Isooctadecanoic acid, mixed esters with oxybis[propanediol]

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:

refer to Analogue 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:

EL50

Effect conc.:

60.53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other: Source: CAS 73296-86-3

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

53.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other: Source: CAS 67938-21-0

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

16 Dec 2012 - 8 Jan 2013

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP guideline study without analytics

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Staatliches Gewerbeaufsichtsamt, Hildesheim, Germany

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 6.25 - 12.5 - 25 - 50 - 100 mg/L (WAF)
- Sampling method: All tested loading levels of the test item and the control were sampled at the start of the exposure (0 h) and at the end of the exposure (48 h). For the old media, an additional replicate of each loading level and the control was prepared, with test media, but without daphnids, and incubated under test conditions until sampling.
- Sample storage conditions before analysis: The samples were stored at 6 ± 2 °C until analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Five water accommodated fractions (WAF) were prepared with nominal loadings of the test item in the range of 6.25 to 100 mg/L, set up in a geometric series with a separation factor of 2. For each loading level, an appropriate amount of the test item was weighed out and transferred into a measuring flask with an appropriate amount of dilution water. These dispersions were stirred for 72 h with 1100 rpm at room temperature. After a separation phase of 1 h, the WAFs were taken from the homogeneous liquid phase (the approximate centre of the glass flask) and used for testing. The test loadings are based on the results of a non GLP preliminary range finding test under static conditions.
- Controls: Dilution water without test item, tested under the same conditions as the test groups

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Freshwater flea
- Source: Institut für Wasser-, Boden- Lufthygiene (WaBoLu), further own breeding
- Age at study initiation (mean and range, SD): 2 to 24 h
-- Method of breeding: In 2-3 L glass vessels with appr. 1.8 L culture medium, at 20 +/- 2 °C, in an incubator, 16 h illumination, illumination strength max. 20 μExm-2 x s-1

ACCLIMATION
- Acclimation period: 2h
- Acclimation conditions (same as test or not): same as test

DILUTION WATER:
Dilution water ISO test water, according to OECD 202, Annex 3:
Component Concentration [mg/L]
KCl 5.76
NaHCO3 64.8
CaCl2 x 2 H2O 294
MgSO4 x 7 H2O 123

pH-value: 7.8 +/- 0.2

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Dilution water at test start: 246 (mg CaCO3/L)

Test temperature:

19 - 20°C

pH:

at test start: 7.65 - 8.03
at test end: 7.66 - 7.81

Dissolved oxygen:

at test start: 8.44 - 8.68 O2 mg/L
at test end: 8.28 - 8.67 O2 mg/L

Nominal and measured concentrations:

nominal loading rates (WAF): blank control, 6.25, 12.5, 25.0, 50.0 and 100 mg/L
measured concentration at test start: < 2.00, < 2.00, 2.63, 3.21, 3.31 and 8.08 mg/L
measured concentration at test end: < 2.00, 2.43, 2.78, 3.13, 3.17 and 8.16 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers, 50 mL
- Type (delete if not applicable): closed with parafilm
- Material, size, headspace, fill volume: Glass beakers (4 cm ID x 7 cm H), 50 mL
- Renewal rate of test solution (frequency/flow rate): static test
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dilution water ISO test water, according to OECD 202, Annex 3
- Conductivity: Dilution water at test start:632 μS/cm
- Intervals of water quality measurement: At test start and test end

OTHER TEST CONDITIONS
- Photoperiod: 16:8 light:dark cycle
- Light intensity: Diffuse light, illumination strength max. 20 μE x m-2 x s-1

EFFECT PARAMETERS MEASURED : Immobility was determined in all groups after 24 h and 48 h.

RANGE-FINDING STUDY
non GLP Preliminary Range Finding Test (n = 20, divided into 2 replicates with 10 daphnids each)
- Concentrations: blank control, 1, 10 and 100 mg/L
- Results: no immoilization in control and 1 and 10 mg/L test solutions after 24 and 48 hrs; 60-70% immobility in highest test concentration after 24 hrs and 100% immobilisation after 48 hrs

Reference substance (positive control):

yes

Remarks:

Potassium dichromate; test duration 24 hrs, performed once per month

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal loading rates (WAF)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

53.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal loading rates (WAF)

Basis for effect:

mobility

Remarks on result:

other: confidence interval: 41.6 - 71.3 mg/L

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal loading rates (WAF)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOELR

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal loading rates (WAF)

Basis for effect:

mobility

Details on results:

- no effects were observed in the control group
- The loading level of 100 mg/L was slightly turbid throughout the exposure. All other loading levels and the control were visually clear throughout the exposure.
- For details on daphnia immobilisation rates, please refer to table 1 in section "Any other information on results"

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50 1.60 mg/L (CI: 1.40 - 1.80 mg/L)

Table 1. Biological data. Daphnia immobilisation rates.

Diglycerol diisostearate   Nominal loading rates of the WAF [mg/L]	Immobilisation [%]
	24 h					48 h
	Replicates					Replicates
	1	2	3	4	MV	1	2	3	4	MV
100	60	40	20	60	45	80	100	80	80	85
50.0	0	20	20	0	10	20	40	80	40	45
25.0	0	0	0	0	0	20	20	20	40	25
12.5	0	0	0	0	0	0	0	0	0	0
6.25	0	0	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0	0	0

Table 2: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	Control: 0%	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	≥ 8.28 mg/L	yes

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

12 Dec - 14 Dec 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

24 August 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

National Institute of Pharmacy and Nutrition, Budapest, Hungary

Analytical monitoring:

yes

Details on sampling:

- Concentrations: blank control and all applied test concentrations
- Sampling method: samples were taken at the beginning and end of the experiment

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)

- Method: Water Accomodated Fractions (WAFs); saturated test item solutions (6.25, 12.5, 25, 50 and 100 mg/L nominal loading rates WAFs) were prepared by dispersing/dissolving the amount of test item into the ISO test medium 3 days before test start. Test solutions were stirred at 1100 rpm for about 72 hours at room temp. and then equilibrated for separation for another hour at the same temp. WAFs were taken from the homogenous liquid phase and used for testing. The test solutions were prepared just before the introduction of the test organisms.

- Controls: blank control without the test item; reference control with potassium dichromate

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Freshwater flea
- Source: István Szent University, Gödöllö, Páter Károly u. 1, Hungary
- Age. < 24 hrs at test start

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

245 mg/L CaCO3

Test temperature:

19.4 - 20.0 °C

pH:

7.33 - 7.70

Dissolved oxygen:

7.8 - 8.8 mg/L

Nominal and measured concentrations:

nominal loading rates (WAFs): blank control, 6.25, 12.5, 25, 50 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers
- Material, size, headspace, fill volume: at least 5 mL test solution per animal
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: ISO medium (reconstituted water) according to OECD guideline 202
- Culture medium different from test medium: no
- Water temperature was measured daily during the test; oxygen concentrations and pH were measured at test start and end

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility

RANGE-FINDING STUDY
- Test concentrations: First RF test: blank, 0.5, 1, 10 and 100 mg/L; Second RF test: blank, 25, 50 and 100 mg/L
- Results used to determine the conditions for the definitive study: 90% immobilised daphnids at 100 mg/L; 0% at 25 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accomodated Fractions (WAFs)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

60.53 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accomodated Fractions (WAFs)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EL100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accomodated Fractions (WAFs)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accomodated Fractions (WAFs)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LOELR

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Water Accomodated Fractions (WAFs)

Basis for effect:

mobility

Results with reference substance (positive control):

The reference substance Potassium dichromate is tested twice a year.
EC50 (24h) = 0.93 mg/L (95% CI 0.86 - 0.99 mg/L)

Table 1: Number and percentage of immobilised animals

Nominals loading rate (WAFs) [mg/L]	Number of treated animals	Immobilised animals
		24 h		48 h
		number	percent	number	percent
Control	20	0	0	0	0
6.25	20	0	0	0	0
12.5	20	0	0	0	0
25	20	0	0	2	10
50	20	0	0	7	35*
100	20	0	0	16	80*

*statistically significantly different compared to the control value (Dunnett's Test; alpha = 0.05)

Table 2: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	Control: 0%	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	≥ 8.6 mg/L	yes

Additional information

Since no studies investigating the short-term toxicity of Isooctadecanoic acid, mixed esters with oxybis[propanediol] to aquatic invertebrates are available, in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5, a read-across to the structurally related source substances Isooctadecanoic acid, ester with oxybis[propanediol] (CAS 73296-86-3) and Di(isooctadecanoic) acid, diester with oxydi(propanediol) (CAS 67938-21-0) was conducted. The source substances are representative to evaluate the short-term toxicity of the target substance to aquatic invertebrates.

The target substance Isooctadecanoic acid, mixed esters with oxybis[propanediol] exists as two different grades. Grade One is characterized by mainly triesters of C18 iso fatty acids of the alcohol component diglycerol. Grade Two is characterized by mainly tetraesters of C18 iso fatty acids of the alcohol component diglycerol.

The source substance Isooctadecanoic acid, ester with oxybis[propanediol] (CAS 73296-86-3) is characterized as a UVCB substance containing polyglycerol as alcohol component. Polyglycerol components are esterified to give mainly monoesters of C18 iso fatty acids.

The source substance Di(isooctadecanoic) acid, diester with oxydi(propanediol) (CAS 67938-21-0) is characterized by the alcohol component diglycerol which is esterified by C18 iso fatty acids and consists only of diesters.

This read-across is justified in detail in the analogue justification in IUCLID section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substances were used for the assessment.

The study with the source substance Isooctadecanoic acid, ester with oxybis[propanediol] (CAS 73296-86-3) was performed according to OECD 202 and EU method C.2. Due to the low water solubility of the test material, WAFs ("water accommodated fractions") prepared with Daphnia test medium were used to prepare the five test material loading rates. The test was performed under GLP conditions. Daphnia magna were exposed to five different loading rates (6.25, 12.5, 25, 50 and 100 mg test material/L) over a period of 48h in a static freshwater system. After 48h, the mobility of Daphnia magna was assessed.No immobility was observed at the two lowest loading rates (6.25 and 12.5 mg/L) and the control group. An EL50 (48 h) of 60.53 mg/L was determined.

The study with the source substance Di(isooctadecanoic) acid, diester with oxydi(propanediol) (CAS 67938-21-0) was performed according to OECD 202. Due to the low water solubility of the test material, WAFs ("water accommodated fractions") prepared with Daphnia test medium were used to prepare the five test material loading rates. The test was performed under GLP conditions. Daphnia magna were exposed to five different loading rates (6.25, 12.5, 25, 50 and 100 mg test material/L) over a period of 48h in a static freshwater system. After 48h, the mobility of Daphnia magna was assessed.No immobility was observed at the two lowest loading rates or the control group. An EL50 (48 h) of 53.5 mg/L was determined.

Based on the results for the structurally related read-across substances (in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5) which is characterized by a similar ecotoxicological profile and comparable structure, it can be concluded that no toxicity to aquatic invertebrates is expected for the target substance Isooctadecanoic acid, mixed esters with oxybis[propanediol]up to the limit of water solubility.