Tin zinc oxide (SnZnO3)

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 April 1989 - 28 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 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

The stability of test concentrations was ensured by daily renewal of test material and verified by chemical analysis at 0, 24 and 96 hours.
Experimental design: 1 test concentration in duplicate plus 1 control and 1 solvent control (including 100 µL/L auxiliary solvent).
Medium renewal: Daily.
Test Concentrations : 0.10 mg/L in duplicate.

Vehicle:

yes

Details on test solutions:

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).

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout.
- Length at study initiation (length definition, mean, range and SD): 4.1cm (SD = 0.2cm)
- Weight at study initiation (mean and range, SD): 0.76g (SD = 0.26g)
- Feeding during test: Food discontinued 24 h prior to test.
- Source: Belleau Bridge Trout Farm. Lincolnshire, UK.


ACCLIMATION
- Acclimation period: Stock held since 4 April 1989 and acclimatised to test conditions 7 days prior to test.
- Type and amount of food: Commercial trout pellets.
- Feeding frequency: Daily.
- Health during acclimation (any mortality observed): Approximately 3 % mortalities in 7 days prior to test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Not stated

Hardness:

Test Water
Laboratory tap water, dechlorinated by the addition of sodium thiosulphate. Total hardness approximately 50 mg/L as CaC03.

Test temperature:

14°C. Measured daily

pH:

pH 7.6 - 7.7. Measured daily.

Dissolved oxygen:

10.4 - 10.6 mgO2/L. Measured daily.

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria holding 20 L of test media
- Aeration: via narrow bore glass tubes.
- No. of organisms per vessel: 10 animals per test concentration.
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.38 g bodyweight/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water, dechlorinated by the addition of sodium thiosulphate. Total hardness approximately 50 mg/L as CaC03.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours darkness

TEST CONCENTRATIONS
- Test concentrations: 0.10 mg/L in duplicate

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

There were no mortalities or other adverse reactions to exposure in 20 fish exposed to a nominal test concentration of 0.10 mg/L for a period of 96 hours. 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.
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.
Highest test concentration resulting in 0 % mortality ≥0.10 mg/L.
Lowest test concentration resulting in 100 % mortality >0.10 mg/L.

Sublethal observations / clinical signs:

Care should be taken in the interpretation of these results as the verification of test concentrations showed that the average test concentration was 79 % of the nominal value i.e. 0.079 mg/L, despite attaining near nominal test concentrations at 0 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 over a 24 hour period.

Samples	Nominal Concentration (mg/L)	Concentration Found (mg/L)	Concentration Expressed as % of Nominal
0 hours       24 hours       96 hours	Control 0.1   0.1     Control 0.1   0.1     Control 0.1   0.1 R₂	* 0.117 0.120   * 0.068 0.054   * 0.123 0.072	* 117 120   * 68 54   * 123 72

 

* The levels of zinc found in the control samples were consistent with those stated in "Typical Water Quality Characteristics, Severn Trent Water Authority Northern Division".

Control	Zinc Concentration (mg/L)
0 hours 24 hours 96 hours	0.031 0.022 0.018

Range = 0.018 - 0.031

Mean = 0.024

The 0 hour values have been omitted from the calculation of percentage of nominal values to give a "worst case" analysis of the data. It is considered that precipitation and/or settlement are the cause of the decrease in test concentrations. Dynamic test conditions were not employed in order to prevent the build-up of precipitated material and the consequent blockage and failure of the system. 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.

Validity criteria fulfilled:

yes

Conclusions:

LD50 >0.10mg/L

Executive summary:

An LD50 of >0.10 mg/L was found under semi-static test conditions according to OECD Guideline No 203 and EEC Directive 67/548 Annex V C.1 as published in 84/449/EEC.

Description of key information

LC50 of >0.10 mg/L was obtained in a 96 h semi-static test conducted on Salmo gairdneri (new name Oncorhynchus mykiss) using the read-across substance Zinc Hydroxystannate.

Additional information

The short term toxicity of the read-across substance Zinc Hydroxystannate to Salmo gairdneri (new name Oncorhynchus mykiss) was investigated in a 96 hour semi-static test conducted in accordance with GLP and the standardised guidelines OECD Guideline No 203 and EEC Directive 67/548 Annex V C.1 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).

An LC50 of >0.10 mg/L was found under the conditions of this study.