Isodecyl pivalate

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 Nov - 10 Jan 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): The stock solutions were prepared in ethanol. The concentrations were calculated so that the test item treatments were achieved by adding 2.0 mL of stock solution to 10 g of sand. Ethanol was then allowed to evaporate and the coated sand was mixed with the soil. De-ionised water was added to moisten the soil up to 45-55% of its total water holding capacity.
- Controls: yes, water control
- Chemical name of vehicle: ethanol
- Evaporation of vehicle before use: yes

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm
- Source: Adult specimens born at the laboratory site.
- Age at test initiation (mean and range, SD): Older than 2 months, and younger than one year. The specimens did not differ in age by more than 4 weeks.
- Weight at test initiation (mean and range, SD): 300 - 600 mg (acute toxicity test), 250 - 600 mg (reproduction test)

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

20 ± 2 °C

pH:

5.9 - 6.3 (study initiation)
5.1 - 5.7 (study termination)

Moisture:

Moisture of the soil substance was controlled to represent 44.8% of the soil total water holding capacity at the end of the test.

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 2 L glass containers covered with plastic mesh
- Amount of soil or substrate: 500 g dw 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

SOURCE AND PROPERTIES OF SUBSTRATE
- Composition (if artificial substrate): Sphagnum peat (grounded and sieved): 10%; kaolinite clay: 20%; quartz sand 150-210 µm: 70%. Calcium carbonate (CaCO3) was added to each container that was previously calculated to give a pH value of 6.0 ± 0.5, in the control.
- Maximum water holding capacity (in % dry weigth): calculated according to ISO 11274 (1992). Result not given in the report.

OTHER TEST CONDITIONS
- Photoperiod: continuous light (acute test), 16 h light / 8 h dark (reproduction test)
- Light intensity: 400 - 800 lux

EFFECT PARAMETERS MEASURED: mortality, mean weight, number of juveniles

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study
- Test concentrations: water control, solvent control, 0.1, 1.0, 10.0, 100.2, 1001.6 mg/kg
- Results used to determine the conditions for the definitive study: No mortality was observed after 7 and 14 d. A NOEC (biomass) of 100.2 mg/kg dw resulted. The definitive test was thus performed as a definitive test for test item treatments between approx. 10 and 1000 mg/kg.

Nominal and measured concentrations:

nominal: water control, solvent control, 16.3, 29.3, 52.8, 95.0, 171.4, 308.6, 555.4, 999.9 mg/kg

Reference substance (positive control):

yes

Remarks:

Carbendazim

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

29.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

52.8 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

EC50

Effect conc.:

132.4 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 95% CI: 33.0 - 531.2 mg/kg soil dw

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

308.6 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Details on results:

- Mortality at end of exposure period: 0%
- Changes in body weigth of live adults (% of initial weight) at end of exposure period: > 100% up to a concentration of 308.6 mg/kg; 87.4% (555.4 mg/kg); 62.4% (999.9 mg/kg) compared to the initial biomass.
- No. of offspring produced: In the water control group, the mean number of juveniles was 309.5 per unit with a relative standard deviation of 15.4%. The solvent control gave similar values. Mean number of juveniles was 269.0. Statistical analysis did not indicate a significant reduction of juveniles. Therefore, both control were pooled and resulted in a mean value of juveniles/unit of 289.3 with a standard deviation of 8.8%. Statistical analysis showed that the reproductive performance was similar to the controls for the two lowest test concentrations. For the six highest test item treatments the production of juveniles was considered as significantly reduced.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: The EC50 value for Carbendazim was between 1 and 5 mg/kg soil.

Reported statistics and error estimates:

F-variance analysis at 5% confidence level served to judge upon significant deviation of the number of juveniles as compared to that of the control group. The percentage of inhibition for the production of juveniles as compared to the controls was plotted against Log concentration of the corresponding soil concentration. The regression analysis was performed using Excel spreadsheet. The resulting regression curve was used for the calculation of the concentration susceptible to induce 50% reduction of the reproductive performance and its statistical 95% confidence internval.

Table 1: Number of juveniles at the end of the test period.

Concentration	Replicates								Mean ± SD
	1	2	3	4	5	6	7	8
Water control	388	311	321	335	303	321	275	222	309.5 ± 47.8
Solvent control	220	326	220	345	250	294	260	237	269.0 ± 47.7
Test item
16.3 mg/kg	262	336	283	220	-	-	-	-	275.3 ± 48.2
29.3 mg/kg	313	242	323	267	-	-	-	-	286.3 ± 38.3
52.8 mg/kg	120	181	135	189	-	-	-	-	156.3 ± 33.9
95.0 mg/kg	156	129	180	204	-	-	-	-	167.3 ± 32.2
171.4 mg/kg	117	136	129	164	-	-	-	-	136.5 ± 19.9
308.6 mg/kg	118	133	175	156	-	-	-	-	145.5 ± 25.1
555.4 mg/kg	11	14	0	26	-	-	-	-	12.8 ± 10.7
999.9 mg/kg	0	0	0	0	-	-	-	-	0.0 ± 0.0
Carbendazim
1.0 mg/kg	201	216	134	163	-	-	-	-	178.5 ± 37.1
2.0 mg/kg	127	83	42	94	-	-	-	-	86.5 ± 35.1
5.0 mg/kg	0	0	0	0	-	-	-	-	0.0 ± 0.0

Table 2: Mean biomass deviation over the 4-week exposure period for the adults

Treatment	Body weight deviation
Water control	107.3%
Sovlent control	105.3%
Test item concentration
16.3 mg/kg	103.7%
29.3 mg/kg	113.3%
52.8 mg/kg	113.1%
95.0 mg/kg	105.3%
171.4 mg/kg	117.2%
308.6 mg/kg	110.4%
555.4 mg/kg	87.4%
999.9 mg/kg	62.4%
Carbendazim
1.0 mg/kg	100.2%
2.0 mg/kg	64.8%
5.0 mg/kg	-4.6%

Description of key information

NOEC (56 d) 29.3 mg/kg dry weight based on reproduction of Eisenia fetida (OECD 222)

Additional information

One study is available investigating the long-term effects of isodecyl pivalate (CAS 60209-82-7) to earthworms. The study was performed according to OECD 222 under GLP-conditions and the effects of the test substance on reproduction, mortality and biomass of Eisenia fetida were recorded. A preliminary range-finding test did not result in any mortality up to 1001.6 mg/kg dry weight after 14 d. Based on this result, the definitive test was performed with eight concentrations (4 replicates) up to a concentration of 999.9 mg/kg dry weight including a water and solvent control. After 56 d no mortality was observed whereas a significant reduction of biomass was recorded at concentrations above 308.6 mg/kg dry weight and a signification reduction of reproduction was observed at concentrations above 29.3 mg/kg dry weight. Thus, a NOEC (56 d) of 29.3 mg/kg dry weight was derived for reproduction. Reproduction was the most sensitive endpoint since the NOEC (56 d) for mortality was ≥ 1000 mg/kg dry weight and 308.6 mg/kg dry weight for biomass, respectively.