Castor oil, hydrogenated, ethoxylated

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:

17 January 2018 to 19 January 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)

Deviations:

yes

Remarks:

no analytics were performed because it was not possible to develop a suitable analytical method

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Remarks:

it was imposible to develop a suitable analytical method

Vehicle:

yes

Details on test solutions:

A primary stock concentrate of the substance, with a nominal concentration of 10 g/L, was prepared by weighing a nominal 0.1 g of test substance (actual weight: 0.10000 g) into a 10 mL volumetric flask and making up to volume with tetrahydrofuran (THF). The stock was then manually shaken to mix. The resultant stock was observed to be clear and colourless and was used to prepare the test solutions.
Total amount of THF present in the test solutions 100 ug/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphmia magna
- Source: laboratory cultures held at Scymaris.
- Age of parental stock (mean and range, SD): 22 ± 1 days (daphnids in test < 24 h)
- Feeding during test: none

ACCLIMATION
- Stock conditions (same as test or not): yes
- Type and amount of food: mixed algae diet of Chlorella vulgaris, strain CCAP 211/12 and Pseudokirchneriella subcapitata, strain CCAP 278/4
- Feeding frequency: daily ad libitum
- Health during acclimation: no evidence of diease before test:

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

248.7 as CaCO2

Test temperature:

19.1-20.2 ˚C

pH:

7.76-8.01

Dissolved oxygen:

9.05-9.35 mg/L

Nominal and measured concentrations:

nominal: 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L (maximum based on solubility)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers of 250 mL
- Type (delete if not applicable):closed
- Fill volume: 200 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS: The reconstituted water medium used for testing (and maintenance of stock cultures) was Elendt's M4 D. magna medium

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8

EFFECT PARAMETERS MEASURED : immobilisation at 24 and 48 h

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY: highest concentration limited by solubility in water
concentrations tested : 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L (max THF 100 ug/L)
results: immobility: 0, 0, 0, 20 and 20% at 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L
behaviour: Daphnia in 0.25, 0.5 and 1.0 mg/L test concentrations showed reduced movement compared to controls. At 0.5 and 1.0 mg/L 4/10 daphnids were at the surface

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Daphnids in the 0.5 and 1.0 mg/L test concentrations were observed as less active compared to the controls.
At the 48 hour time point, the two immobile daphnids in 0.5 mg/L replicates A and D were observed to be still alive as they were twitching. The immobile daphnid in 0.5 mg/L replicate C was on the surface of the solution.

Daphnia magna response

Time (hour)	Nominal concentration of test substance   (mg/L)	Number immobilised per replicate				Total number tested	Total number immobilised	Percentage immobilised
		A	B	C	D
24	Control	0	0	0	0	20	0	0
	Solvent Control	0	0	0	0	20	0	0
	0.0625	0	0	0	0	20	0	0
	0.125	0	0	0	0	20	0	0
	0.25	0	0	0	0	20	0	0
	0.5	0	0	0	0	20	0	0
	1.0	0	0	0	0	20	0	0
48	Control	0	0	0	0	20	0	0
	Solvent Control	0	0	0	0	20	0	0
	0.0625	0	0	0	0	20	0	0
	0.125	0	0	0	0	20	0	0
	0.25	0	1	0	0	20	1	5
	0.5	1	1	1	1	20	4	20 *
	1.0	1	2	0	0	20	3	15

 * Significant difference (p <0.05) from the control. LOEC value not affected, see section 5.1.

Validity criteria fulfilled:

yes

Conclusions:

The EC50 for Daphnia magna is > 1.0 mg/L

Executive summary:

Due to the low solubility of the substance, a 1 mg/L test concentration was selected as the highest concentration based on a non-GLP range finding study. The test substance was dosed to the media via a solvent carrier (tetrahydrofuran (THF)) to assist in dosing the test compound. The concentration of solvent used in all exposure solutions with the exception of the control was 100 µL/L.

Daphnids were exposed during 48 h (static test) to control, Solvent Control and nominal concentrations of 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L. No confirmatory analysis of the test solutions was performed due to lack of an analytical method.

The EC50 is >1.0 mg/L. Based on immobility compared to the control (p <0.05) the 48h NOEC was determined to be 1.0 mg/L. Immobility in the 0.5 mg/L test concentration was significantly different (p <0.05) from the control. However, as immobility in the 1.0 mg/L test concentration was not significantly different (p <0.05) from the control, the NOEC was not affected.

Description of key information

Daphnids were exposed during 48 h (static test) to control, solvent control and nominal concentrations of 0.0625, 0.125, 0.25, 0.5 and 1.0 mg/L. No confirmatory analysis of the test solutions was performed due to lack of an analytical method.

The EC50 is >1.0 mg/L. Based on immobility compared to the control (p <0.05) the 48h NOEC was determined to be 1.0 mg/L. Immobility in the 0.5 mg/L test concentration was significantly different (p <0.05) from the control. However, as immobility in the 1.0 mg/L test concentration was not significantly different (p <0.05) from the control, the NOEC was not affected.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 mg/L