Dodecyl nonan-1-oate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Please refer to the analogue justification provided in Section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

water phase only, separated by pipetting

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

water phase only, separated by pipetting

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

water phase only, separated by pipetting

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: The daphnids did not show any abnormal behaviour throughout the test.
- Effect concentrations exceeding solubility of substance in test medium: yes

Results with reference substance (positive control):

The EC50 (24 h) of the reference substance potassium dichromate was 0.9 mg/L and hence within the target range of 0.9 - 1.9 mg/L.

In the range of water solubility no adverse effects of the test substance on Daphnia magna was observed (Table 1). The analytical results presented in Table 2 verify the poor water solubility of the test item.

Table 1: Immobilisation of D. magna exposed to the test substance

Nominal Loading (mg/L)	Parallel	Immobilised daphnids after
		24 h	48 h
0	1	0	0
	2	0	0
1	1	0	0
	2	0	0
3	1	1	2
	2	0	2
10	1	4 (a)	9 (a)
	2	3 (a)	4 (a)
30	1	1	4
	2	0	3
100	1	0	4
	2	2	5

(a) The daphnids got stuck at the water surface, probably due to contamination of the test vessels. Therefore, these data were omitted.

Table 2: Analytical monitoring of the nominal loading rates of three test substance concentrations.

Nominal Loading (mg/L)	Measured concentrations (mg/L) after
	0 h	24 h	48 h
1	0.47	<< 0.1	<< 0.1
10	0.46	< 0.1	<< 0.1
100	23.6	2.7	0.1

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 Jul - 20 Jul 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Appendix of the EU-guideline 92/69/EWG, adopted in 1992

Deviations:

yes

Remarks:

Spacing factor of test concentrations exceeds 2.2

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Loadings of 1 to 100 mg product/L (nominal) were stirred in test medium for about 24 hours. After a settling time of about 2 hours oil drops were observed on the surface of the water phases with loadings > 3 mg/L. The dissolved phases were transferred with a pipette into the test tubes. Subsequently the neonates were transferred into the separated water phase.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: CREASEL, 9800 Deinze, Belgium; delivery: 07 April 2000; batch-no. M280599
- Method of breeding: The neonates used in this test were hatched from ephippia

CULTURE CONDITIONS
- M4 medium according to Elendt
- Hatching of ephippia: approx. 4800 lux, continuous illumination, approx. 20 °C
- Incubation of neonates: 900 lux, 16h light/8 h dark, approx. 20 °C
- Type and amount of food: Scenedesmus subspicatus

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20 °C

pH:

8.1 - 8.2 after 48 h

Dissolved oxygen:

98 - 99% after 48 h

Nominal and measured concentrations:

Nominal: 0, 1.0, 3.0, 10, 30, 100 mg/L
Measured (test end): ≤ 0.1 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: beakers
- Type (delete if not applicable): covered with glass plates
- Material, size, fill volume: glass, 100 mL, 50 mL
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Synthetic mineral water (M4 medium according to Elendt) was stirred after addition of the test substance for about 24 h. After a settling time of about 2 h oil drops were observed on the surface of the water phases with loadings > 3 mg/L. The dissolved phases were transferred with a pipette into the test tubes.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/8 h dark
- Light intensity: 900 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): The number of immobilised daphnids was recorded after 24 and 48 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

water phase only, separated by pipetting

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

water phase only, separated by pipetting

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

water phase only, separated by pipetting

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: The daphnids did not show any abnormal behaviour throughout the test.
- Effect concentrations exceeding solubility of substance in test medium: yes

Results with reference substance (positive control):

The EC50 (24 h) of the reference substance potassium dichromate was 0.9 mg/L and hence within the target range of 0.9 - 1.9 mg/L.

In the range of water solubility no adverse effects of the test substance on Daphnia magna was observed (Table 1). The analytical results presented in Table 2 verify the poor water solubility of the test item.

Table 1: Immobilisation of D. magna exposed to the test substance

Nominal Loading (mg/L)	Parallel	Immobilised daphnids after
		24 h	48 h
0	1	0	0
	2	0	0
1	1	0	0
	2	0	0
3	1	1	2
	2	0	2
10	1	4 (a)	9 (a)
	2	3 (a)	4 (a)
30	1	1	4
	2	0	3
100	1	0	4
	2	2	5

(a) The daphnids got stuck at the water surface, probably due to contamination of the test vessels. Therefore, these data were omitted.

Table 2: Analytical monitoring of the nominal loading rates of three test substance concentrations.

Nominal Loading (mg/L)	Measured concentrations (mg/L) after
	0 h	24 h	48 h
1	0.47	<< 0.1	<< 0.1
10	0.46	< 0.1	<< 0.1
100	23.6	2.7	0.1

Description of key information

No effects up to the limit of water solubility (D. magna, EU-guideline 92/69/EWG, 1992); read-across

Additional information

There is no study available, in which the short-term toxicity of the target substance lauryl nonanoate (CAS 17671-26-0) to aquatic invertebrates was assessed. Therefore, a read-across to the structurally related source substance octyl octanoate (CAS 2306-88-9) was conducted in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. The source substance is characterized by a similar fatty acid chain length (C8, octanoic acid) as well as alcohol component (C8, octanol) and is therefore considered a suitable representative for the assessment of the acute toxicity of the target substance to aquatic invertebrates. A detailed read-across justification is provided in the analogue justification in IUCLID Section 13.

The available study with the source substance octyl octanoate (CAS 2306-88-9) was conducted according to EU guideline 92/69/EWG and GLP. In a static test, D. magna was exposed to five, nominal loading levels ranging from 1.0 to 100 mg/L with a spacing factor of 3, for 48 h. The test solution was prepared as water accommodated fraction and the test item concentrations were analytically verified at the beginning and end of the test by GC. After 48 h, no adverse effects of the test substance in the range of the water solubility were observed on D. magna. The analytical results confirmed the poor water solubility of the test item.

Based on the structural and chemical similarity of the target and source substance, the target substance is expected to exhibit a similar ecotoxicological profile. Therefore, it can be concluded that lauryl nonanoate (CAS 17671-26-0) will not exhibit short-term effects to aquatic invertebrates up to the limit of water solubility.