Dodecanoic acid, 2,2-dimethyl-3-oxopropyl ester

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:

2020-08-27 to 2020-10-23

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:

1984

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Acetone

Details on preparation and application of test substrate:

The constituents of artificial soil (calculated as dry weight) are listed as follows:
-10 % sphagnum peat (no visible plant remains, finely ground, dried and the moisture content was measured, calculated as dry weight);
- 20 % kaolin clay
- 70 % quartz sand.
The artificial soil (calculated as dry weight) was prepared and mixed thoroughly in a mixer. The pH value of the soil was determined to be 6.28. The dry artificial soil was taken and add pure water to premoisten it. Before the test, the wet soil was sampled, four replicates, and dried for about 3 hours at 105 °C to determine the moisture content to be 13.3 %.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: Wuxi Earthworm Breeding Base
- Age at test initiation: Earthworms were adults (at least two months old with clitellum)
- Weight at test initiation: 332 – 492 mg

ACCLIMATION
Prior to test, the earthworms were placed in the artificial soil 24 hours under the test condition.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

19.1 – 21.7 °C

pH:

6.51 – 6.58

Moisture:

Control groups: 32.0 % - 32.8 %;
Test item treatment group: 31.5 % - 32.0 %

Details on test conditions:

TEST SYSTEM
- Amount of soil or substrate: 750 g dw
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4
- No. of replicates per solvent control: 4

OTHER TEST CONDITIONS
- Photoperiod: continuous illumination
- Light intensity: 400 – 800 Lux

EFFECT PARAMETERS MEASURED: The survivals and toxic symptoms of the test earthworms were assessed after 7 and 14 days of exposure

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 20, 100, 500 and 1000 mg/kg
- Results used to determine the conditions for the definitive study: yes

Nominal and measured concentrations:

Nominal conc.: 1000 mg/kg
Measure conc.: not determined

Key result

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:

Therefore, the 7d-LC50 and 14d-LC50 of test item to earthworm (Eisenia fetida) were more than 1000 mg/kg.

Validity of the Test

The mortality rate of earthworms was 0% in the blank control group and 2.5% in the solvent control group at the end of the test (less than 10%), which satisfied the validity of the test.

Results and Discussion

After 7 days and 14 days, the mortality of earthworms in blank control group was 0%, and there were no abnormal symptoms. After 7 days and 14 days, the mortality of earthworms in solvent control treatment group and test item treatment group was 2.5 % and there were no abnormal symptoms.

The mean wet weight of the earthworms in control groups and test item treatment group was 312-394 mg at the start of the test. The mean wet weight of the earthworms was 300-386 mg at the end of the test.

 

Table 1: Mortality of Earthworm

Concentration (mg/kg)	Replicates	Number of initial exposed earthworms was 10 for each replicate
		Cumulative number of death		Cumulative Mortality(%)		Abnormal Symptoms
		7-d	14-d	7-d	14-d	7-d	14-d
Blank Control	1	0	0	0	0	/	/
	2	0	0
	3	0	0
	4	0	0
Solvent Control	1	0	0	2.5	2.5	/	/
	2	0	0
	3	1	1
	4	0	0
1000	1	0	0	2.5	2.5	/	/
	2	1	1
	3	0	0
	4	0	0

Remark: /" means the survived earthworms have no abnormal symptoms.

 

Table 2: Weight of Earthworm         

Concentration (mg/kg)	Replicate	Earthworms total weight (mg)		Mean Weight (mg)
		0-d	14-d	0-d	14-d
Blank Control	1	3936	3858	394	386
	2	3929	3711	393	371
	3	3744	3590	374	359
	4	3910	3803	391	380
Solvent Control	1	3549	3400	355	340
	2	3555	3367	356	337
	3	3306	2754	331	306
	4	3696	3485	370	349
1000	1	3124	2999	312	300
	2	3829	3360	383	373
	3	3418	3351	342	335
	4	3719	3598	372	360

Validity criteria fulfilled:

yes

Conclusions:

In this study, the 7d-LC50 and 14d-LC50 of test item to earthworm (Eisenia fetida) were more than 1000 mg/kg.

Executive summary:

The study was performed to evaluate the acute toxicity of test item to earthworm (Eisenia fetida). The artificial soil was selected as test medium, the test duration was 14 days. The adult earthworms were exposed to the artificial soil with test item concentrations of 1000 mg/kg. Blank control and solvent control were set in parallel. Four replicates were prepared for each group and each replicate contained 10 earthworms. The survivals and toxic symptoms of the test earthworms were assessed after 7 and 14 days of exposure. The LC₅₀ and its 95% confidence limits of test item to earthworm were calculated. The mean wet weight of the earthworms in control groups and test item treatment group was 312 – 394 mg at the start of the test. The mean wet weight of the earthworms was 300 – 386 mg at the end of the test. After 7 days and 14 days, the mortality of earthworms in blank control group was 0 %, and there were no abnormal symptoms. After 7 days and 14 days, the mortality of earthworms in solvent control treatment group and test item treatment group was 2.5 % and there were no abnormal symptoms. In this study, the 7d-LC₅₀ and 14d-LC₅₀ of test item to earthworm (Eisenia fetida) were more than 1000 mg/kg.

Description of key information

The 7d-LC₅₀ and 14d-LC₅₀ of test item to earthworm (Eisenia fetida) were more than 1000 mg/kg.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw

Additional information

The study was performed to evaluate the acute toxicity of test item to earthworm (Eisenia fetida). The artificial soil was selected as test medium, the test duration was 14 days. The adult earthworms were exposed to the artificial soil with test item concentrations of 1000 mg/kg. Blank control and solvent control were set in parallel. Four replicates were prepared for each group and each replicate contained 10 earthworms. The survivals and toxic symptoms of the test earthworms were assessed after 7 and 14 days of exposure. The LC₅₀ and its 95% confidence limits of test item to earthworm were calculated. The mean wet weight of the earthworms in control groups and test item treatment group was 312 – 394 mg at the start of the test. The mean wet weight of the earthworms was 300 – 386 mg at the end of the test. After 7 days and 14 days, the mortality of earthworms in blank control group was 0 %, and there were no abnormal symptoms. After 7 days and 14 days, the mortality of earthworms in solvent control treatment group and test item treatment group was 2.5 % and there were no abnormal symptoms. In this study, the 7d-LC₅₀ and 14d-LC₅₀ of test item to earthworm (Eisenia fetida) were more than 1000 mg/kg.