Butylchlorodihydroxystannane

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:

experimental study

Adequacy of study:

key study

Study period:

Not specified

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 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

no details available

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

no details available

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: samples were taken in duplicate at the start of the test (t=0 h) and at the end of the test (t=48 h). Samples were taken again from the lowest, middle and highest concentrations. Aliquots of 10 mL were taken in plastic Corning tubes.
- Sample storage conditions before analysis: One sample was transferred to analytical laboratories immediately after sampling. All other samples were stored in a freezer.

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

- The test organism used was the freshwater crustacean Daphnia magna, cultured in the laboratory under standard conditions.
- Every week a number of cultures is started with ca. 150 daphnids of the same age (about one day) in ca. 4 litres of dilution water. The cultures are fed daily with ca. 4x10^9 algae cells (Chlorella) and ca. 0.13 grams of yeast per 4 litres. The medium is completely replaced at least once a week; at the same time all young born are removed.
- The cultures are kept at 20 ± 1 °C under a 16 h light and 8 h dark regime with transition periods of ca. 30 minutes.
- After 4 weeks the cultures are discarded.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

1.24 - 1.27 mmol/L

Test temperature:

20 ± 1 °C

pH:

The pH was measured at the beginning and at the end of the test and after 24 hours in the exposure media in which all animals were immobile.

Dissolved oxygen:

The oxygen concentrations was measured at the beginning and at the end of the test and after 24 hours in the exposure media in which all animals were immobile.

Nominal and measured concentrations:

0, 5.6, 10, 19, 32, 56, 100 mg/L (nominal) were determined in a preliminary range-finding test.

<0.05, 5.57, 10.1, 18.6, 29.7, 56.6, 102.8 mg/L (measured, t=0 h)
<0.05, 5.37, 8.37, 17.2, 30.9, 53.1, 90.9 mg/L (measured, t=48 h)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 150 mL all glass beakers each containing 100 mL of exposure medium.
- Aeration: None
- Renewal rate of test solution (frequency/flow rate): None
- 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: The dilution water used was DSWL-E prepared from ground water.
- The nominal composition of the synthetic medium DSWL-E is: Na+ 1.19 mmol/L, K- 0.20 mmol/L, Ca2+ 1.36 mmol/L, Mg 2+ 0.73 mmol/L, Cl- 2.72 mmol/L, SO4 2- 0.73 mmol/L and HCO3- mmol/L.
- This medium is prepared by the addition of several salts to ground water from a locality near Linschoten (the Netherlands). The ground water contains several other trace elements (<< 1 mg/L). Media prepared from it have proved to be suitable for growing several species of water organisms. The equilibrium pH of the medium, after aeration, should be 8.3 - 8.5, but is usually slightly less, i.e. 8.0 - 8.2. The hardness, expressed as CaCO3, is about 210 mg.rt .

OTHER TEST CONDITIONS
- Photoperiod: 16h light/ 8h dark

- The mobile, and if applicable the immobile animals, were counted after 24 hours and at the end of the test according to the definition given in OCED 202. At the same time the immobile animals were removed and the condition of the mobile animals was compared to that of the control animals. The daphnias exposed to 56 and 100 mg/L were also checked under a microscope.

- The actual concentrations of test material in the exposure media were determined by chemical analysis.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Basis for effect:

other: condition

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

83 mg/L

Basis for effect:

mobility

Remarks on result:

other: 62-111 mg/L (95% confidence limits)

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Basis for effect:

mobility

Details on results:

There were no immobile animals in the control medium at the end of the test. At 56 and 100 mg/L, immobility and lethality were observed at the ends of the test period. At concentrations of 32 mg/L and lower, there were no effects with respect to mobility or lethality except for two dead animals at 19 mg/L. As 10% immobility is allowed for the control and as the mortality observed at 19 mg/L was not dose-related, these observations were not taken into account in estimating the NOEC for mobility in this study. At the end of the test, at 19 mg/L and higher, the condition of the animals was less than that of the controls. The NOEC values for mobility and conditions are therefore 32 mg/L and 10 mg/L respectively.

Results with reference substance (positive control):

not applicable

Variation of pH value: 6.9 - 8.2

Lowest measured oxygen concentration: 8.9 O₂/L

Variation of temperature measured in one of the control vessels at the start and end of the test respectively: 20.1 - 19.6 °C

Table 1: Results of the acute toxicity with Daphnia magna

Parameter (h = hours)	Effect	Concentration (mg/L)
24h EC50	mobility	> 100
48h EC50	mobility	83 (62-111)
48h EC100	mobility	> 100
48h NOEC	mobility	32
48h NOEC	condition	10

Validity criteria fulfilled:

yes

Conclusions:

Under the circumstances of the test, the 48h EC50 of the test material for Daphnia magna was 83 mg/L and the 48h NOEC for mobility was 32 mg/L

Executive summary:

The acute toxicity of the test material to the fresh-water crustacean Daphnia magna was determined according to the standardised guidelines OECD 202 and EU Method C.2, under GLP conditions.

The test was carried out as a static test with 4 x 5 daphnids (four-fold exposure media) for the control medium and each concentration. The exposure duration was 48 hours. The nominal concentrations tested were 5.6, 10, 19, 32, 56 and 100 mg/L. The test material was dissolved directly in the diultion water used for the test. The dilution water was also used as control medium.

All exposure media were completely clear throughout the test.

The actual concentration of the test material in the exposure media was determined by chemical analysis. Therefore, samples for chemical analysis were taken from all test concentrations at the start of the test and at the end of the test. At t=0 h, the average measured concentration of the test material in the exposure media was 99% of the nominal value. After 48 hours, the spent solutions contained 92% of the nominal value. As this is above 80% it is allowed to express the results of the test in nominal concentrations. The results of the test were (95% confidence interval in parentheses):

Parameter       Effect       Concentration in mg/L

(h = hours)

24 h EC50       mobility       > 100

48 h EC50       mobility       83 (62 -111)

48 h EC100     mobility       > 100

48 h NOEC     mobility       32

48 h NOEC     condition     10

Under the circumstances of the test, the 48h EC50 of the test material for Daphnia magna was 83 mg/L and the 48h NOEC for mobility was 32 mg/L

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

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 structurally similar substance monobutyltin trichloride (MBTC, CAS No.: 1118-46-3), see attached justification.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Basis for effect:

other: condition

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

83 mg/L

Basis for effect:

mobility

Remarks on result:

other: 62-111 mg/L (95% confidence limits)

Key result

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Basis for effect:

mobility

Description of key information

Read across to structurally similar substance monobutyltin trichloride (MBTC, CAS No.: 1118-46-3).

Under the circumstances of the test, the 48h EC50 of the test material for Daphnia magna was 83 mg/L and the 48h NOEC for mobility was 32 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

83 mg/L

Additional information

Read across to structurally similar substance monobutyltin trichloride (MBTC, CAS No.: 1118-46-3).

The acute toxicity of the test material to the fresh-water crustacean Daphnia magna was determined in accordance with the standardised guidelines OECD 202 and EU Method C.2, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The test was carried out as a static test with 4 x 5 daphnids (four-fold exposure media) for the control medium and each concentration. The exposure duration was 48 hours. The nominal concentrations tested were 5.6, 10, 19, 32, 56 and 100 mg/L. The test material was dissolved directly in the diultion water used for the test. The dilution water was also used as control medium.

All exposure media were completely clear throughout the test.

The actual concentration of the test material in the exposure media was determined by chemical analysis. Therefore, samples for chemical analysis were taken from all test concentrations at the start of the test and at the end of the test. At t=0 h, the average measured concentration of the test material in the exposure media was 99% of the nominal value. After 48 hours, the spent solutions contained 92% of the nominal value. As this is above 80% it is allowed to express the results of the test in nominal concentrations.

Under the circumstances of the test, the 48h EC50 of the test material for Daphnia magna was determined to be 83 mg/L and the 48h NOEC for mobility was determined to be 32 mg/L.