3,5-bis(difluoromethyl)-1H-pyrazole

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Mar. 2019 - May 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Version / remarks:

2016

Test guideline 2

Qualifier:

according to guideline

Guideline:

ISO 11268-2 (Effects of Pollutants on Earthworms. 2. Determination of Effects on Reproduction)

Version / remarks:

July 1998

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,5-bis(difluoromethyl)-1H-pyrazole

EC Number:

814-072-3

Cas Number:

77614-79-0

Molecular formula:

C5H4F4N2

IUPAC Name:

3,5-bis(difluoromethyl)-1H-pyrazole

Sampling and analysis

Analytical monitoring:

no

Test substrate

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil: Preparation of a stock solution of the test item in acetone. Preparation of application solutions depending on the desired concentrations in the final test substrate.
2 mL of the respective application solution were given onto 5 g quartz sand per treatment.
- Controls: Control (quartz sand only) and Solvent control (2 mL actone and quartz sand)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Evaporation of vehicle before use: Yes, evaporation of acetone before mixing the quartz sand into the artificial soil.

Test organisms

Test organisms (species):

Eisenia andrei

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Source: Inhouse breeding since several years, Original strain from Forschungsanstalt für Landwirtschaft Braunschweig, Germany
- Age at test initiation (mean and range, SD): 9 - 10 months old.
- Weight at test initiation (mean and range, SD): 340 - 430 mg per worm.

ACCLIMATION
- Acclimation period: 1 day before test start
- Acclimation conditions (same as test or not): same as test
- Health during acclimation (any mortality observed): not reported

Study design

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

8 wk

Test conditions

Test temperature:

18.5 - 20.5 °C

pH:

5.54 - 6.25 in all controls and treatments at the start and the end of the study

Moisture:

48.17 - 51.19 in all controls and treatments at the start and the end of the study

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Non-re-usable plastic boxes (length x width x height ca. 16.5 cm x 12 cm x 6 cm, area approximately 200 cm²
- Amount of soil or substrate: 500 g dry weight artificial soil
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8
- No. of replicates per vehicle control: 8

PROPERTIES OF SUBSTRATE
- Artificial soil according to Guideline:
Sphagnum peat (shredded): 10 %
Kaolinite clay (content of Kaolinite = 30.2 %): 20 %
Industrial quartz sand (Particle size: 0.20 mm – 0.05 mm = >50 %): 70 %

VEHICLE CONTROL PERFORMED: Yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8

OTHER TEST CONDITIONS
- Photoperiod: 16 h light and 8 h dark
- Light intensity: 400 – 800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : number of surviving adult earthworms and weight after further 28 days, number of offspring after 56 days

Nominal and measured concentrations:

Control, Solvent control, 10, 18 , 32, 56, 100 mg/kg d.w. nominal concentrations

Reference substance (positive control):

yes

Remarks:

Carbendazim EC 360 G

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

Adult mortality

Effect concentrations 2

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks:

Adult growth

Effect concentrations 3

Duration:

56 d

Dose descriptor:

EC10

Effect conc.:

50 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Effect concentrations 4

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

56 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Effect concentrations 5

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Details on results:

- Mortality at end of exposure period adults, 28 days):
Control: 0 %
Solvent control: 1.3%
10 mg/kg: 2.5 %
18 - 100 mg/kg: 0 %

- Changes in body weight of live adults (% of initial weight) at end of exposure period (28 days):
Control, solvent control, 10, 18, 32, 56, 100 mg/kg: 37.87 %, 33.72 %, 34.69 %, 32.55 %, 31.23 %, 33.72 %, 36.88 %

- No. of offspring produced (mean after 56 days):
Control, solvent control, 10, 18, 32, 56, 100 mg/kg: 297.1, 281.3, 279.0, 264.0, 261.5, 249.8 , 237.3

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: Significant toxic effects onto reproduction at 2.5 and 5.0 mg reference item / ky dry weight soil

Any other information on results incl. tables

Table 1: Results

Concentration mg /kg soil dw	Control	Solvent Control	10	18	32	56	100
Mortality of adult earthworms [%] after 28 days	0	1.3	2.5	0	0	0	0
Significance (Mortality)*	--	-	-	-	-	-	-
Mean change of body fresh weight of the adults from day 0 to day 28 [%]	37.87	33.72	34.69	32.55	31.23	33.72	36.88
Standard Deviation	6.89	4.59	7.32	12.17	16.97	16.14	12.72
Significance (body fresh weight)**	--	-	-	-	-	-	-
Mean number of offspring per test vessel after 56 days	297.1	281.3	279	264	261.5	249.8	237.3
Standard Deviation	59.8	32.4	35.5	60.6	35.5	22.6	33.1
% of Solvent control	--	--	99.2	93.9	93	88.8	84.4
Coefficient of variance (%)	20.1	11.5	12.7	22.9	13.6	9.1	14
Significance (reproduction)***	--	-	-	-	-	-	+

* (Multiple Sequentially-rejective Fisher Test After Bonferroni-Holm, one-sided greater, α = 0.05

** (Dunnett`s Multiple t-test, two-sided, α = 0.05), + = significant, - = not significant

*** (William’s t-test, one-sided smaller, α = 0.05), + significant, - not significant

 

Table 2: Validity criteria for OECD 222.

Criterion from the guideline to be satisfied in the controls	Outcome	Validity criterion fulfilled
Each replicate (containing 10 adults) to have produced ≥ 30 juveniles by the end of the test.	240 - 406	Yes
The coefficient of variation of reproduction is ≤ 30%.	20.1 %	Yes
Adult mortality over the initial 4 weeks of the test is ≤ 10%.	0 %	Yes

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

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