Fatty acids, C16, C18 and C18-unsaturated, C12-15 alcohol (linear and branched), esters

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 Aug - 11 Dec 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

LUBW Landesanstalt für Umwelt, Messungen und Naturschutz, Baden-Württemberg, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Control, 6.75, 25 and 100 mg/L
- Sampling method: At the start (0 h), at the end (21 d) and at least once a week, 3.8 mL sample were taken from the test vessels A, C and E (100, 25 and 6.75 mg/L) and the control vessels at the beginning and at the end of a medium-change interval or chemical analysis.
- Sample storage conditions before analysis: Sample storage in 4 mL brown glass vials (filled up to the brim to avoid oxidative processes), maximum storage period of 8 d at 5 °C ± 3 °C before analysis.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to the low water solubility of the test item, the study was performed with the water accommodated fraction (WAF) prepared with M4 medium according to OECD 202. The suspension was stirred for 24 hours at 20 – 22 °C in diffuse light. After stirring was stopped, the suspension was allowed to float and sediment for a period of 1 hour. After sedimentation and floatation period the WAF was clear and no particles could be observed. The test solution was taken from the middle of the suspension on the beaker using a glass tube and transferred into the test vessels. About 75 mL test solution was transferred into each test vessel (100 mL glass beakers). WAFs were prepared 3 x week.
- Controls: yes, M4 medium

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain/clone: Straus
- Source: German Federal Environmental Agency, department V 3.2, Berlin, Germany
- Age of parental stock: 0.5 – 21.5 h
- Feeding during test
- Food type: Suspension of the algae Desmodemus subspicatus
- Amount: 0 to 6 days: 0.1 mg C/Daphnia/day, 7 – 21 days: 0.2 mg C/Daphnia/day
- Frequency: daily

ACCLIMATION
- Acclimation conditions (same as test or not): The Daphnia are held at 20 ± 2 °C with a light : dark cycle of 16 : 8 h.
- Type and amount of food: Suspension of the algae Desmodesmus subspicatus, 0.1 mg C/Daphnia/days
- Feeding frequency: Fed during working days.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

20.6 - 21.8 °C

pH:

7.6 - 8.2

Dissolved oxygen:

7.7 - 8.5 mg O2/L

Nominal and measured concentrations:

Nominal: control, 6.75, 12.5, 25, 50, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL beakers
- Type (delete if not applicable): covered with a transparent plastic foil
- Material, size, headspace, fill volume: glass, 100 mL, headspace: 25 mL, fill volume: 75 mL
- Renewal rate of test solution (frequency/flow rate): three times per week
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt-M4-medium, according to OECD 202. Before the addition of the M4 stock solutions the water was aerated for 2 hours to allow the dissolved oxygen concentration to reach its saturation.
- Intervals of water quality measurement: With every medium renewal the pH and oxygen content were measured.

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16 h light : 8 h dark
- Light intensity: 6.73 µmol/m2

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobility and reproduction (cumulative offspring was recorded daily.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Details on results:

- Mortality of parent animals: Only in one vessel (B: 50 mg/L) one dead Daphnia was found among the parent animals. This animal died because of an accident during the medium change and not because of influence of the test item.

- Body length and weight of parent animals: Control: mean 4.282 ± 0.152 mm; 6.8 mg/L: mean 4.285 ± 0.120 mm; 12.5 mg/L: mean 4.211 ± 0.146 mm; 25 mg/L: mean 4.284 ± 0.139 mm; 50 mg/L: mean 4.373 ± 0.122 mm; 100 mg/L: mean 4.278 ± 0.114 mm

- Time to first brood release or time to hatch: Control: mean 8.50 ± 0.00 day; 6.8 mg/L: mean 9.20 ± 1.16 day; 12.5 mg/L: mean 9.20 ± 0.82 day; 25 mg/L: mean 9.70 ± 1.14 day; 50 mg/L: mean 9.60 ± 2.62 day; 100 mg/L: mean 9.20 ± 1.64 day

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 (24 h): 1.92 mg/L; EC50 (48 h): 1.50 mg/L

Reported statistics and error estimates:

Williams Multiple t-test procedure using ToxRat v2.09 (ToxRat solutions, Alsdorf, Germany)

Table 1: Effective Concentrations for Mean Cumulative Offspring per parent animal

Concentration [mg/L]	Mean offspring	Standard deviation	n	% Reduction
Control	99.0	6.80	10	0.0
6.8	97.0	8.80	10	2.3
12.5	102.0	6.10	10	-3.1
25.0	103.0	10.60	10	-4.6
50.0	97.0	37.60	9	1.9
100.0	108.0	10.40	10	-9.5

 

The analytical determination of the test substance concentration indicated that in almost all vessels no test substance concentration could be measured up to the limit of quantification (LLOQ) of 5 µg/L reflecting the very low water solubility of the test substance. Only in three test samples the test substance could be detected with a recovery rate of ≤ 4.4%.

Reference 2

Endpoint:

long-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 IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 36078-10-1, Dako, 2013, D. magna, 21 d

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

reproduction

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 36078-10-1, Dako, 2013, D. magna, 21 d

Conclusions:

The effect concentration retained for the long-term toxicity to aquatic invertebrates is a NOELR (21 d) of ≥ 100 mg/L (nominal), based on an experimental study with a structurally and chemically closely related source substance (OECD 211, D. magna); read-across

Description of key information

No effects up to the limit of water solubility (OECD 211, D. magna); read-across

Additional information

There is no study available, in which the long-term toxicity of Fatty acids, C16, C18 and C18-unsaturated, C12-15 alcohol (linear and branched), esters to aquatic invertebrates was assessed. Therefore, read-across to the structurally and chemically closely related source substance Dodecyl oleate (CAS 36078-10-1) was performed in accordance with Regulation (EC) No 1907/2006 Annex XI, section 1.5 in order to fulfill the data requirements for this substance. The source substance is characterized by similar fatty acid chain lengths and alcohol components as the target substance and is therefore considered a suitable representative for the assessment of the long-term toxicity of the target substance to aquatic invertebrates. A detailed read-across justification in provided in IUCLID section 13.

The available study with the source substance Dodecyl oleate was conducted according to OECD guideline 211 in compliance with GLP. In a semi-static test, the water flea Daphnia magna was exposed to five Water Accommodated Fractions with nominal test item loading levels ranging from 6.75 to 100 mg/L for 21 d. After 21 d, no effects on reproduction were observed and a NOELR (21 d) of ≥ 100 mg/L (nominal) was derived. The chemical analysis of test solutions resulted in concentrations below the analytical detection limit of 0.005 mg/L reflecting the very low water solubility of the test item. Thus, it is concluded that Dodecyl oleate does not cause chronic effects to aquatic invertebrates up to the limit of water solubility.

Based on the high degree of structural and chemical similarity between the target and the selected source substance, the target substance is expected to exhibit a similar ecotoxicological profile as the source substance. Therefore, it can be concluded that the target substance Fatty acids, C16, C18 and C18-unsaturated, C12-15 alcohol (linear and branched), esters does not cause long-term toxic effects to aquatic invertebrates up to its limit of water solubility (< 6.57 µg/L at 20 °C, pH 6.3, OECD 105).