monoesters of C16 and C18 (branched and linear) fatty acids with decan-1-ol

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:

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

Adequacy of study:

key study

Justification for type of information:

Refer to the analogue approach 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

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

Conclusions:

The effect value for long-term toxicity to aquatic invertebrates is an EL50 (21 d) of > 100 mg/L (nominal) based on experimental data from a reliable read-across source substance (OECD 211).

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

06 Oct - 28 Oct 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: OECD 202, part 2 (1993)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Eluate of 1 and 100 mg/L at 0, 24, 48 and 72 hours

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solutions of 1 and 100 mg/L in test medium (M4) were prepared and stirred for 16 h up to 5 d. The suspension was filtered via glass fibre filter, the water phase, supposedly satisfied with test substance to the limit of solubility, was used without further dilution

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house culture, originally obtained from BGA Berlin (May 1994)
- Feeding during test: yes
- Food type: Scenedesmus subspicatus
- Amount: 2.5*10E6 cells/daphnid/day for 0-7 day old animals; 5.0*10E6 cells/daphnid/day for >7 day old animals
- Frequency: daily

ACCLIMATION
- Acclimation conditions (same as test or not): same

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Test temperature:

20.9 - 22.1 °C

pH:

7.8 - 8.2

Dissolved oxygen:

89 - 100 % (air saturation)

Nominal and measured concentrations:

Nominal: 1 and 100 mg/L
Measured: <0.01 and <0.01 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flask
- Type: closed by hourglass
- Size: 100 mL; Fill volume: 50 mL
- Renewal rate of test solution: every 2 to 3 days
- No. of organisms per vessel: 1
- No. of vessels per concentration: 10
- No. of vessels per control: 10

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: same, M4-Elendt

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: 300 Lux

EFFECT PARAMETERS MEASURED: The number of offspring and mortality of parental animals were recorded daily.

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

other: filtered test solution

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 mg/L

Nominal / measured:

nominal

Conc. based on:

other: filtered test solution

Basis for effect:

reproduction

Remarks:

number of offspring

Details on results:

- Measured concentration of test substance: < 0.01 mg/L in the 1 mg/L as well as in the 100 mg/L sample at all sampling times.
- Mortality of parent animals: 0% in control and 1 mg/L (nominal) at the end of the test, 90% died on day 19 in 100 mg/L (nominal);
- No. of offspring produced per day per female: 5.8 offspring/daphnid/day in control over 21 days; 6.0 offspring/daphnid/day in 1 mg/L (nominal) over 21 days and 6.7 offspring/daphnid/day in 100 mg/L (nominal) over first 17 days as well as 4.5 offspring/daphnid/day in 100 mg/L (nominal) over full 21 days (23% reduced due to mortality of parent animals);
- other: limit of solubility of test substance <0.01 mg/L.
- The authors state, that the deaths of 90% of parent animals on day 19 in the 100 mg/L (nominal) sample could have resulted from sample contamination. Another course to explain the given results would be an error in eluate preparation. Either way, it is safe to say that a NOEC > 1 mg/L (nominal) is given for reproduction (number of offspring) and mortality (parent animals).

The analytic shows a similarly small concentration of test substance (< 0.01 mg/L) in the 1 mg/L as well as in the 100 mg/L sample at all sampling times. Detailed information on offspring numbers and mortality is presented in Table 1.1 to 1.3.

Table 1.1: Number of offspring and average offspring per daphnid per day in the control:

Control
Daphnid no.	Day 10	Day 12	Day 14	Day 17	Day 19	Day 21	Σoffspring in 21 days per animal	Average offspring/ daphnid/d
1	8	23	0	20	20	13	84	6.5
2	7	0	24	18	21	0	70	5.4
3	6	0	28	19	18	0	71	5.5
4	12	0	21	21	19	11	84	6.5
5	5	13	19	0	12	18	67	5.2
6	5	19	0	21	24	12	81	6.2
7	10	0	21	18	19	15	83	6.4
8	7	0	22	19	25	0	73	5.6
9	6	0	16	18	18	17	75	5.8
10	4	20	0	22	10	13	69	5.3
Average							75.7	5.8

Table 1.2: Number of offspring and average offspring per daphnid per day in the 1 mg/L concentration:

Nominal 1 mg/L (analytically <0.01 mg/L)
Daphnid no.	Day 10	Day 12	Day 14	Day 17	Day 19	Day 21	Σoffspring in 21 days per animal	Average offspring/ daphnid/d
1	11	19	0	15	19	16	80	6.2
2	0	12	17	10	0	33	72	5.5
3	11	0	21	16	20	0	68	5.2
4	8	17	0	21	29	16	91	7.0
5	7	19	0	21	13	16	76	5.8
6	10	0	23	19	26	0	78	6.0
7	10	0	20	18	21	15	84	6.5
8	9	18	0	18	18	20	83	6.4
9	5	17	0	18	22	18	81	6.2
10	8	0	14	18	29	0	67	6.2
Average							78.0	6.0

Table 1.3: Number of offspring and average offspring per daphnid per day in the 100 mg/L concentration up to day 17. On day 19 parent animals started dying, so this values were excluded. T=animal found dead.

Nominal 100 mg/L (analytically <0.01 mg/L)
Daphnid no.	Day 10	Day 12	Day 14	Day 17	Day 19	Day 21	Σoffspring in 17 days per animal	Average offspring in/ daphnid/d
1	10	19	0	21	T		50	6.3
2	13	25	0	25	T		63	7.9
3	5	21	26	0	0	T/9	52	6.5
4	8	20	0	23	6	T	51	6.4
5	7	26	0	25	T		58	7.3
6	9	0	24	16	T		49	6.1
7	6	20	27	11	0	12	64	8.0
8	8	23	0	23	T/8		54	6.8
9	3	15	23	0	9	T	41	5.1
10	10	5	23	17	T		55	6.9
Average							53.7	6.7

Description of key information

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

Additional information

There is no study available, in which the long-term toxicity of the target substance Monoesters of C16 and C18 (branched and linear) fatty acids with decan-1-ol to aquatic invertebrates was assessed. Therefore, read-across to the structurally related source substancesdodecyl oleate (CAS 36078-10-1) and 2-ethylhexyl oleate (CAS 26399-02-0) was conducted in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. Both source substances are characterized by similar fatty acid and alcohol components as the target substance and are therefore considered suitable representatives for the assessment of the long-term 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 dodecyl octadec-9-enoate (CAS 36078-10-1) was conducted according to OECD 211 and GLP (key study). In a semi-static test, the model organism Daphnia magna was exposed to five nominal concentrations ranging from 6.75 to 100 mg/L in a geometric series with a spacing factor of 2 for 21 d. Due to the poor water solubility of the test item, Water Accommodated Fractions (WAFs) were prepared. The actual test item concentrations in the test media were below the limit of detection (0.005 mg/L), reflecting the very low water solubility of the test item.

After 21 d, no effects on the reproduction of D. magna were observed, resulting in a NOELR (21 d) of ≥ 100 mg/L (nominal). Thus, the source substance dodecyl octadec-9-enoate (CAS 36078-10-1) did not cause long-term toxic effects towards aquatic invertebrates up to the limit of solubility.

The available study with the source substance2-ethylhexyl oleate (CAS 26399-02-0)was performed according to OECD 202, part 2 (1993, equivalent to OECD 211) and GLP (supporting study). In a semi-static test, D. magna was exposed to 1 and 100 mg test item/L (nominal) for 21 d. For the test media, stock solutions of 1 and 100 mg/L were prepared and stirred for 16 h up to 5 d. The suspensions were then filtered (glass fibre) and the supposedly test substance satisfied water phases (up to the limit of water solubility) was used for the test without further dilution. The actual test item concentrations in the test media were analytically verified by gas chromatography.

Chemical analysis resulted in concentrations of < 0.01 mg test item/L in both concentrations.

After 21 d, effects on D. magna were observed with no effect at 1 mg/l and 90% mortality at 100 mg/L (Day 19). The authors attributed the deaths in the higher concentration to sample contamination and a NOEC(21 d, mortality) of > 1 mg/L (nominal) was reported. Similarly, 23% reduction of reproduction (number of offspring) in the 100 mg/L sample occurred after 21 days, with no effect in the 1 mg/L sample, resulting in a NOEC(21 d, reproduction) of > 1 mg/L. Comparison of reproduction up to Day 17 in the 100 mg/L treatment with reproduction in the control showed no reduction of reproduction.

Based on the structural and chemical similarities between the target and source substances, the target substance is expected to exhibit a similar ecotoxicological profile as the source substances. Therefore, it is concluded that Monoesters of C16 and C18 (branched and linear) fatty acids with decan-1-ol does not cause long-term effects to aquatic invertebrates up to the limit of water solubility (< 0.16 mg/L).