Undec-10-enoic acid

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:

Q4 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable.

Analytical monitoring:

no

Details on sampling:

Analytical analysis not required by OECD 222.

Vehicle:

no

Details on preparation and application of test substrate:

ARTIFICIAL SOIL COMPOSITION
- Sphagnum Peat: 10 % of dry matter of artificial soil. The peat was air dried before use.
- Kaolin Clay: 20 % of dry matter of artificial soil. Bolus alba (white clay), pharmaceutical quality:
- Quartz Sand: 70 % of dry matter of artificial soil. Fine quartz sand (round grains) was used.
- Calcium Carbonate CaCO3: Analytical grade, used for pH adjustment

Preparation of Artificial Soil: the dry constituents of the soil were mixed thoroughly in a well-ventilated area.

The pH of the final mixture was measured as 6.1. A small part of this mixture was used for the 24 hours acclimatisation of the animals used in this test. For this it was adjusted with demineralised water to a calculated water content of 50 % of the maximum water holding capacity calculated in relation to dry matter.

For the test the artificial soil described above was divided into 10 portions of an appropriate amount (4400 g for the blank control resp. 2200 g for each treatment dry weight). The required amount of test item was given to each portion using demineralised water which was used for adjustment of the artificial soil to a calculated water content of 50% of the maximum water holding capacity calculated in relation to dry matter. Afterwards, it was mixed and 640.5 g wet weight of each portion was introduced into a 1 L glass preserving jar.

Test organisms (species):

Eisenia andrei

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm (Eisenia andrei)
- Source: Bred at LAUS GmBH facilities
- Age at test initiation (mean and range, SD): at least 2 months
- Weight at test initiation (mean and range, SD): mean weight was 345 mg (281 - 587 min - max)

ACCLIMATION
- Acclimation period: 24 hours
- Acclimation conditions (same as test or not): Yes
- Health during acclimation (any mortality observed): Not reported.

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Post exposure observation period:

None.

Test temperature:

18.2 - 22°C

pH:

5.9-6.0

Moisture:

53 - 64% of Maximum Water Holding Capacity (MWHC = 60% of dry soil), (min-max)

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1 L glass jar
- Amount of soil or substrate: 650 g of soil wet weight per jar
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 8

OTHER TEST CONDITIONS
- Photoperiod: 16L:8D
- Light intensity: 500 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

- Adult survival after 28 days
- Adult growth after 28 days
- Juvenile production after 56 days (28 days after adult removal)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2
- Test concentrations: 0.1 ; 0.32 ; 1 ; 3.2 ; 10 ; 32 ; 100 ; 320 ; 1000

Nominal and measured concentrations:

0.1 / 0.32 / 1.0 / 3.2 / 10 / 32 / 100 / 320 / 1000 mg/kg (dry matter). Concentrations not measured (not required by OECD 222 guideline).

Reference substance (positive control):

yes

Remarks:

Benomyl

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: No dead worm in any treatment

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

3.2 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Details on results:

- Mortality at end of exposure period: None in any treatement
- Total mass of adults at beginning of test:
- Changes in body weigth of live adults (% of initial weight) at end of exposure period: -8 - 4% growth across treatements (min - max)
- No. of offspring produced: 98 - 142 juveniles across treatments (min - max)

Results with reference substance (positive control):

The 56d-EC50 of Benomyl (CAS-Nr. 17804-35-2) was tested in a current reference test. The value was determined as 1.9 mg/kg dry soil, lying within the required range of OECD Guideline 222 of 1 – 5 mg/kg.

Reported statistics and error estimates:

The estimation of the biological data was accomplished using the software ToxRat® Professional (version 3.2) using the analysis set by default by Toxrat producers. Data were checked for normal distribution of residues (Shapiro-Wilk) and variance homogeneity among treatments (Levene). Both tests passed for all endpoints. For mean comparison, Williams multiple sequential t-test procedure was used.

See attached files

Validity criteria fulfilled:

yes

Conclusions:

Eisenia andrei adults were exposed to 9 graded concentrations of undecylenic acid for 28 days and cocoon/juveniles for another 28 day period. Adult survival and growth and number of juvenile produced per treatment were examined. No adult mortality occur. No significant diffence nor trend were observed for growth. Regarding juvenile production, a NOEC of 3.2 mg/kg soil dry wet was determined, although non-monotonic dose-response was observed.

Executive summary:

The study was performed using 9 concentrations ranging from 0.1 to 1000 mg/kg dry soil (4 replicates) and a control (8 replicates), following OECD 222 guideline protocol. In each replicate, 10 adult animals were exposed to the test item for 28 days in an artificial soil (except control group). After 28 days, the living adult animals were counted and weighted, and 28 days later, the number of juveniles produced was determined.

Non-monotonic statistical significant inhibition of reproduction (juvenile production) were observed compared to the control. None of the adult animals were dead in any treatment or control after the first 28 days. Adult growth was not significantly different between treatments. A NOEC of 3.2 mg/kg soil dry weight was determined.

Description of key information

 One reliable study assessing the long-term toxicity of the test item to the earthworm Eisenia andrei (OECD 222) is available. The study was performed using 9 concentrations ranging from 0.1 to 1000 mg/kg dry soil. The highest concentrations showed statistical significant inhibition of reproduction (juvenile production) compared to the control. None of the adult animals were dead in any treatment or control after the first 28 days. Growth was not significantly different between treatments. A NOEC of 3.2 mg/kg soil dry weight was determined. 

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

3.2 mg/kg soil dw