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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:
experimental study
Adequacy of study:
key study
Study period:
1995-09-20 to 1995-10-04
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
EU Method C.8 (Toxicity for Earthworms: Artificial Soil Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
no
Vehicle:
no
Details on preparation and application of test substrate:
- Controls: Untreated soil
Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
TEST ORGANISM

- Common name: Earthworm, Eisenia foetida foetida

- Source: Eisenia GmbH und Co, Wiesbaden, Germany

- Age at test initiation (mean and range, SD): 2 months

- Weight at test initiation (mean and range, SD): 439 mg (303-565) in Control and 452 mg (313-581 in treatment).
Study type:
laboratory study
Substrate type:
other: quartz sand
Limit test:
yes
Total exposure duration:
14 d
Test temperature:
20 +/-2 ºC
pH:
6.6-6.8
Moisture:
40% of holding capacity
Details on test conditions:
TEST SYSTEM

- No. of organisms per container (treatment): 10

- No. of replicates per treatment group: 4

- No. of replicates per control: 4


SOURCE AND PROPERTIES OF SUBSTRATE (if soil)

- Composition (if artificial substrate): Quartz sand


OTHER TEST CONDITIONS

- Photoperiod: Daylight

- Light intensity: ca. 400-600 Lux


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality after 7 and 14 days exposure


VEHICLE CONTROL PERFORMED: no


TEST CONCENTRATIONS

- Limit test at 1000 mg/kg
Nominal and measured concentrations:
Nominal: 1000 mg/kg
Reference substance (positive control):
yes
Remarks:
Chloracetamide
Duration:
14 d
Dose descriptor:
LC50
Effect conc.:
> 1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
other: hydrolysis products
Basis for effect:
mortality
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
>= 1 000 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
other: hydrolysis products
Basis for effect:
mortality
Details on results:
- Mortality at end of exposure period: 0
Results with reference substance (positive control):
After 7 and 14 days exposure mortality was 0 in the 30 mg/kg treatment and 100% in the 100 mg/kg treatment.
Reported statistics and error estimates:
There were no toxic effects observed in the test and therefore statistical analysis of the test results was not required.

No toxic effects were observed in the test.

Validity criteria fulfilled:
yes
Conclusions:
A 14-day LC50 value of >1000 mg/kg dry weight and NOEC of =1000 mg/kg dry weight have been determined for the effects of the test substance on mortality of Eisenia foetida. It is likely that the test organisms were exposed primarily to the hydrolysis products of the test substance.

Description of key information

short-term earthworm toxicity: 14 day LC50 >1000 mg/kg nominal, according to EU A.8

Key value for chemical safety assessment

Additional information

Only a short-term study is available with the registered substance, 3-trimethoxysilylpropyl methacrylate CAS 2530-85-0):

A 14-day LC50 value of >1000 mg/kg dry weight and NOEC of =1000 mg/kg dry weight have been determined for the effects of the registered substance on mortality of Eisenia fetida (Evonik 1995). It is likely that the test organisms were exposed primarily to the hydrolysis products of the test substance. This study has been selected as key for short-term data (Annex IX requirement).

The results may be expressed in terms of concentration of the hydrolysis product, 3-(trihydroxysilyl)propyl methacrylate, by applying a molecular weight correction: (MW of silanol=206.27 / MW of parent=248.35) * [Conc. of parent] = [conc. of silanol]. Using this method, the 14-day results are equivalent to an LC50 of 830 mg/kg dwt and a NOEC of = 830 mg/kg dwt, when expressed in terms of the silanol hydrolysis product.

No long-term data to terrestrial invertebrates are available. Further testing for toxicity to terrestrial invertebrates and higher plants is not considered necessary because: A short-term terrestrial toxicity test with soil macro-organisms and a terrestrial test with soil micro-organisms have been carried out with the registered substance.

  • In accordance with Column 2 of REACH Annex IX, there is no need to further investigate the effects of this substance in long-term terrestrial toxicity studies because, as indicated in guidance R.7.11.6 (ECHA 2016), the quantitative chemical safety assessment (conducted according to Annex I of REACH) indicates that the Risk Characterisation Ratio is well below 1, and therefore the risk is already adequately controlled and further testing is not justifiable.
  • The silanol hydrolysis product has a low log Kow value and, therefore, exposure of the soil compartment is expected to be low.
  • The substance is not adsorbing (based on log Koc 0.55), has low bioavailability (based on log Kow <3 (-0.9)) and low toxicity was observed in short-term aquatic tests as well as in the available terrestrial tests. Therefore, the occurrence of more severe toxic effects in the terrestrial compartment that were not expressed in the aquatic studies would be considered unlikely.

Overall it is concluded that the risk characterisation conclusion is sufficiently conservative in respect of any uncertainties and therefore further in vivo testing is not considered necessary.

Details on how the PNEC and the risk characterisation ratio have been derived can be found in IUCLID Section 6.0 and Chapters 9 and 10 of the Chemical Safety Report, respectively.