Fatty acids, C16-18, isononyl esters

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)

Remarks:

Summary of available data used for the endpoint assessment of the target substance.

Adequacy of study:

key study

Justification for type of information:

Refer to read across justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 26399-02-0, BASF, 1995, D. magna, 48 h

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

2 046.63 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Source: CAS 85049-37-2, BASF, 2000, A. tonsa, 48 h

Conclusions:

No toxic effects to freshwater and marine aquatic invertebrates were recorded up to the limit of water solubility (EU method C. 2/ISO 6341 15, D. magna/A. tonsa, RA CAS 26399-02-0, 85049-37-2).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 Jun - 01 Sep 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Principles of method if other than guideline:

The test concentrations were chosen under consideration of the "VCI-Konzept-Entwurf für die (akute) aquatische Prüfung von schwerlöslichen Stoffen vom 31.1.1994"

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

1.) Samples taken at 0 and 48 hours from 100 mg/l direct weighted sample;
2.) samples taken at 0 and 48 hours from 100 mg/l after separation of the unsoluble test substance;
3.) samples taken at 0 and 48 hours from 3-5-fold amount of saturation.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: According to VCI-concept based on the low solubility of the test substance (VCI-Konzept-Entwurf für die (akute) aquatische Prüfung von schwerlöslichen Stoffen vom 31.1.1994)
- Differential loading: 3 test levels were realised in two main tests.
Main test I (07.06.1995 - 09.06.1995):
- 100 mg/L direct weighted samples: test substance was directly weighted and was treated with ultrasound for 5 min.
Main test II (30.08.1995 - 01.09.1995):
- 100 mg/L after separation of the unsoluble test substance: 100 mg test substance was added to 1 L M4-medium and was mixed with a magnetic stirrer for 24 hours. The unsoluble test substance was separated with a glass fibre filter (pre-treated with sodium hydroxide solution).
- 3-5-fold amount of saturation: 0.30 mg substance was added in 3 L M4-medium and was mixed with a magnetic
stirrer for 24 hours. The unsoluble test substance was separated with a glass fibre filter (pre-treated with sodium hydroxide solution).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: BGA Berlin (May 1994)
- Age at study initiation: 6-24 h
- Feeding during test: no

HOUSING
- Type and amount of food: Scenedesmus subspicatus

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

21.9 - 22°C

pH:

7.8 - 8.0

Dissolved oxygen:

lowest concentration: 90% saturation

Nominal and measured concentrations:

Nominal: 100 mg/L
Measured (direct weighted sample): 8.92 mg/L (0 h), 0.71 mg/L (48 h)
Measured (after separation of the unsoluble test substance): < 0.01 mg/L (0 h, 48 h)
Measured (3-5-fold amount of saturation): < 0.01 mg/L (0 h, 48 h)

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker with watchglass as coverage
- Material: glass; Size: 100 mL; Fill volume: 50 mL
- No. of organisms per vessel: 5 with test substance/ 10 in control
- No. of vessels per concentration: 4
- No. of vessels per control: 2 controls for main test I and 2 controls for main test II

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/ 8 h dark

EFFECT PARAMETERS MEASURED: Immobilisation was recorded after 24 and 48 h test duration.

TEST CONCENTRATIONS
The test concentrations were choosen under consideration of the "VCI-Konzept-Entwurf für die (akute) aquatische Prüfung von schwerlöslichen Stoffen vom 31.1.1994"

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: without insoluble test substance: no effects within the water solubility

Details on results:

First test level (100 mg/L direct weighted samples):
- Behavioural abnormalities: after 24 h and 48 h: daphnids swam at the surface and stuck together in oil drops.
- Other adverse effects control: 10% of the daphnids (one daphnia) showed immobilisation after 48 h by adhere at the wall.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: All replicates showed an oil film on the surface.
- Effect concentrations exceeding solubility of substance in test medium: yes, the nominal effect concentration of above 100 mg/L was exceeded the water solubility of 0.025 mg/l. The analytical monitoring showed lower concentrations of the test substance, but nevertheless the measured concentration exceeded the water solubility (results see above at "Test conditions").

Second test level (100 mg/L after separation of the unsoluble test substance):
- Behavioural abnormalities: none
- Other adverse effects control: 10% of the daphnids (one daphnia) showed immobilisation at 24 h and 48 h.
- Effect concentrations exceeding solubility of substance in test medium: yes, no effects were observed within the water solubility

Third test level (3-5-fold amount of saturation):
- Behavioural abnormalities: none
- Other adverse effects control: 10% of the daphnids (one daphnia) showed immobilisation at 24 h and 48 h.
- Effect concentrations exceeding solubility of substance in test medium: yes, no effects were observed within the water solubility

In one of the replicates of the first test level (100 mg/L direct weighted samples) the daphnids showed an immobilisation of about 20% after 24 h and 100% after 48 h (Table1). No immobilisation was observed at all other replicates of the first test level. But at all replicates of this first test level daphnids swam at the surface and stuck together in oil drops. The daphnids of the two other test levels (100 mg/L after separation of the unsoluble test substance; 3-5-fold amount of saturation) showed no immobilisation or other negative effects (Table 2 + 3). In all tests one control showed a marginal immobilisation of 10 % after 48 h.

The nominal effect concentration of above 100 mg/L was exceeded the water solubility of < 0.025 mg/L. The analytical monitoring showed lower concentrations of the test substance, but nevertheless at the first test level (100 mg/L direct weighted samples) the measured concentration exceeded the water solubility (see above at "Nominal and measured concentrations"). On the basis of the results can be assumed, that in present of unsolved test substance the observed effects can be attribute to physical effects of the unsolved components (e.g. by sticking the gills together) and not to a systemic toxicity. Since after separation of the unsoluble test substance (second and third test level) no negative effects were observed, the effect concentration can be stated as EC50 > water solubility.

Table 1: Immobilisation [%] of the first test level (100 mg/L direct weighted samples)

Conc. (mg/L)	Immobilisation [%]
	24 h	48 h
0/1	0	0
0/2	0	10
100/1	0	0
100/2	0	0
100/3	0	0
100/4	20	100

Table 2: Immobilisation [%] of the second test level (100 mg/l after separation of the unsoluble test substance)

Conc. (mg/L)	Immobilisation [%]
	24 h	48 h
0/1	0	0
0/2	10	10
100/1	0	0
100/2	0	0
100/3	0	0
100/4	0	0

 

Table 3: Immobilisation [%] of the third test level (3-5-fold amount of saturation)

Conc. (mg/L)	Immobilisation [%]
	24 h	48 h
0/1	0	0
0/2	10	10
0,075-0,125/1	0	0
0,075-0,125/2	0	0
0,075-0,125/3	0	0
0,075-0,125/4	0	0

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 - 11 Feb 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP-Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: WAF; direct addition of the nominal weights to seawater followed by gently stirring for approx. 20 h followed by a settling period of approx. 1 h. After the settling period, the middle phase of the preparation is siphoned, avoiding incorporation of undissolved particles.

Test organisms (species):

other aquatic crustacea: Acartia tonsa

Details on test organisms:

TEST ORGANISM
- Source: cultured in the test laboratory
- Age at study initiation: 20 days, age standardised cohort

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

19.1 - 20.5 °C

pH:

7.82 - 8.09

Dissolved oxygen:

94 - 97% (saturation)

Salinity:

Conductivity: 50.7 - 51.4 mS/cm (salinity approx. 3.75% at 20 °C)

Nominal and measured concentrations:

nominal: 0, 1000, 1800, 3200, 5600 and 10000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL capacity borosilicate glass crystallising dishes
- Type: closed, covered by soda glass watch covers
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: natural seawater supplied by pump from Scapa Flow, Orkney; UV sterilised and filtered to 0.2 µm
- Intervals of water quality measurement: every 24 hours in one replicate

EFFECT PARAMETERS MEASURED: immobility at test start and after 24 and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: approx. 1.8
- Range finding study
- Test concentrations: control, 1, 10, 100 and 1000 mg/L
- Results used to determine the conditions for the definitive study: no immobilities observed at any concentration

Reference substance (positive control):

yes

Remarks:

3,5 - Dichlorophenol

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

2 046.63 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other: 1646.12 - 2470.12 mg/L (95% C.L.)

Details on results:

- Behavioural abnormalities: none observed

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Mortality: 10% at 0.1 mg/L, 0% at 0.32 mg/L, 15% at 0.56 mg/L, 58% at 1.0 mg/L and 100% at 1.8 mg/L
- EC50/LC50: EC50(48h) = 0.85 mg/L (0.74-1.00, 95% C.L.)

Percentage of immobilised copepods at the tested nominal concentrations (WAF) after 24 and 48 hours:

Concentration	Incubation time (in h)
in mg/L	24	48
1000	5	15
1800	11	39
3200	25	75
5600	100	100
10000	95	100

Description of key information

No effects up to the limit of water solubility (EU method C. 2/ISO 6341 15, D. magna/A. tonsa); read-across

Additional information

There is no study available assessing the short-term toxicity of the target substance Fatty acids, C16-18, isononyl esters (CAS 91031-57-1) to aquatic invertebrates. Therefore, read-across to the two structurally related source substances 2-ethylhexyl oleate (CAS 26399-02-0) and Fatty acids, C16-18 and C18-unsatd., 2-ethylhexyl esters (CAS 85049-37-2) was conducted in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. The source substances are considered suitable representatives for the assessment of the acute toxicity of the target substance to aquatic invertebrates. A detailed read-across justification is provided in IUCLID section 13.

The study with the source substance 2-ethylhexyl oleate (CAS 26399-02-0) was conducted according to EU method C. 2 considering the VCI concept draft for the acute testing of poorly soluble substances from 1994-01-31 and GLP. In a static limit test, D. magna was exposed to the nominal concentration of 100 mg/L test item for 48 h. Two main tests were performed in which the test solutions were prepared in two different ways. The first approach without removal of the insoluble particles resulted in immobilization rates between 0 and 100% (mean: 25%). After removal of insoluble particles (filtration) in the second approach, no effects to Daphnia magna were observed. Thus, it can be stated that the insoluble particles of the test substance resulted in negative physical effects (e.g. agglutination of gills) and no effects were observed in the range of water solubility. This resulted in an EC50 (48 h) > 100 mg/L (nominal).

The study investigating the source substance 2-ethylhexyl esters (CAS 85049-37-2) was performed according to ISO 6341 15 and GLP with a marine test organism. In a static test, A. tonsa was exposed to five water accommodated fractions with nominal loading rates ranging from 1000 to 10000 mg/L test item for 48 h. The derived EL50 (48 h) was > 2047 mg/L (95% CI: 1646 -2470 mg/L).

Based on the structural and chemical similarity of the target and source substances, the target substance is expected to exhibit a similar ecotoxicological profile. Therefore, it can be concluded that Fatty acids, C16-18, isononyl esters (CAS 91031-57-1) will not exhibit short-term effects to freshwater and marine aquatic invertebrates up to the limit of water solubility.