Triisooctyl 2,2',2''-[(octylstannylidyne)tris(thio)]triacetate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 March 2010 to 19 March 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

other: read-across target

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 1: Static Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Duplicate samples for analysis were taken from the highest test concentration and the control according to the schedule below. The method of analysis is described in the appended Analytical Report (Appendix II).

Frequency: at t=0 h, t=24 h and t=96 h
Volume: 25 ml
Storage: Not applicable, samples were analysed on the day of sampling.

Vehicle:

no

Details on test solutions:

The standard test procedures required generation of test solutions, which should contain completely dissolved test substance concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that disturb the test system should be prevented (e.g. film of the test substance on the water surface).

The batch of Octyltintris(2-ethylhexyl mercaptoacetate) tested was a clear colourless to light yellow liquid with a purity of 98.00% and the substance was not completely soluble in test medium at the initial loading rate prepared.

Preparation of test solutions started with a loading rate of 100 mg/l applying one day of magnetic stirring followed by a one day stabilisation period to reach maximum solubility of the test substance in the test medium. The slightly hazy and colourless Water Soluble Fraction (WSF) was filtered through glass wool and used as the highest test concentration, which was observed to be still slightly hazy. The lower test concentrations were prepared by subsequent dilutions of the WSF in test medium. These lower test concentrations were clear and colourless.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Source: Zodiac, proefacc, "De Haar Vissen", Wageningen University and Research Centre, The Netherlands.
Mean length': 2.3 ± 0.2 cm
Mean weight': 0.33 ± 0.09 g
Characteristics: F1 from a single parent-pair bred in UV-treated water.
Total fish used: 20

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

180 mg CaCO3/L

Test temperature:

20.6 to 21.1°C depending on the sampling timing and considered series.

pH:

7.5 to 7.7 depending on the sampling timing and considered series.

Dissolved oxygen:

5.5 to 9.1 mg/L depending on the sampling timing and considered series.

Salinity:

Not applicable

Nominal and measured concentrations:

1.0, 10 and 100 % of a WSF prepared at a loading rate of 100 mg/l

Details on test conditions:

Test duration: 96 hours
Test type: Static
Test vessels: 3.5 litres, all-glass, containing 3 litres of test solution
Test medium: Adjusted ISO medium with a hardness of 180 mg CaCO3 per litre and a pH of 7.7 ± 0.3.
Number of fish per concentration: 7 for the control and the highest test concentration; 3 for each lower concentration
Loading: 0.77 g fish/litre, i.e. 7 fish per 3 litres of test medium; 0.33 g fish/litre, i.e. 3 fish per 3 litres of test medium
Illumination: 16 hours photoperiod daily
Aeration: Aeration was introduced after 72 hours of exposure and maintained for 6 hours.
Feeding: No feeding from 24 hours prior to the test and during the total test period
Introduction of fish: Within 10 minutes after preparation of the test media from a holding tank with comparable water quality parameters and pH and temperature differences

Reference substance (positive control):

yes

Remarks:

Pentachlorophenol

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: %WSF

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 other: %WSF

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No LC50 could be calculated because the test material proved to be non-toxic (LC50 > maximum concentration tested).

Results with reference substance (positive control):

Results acceptable

Sublethal observations / clinical signs:

The measured concentration of octyltin species in the duplicate samples taken from the undiluted WSF showed initial concentrations of 1805 and 849 µg/L. The large variance between duplicate samples together with the slight haziness of the test solutions indicated that the initial concentration was above the solubility limit. Measurements at 24 and 96 hours of exposure showed that actual test concentrations were still above the solubility limit. Note that at the end of the test, a precipitate of test substance was observed in the vessel containing the highest test concentration. Given these results, the effect parameters were expressed in terms of both loading rate (Octyltintris(2-ethylhexyl mercaptoacetate)) and the mean concentration of octyltin species. The mean concentration was calculated to be 945 µg/L.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this study, the test material induced no visible effects in carp exposed to the concentration obtained in a WSF prepared at a loading rate of 100 mg/L (NOEC). The 96h-LC50was beyond the concentration obtained in a WSF prepared at a loading rate of 100 mg/L. The mean concentration of organotin species measured in this WSF was 945 µg/L.

Executive summary:

The study procedure described in this report was based on the OECD guideline No. 203, 1992. In addition, the procedures were designed to meet the test methods of the Commission Regulation (EC) No 440/2008, Part C.1, 2008, the ISO International Standard 7346-1: Static method, 1996 and the OECD series on testing and assessment number 23, 2000.

The batch of test material used was a clear colourless to light yellow liquid with a purity of 98.00 % and the test material was not completely soluble in test medium at the initial loading rate prepared.

Preparation of test solutions started with a loading rate of 100 mg/L applying one day of magnetic stirring followed by a one day stabilisation period to reach maximum solubility of the test material in the test medium. The slightly hazy and colourless Water Soluble Fraction (WSF) was filtered through glass wool and used as the highest test concentration, which was observed to be still slightly hazy. The lower test concentrations were prepared by subsequent dilutions of the WSF in test medium. These lower test concentrations were clear and colourless.

A combined limit/range-finding test was performed, exposing seven fish per concentration to the WSF prepared at a loading rate of 100 mg/L and to a control group. In addition, three fish per concentration were exposed to 1.0 and 10 % of the WSF. The total test period was 96 hours and duplicate samples for analytical confirmation of actual exposure concentrations were taken at the start, after 24 hours of exposure and at the end of the test. Analysis was performed on the octyltin species in the test material.

The measured concentration of octyltin species in the duplicate samples taken from the undiluted WSF showed initial concentrations of 1805 and 849 µg/L. The large variance between duplicate samples together with the slight haziness of the test solutions indicated that the initial concentration was above the solubility limit. Measurements at 24 and 96 hours of exposure showed that actual test concentrations were still above the solubility limit. Note that at the end of the test, a precipitate of test material was observed in the vessel containing the highest test concentration. Given these results, the effect parameters were expressed in terms of both loading rate of the test material and the mean concentration of octyltin species. The mean concentration was calculated to be 945 pg/L.

The study met the acceptability criteria prescribed by the protocol and was considered valid.

Under the conditions of this study, the test material induced no visible effects in carp exposed to the concentration obtained in a WSF prepared at a loading rate of 100 mg/L (NOEC). The 96h-LC50was beyond the concentration obtained in a WSF prepared at a loading rate of 100 mg/L. The mean concentration of organotin species measured in this WSF was 945 µg/L.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted on read-across material

Justification for type of information:

Read Across to Octyltin tris(2-ethylhexylmercaptoacetate) (MOTE) (EC Number 248-227-6 and CAS No 27107-89-7) based on structural similarity and hydrolytical behaviour, see attached justification.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: %WSF

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

100 other: %WSF

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Description of key information

Read-across to structurally similar substance: Octyltin tris(2-ethylhexylmercaptoacetate) (MOTE) (CAS No 27107 -89 -7)

Under the conditions of this study, the test material induced no visible effects in carp exposed to the concentration obtained in a WSF prepared at a loading rate of 100 mg/L (NOEC).The 96h-LC50was beyond the concentration obtained in a WSF prepared at a loading rate of 100 mg/L. The mean concentration of organotin species measured in this WSF was 945 µg/L.

Additional information

Read-across to structurally similar substance: Octyltin tris(2-ethylhexylmercaptoacetate) (MOTE) (CAS No 27107-89-7).

The study procedure described in this report was based on the OECD guideline No. 203, 1992.In addition, the procedures were designed to meet the test methods of the Commission Regulation (EC) No 440/2008, Part C.1, 2008, the ISO International Standard 7346-1: Static method, 1996 and the OECD series on testing and assessment number 23, 2000. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The batch of test material used was a clear colourless to light yellow liquid with a purity of 98.00 % and the test material was not completely soluble in test medium at the initial loading rate prepared.

Preparation of test solutions started with a loading rate of 100 mg/L applying one day of magnetic stirring followed by a one day stabilisation period to reach maximum solubility of the test material in the test medium. The slightly hazy and colourless Water Soluble Fraction (WSF) was filtered through glass wool and used as the highest test concentration, which was observed to be still slightly hazy. The lower test concentrations were prepared by subsequent dilutions of the WSF in test medium. These lower test concentrations were clear and colourless.

A combined limit/range-finding test was performed, exposing seven fish per concentration to the WSF prepared at a loading rate of 100 mg/L and to a control group. In addition, three fish per concentration were exposed to 1.0 and 10 % of the WSF. The total test period was 96 hours and duplicate samples for analytical confirmation of actual exposure concentrations were taken at the start, after 24 hours of exposure and at the end of the test.Analysis was performed on the octyltin species in the test material.

The measured concentration of octyltin species in the duplicate samples taken from the undiluted WSF showed initial concentrations of 1805 and 849 µg/L. The large variance between duplicate samples together with the slight haziness of the test solutions indicated that the initial concentration was above the solubility limit. Measurements at 24 and 96 hours of exposure showed that actual test concentrations were still above the solubility limit. Note that at the end of the test, a precipitate of test material was observed in the vessel containing the highest test concentration. Given these results, the effect parameters were expressed in terms of both loading rate of the test material and the mean concentration of octyltin species. The mean concentration was calculated to be 945 pg/L.

The study met the acceptability criteria prescribed by the protocol and was considered valid.

Under the conditions of this study, the test material induced no visible effects in carp exposed to the concentration obtained in a WSF prepared at a loading rate of 100 mg/L (NOEC).The 96h-LC50was beyond the concentration obtained in a WSF prepared at a loading rate of 100 mg/L. The mean concentration of organotin species measured in this WSF was 945 µg/L.