Dodecyl nonan-1-oate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

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

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: CAS 95912-86-0, BASF, 2013, D. subspicatus

Key result

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: CAS 95912-86-0, BASF, 2013, D. subspicatus

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: CAS 95912-86-0, BASF, 2013, D. subspicatus

Key result

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WSF

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: CAS 2306-88-9, BASF, 2013, D. subspicatus

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 Jan 2013 - 15 Feb 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline Study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health, Bern, Switzerland

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test loading was prepared by adding the respective amount of an acetonic stock solution to an empty glass vessel. After complete evaporation of the solvent, the aerated algal medium was added, moderately stirred for 24 h, followed by filtration (0.45 μm cellulose acetate membrane sterile syringe filter, VWR International). The resulting water soluble fraction (WSF) was used in the test.
- Controls: Blank control containing test medium and algae
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) including control(s)): complete evaporation before addtion of algal medium

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Collection of Algal Cultures, Institute of Freshwater Ecology, University of Göttingen, D-37073 Göttingen, Germany

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

Min: 20.7 °C
Max: 21.4 °C
Mean: 21.1°C

pH:

blank control: 8.0 to 8.7
100 mg/L: 8.0 to 9.3

Nominal and measured concentrations:

mominal: control, 100mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: all-glass, 250 mL flasks, with 100 mL of test medium
- Initial cells density: 0.50–0.85 μg/mL with respect to dry weight corresponding to about 2000-5000 cells/mL (i.e. OD680 of about 0.005 units)
- Control end cells density: OD680: 0.262 - 0.416
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: no
- Intervals of water quality measurement: pH at 0 hours and 72 hours

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: with air
- Photoperiod: continuous illumination
- Light intensity and quality: the light intensity amounts to about 3000 lux which corresponds to about 40 μE /m2 s2 according to the OECD 201

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: spectrophotometer (680 nm wavelength)

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: limit test
- Range finding study
- Test concentrations: 1.0 mg/L, 10.0 mg/L, 100 mg/L
- Results used to determine the conditions for the definitive study: no significant inhibition at any test concentrations

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WSF

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WSF

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes

Results with reference substance (positive control):

Potassium dichromate is used to control the sensitivity of the culture twice a year.

Reference 3

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 Nov - 29 Nov 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesamt für Umwelt, Wasserwirtschaft und Gewerbeaufsicht, Mainz, Germany

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The test solution(s) were prepared following general guidance provided in OECD 23 in order to achieve a water accommodated fraction of the test substance. Generally, each test solution was prepared separately (differential loading) by directly adding test substance to test medium according to the loading of 10, 32, 100, 320, 1000 mg/L. A defined volume of test media was placed into a beaker and a glass sampling tube was suspended in the beaker with the top of the tube sufficiently above the surface of the test medium to avoid overflow from the surrounding surface layer. The test substance was pipetted carefully, on the water surface outside of the glass tubes. The beakers were covered and shaken gently (approx.. 50 RPM, to avoid emulsion formation) for about one day. Afterwards stirring, the required volume of aqueous fraction was drawn off for testing via the glass sampling tube. The aqueous fraction was inspected visually for the presence of any undissolved test substance. The exposure was started after separation of the undissolved material by adding inoculum culture to the WAF at a ratio of 1:100. According to OECD 23 the aqueous fraction of the test solution, after separation of the undissolved material, was a water accommodated fraction (OECD 23 definition) and was considered analogous to nominal concentration.
- Eluate: no
- Differential loading: yes
- Controls: yes, test medium control

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: SAG 86.81
- Source (laboratory, culture collection): Collection of algal cultures in University of Göttingen/Germany
- Age of inoculum (at test initiation): A stock algal culture is maintained continuously at the test facility. Before the exposure an inoculum culture is prepared from the stock culture and incubated for 4 days at 21 – 24 °C (max. temperature difference 2 °C). After this time, the inoculum culture is in exponential growth phase and can be used to initiate the test (study day 0).
- Method of cultivation: same as test

ACCLIMATION
- Culturing media and conditions (same as test or not): same as test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.7 – 23.0 °C

pH:

7.9 - 8.4

Nominal and measured concentrations:

nominal: 0, 10, 32, 100, 320, 1000 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): plugged with gas permeable silicone sponge caps
- Size, headspace, fill volume: 250 mL, headspace: 150 mL, fill volume: 100 mL
- Aeration: continuous shaken
- Initial cells density: 0.5 x 10E+04 cells/mL
- Control end cells density: 80.2 x 10E+04 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, according to guideline

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: no
- Photoperiod: continuous illumination
- Light intensity and quality: Artificial light, type universal white (OSRAM L 25), permanent illumination. To minimize the potential effect of slight variations in illumination, the test vessels were re-arranged daily. Average 7009 lux (within ± 15% variability) at a wave length of 400 - 700 nm

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: Algal growth measured as in vivo chlorophyll-a fluorescence (pulsed excitation with light flashes having a wavelength of 430 nm)
- Determination of correlation between fluorescence and cell density: After the end of the exposure the control replicates were mixed and serially diluted by factor 2. The fluorescence of aliquots from the undiluted mixture and the dilutions were measured and in parallel cell density was determined by a direct microscopic count (two counts in a Neubauer haemocytometer). These data were used to derive a linear correlation between fluorescence and cell density.
- Algal morphology: The inoculum culture was observed microscopically at the start of the test to verify normal and healthy cells. At test termination, a pooled sample from each test concentration was examined and any abnormal appearance of the algae noted.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: ≤ 3.2
Range finding study
- Results used to determine the conditions for the definitive study: The test concentrations were selected on the basis of a range finding test (experimental conduct in accordance with GLP but without a GLP Status). The results of the 72 hour range finding test were (as nominal concentrations):EfluorescenceC50 > 100 mg/L; ErC50 > 100 mg/L. However there was 14% effect (yield) at 100 mg/L therefore a full concentration range will be performed including concentrations >100 mg/L in order to estimate the EC50.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

other: yield

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

other: yield

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

other: yield

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no abnormalities observed
- Unusual cell shape: no remarkable observations
- Any stimulation of growth found in any treatment: yes, inevery treatment for growth rate and in test group 32, 100 and 320 investigating yield.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: All of the test solutions were visibly clear and colorless after preparation. There was no visible undissolved test substance and no other remarkable observations through the end of exposure (72 h).

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: The ErC50 (72 h) of the control substance potassium dichromate was 0.78 mg/L (Date of the last control experiment: 25 Sep 2012) which is in the range of 0.71 - 0.97 mg/ as indicated in ISO Guideline 8692.

Reported statistics and error estimates:

SAS statistical software was used for the statistical evaluation of the data.

The 72-hour results of the algal growth inhibition test including effect concentrations based onnominal (loading rate) concentrations are summarized below.

Test Group (Loading rate) [mg/L]	Mean Cell Density (cells/mL)x 10^4 at 72 hours	% Inhibition (as yield)^a	% Inhibition (as growth rate)^a
0 (control)	80.2	0.0	0.0
10	77.7	3.05	-0.83
32	80.2	-0.08	-1.73
100	81.2	-1.32	-0.07
320	80.3	-0.12	-0.63
1000	79.5	0.80	-0.42

a: Negative values indicate a stimulatory effect relative to the control.

The results in this study are consistent with all validity criteria and the test is valid according to the guidelines of this study. No deviations from test guidelines or other incidents occurred during the course of the reported test which may have influenced the results.

Description of key information

No effects up to the limit of water solubility (D. subspicatus, OECD 201); read-across

Additional information

There is no study available, in which the toxicity of the target substance lauryl nonanoate (CAS 17671-26-0) to algae was assessed. Therefore, read-across to the two structurally related source substances Fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0) and octyl octanoate (CAS 2306-88-9) was conducted in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. Both source substances are characterized by similar fatty acid chain lengths as well as alcohol components and are therefore considered suitable representatives for the assessment of the toxicity of the target substance to algae. A detailed read-across justification is provided in the analogue justification in IUCLID Section 13.

Both available read-across studies were conducted according to OECD 201 and GLP.

In the study with the source substance Fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0), D. subspicatus was exposed to five, nominal loading levels of 10, 32, 100, 320 and 1000 mg/L in a static test for 72 h. Each test solution was separately prepared as water accommodated fraction (WAF) but no analytical verification of test item concentrations was performed. After 72 h, no significant effects on the growth rate was observed and the reported EL50 (72 h) was > 1000 mg/L (nominal) and a NOELR (72 h) ≥ 1000 mg/L.

In the available study assessing the source substance octyl octanoate (CAS 2306-88-9), D. subspicatus was exposed to a loading level of 100 mg/L (nominal) in a static limit test for 72 h. The test solution was prepared as water accommodated fraction but no analytical verification of the test item concentration was performed. After 72 h, no significant effect on the growth rate was observed and the reported EL50 (72 h) was > 100 mg/L (nominal).

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 lauryl nonanoate (CAS 17671-26-0) will not exhibit toxic effects to algae up to the limit of water solubility.