Tin dioxide

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study in compliance with international recognized guidelines

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: Tin Dioxide 100% / K29222818
- Expiration date of the lot/batch: 30 April 2006
- Purity test date:

Analytical monitoring:

no

Details on sampling:

no data

Vehicle:

yes

Details on test solutions:

The water solubility of tin (IV) oxide is described to be very low and depending on temperature and pressure ( see point 4.8, The solubility of tin from tin dioxide in double distilled water at 20°C is below the limit of quantification (2.5 µl)) therefore no analysis was scheduled.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Straus)
Age: Daphnia magna, not older than 24 hours.
The strain with the parent generation was bred and maintained in vessels containing a batch of Daphnia magna of different ages.
Preparing a new study, juvenile Daphnia magna were separated and placed in 100 ml of reconstituted water. The water was renewed and the Daphni magna were fed with a suspension of fresh water algae once a week.
Newborn animals were separated and allocated to the different dose groups.
The Daphnia magna were kept in reconstituted water in glass vessels. The study was located in an air-conditioned room in the Institute of Toxicology
Lighting was controlled by a timer to provide a 16 hours light - 8 hours dark regime.
Temperature and humidity in the experimental room were measured using a thermohygrograph.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

not applicable

Hardness:

250 mg/L expressed as CaCO3

Test temperature:

During the experimental part, the temperature was registered in a control vessel with an electronic thermometer containing a maximum and minimum memory display: 22°C

pH:

The pH-values were measured in the control and all test material concentrations at the beginning and at the end of the experimental part.
7.9 ± 0.3

Dissolved oxygen:

The dissolved oxygen concentration (02) were measured in the control and all test material concentrations at the beginning and at the end of the experimental part.
Start of the experimental part (t=0): 97.8% ( control) and 94.4% (test item)
End of the experimental part: 96.8% (control) and 95.9% (test item)

Salinity:

no data

Nominal and measured concentrations:

Nominal concentration: 0.1 g/L

Details on test conditions:

The test medium (reconstituted water and test material) was freshly prepared. Therefore, the calibrated flask with test material and vehicle, reconstituted water, was treated in an ultrasonic device for 1 hour. Subsequently the preparation was aerated, and stirred with a magnetic stirrer for further 23 hours. After 24 hours the preparation was given through a nutsch filter (pore size >10 - <16µm). The filtrate of the test material preparation was used for the study.
20 daphnia magna were used per test material concentration and 20 per control.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.1 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.1 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.1 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

In the control and in an aqueous solution of the test material concentration of nominal 0.1 g/L (limit test), no immobilized test animals were observed during the test period of 48 hours in a static open test system.
No remarkable observations were made concerning the appearance of the solution of the test material preparation. The test medium was a clear preparation and stayed unchanged throughout the study.

Results with reference substance (positive control):

no data

Reported statistics and error estimates:

not applicable

Validity criteria fulfilled:

yes

Conclusions:

Under the given experimental conditions, the test material (Tin (IV) oxide) showed a nominal 24 h and 48 h EC50 value> 0.1 g/L. Thus the EC50 of Tin dioxide exceeds the water solubility.
The no effect concentration for Daphnia magna was 0.1 g/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:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The main assumption for this read across approach is that the source substance ionic Tin (IV) and the target substance Tin (IV) dioxide NP have a common moiety (Tin ion).
Although the target substance, Tin (IV) dioxide NP, is insoluble in water, it is an amphoteric oxide (F. Sherwood Taylor, 1942). The dissolving part of Tin (IV) dioxide NP in aqueous media will react with acids and become ionic Tin (IV).
2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Please refer to test item sections for details.
3. ANALOGUE APPROACH JUSTIFICATION
A reliable aquatic toxicity study on Daphnia is available for the source substance ionic Tin (IV), showing that the substance is has no acute toxicity on Dapnia (Under the given experimental conditions, the test material (Tin (IV) oxide) showed a nominal 24 h and 48 h EC50 value> 0.1 g/L. Thus, the EC50 of Tin dioxide exceeds the water solubility.)
The no effect concentration for Daphnia magna was 0.1 g/L. Since the target and the source substance dissociate to the same ion, both target and read-across substance, do share the same toxicological mechanisms and the effects of the target substance is predicted to be equal to the effects of the source substance.
The common compound ionic Tin (IV) is solely responsible for the absence or presence of effects.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 0.1 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.1 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.1 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Description of key information

EC50 (48 hrs, daphnia magna) > 0.1 g/L

Additional information

A GLP study on acute toxicity on Daphnia magna is available. Under the given experimental conditions, the test material (Tin (IV) oxide) showed a nominal 24 h and 48 h EC50 value > 0.1 g/L. Thus the EC50 of Tin dioxide exceeds the water solubility.

The study brings to the conclusion that the substance was not acutely toxic to Daphnia magna when tested according to OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test).

As the Tin dioxide bulk form and the Tin Dioxide NP insoluble (< 0.1 mg/L) are both highly insoluble in water insoluble, the same conclusions on Toxicity in Daphnia are valid for the Tin Dioxide NP.