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Ecotoxicological information

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:
toxicity to soil macroorganisms except arthropods: short-term
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2002-10-16 to 2003-01-28
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: OECD study, GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2003
Report Date:
2003

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 207 (Earthworm, Acute Toxicity Tests)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test substrate

Details on preparation and application of test substrate:
- Method of mixing into soil:
The total amount of soil needed for the 4 replicates per treatment level was prepared in one batch, hence 2100 g of dry soil corresponding to 2940 g of wet soil (at a moisture content of 40 % of the dry weight) was made up. Mixing of the soil took place in a BEAR Varimixer RN 20. Since the test item was not soluble at the desired concentrations in deionised water, 40 g of a stock mixture of test item and fine quartz sand was made up for each test concentration. To reach a test concentration of 95 mg/kg of dry weight of soil, 199.6 mg of test item was mixed thoroughly into the sand and then added to the dry blended constituents of the artificial soil. For test concentrations of 171, 309, 556 and 1000 mg/kg dry weight of soil, 359.2, 648.9, 1167.8 and 2099.8 mg of test item, respectively, were pre-mixed with sand and then added to 2060 g (dry weight) of artificial soil. To obtain the desired soil moisture of approximately 40%, for each treatment level 430 mL of deionised water were added to the soil. The moist soil was again thoroughly mixed and then divided up into the test vessels with each test vessel containing approximately 700g of soil (wet weight) corresponding to 500 g dry soil.

Test organisms

Test organisms (species):
Eisenia fetida
Animal group:
annelids
Details on test organisms:
TEST ORGANISM
- Common name: earthworm
- Source: Ecotox Center, Solvias AG
- Age at test initiation: 10 months
- Weight at test initiation: wet mass between 299 and 321 mg

ACCLIMATION
- Acclimation period: 24 hours
- Acclimation conditions: same as test

Study design

Study type:
laboratory study
Substrate type:
artificial soil
Limit test:
no
Total exposure duration:
14 d

Test conditions

Test temperature:
20.0 - 20.5°C
pH:
6.0 ± 0.5
Moisture:
40 %
Details on test conditions:
TEST SYSTEM
- Test container (material, size): 1.5 L glass bottling jars
- Amount of soil or substrate: 700 g of moist soil (500 g dry weight)
- No. of organisms per container (treatment): 40 per treatment level
- No. of replicates per treatment group: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- artificial soil in accordance to the guideline

OTHER TEST CONDITIONS
- Photoperiod: Continuous fluorescent light
- Light intensity: 650 Lux

EFFECT PARAMETERS MEASURED:
- Soil water content: each test concentration and the control measured at the start and the end of the test
- pH: each batch of soil was measured using a Knick Portamess 751 pH meter with a Mettler Toledo probe
- Temperature: in the environmental chamber was recorded continuously using an Atkins Recorder & Thermometer
- Light intensity: measured at the beginning of the test using a Metrux K Lux meter
- Weight of each earthworm: determined individually at test initiation, the weight of ten earthworms for each replicate was recorded. At test termination, the weight of the surviving earthworms for each replicate of each test concentration was recorded.
- Mortality and perceivable sublethal effects, such as abnormal behaviour or flaccidity: after 7 and 14 days of exposure

VEHICLE CONTROL PERFORMED: no

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
Nominal and measured concentrations:
95,171, 309, 556 and 1000 mg test item/kg dry weight of soil (nominal)
Reference substance (positive control):
yes
Remarks:
Chloracetamide

Results and discussion

Effect concentrationsopen allclose all
Duration:
14 d
Dose descriptor:
LC0
Effect conc.:
309 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Duration:
14 d
Dose descriptor:
LC50
Effect conc.:
437 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks on result:
other: 309 - 556
Duration:
14 d
Dose descriptor:
NOEC
Effect conc.:
309 mg/kg soil dw
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: weight
Details on results:
- Changes in body weigth of live adults (% of initial weight) at end of exposure period: The average live weight of the earthworms in the control and test concentrations of 95, 171, 309 and 556 mg test item/kg dry weight of soil, changed to a weight of 101, 98, 99, 101 and 104% of the initial weight during the 14 days of exposure, respectively. The average weight change (in %) in comparison to the controls was not significantly different (Dunnett-test; a = 0.05, one-sided, smaller) in any of the test concentrations. The treatment concentration of 556 mg/kg test item was excluded from statistical comparison since too few individuals survived the treatment. Hence the NOEC (14d) regarding earthworm weight was determined to be 309 mg test item/kg dry weight of soil.
- Morphological abnormalities: At a test concentration of 556 mg/kg dry weight of soil, light sublethal effects (flaccidity of surviving earthworms) were observed at 7 and 14 days of the test.
Reported statistics and error estimates:
The statistical analysis of the data was performed with a statistical program (Easy Assay 3.0). The LC 50 value at 7 and 14 days and the confidence limits were determined by binomial distribution. For the determination of the NOEC in regard to average live weight of test organisms, Dunnett multiple sequential test procedure was performed (Easy Assay 4.0).

Applicant's summary and conclusion