diethyl 1-(2,4-dichlorophenyl)-5-methyl-4,5-dihydro-1H-pyrazole-3,5-dicarboxylate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil:
For the preparation of the test substrates 740 g basic substrate for each concentration step were filled into a glass aquarium.
Each replicate for each concentration was mixed separately.To obtain a fresh stock mixture for the test, the test substance was weighed out to a precision of 0.1 mg and mixed in industrial sand. Defined amounts of stock mixture were added to the basic substrate in the mixing aquarium and well mixed with a rapid mixer .

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: own culture
- Age at test initiation: older than 2 months
- Weight at test initiation: 372 mg (325 - 409 mg)

ACCLIMATION
- Acclimation period: 24 hours prior to testing the worms were taken from the culture and acclimatized to the test conditions in the freshly prepared basic substrate

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20 ± 1 °C

pH:

6.4

Moisture:

26.1 %

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1.5 L glass jars,
- Amount of soil or substrate: 750 g of test substrate
- 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)
The artificial soil was prepared from:
- 10% (2.75 kg) dried and sifted sphagnum peat (residual
moisture content of 9.9 % taken into calculation)
- 20% (5.0kg) kaolin clay (type 1777, ziegler & Co., Wunsiedel,
FRG; kaolinite content 87.5%)
- 69.7% (17.4 kg) industrial sand (Quarzsand type 155-0,
Gebr. Willersinn GmbH & Co. KG, Ludwigshafen , FRG;
particle analysis: 40% 0.125 mm, 27% 0.09-0.125 mm,
13-15% 0.063 - 0.09 mm)
- 75 g Calcium carbonate (CaC03) were used to adjust the pH of this medium to 6.4.

OTHER TEST CONDITIONS
- Photoperiod: a 16-hour daylight photoperiod
- Light intensity: illuminated by wide spectrum fluorescent lights


EFFECT PARAMETERS MEASURED : The biomass of live worms was determined at the start and end of testing. Seven and 14 days after starting
the test, mortality and intoxication symptoms were recorded.

Nominal and measured concentrations:

Limit dose of 1000 mg test item /kg dry substrate

Reference substance (positive control):

yes

Remarks:

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

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks:

, weight gain, intoxication symptoms

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: 14-day LC50 value of 24.0 (18 – 32) mg /kg

Findings:

Soil substrate parameters such as moisture, pH and temperature were determined to be within the acceptable

limits. There was no mortality, intoxication symptoms and significant differences in weight loss and cocoon

production between 1000 mg/kg treatment and control groups. .

Conclusion:

In a 14-day Artificial Soil Test to determine the effects of AE F107892 technical on Eisenia fetida, the 14-day

LC50 was > 1000 mg/kg test item as no death occurred at this limit dose. In the absence of any sublethal findings

(intoxication symptoms, weight gain and intoxication symptoms) the NOEC 1000 mg/kg test item.

Description of key information

LC50 (14 d)>1000 mg/kg soil dw

Additional information

The substance is not expected to pose a risk to soil macroorganisms. There is no indication for high adsorption or high persistence of the substance in soil. The determined log Pow of the substance is 4 and the adsorption potential is low (Koc range 486 – 823). Available tests on the biodegradation of the substance in soil determined half-lives of 7-13 days. Thus a long-term exposure of terrestrial organisms to substance is not likely. The substance is not acutely very toxic to aquatic organisms. All available effect concentrations (EC/LC50) are > 1 mg/L . Furthermore the available acute toxicity test conducted with earthworms determined no toxic effects of the substance. The study was conducted according to OECD guideline 207 (1991) using artificial soil as substrate. Earthworms of the species Eisenia fetida were exposed to a limit concentration of 1000 mg/kg. The artificial soil, prepared from a mixture of dried sphagnum peat, kaolin clay and industrial sand, was mixed with the test substance. No mortalities or symptoms of intoxication were observed. The determined 14-day LC50 was > 1000 mg/kg soil dw was no death occurred at this limit dose. In the absence of any sublethal findings (intoxication symptoms, weight gain and intoxication symptoms) the NOEC (14 d) was 1000 mg/kg soil dw. According to Annex IX, column 2 of Regulation (EC) No 1907/2006, chronic toxicity testing with soil macroorganisms does not need to be conducted as the Chemical Safety Assessment does not indicate a need for further investigations. According to Annex XI, Section 3 of Regulation (EC) No 1907/2006 toxicity tests on soil macroorganisms are considered not necessary. The exposure concentrations for the terrestrial compartment during the lifecycle of the substance are low. The environmental exposure assessment for the substance indicates no risk for the terrestrial compartment (all RCR< 1; please refer to Chapter 9 and 10 of the Chemical Safety Report for detailed information).