Fatty acids, tall-oil, esters with ethylene glycol

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 - 23 Nov 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted April 13, 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Hessisches Ministerium für Umwelt, Klimaschutz, Landwirtschaft und Verbraucherschutz, Wiesbaden, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All test item concentrations and the control.
- Sampling method: The concentrations of the test item were analysed in the duplicate test media samples, and in the duplicate control samples, from both sampling times (0 and 48 hours).
- Sample storage conditions before analysis: All samples were stored in a refrigerator (4 ± 4 °C), protected from light until analysis was performed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Defined amounts of test item were added directly to the test water for each test concentration separately and were carefully stirred for 96 hours in the dark to dissolve as much of the test item as possible. After cessation of mixing and a following period (1 hour) of settling to allow phase separation, the aqueous phase, i.e. the water accommodated fraction, was drawn off carefully. Since the water accommodated fraction was not clear in all loading rates, non-dissolved fractions (if any) in all five loading rates were separated from the test medium by membrane filtration (0.65 and 0.45 µm cellulose acetate filter).
- Controls: test medium control
- Dosage of test item: The highest loading rate of 100 mg test item/L was prepared by mixing 99.6 mg test item into 996 mL test water, for the test item loading rate of 50 mg test item/L, 49.6 mg test item were mixed into 992 mL test water, for the loading rate of 25 mg test item/L, 25 mg were mixed into 1000 mL test water. The loading rate of 12.5 mg test item/L was prepared by mixing 12.5 mg into 1000 mL test water and for 6.25 mg test item/L, 6.1 mg were mixed into 976 mL test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Female Daphnia magna, clone 5
- Source: in-house laboratory culture
- Feeding during test: no
- Age: < 24 h

ACCLIMATION
- Acclimation conditions: same
- Type and amount of food: Desmodesmus subspicatus
- Frequency: at least on all working days

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: The test organisms were not first brood progeny.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (= 250 mg/L) as CaCO3

Test temperature:

19.2 - 19.3 °C (Control)
19.3 - 20.0 °C (Test item concentrations)

pH:

7.7 - 7.8 (Control)
7.7 - 7.8 (Test item concentrations)

Dissolved oxygen:

9.0 mg/L (Control)
8.7 - 9.1 mg/L (Test item concentrations)

Conductivity:

< 5 µScm-1

Nominal and measured concentrations:

nominal: Control, 6.25, 12.5, 25, 50 and 100 mg test material/L
measured: Control, 2.20, 1.56, 2.36, 3.40 and 3.85 mg Carbon/L

Details on test conditions:

TEST SYSTEM
Test vessel:
- Type: open (covered with a lid)
- Material, size, headspace, fill volume: Glass beakers of 100 mL volume containing approximately 60 mL of test medium.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt "M4" according to the guideline OECD 202
- Alkalinity: 0.9 mmol/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: every 24 h

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark
- Light intensity: 550 to 760 lux

EFFECT PARAMETERS MEASURED: The mobility of the daphnids was determined by visual observation after 24 and 48 h. Those animals that are not able to swim within 15 sec after gentle agitation of the test beaker were considered to be immobile.

RANGE-FINDING STUDY: yes, non-GLP; no further information was provided in the report

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Biological observations: After 48 h of exposure no immobilisation of the test animals was observed up to and including the loading rate of 50 mg test item/L. At the loading rate of 100 mg test item/L, seven animals (35%) were immobile.
- Mortality of control: No immobilisation was observed

Results with reference substance (positive control):

The EC50 (24 h) of 1.58 mg/L indicate that the sensitivity of the daphnids was consistent with the level proposed by the OECD 202 guideline (EC50-24 h between 0.6 and 2.1 mg potassium dichromate/L).

Reported statistics and error estimates:

The 24 h and 48 h EC50, EC20 and EC10 and the 95 % confidence limits were calculated by probit analysis. The NOEC and LOEC after 24 and 48 hours were calculated by Step-down Cochran Armitage test procedure. The software used to perform the statistical analysis was ToxRat Professional, Version 3.2.1, ToxRat® Solutions GmbH.

Table 1: Summary of Biological Results

Loading rate	% of immobilised daphnids after
[mg test item/L]	24 hours	48 hours
Control	0	0
6.25	0	0
12.5	0	0
25	0	0
50	0	0
100	15	35
EC50 [mg test item/L]:	n.d.	> 100
EC20 [mg test item/L]:	> 100	92.8
EC10 [mg test item/L]:	97.6	86.4
NOEL [mg test item/L]:	50	50
LOEL [mg test item/L]:	100	100

Values refer to nominal loading rates
n.d.: not determinable
NOEL and LOEL were determined by Step-down Cochran Armitage Test.

Table 2: Summary of Analytical Results

Sample Description	Total Organic Carbon	SD
[mg test item/L]	[mg C/L]*	[mg C/L]	n
Control	<LOQ	n.a.	4
WAF 6.25 mg/L	2.20	0.285	4
WAF 12.5 mg/L	1.56	0.151	4
WAF 25 mg/L	2.36	0.0929	4
WAF 50 mg/L	3.40	0.218	4
WAF 100 mg/L	3.85	0.321	4

* Mean value of all measured samples per treatment group. Values rounded to three significant digits

RSD: relative standard deviation per treatment group
n: number of analysed samples
n.a.: not applicable

Table 3: Validity Criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	0%	Yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	9.0 mg O2/L	Yes

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.

Description of key information

EL50 (48h) >100 mg/L (nominal, D. magna)

Additional information

One study is available testing the acute toxicity of fatty acids, tall-oil, esters with ethylene glycol (CAS 68187-85-9) to aquatic invertebrates. The study was conducted according to the OECD guidance 202 and GLP standards. In a static system the test organism Daphnia magna was exposed for 48 h to nominal test concentrations of 6.25, 12.5, 25, 50 and 100 mg test material/L. The nominal concentrations were analytically verified by TOC analysis conducted at test start (0 h) and at test end (48 h). The determined actual exposure concentrations were 2.20, 1.56, 2.36, 3.40 and 3.85 mg Carbon/L. After 48 h of exposure no immobilisation of the test animals was observed up to and including the loading rate of 50 mg test item/L. At the loading rate of 100 mg test item/L, seven animals (35%) were immobile. Therefore, the EL50 (48h) was determined to be > 100 mg/L.