Fatty acids, C8-10, C12-18-alkyl esters

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:

15 Apr - 10 Jun 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Soil moisture was >10% higher as at the start of the test. At the beginning of the test three worms were up to 15 mg below the recommended minimum of 250 mg fresh weight.

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

Hess. Ministerium für Umwelt, Energie, Landwirtschaft und Verbraucherschutz, Wiesbaden, Germany

Analytical monitoring:

no

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): The test item was dissolved in an amount of acetone sufficient to prepare a stock solution. This stock solution was used to produce the various dosage solutions of the test item. An appropriate amount of the stock and the dosage solutions respectively was used to soak a portion of the quartz sand of the artificial soil by the solvent solution. After evaporation of the solvent by placing under a fume hood, the quartz sand was coated by the test item. The test item coated fraction of the quartz sand was then incorporated into the remainder of the artificial soil by thoroughly mixing it in for approx. 10 min. Finally the contaminated artificial soil was filled into the test vessels. Per test vessel an amount corresponding to 500 g dw was used.
- Controls: yes, solvent control and deionised water control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Evaporation of vehicle before use: yes

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm
- Source: Originally obtained by Co. Landenberger, Schömberg, Germany. The earthworms used in this test are kept at ECT Oekotoxikologie GmbH since February 1994.
- Age at test initiation (mean and range, SD): At least two months old, but not more than one year old. The age of individuals did not differ by more than four weeks. Animals which do fulfil these requirements, were taken from a synchronised culture.
- Weight at test initiation (mean and range, SD): 250 - 600 mg

ACCLIMATION
- Acclimation period: 24 h before study initiation
- Acclimation conditions (same as test or not): same as test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

17.4 - 21.2 °C

pH:

6.3 - 6.9

Moisture:

Start: 50.9 - 53.9% of WHCmax
End: 56.0 - 64.1% of WHCmax

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Bellaplast containers (Company Polarcup GmbH, Alf/Mosel, Germany) consisting of inert (non-toxic) plastic (Polystyrol). The test vessels have a bottom area of 11 x 15.5 cm (= 170.5 cm²) and a hight of 6 cm. The test vessels were covered by a transparent lid.
- Amount of soil or substrate: 500 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 vehicle control: 8

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): 5% Sphagnum peat (no visible plant remains; finely ground and air-dried), 20% Kaolin Clay (kaolinite content > 30%), 74-75% quartz sand (fine sand content with particles between 50 and 200 µm higher than 50%), 0.3 - 1% Calcium carbonate (CaCO3). The peat content was 5% instead of 10% to reduce adsorption.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light / 8 h dark
- Light intensity: 453 - 550 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality and biomass (after 28 d), reproduction (after 56 d)

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Nominal and measured concentrations:

nominal: control, 62.5, 125, 250, 500 and 1000 mg/kg soil dw

Reference substance (positive control):

yes

Remarks:

carbendazim

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil ww

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 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%
- Total mass of adults at beginning of test:
- Changes in body weigth of live adults (% of initial weight) at end of exposure period: 155.5 - 172.4% of the initial weight
- No. of offspring produced: see table 1 "Any other information on results incl. tables"
- Morphological abnormalities: none
- Behavioural abnormalities: none
- Other biological observations: Almost the whole food was consumed by the worms in all concentrations after 7, 14, 21 and 28 days of the application of the test item.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: NOEC (56 d): 0.32 mg/kg soil dw

Reported statistics and error estimates:

Mortality: No statistical analysis was performed.
Biomass and reproduction: Data were checked for normality by R/s test procedure and for homogeneity by Cochran’s test. Solvent control and water control data were compared by the pairwise Student t-test (p ≤ 0.05, two-sided). Treatment means were compared by ANOVA followed by Dunnett’s test (p ≤ 0.05, one-sided) for reproduction and tested for statistically significant differences compared to the solvent control. The statistical software package ToxRat 2.10 was used for these calculations.

Table 1: Reproduction (given as mean number of juveniles ± standard deviation and as % of the control) in the treated test vessels.

Concentration [mg test item/kg soil (dw)]	Number of juveniles per treatment [mean ± SD]	Number of juveniles [% of solvent control]
Control	333.5 ± 41.0	99.6
Solvent control	335.0 ± 62.5	100.0
62.5	376.5 ± 32.4	112.4
125	335.3 ± 38.0	100.1
250	317.3 ± 38.2	94.7
500	300.5 ± 65.9	89.7
1000	262.3 ± 90.7	78.3*

* significantly different to control (Williams t-test; 1-sided, p ≤ 0.05)

Table 2: Average live weight (mg) per surviving adult worm at the beginning of the test and after 28 d (n=80 for solvent control; n=40 for concentrations and additional water control). Data are given as absolute value and in percent of the initial weight (biomass).

Concentration [mg test item/kg soil (dw)]	Biomass [mg fresh weight]		Percent of the initial weight
	Day 0	Day 28	Day 28
Control	364.5±49.6	566.9±30.8	155.5
Solvent control	361.4±48.5	575.1±37.9	159.1
62.5	367.2±50.5	591.3 ±19.5	161.0
125	366.0±40.9	622.6±17.9	170.1
250	362.4±40.9	578.4±51.8	159.6
500	366.9±46.3	632.6±30.7	172.4
1000	367.3±42.1	606.3±30.1	165.1

Description of key information

NOEC (56 d) 500 mg/kg soil dw based on reproduction of Eisenia fetida (OECD 222)

Key value for chemical safety assessment

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

500 mg/kg soil dw

Additional information

One study is available investigating the long-term effects of Fatty acids, C8-C10, C12-18-alkyl esters (CAS 95912-86-0) to the earthworm Eisenia fetida (Scheffczyk, 2013). The study was performed according to OECD 222 (GLP) for 56 d with artificial soil. Test concentrations up to nominal 1000 mg/kg dw were tested for impacts on mortality, biomass and reproduction. Mortality and biomass were investigated after 28 d whereas the number of juveniles was measured after 56 d. No mortality and no effects on biomass were recorded after 28 d. However, effects on reproduction expressed in the number of juveniles was observed at the highest test concentration of 1000 mg/kg soil dw. Thus, a NOEC (56 d) of 500 mg/kg soil dw was derived. Analyzing the results in detail shows that the number of juveniles was very variable within the replicates at the highest concentration. In two replicates out of four the number of juveniles were 186 and 189, respectively whereas in the other two replicates 303 and 371 juveniles were recorded which is in the range of the solvent control. Nevertheless, since no indications are given in the report why the replicates show such a high variability at the highest test concentration the reported NOEC of 500 mg/kg soil dw has to be used for the assessment as a worst case assumption.