α-(2,4-dichlorophenyl)-1H-imidazole-1-ethanol

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16-01-2008 to 18-01-2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 11268-1 (Effects of Pollutants on Earthworms. 1. Determination of Acute Toxicity Using Artificial Soil Substrate)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.8 (Toxicity for Earthworms: Artificial Soil Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- batch 00512242, purity 100.3% (w/w)
- expiry date: 27/06/2013
- storage conditions: room temperature, cool and dry in closed packaging

Analytical monitoring:

no

Details on sampling:

- Concentrations:
- Sampling method:
- Sample storage conditions before analysis:

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): to achieve a moisture content of approx. 35% of the dry weight, 195g deisonised water was added to 555g dry soil. 170 g of this water was mixed with artificial soil, 24h prior testing. Moistened substrate was stored in a closed container until use. Each batch of the pre-moistened soil (715 g) was mixed with 10 g of test iem treated quartz sand and 25g deionised water at high speed using an electric mixer. Immediately after mixing, test substrate was placed into test containers. In the definitive test, the test item was weighted directly on 10 g quartz sand on the day of test initation.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Eisenia fetia (Michaelsen), sub-species Eisenia fetida andrei
- Source: healthy laboratory rearing stock of the testing facility
- Age at test initiation (mean and range, SD): at least 2 months but less than 1 year old
- Weight at test initiation (mean and range, SD): adults, with individual weight of 329-429 mg at the beginning of the study

ACCLIMATION
- Acclimation period: 24h before initiation, earthworms were transferred from the rearing medium into moist, untreated test substrate for acclimation.
- Acclimation conditions (same as test or not): Prior to the introduction into the containers, the earthworms were rinsed, blotted dry and weighed individually. afterwards 10 earthworms were placed onto the soil surface of each container. The jars were covered with glass lids allowing ventilation and incubated under test conditions for 14 days.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

19.5-21.5°C under long day conditions (16h light/8h darkness)
450-700 lux

pH:

day 0: 7.08-7.14
day 14: 7.20-7.29
the pH of the test substrate was adjusted to 6.0±0.5 on the day of substrate preparation (actual : 5.9-6.17)

Moisture:

day 0: 35.9-36.9 %
day 14: 32.1-33.6 %
the water holding capactiy in the definitive test was 49.07%

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1L glass vessels
- No. of organisms per container (treatment): 10 earthworms per vessel
- No. of replicates per treatment group: 5 test item treatments each 4 replicates

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): 10% sphagnum peat; 20% kaolin clay; 69-70% industrial sand; 1% calcium carbonate

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 7.18
- Range finding study: 0-0.1-10-100-1000 mg/kg soil dw
- Results used to determine the conditions for the definitive study: Yes

OTHER TEST CONDITIONS
- Photoperiod: incubation under long day conditions (16h light/8 h darkness)
- Light intensity: 450-700 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality, abnormalities in behaviour (lethargy, absence of burrowing) and pathological symptoms (color changes)

Nominal and measured concentrations:

nominal concentrations definitive test: 0-178-316-562-1000 mg/kg soil dw

Reference substance (positive control):

yes

Remarks:

2-chloroacetamide

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Mortality at end of exposure period:
In the range finder test: no mortality was observed in the test item treatment groups and the control group. Test item treatment groups: 0-0.1-1-10-100-1000 mg/kg dw
After 7 and 14 days no mortaility was observed in the control group and in the test item treatment groups: 100, 316, 562 mg/kg soil dry weight. In the treatment groups of 178 and 1000 mg/kg soil dw one earthworm was dead after 7 days of exposure

- Changes in body weight of live adults (% of initial weight) at end of exposure period:
In the range finder test: the body weight change was between -8.7% (0.1 mg/kg soil dw) and -29.6% (1000 mg/kg soil dry weight). In the control group the average body weight was -12.9% of the initial weight.
the body weight change of the test organisms in the test item treatment groups was between -11.1 % (178 mg/kg soil dw) and -34.2 % (1000 mg/kg soil dw) from the initial weight. In the control group the average body weight loss was -4.6% of the inital weight. At all treatment rates up to and including 1000 mg/kg soil dw the biomass development was statistically inhibited as compared to the control treatment.

Results with reference substance (positive control):

LC50 = 14.7 mg 2-chloroacetamide/kg soil dw
NOEC = 8 mg 2-chloroacetamide/kg soil dw

The validity criteria in this study were fulfilled and therefore the test results are valid

Reported statistics and error estimates:

Test on normality and homogenicity of data using Shapiro-Wilks and Bartkett-test followed by Dunnett's t-test (weight change) and Fisher Exact test (mortality)

Earthworm mortality after exposure to the test item (definitive test)

test item (mg/kg)	day 7 (mean %)	day 14 (mean %)
control	0	0
100	0	0
178	2.5	2.5
316	0	0
562	0	0
1000	2.5	2.5

Validity criteria fulfilled:

yes

Conclusions:

In the 14-day toxicity study with T000824 to earthworms (Eisenia fetida) the LC50 was determined to be above 1000 mg/kg soil dry weight. The overall NOEC could not be determined, but the LOEC was determined to be 100 mg/kg sdw. As a conclusion, no effects on mortality of T000824 were seen in the OECD 107 guideline study.

Description of key information

In the 14-day toxicity study with T000824 to earthworms (Eisenia fetida) the LC50 was determined to be above 1000 mg/kg soil dry weight. The overall NOEC could not be determined, but the LOEC was determined to be 100 mg/kg sdw. As a conclusion, no effects on mortality of T000824 were seen in the OECD 107 guideline study.