spirodiclofen (ISO);3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl 2,2-dimethylbutyrate

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Details on sampling:

Earthworms were exposed to test material at 1000 mg a.i/kg dw of the soil.

Vehicle:

not specified

Details on preparation and application of test substrate:

The artificial soil consists of 69 % fine quartz sand (84 % of the sand has a particle size of 0.06 - 0.2 mm), 10 % dried, finely ground peat (sphagnum peat; pH 2 - 4), 20 % kaolin (kaolinite content of about 36 %, pH value approximately 7, "Kaolin W", from Erbsloh / Giesenheim) and around 1% calcium carbonate (pure) to adjust the pH value to 6 ±0.5 (figures refer to dry weight). The test soil was first of all mixed dry from these components in a plough-share mixer, and moistened with some of the final volume of water required.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Age at test initiation: over two months old
Weight at study initiation: 0.36 g. Range in control group 0.30 to 0.50 g.
Source: laboratory culture. Original source Prof. Graff, 38104 Braunschweig, Germany.

Acclimatization: The earthworms were taken from a laboratory culture maintained for several years. Culture conditions were 22 ± 2 °C, 70 to 90 % humidity, 12:12 light/dark cycle. The worms were removed from the culture and placed in test soil on the day prior to the study. The test conditions were very similar to the test conditions.
No specifics on health of the organisms

Study type:

laboratory study

Substrate type:

artificial soil

Total exposure duration:

14 d

Test temperature:

Temp: 20 ± 1°C

pH:

pH = 5.6 at initiation; 5.8 - 5.9 at
termination.
100 mL deionized water to 500 g
dry weight soil

Moisture:

Target for artificial soil was 35%
when the worms were introduced.
Initiation: 24 - 25%
Termination: 33%

Details on test conditions:

Soil: Freshly mixed artificial soil.
Test container: 1.5 liter glass jars with glass lids. Each container had 500 g dry weight soil.
No. of replicates: Control and 1000 mg ai/kg dry wt. soil
Per treatment group: Four replicates
Per control: Four replicates
No. of earthworms per treatment: 10 earthworms per replicate; 40 worms per
treatment.
Co-solvents used or not (if yes
report the name and concentration): no solvents used
Test conditions:
Temp: 20 ± 1°C
continuous light at 400 to 800 lux
70-90% humidity
25 - 34 % soil moisture

Stability and homogeneity of test material in the medium?
A pre-check was done with 14C labeled compound to prove the mixing process was
homogenous and reproducible.
Stability was not a required element of this 14 day test.

Observation interval: Day 0, Day 7 and Day 14
Parameters measured including the sublethal effects/toxicity symptoms: Mortality, weight, toxicity symptoms
Raw data included: Yes

Definitive study:
The artificial soil consists of 69 % fine quartz sand (84 % of the sand has a particle size of 0.06 - 0.2 mm), 10 % dried, finely ground peat (sphagnum peat; pH 2 - 4), 20 % kaolin (kaolinite content of about 36 %, pH value approximately 7, "Kaolin W", from Erbsloh / Giesenheim) and around 1% calcium carbonate (pure) to adjust the pH value to 6 ±0.5 (figures refer to dry weight). The test soil was first of all mixed dry from these components in a plough-share mixer, and moistened with some of the final volume of water required.


Range-finding Study: A pre-study was conducted using the concentrations of control, 0.1, 1,
10, 100 and 1000 mg ai/kg dw soil. No mortality was noted at any concentration, except the 1
mg ai/kg dw soil which had 5%. The weight alteration across all treatments was from -2 to 5 %.
There were no adverse effects at any concentration. The pre-study was conducted with two
replicates of 10 earthworms at each concentration.

Nominal and measured concentrations:

Nominal: control and 1000 mg ai/kg dry
wt. soil.
No analysis was done. This is not a
required element of the test.
A pre-check was done with 14C labeled
compound to prove the mixing process was
homogenous and reproducible

Reference substance (positive control):

yes

Remarks:

chloroacetamide at 10, 18, 24, 32 and 56 mg/kg. The 14 day LC50 was 33 mg/kg dw soil (95% CI = 31 to 35 mg/kg)

Key result

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

There were no mortalities (0%) in the controls and in the treatment. The weight alteration in the
controls was -12% and in the treatment was -15%. There were no significant differences from
the control for the 1000 mg ai/kg dw soil treatment.

Reported statistics and error estimates:

No statistics were needed for evaluation of mortality and toxic symptoms since none (0%) were
observed during the 14-day study.
The weight alterations of the test organisms were statistically evaluated by the U-Test of
Wilcoxon, Mann & Whitney (Probability level P = 0.05, two sided).

Table 4: Effect of spirodiclofen technical on mortality of Acini fetida.

Treatment (mg a.i./kg dw soil) [nominal conc.]		Observation period
		Day 0		Day 7		Day 14
		No. Dead	% mortality	No. Dead	% mortality	No. Dead	% mortality
Control		0	0	0	0	0	0
1000		0	0	0	0	0	0
NOEC		1000 mg ai/kg dw soil.
LOEC		> 1000 mg ai/kg dw soil.
LC50		> 1000 mg ai/kg dw soil.
Reference chemical	LC50:	chloroacetamide at 10, 18, 24, 32 and 56 mg/kg. The 14 day LC50 was 33 mg/kg dw soil (95% CI = 31 to 35 mg/kg)

1. SUB-LETHAL TOXICITY ENDPOINTS:

 

Table 5: Sub-lethal effect of spirodiclofen technical on Acini fetida. Average of 4 replicates used for the study.

Treatment (mg a.i./kg soil) [nominal conc.]	Observation period
	Day 0		Day 14
	weight (g)	% loss	weight (g)	% loss
Control	0.36	-	0.32	12
1000	0.36	-	0.31	15
NOEC	1000 mg ai/kg dw soil
LOEC	> 1000 mg ai/kg dw soil
EC50	> 1000 mg ai/kg dw soil

Validity criteria fulfilled:

yes

Conclusions:

The 14 day EC50 and LC50 were greater than 1000 mg ai/kg dw soil. There were no adverse
effects noted in this study for mortality, toxic symptoms or weight alteration.
NOEC = 1000 mg ai/kg dw soil
LOEC = > 1000 mg ai/kg dw soil

Executive summary:

In a 14-day acute toxicity study, earthworms {Acini fetida} were exposed to spirodiclofen technical at 1000 mg a.i./kg dry weight of soil. The reference chemical used was chloroacetamide at 10, 18, 24, 32 and 56 mg a.i/kg dw of the soil. The experiment was carried out in accordance with OECD 207. The 14-day LC50 was > 1000 mg a.i/kg dw of soil. The 14-day NOEC, based on all endpoints was 1000 mg a.i./kg dw of soil. The LOEC, based on all endpoints was greater than 1000 mg a.i./kg dw of soil. The technical a.i. is considered to be non-toxic to earthworms up to and above a concentration of 1000 mg a.i./kg dw of soil.
There was no mortality, no toxic symptoms and no significant difference in weight of the earthworms in the 1000 mg ai/kg dw soil.
This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with earthworms.

Description of key information

In an acute tox study with, Eisenia fetida, were exposed to a concentration of 1000.0 mg a.s./kg soil dry weight (dw). The EC₅₀ was determined to be 1000 mg/kg soil (dw).

 

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw