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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

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Reference
Endpoint:
toxicity to soil macroorganisms except arthropods: long-term
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
see read-across justification
Reason / purpose:
read-across source
Duration:
56 d
Dose descriptor:
NOEC
Effect conc.:
78 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other: corrected for MW
Duration:
56 d
Dose descriptor:
LOEC
Effect conc.:
138.8 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
reproduction
Remarks on result:
other: corrected for MW
Duration:
56 d
Dose descriptor:
NOEC
Effect conc.:
>= 246.5 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth
Remarks on result:
other: corrected for MW
Duration:
56 d
Dose descriptor:
LOEC
Effect conc.:
> 246.5 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth
Remarks on result:
other: corrected for MW
Validity criteria fulfilled:
yes
Conclusions:
The long-term toxicity of 7PPD to earthworm (Eisenia fetida) was tested according OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei)) and ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction). During 56 days exposure an NOEC(Reproduction) was determined to be 100 mg 7PPD/kg soil (dw) and the LOEC(Reproduction) as 178 mg 7PPD/kg soil (dw). This study is used for read-across to 44PD. After correction for molecular weight, this results in an NOEC (reproduction) = 78 mg 44PD/kg soil (DW) and LOEC (reproduction) = 138.8 mg 44PD/kg soil (DW).
Executive summary:

For 44PD, read-across from 7PPD is done. There is one study available which assesses toxicity to soil macroorganisms. This study on 7PPD was designed to comply with the following method:

- OECD Guideline No. 222 for the Testing of Chemicals "Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei)" adopted April 13, 2004

- ISO Guideline 11268-2 "Soil quality - Effects of pollutants on earthworms (Eisenia fetida) Part 2: Determnation of effects on reproduction" adopted July 1998

The purpose of this study was to determine a NOEC/LOEC and/or an EC50 for the effects of the test item on the reproduction (56 days after application), mortality and the biomass development (28 days after application) of the earthworm Eisenia fetida (Lumbricidae) by dermal and alimentary uptake using a standardised artificial soil. The test item was tested in five concentrations and was mixed with the substrate. Four replicates per concentration, eight solvent control replicates and additionally four deionised water control replicates (ten worms per replicate) were tested.

7.5 and 1.3% mortality was observed at the control and the solvent control, respectively. At all concentrations of the test item 0-7.5% mortality was determined.

Statistical analysis (Williams test; 1-sided, p ≤ 0.05) showed a significant difference concerning the number of juveniles between the solvent control and the concentrations of 178 and 316 mg 7PPD/kg. All other concentrations tested did not differ statistically significant from the solvent control.

Therefore, the NOECReproductionwas determined to be 100 mg 7PPD/kg soil (dw) and accordingly, the LOECReproductionas 178 mg 7PPD/kg soil (dw). This corresponds (after correction for molecular weight) to the NOECReproduction of 78 mg 44PD/kg soil (dw) and accordingly, the LOECReproduction of 138.8 mg 44PD/kg soil (dw).

Since inhibition of reproduction was < 50% compared to the solvent control in all concentrations of the test item tested (31.3% inhibition was observed in the highest concentration) no EC50 value was calculated.

Description of key information

The long-term toxicity of 7PPD to earthworm (Eisenia fetida) was tested according OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei)) and ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction). During 56 days exposure an NOEC(Reproduction) was determined to be 100 mg 7PPD/kg soil (dw) and the LOEC(Reproduction) as 178 mg 7PPD/kg soil (dw). After correction for molecular weight, this corresponds to an NOEC (reproduction) of 78 mg 44PD/kg soil (dw) and an LOEC (reproduction) of 138.8 mg 44PD/kg soil (dw).

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:
78 mg/kg soil dw

Additional information