5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-(ethylsulfinyl)-1H-pyrazole-3-carbonitrile

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:

04 Jun - 19 Jun 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

adopted 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1987

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): Nominal concentrations were attained by mixing the test substance directly into the dry artificial substrate. The total weight of test substance required for each concentration were added to 2.2 kg of dry substrate and thoroughly mixed. The mixture was then equally divided between each of the four replicate test vessels before addition of the humidification water. When adding the humidification water (180 mL) each test medium was mixed with a spatula.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: Batch no. 98V051 from SARL Moulin, 60510 Litz, France
- Age at test initiation: ≥ 2 months
- Weight at test initiation (mean and range, SD): 327 - 435 mg per batch of 10 worms

ACCLIMATION
- Acclimation period: ≥ 24 h
- Acclimation conditions (same as test or not): same as test
- Health during acclimation (any mortality observed):
- Feeding during aclimation: none

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

20 °C

pH:

5.6 - 5.8

Moisture:

35.14% - 37.93%

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1.5 L plastic containers, covered
- Amount of soil or substrate: 500 g dry weight of test substrate, 180 mL of deionised water
- 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): 69.4% Industrial quartz sand, 20.1% Kaolinite clay, 10.1% Sphagnum moss, 0.4% Calcium carbonate

OTHER TEST CONDITIONS
- Photoperiod: continuous light
- Light intensity: 597 - 608 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortalities and behavioural alterations were recorded after 7 and 14 days of exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3x
- Range finding study
- Test concentrations: 50 and 500 mg/kg
- Results used to determine the conditions for the definitive study: After 7 days no mortality was observed, all worms presented reduced mobility.

Nominal and measured concentrations:

Nominal: 0, 4, 12, 37, 111, 333, 1000 mg/kg

Reference substance (positive control):

no

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:

mortality

Details on results:

- Mortality at end of exposure period: No mortality was observed in the control and in any of the test concentration groups.
- Morphological abnormalities: None
- Behavioural abnormalities: None

Reported statistics and error estimates:

- Statistics for effect concentrations: LC50 values are estimated by means of a computer program using one of the three statistical methods: probit analysis, moving average method or binomial probability. The method selected is determined by the data set. LC50 values are presented with 95% confidence limits when the methods of probit analysis or moving average are used to perform the calculation.
- Statistics for weight change data: The raw data are analysed for homogeneity of variances by using the BARTLETT’S test.
If BARTLETT’S test indicates homogeneous variances and the ANOVA is significant, the group means are intercompared to the control mean using the DUNNETT’S test.
If BARTLETT’S test indicates heterogeneous variances, a non-parametric statistical procedure is performed using the KRUSKAL-WALLIS non-parametric one-way analysis of variance by ranks. If the KRUSKAL-WALLIS test is significant the MANN-WHITNEY test is used to compare each exposed group to the control. The alpha levels for statistical comparisons are 0.05 and 0.01.
- Determination of the NOEC: The No Observed Effect Concentration (NOEC) at Day 14, defined as the highest tested concentration at which there was no significant toxicant-related mortality or adverse physical and behavioural abnormalities was determined based on mortality counts, biological observations and on statistical analysis of mean % weight change.

A net decrease in mean body weight between day 0 and day 14 was observed in the control group (- 4.11%) and at each of the test substance concentrations (- 1.30% to - 2.42%). The statistical analysis of the weight changes showed that the mean percentage weight loss observed in the groups exposed to 12, 37, 111, 333 and 1 000 mg/kg was significantly lower (α = 0.01) than that observed in the control group. No significant differences were found between earthworms exposed to 4 mg/kg and the controls. Since the most pronounced mean weight loss was observed in the control group, these differences were not considered to be adverse effects of the test substance on Eisenia fetida.

Table 1: Validity criteria for OECD 207.

Criterion	Outcome	Criterion fulfilled
Mortality in the control≤10 % at the end of the test	0%	yes

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Description of key information

LC50 (14 d) > 1000 mg/kg dw (nominal, Eisenia fetida, OECD 207)

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw

Additional information

The toxicity towards soil organisms was investigated in a 14-day artificial soil test with the earthworm Eisenia fetida following OECD guideline 207 and GLP. No death or intoxication symptoms and no significant changes in weight were observed up to 1000 mg/kg soil dry weight, the maximum concentration tested.