/L

Nominal and measured concentrations:

A WSF (Water soluble fraction) was prepared for the performance of this test. 0.15 mg/L (initial concentration) as determined by ICP-AES.

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 mL all glass beakers
- Aeration: The beakers were not aerated
- Renewal rate of test solution: The test solutions were replaced at t = 24
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The groundwater was obtained from a locality near Linschoted (the Netherlands).
- Total organic carbon: 1.55 mg/L
Composition:
6.05 mg/L CO2
164 mg/L Hydrocarbon dioxide
< 2 mg/L Carbonate
<1 mg/L Sulphate
<1 mg/8.03 mg/L Silicate
0.004 mg/L Manganese
0.069 mg/L Fluoride
1.22 mmol/L Na^+
0.20 mmol/L K^+
1.38 mmol/L Ca2^2+
0.71 mmol/L Mg^2+
2.81 mmol/L Cl^-
0.65 mmol/L SO4^2-
1.39 mmol/L HCO3^-
46.25 µmol/L B
1.82 µmol/L Mn
7.22 µmol/L Li
0.59 µmol/L Rb
0.57 µmol/L Sr
0.16 µmol/L Br
0.26 µmol/L Mo
0.10 µmol/L Cu
0.10 µmol/L Zn
0.04 µmol/L Co
0.02 µmol/L I
0.01 µmol/L Se
0.05 µmol/L V
0.36 µmol /L Fe
0.67 µmol/L Na2EDTA
- Conductivity: 26.7 Ms.m^-1
- Culture medium different from test medium: Culture medium was the same used in the test

OTHER TEST CONDITIONS
- Photoperiod: 16 h light and 8 h dark with a 30 minutes dusk transition period

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The mobile and immobile animals were counted after 24 hours and at the end of the test (animals not able to swim within 15 seconds after gentle agitation of the containers). Observations of the condition (swimming behaviour, colour and any other visually observable morphological or behavioural criterion) of the mobile animals was performed at the same time and compared with the control vessels.

TEST CONCENTRATIONS
- Range finding study: A range finding study demonstrated that no adverse effects were expected within the aqueous solubility of the test material. The test was therefore carried out using a limit test with a WSF (water soluble fraction).

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.21 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: EC50 of the test material is greater than the limit of solubility of the test material. Aqueous solubility of the test material is between 0.09 and 0.54 mg/L

Details on results:

- Behavioural abnormalities: One daphnid in the WSF was found to be swimming with irregular movements at the end of the test.
- Mortality of control: No daphnids were found to be immobile in the control

Table 1: Results of the chemical analysis

Dose	Measured concentrations
	t = 0 h (clean) mg/L	t = 24 h (spent)		t = 24 h (clean) mg/L	t = 48 h (spent)
		mg/L	% of initial		mg/L	% of initial
0	<0.04	<0.04		<0.04	<0.04
WSF	0.15	0.1	67	0.54	0.27	50
WSF		0.09	60	0.51	0.2	39

 

Table 2: Number of mobile daphnids and their condition

Time (h)	Concentration as volume % of a saturated solution
	0				WSF
0	5a	5a	5a	5a	5a	5a	5a	5a
24	5a	5a	5a	5a	5b	5b	5b	5b
48	5a	5a	5a	5a	4b 1j	5b	5b	5b
a = Condition of all test animals, visually assessed, normal (=good) b = Condition of all test animals visually assessed, equal to that of the control animals j = The daphnia swam with irregular movements WFS = Water soluble fraction

 

Table 3: Summary of results

Parameter	Effect	Dose	Concentration
24 h EC50	Mobility	WSF	> Aqueous solubility
48 h EC50	Mobility	WSF	> Aqueous solubility
48 h EC100	Mobility	WSF	> Aqueous solubility
48 h NOEC	Mobility	WSF	> Aqueous solubility
48 h NOEC	Condition	WSF	> Aqueous solubility

 

Table 4: pH and oxygen concentrations of test solutions

Time	Concentration as volume percentage of a saturated solution^1
	0								100
	A		B		C		D		A		B		C		D
	pH	O2(mg/L)	pH	O2(mg/L)	pH	O2(mg/L)	pH	O2(mg/L)	pH	O2(mg/L)	pH	O2(mg/L)	pH	O2(mg/L)	pH	O2(mg/L)
0 h (Newly prepared solutions)	8.1	9.3	8.1	9.4	8.1	9.4	8.1	9.3	8.2	8.6	8.2	8.6	8.2	8.5	8.2	8.5
24 h (Newly prepared solutions)	8.2	9.3	8.2	9.3	8.2	9.3	8.2	9.3	8.2	8.9	8.2	8.8	8.2	8.8	8.2	8.8
24 h (Spent solutions)	8.2	9.4	8.2	9.3	8.2	9.3	8.2	9.3	8.2	9.1	8.2	9.1	8.2	9.1	8.2	9.1
48 h (Spent solutions)	8.2	9.3	8.2	9.3	8.2	9.2	8.2	9.3	8.2	9.2	8.1	9.2	8.1	9.2	8.1	9.3
^1Water Soluble Fraction, prepared by stirring 100 mg test material per litre of media

Validity criteria fulfilled:

no

Remarks:

This was attributed to the preparation method.

Conclusions:

Under the conditions of the study, the 48 h EC50 of the test material with Daphnia magna was greater than the water solubility of the test material.

Executive summary:

The acute toxicity of the test material to the fresh-water crustacean Daphnia magna was determined in a semi-static test conducted in accordance with OECD 202 and EU method C.2 and in line with GLP. Due to the insolubility of the test material, the study was performed with a water soluble fraction as a limit test. Under the conditions of the test, the 48 h EC50 of the test substance was found to be greater than the water solubility of the test material.

Description of key information

EC50 >0.21 mg/L  (geometric mean of the solubility of the test material), EC50> water solubility ( 0.09 - 0.54 mg/L), dioctyltin oxide, OECD 202, EU Method C.2,  Hooftman & de Wolf 2004

Additional information

The data requirement was addressed by the key study, Hooftman & de Wolf (2004). The study was performed to GLP and in line with the OECD guideline 202 and EU method C.2. As the study was performed on a read-across substance in the same category as the registered substance (di-n-octyltin oxide), it was assigned a reliability score of 2 (reliable with acceptable restrictions) in accordance with the criteria for assessing data quality as outlined in Klimisch (1997) and considered suitable for assessment as an accurate reflection of the test material.

Due to the insolubility of the test material, the study was performed with a water soluble fraction as a limit test to Daphnia magna. Under the conditions of the study, the 48 h EC50 was found to be greater than the water solubility of the test material (aqueous solubility is between 0.09 and 0.54 mg/L). The EC50 is >0.21 mg/L (geometric mean of the solubility of the test material).

 

Supporting information was available in the form of a study reported by Rufli (1988). The study was performed to the OECD guideline 202 and was also conducted with the read across substance, dioctyltin oxide. However the observations performed during the study did not extend past the 24 hour period, with no explanation as to why the 48 hour observation was not performed. The study lacked details in the reporting in some areas and some deficiencies were present in the performance of the test, such as the test concentrations were not maintained throughout the entire test period. As such the study was assigned a reliability score of 2 in line with the principles of assigning data quality as outlined in Klimisch (1997). As the results of the study confirmed the lack of toxicity observed in the more reliable key study, the study was considered reliable with restrictions and suitable as supporting information to the key study. Under the conditions of the test, the EC50 of the test substance in Daphnia magna was determined to be greater than the water solubility of the test substance.