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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Reference
Endpoint:
toxicity to soil macroorganisms except arthropods: short-term
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
For tin disulfide an algal study is available. This study demonstrated that the tin sulfide has no toxic effects at the limit of water solubility, i.e., at 0.67 µg/L. The other aquatic endpoints were covered using data from tin sulfide which has an almost identical water solubility, i.e., 0.6 µg/L. The algal study was used as bridging study since the WHO concluded in their report that alge are the most sensitive group. Furthermore, the WHO concluded that Sn II is more toxic than Sn IV. Hence, read across from tin sulfide (Sn II) to tin disulfide (Sn IV) was considered justified.
Reason / purpose for cross-reference:
read-across source
Key result
Duration:
14 d
Dose descriptor:
LC50
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Basis for effect:
mortality
Key result
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Basis for effect:
mortality
Results with reference substance (positive control):
Test conditions were adaquate.
Reported statistics and error estimates:
Validity of Test:
- mortality in untreated control group must not exceed 10%
- reference control to asure adequate test conditions

LC50 and 95% confidence limits were calculated by Trimmed Spearman-Karber Method. No statistical method was used, because of low toxicity of test substance on earthworm.

For tin disulfide an algal study is available. This study demonstrated that the tin sulfide has no toxic effects at the limit of water solubility, i.e., at 0.67 µg/L. The other aquatic endpoints were covered using data from tin sulfide which has an almost identical water solubility, i.e., 0.6 µg/L. The algal study was used as bridging study since the WHO concluded in their report that alge are the most sensitive group. Furthermore, the WHO concluded that Sn II is more toxic than Sn IV. Hence, read across from tin sulfide (Sn II) to tin disulfide (Sn IV) was considered justified.

Validity criteria fulfilled:
yes
Conclusions:
Test results indicated that the 14 d LC50 of test item in artifical soil was greater than 1000 mg/kg dry weight soil. NOEC after 14d was greater than 1000 mg/kg dry weight soil.
Executive summary:

The acute toxicity of tin sulfide on earthworm Eisenia foetida was determined in accordance OECD Guideline 207 "Earthworm, Acute Toxicity Tests". Therefore 10 organism/ replicate (4) were exposed in samples of artificial soil mixed with test item. Mortality was assessed 7 days and 14 days after application of test item (1000 mg/kg dry weigth soil). Based on the results of Limit Test the 14 d NOEC and LC50 were determined and be greater than 1000 mg tin sulfide/kg dry weigth soil. Therefore, tin sulfide is low toxic to earthworms.

The results are considered relevant for tin disulfide since both substances have the same metal moiety and have similar physico-chemical properties, e.g., they are almost insoluble in water. Further evidence is provided in the read across justification.

Description of key information

The endpoint was covered by read-across from tin sulfide. Based on the results of Limit Test the 14 d NOEC and LC50 were determined and be greater than 1000 mg tin sulfide/kg dry weigth soil. Therefore, tin sulfide is low toxic to earthworms.

Key value for chemical safety assessment

Additional information

The acute toxicity of tin sulfide on earthworm Eisenia foetida was determined in accordance OECD Guideline 207 "Earthworm, Acute Toxicity Tests". Therefore 10 organism/ replicate (4) were exposed in samples of artificial soil mixed with test item. Mortality was assessed 7 days and 14 days after application of test item (1000 mg/kg dry weigth soil). Based on the results of Limit Test the 14 d NOEC and LC50 were determined and be greater than 1000 mg tin sulfide/kg dry weigth soil. Therefore, tin sulfide is low toxic to earthworms.

The results are considered relevant for tin disulfide since both substances have the same metal moiety and have similar physico-chemical properties, e.g., they are almost insoluble in water. Further evidence is provided in the read across justification.