Tin zinc oxide (SnZnO3)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 April 1989 - 26 April 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Read across to similar substance. Study conducted to GLP in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results.

Justification for type of information:

See read-across justification in Section 13.

Reason / purpose for cross-reference:

other: Target substance

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

Analytical monitoring:

yes

Vehicle:

yes

Details on test solutions:

Preliminary solution in 1 % Tween 80-acetone

Test organisms (species):

Daphnia magna

Details on test organisms:

Test Species
Name: Daphnia magna (Straus).
Culture: At 20 ± 2 °C in glass vessels containing two litres of dechlorinated and aged tap water. Cultures were fed daily with a mixture of fry fish food (Liquifry) and a suspension of mixed algae (predominantly Chlorella spp.). Culture conditions ensured that reproduction was by parthenogenesis.
Selection: Gravid adults were isolated 24 hours prior to initiation of the test. Young daphnids produced overnight were used for testing.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Total hardness approximately 50 mg/L as CaCO3.

Test temperature:

21 °C

pH:

pH 7.7 - 7.8

Dissolved oxygen:

At 0 hours 8.5 - 8.6 mgO2/L. At 48 hours 8.3 - 8.4 mgO2/L

Nominal and measured concentrations:

Nominal concentration of 0.10 mg/L

Details on test conditions:

Test Water
Dechlorinated (with sodium thiosulphate) and aged laboratory tap water. Total hardness approximately 50 mg/L as CaCO3.

Exposure Conditions
Test vessels: Glass jars each containing 200 mL test solution.
Experimental design: 1 test concentration, 4 replicates, plus 1 control and 1 solvent control (including 100 µL/L auxiliary solvent) each in duplicate. 40 animals per concentration.
Method of initiation: Daphnia were placed in the test solutions after addition of the test substance.
Loading: 20 mL test solution per organism.
Photoperiod: 16h light, 8h dark.
Temperature: 21 °C
Aeration: None
Test concentration: 0.10 mg/L, 4 replicates.
Medium renewal: None.
Duration of exposure: 48 hours.
Criteria of effect: Daphnia were considered to be immobilised if they were unable to swim for approximately 15 seconds after gentle agitation.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There were no mortalities in 40 daphnids exposed to a nominal test concentration of 0.10 mg/L for a period of 48 hours. 0.10 mg/L was the highest test concentration that could be prepared due to the low water solubility of the test material and having regard to the amount of auxiliary solvent permitted in the test.

0.10 mg/L was the highest concentration tested as the test material was observed to precipitate/settle out over a 24-hour period, in the range finding test, at higher test concentrations.

Care should be taken in the interpretation of these results as the verification of test concentrations showed that the average test concentration was 23 % of nominal i.e. 0.023 mg/L after 48 hours and it is recommended that this level be taken as the true exposure level. However, the material was shown to be chemically stable in water.
The 0 hour values were omitted from the calculation of percentage of nominal values to give a "worst case" analysis of the data. The decrease in test concentrations is considered to be due to precipitation and/or settlement.
Other combinations of the various recognised auxiliary solvents and mixtures of Tween 80 (up to 20 % Tween in solvent) were used during the range finding experiments, however, the combination of 1 % Tween 80-acetone was found to give the best testable dispersion of the test material.

Cumulative Immobilisation Data for Daphnia Magna Exposed for 48 Hours

Concentration (mg/L)	Cumulative immobilised Daphnia (initial population: 10)
	24 hours			48 hours
		Total	%		Total	%
Control  R1 R2   Solvent Control      R1 R2   0.10          R1 R2 R3 R4	0 0     0 0   0 0 0 0	0       0       0	0       0       0	0 0     0 0   0 0 0 0	0       0       0	0       0       0

R1 – R4: Replicates 1, 2, 3, and 4

Validity criteria fulfilled:

yes

Conclusions:

48 h NOEC > 0.10 mg/L

Executive summary:

48 h NOEC > 0.10 mg/L was found under static test conditions according to OECD Guideline No. 202, Part 1 and EEC Directive 67/548 Annex V C.2 as published in 84/449/EEC.

Description of key information

A 48 h NOEC of >0.10 mg/L was obtained in a static test conducted on Daphnia magna using the read-across substance Zinc Hydroxystannate.

Additional information

The short term toxicity of the read-across substance Zinc Hydroxystannate to Daphnia magna was investigated in a 48 hour static test conducted in accordance with GLP and the standardised guidelines OECD Guideline No. 202, Part 1 and EEC Directive 67/548 Annex V C.2 as published in 84/449/EEC.

0.10 mg/L was the highest test concentration that could be prepared due to the limited water solubility of the test material and having regard to the limitations on the amount of auxiliary solvent permitted in the test (100 µL/L of 1 % Tween -80 in acetone).

A 48 h NOEC of >0.10 mg/L was found under the conditions of this study.