Octanoic acid, 1,1'-(1,3-propanediyl) ester

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

fish early-life stage toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From November 2021 to January , 2023

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed according to OECD and according to GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)

Version / remarks:

2013

Qualifier:

according to guideline

Guideline:

EU Method C.15 (Fish, Short-term Toxicity Test on Embryo and Sac-fry Stages)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

CAS number: 56519-71-2
Vapour pressure: 0.0791 mPa (20°C)
Density: 0.93 g/cm³ (20°C)
Log Kow: 7.6

Analytical monitoring:

yes

Details on sampling:

The concentration of the test item in the water phase was assessed by chemical analysis.
At test start, fresh samples, i.e. one test sample and one retain sample, of approximately 20 mL volume were taken from the test solutions and controls at the beginning of the test and at one media renewal per week prior to addition of test organisms.
Aged samples were taken for all test vessels at the day of the first medium renewal.
Thereafter, sampling was performed once per week in fresh and aged test media. For each week, one representative vessel of dilution water control and solvent control and all vessels of the treatment were sampled (fresh medium). For the aged medium, one representative vessel of the control, solvent control and treatment were sampled.

Vehicle:

yes

Remarks:

Acetone was used as test vehicle

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Fertilized eggs for the test were obtained from individuals reared in the laboratory of the Fraunhofer Institute, Schmallenberg, Germany.
Origin of the used strain of zebrafish:
West Aquarium GmbH
37431 Bad Lauterberg, Germany

Test type:

semi-static

Water media type:

other: Purified drinking water

Limit test:

yes

Total exposure duration:

35 d

Post exposure observation period:

No post exposure observation

Test temperature:

between 24.9 °C to 25.9 °C

pH:

between 7.57 and 8.11

Dissolved oxygen:

between 76% and 101% throughout the study

Salinity:

freshwater

Nominal and measured concentrations:

The test was performed at one loading rate of 10 mg/L test item and with water and solvent controls

Details on test conditions:

TEST SYSTEM
- Test vessel: glass tanks with a total volume of 6.5 L and approx. 2.5 L of test medium
- Type (delete if not applicable): open
- Aeration: none
- Renewal rate of test solution (frequency): two times per week
- No. of fertilized eggs/embryos per vessel: 20
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4
- Biomass loading rate: loading rate did not exceeding 0.5 g/L fish wet weight at any time. The definitive loading rate in the study was 0.15 g fish/L


OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 12 hours light / 12 hours dark
- Light intensity: approximately 1000 lux
- pH-Value of Test Medium: between 7.57 and 8.11 ; the pH-value should not vary by more than 1.5 units
- Oxygen Concentration: between 76% and 101% throughout the study
- Water Temperature: 24.9 °C to 25.9 °C

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: hatching success

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: hatching success

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

length

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

length

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

weight

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

weight

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: hatching success

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: hatching success

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

>= 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

> 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

other: Post hatch survival

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

>= 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

length

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

> 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

length

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

35 d

Dose descriptor:

NOEC

Effect conc.:

>= 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

weight

Remarks on result:

other: Mean measured initial concentration

Key result

Duration:

35 d

Dose descriptor:

LOEC

Effect conc.:

> 15.83 µg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

weight

Remarks on result:

other: Mean measured initial concentration

Details on results:

Hatching success and post hatch survival
First larvae hatched day 3 post fertilization (pf). Hatch was completed at day 6 pf in all replicates, with no difference between treatments. No coagulated eggs were found, thus, hatching success was 100% across all treatments.

The occurrence of fish mortality for larvae and juveniles was observed daily. The number of surviving fishes was recorded at day 21 pf and at test end at day 35 pf by photo recording and evaluation. Mortality of larvae occurred completely before day 21 pf, during the phase of transition from yolk sac feeding to external feeding. Between day 21 pf and test end, no mortality occurred.
At test end, the mean post hatch survival rate was 81.3% in the water control and 86.1% in the solvent control. Thus, both water- and solvent-control met the validity criterion for post hatch survival in controls of ≥75% as required by the guideline.
At test end, the post hatch survival in the treatment was determined to be 85.0% in the test concentration of 10 mg Propanediol dicaprylate/L. Statistical analysis did not show a significant difference in post hatch survival between controls and treatments (STUDENT t-test, α = 0.05, one-sided smaller).

Individual total length at test termination
The mean individual total length of the fish at test end was 13.6 mm in both, dilution water- and solvent control, while 13.7 mm were measured in the treatment of 10 mg Propanediol dicaprylate/L.
Statistical analysis did not show any significant differences in individual total length between control and treatments (STUDENT t-test, α = 0.05, two-sided).

Individual dry weight at test termination
At test end, the mean individual dry weight was 5.4 mg in the water control and 5.5 mg in the solvent control. In the treatment the mean individual dry weight was calculated to be 5.4 mg in test item concentration of 10 mg Propanediol dicaprylate/L.
Statistical analysis did not show any significant differences in individual dry weight between control and treatments (STUDENT t-test, α = 0.05, two-sided).

Behaviour
No abnormal behavior of the fish was observed during the study.

Validity criteria fulfilled:

yes

Conclusions:

Statistical evaluation revealed no significant effect of Propanediol dicaprylate on hatchability, post hatch survival or growth in terms of individual total length and individual dry weight.

Executive summary:

An early life stage toxicity test with zebrafish (Danio rerio) was performed withe test item Propanediol dicaprylate. The aim of the study was to derive a NOEC (no observed effect concentration). For this reason, early life stages of zebrafish (Danio rerio) were exposed to one concentration of the test item, a solvent control and a dilution water control under semi-static conditions for a period of 35 d (according to Annex 2 of OECD guideline 210 [8]). Renewals of test media were performed two times per week.
The study was performed at one nominal test concentration of 10 mg Propanediol dicaprylate/L. All treatments were applied in four replicates each. At test start, 20 fertilised eggs were placed in each test tank. During the study, hatching rate, survival, growth, and behavioral abnormalities were recorded.

Chemical analysis
The concentrations of Propanediol dicaprylate were assessed by chemical analysis using Ultra-High-Performance Liquid Chromatography (UHPLC) coupled to a triple quadrupole mass spectrometer operated in the tandem mass spectrometry mode (MS/MS). The LOQ was set to 3.00 µg Propanediol dicaprylate/L. Limit of detection (LOD) on test sample level was set to 1.00 µg/L (i.e. 30% of LOQ). At test start, samples of fresh test solutions were taken from each test vessel before adding of test organisms. For aged test solutions, samples were taken also for all test vessels at the day of the medium renewal. Thereafter, sampling was performed once per week in fresh and aged test media.
For one renewal event per week, samples of fresh test medium were taken from one test replicate of dilution water and solvent control, and furthermore from all four treatment replicates. For the measurement of the aged test medium, samples from one representative vessel from the control, solvent control and treatment were taken.

Initial propanediol dicaprylate concentrations (i.e. fresh medium samples) were considered for the calculation of the replicate arithmetic means. The mean measured initial concentration in the test tanks were calculated to be between 11.09 and 22.81 µg Propanediol dicaprylate/L. Based on this, the mean measured initial concentration for the treatment was determined at 15.83 µg Propanediol dicaprylate /L. This concentration equates to 0.16% of the nominal concentration of 10 mg Propanediol dicaprylate/L). For the aged test medium, all of the measured samples from control, solvent control and treatment were below the limit of detection (LOD).

The biological effect concentrations were based on arithmetic mean measured initial concentrations and the nominal loading concentrations.
 
Test conditions
The water temperature was in the range of 24.9 °C to 25.9 °C in all test vessels throughout the in-life phase of the study and did not differ by more than 1.5°C on successive days. The oxygen saturation in all test vessels was between 76% and 101% throughout the study. The pH in the test vessels was between 7.57 and 8.11.
All values were within the range as specified in the guideline [8].

Biological effects

Hatching success and post hatch survival
First larvae hatched day 3 post fertilization (pf). Hatch was completed at day 6 pf in all replicates, with no difference between treatments. No coagulated eggs were found, thus, hatching success was 100% across all treatments.

The occurrence of fish mortality for larvae and juveniles was observed daily. The number of surviving fishes was recorded at day 21 pf and at test end at day 35 pf by photo recording and evaluation. Mortality of larvae occurred completely before day 21 pf, during the phase of transition from yolk sac feeding to external feeding. Between day 21 pf and test end, no mortality occurred.
At test end, the mean post hatch survival rate was 81.3% in the water control and 86.1% in the solvent control. Thus, both water- and solvent-control met the validity criterion for post hatch survival in controls of ≥75% as required by the guideline.
At test end, the post hatch survival in the treatment was determined to be 85.0% in the test concentration of 10 mg Propanediol dicaprylate/L. Statistical analysis did not show a significant difference in post hatch survival between controls and treatments (STUDENT t-test, α = 0.05, one-sided smaller).

Individual total length at test termination
The mean individual total length of the fish at test end was 13.6 mm in both, dilution water- and solvent control, while 13.7 mm were measured in the treatment of 10 mg Propanediol dicaprylate/L.
Statistical analysis did not show any significant differences in individual total length between control and treatments (STUDENT t-test, α = 0.05, two-sided).

Individual dry weight at test termination
At test end, the mean individual dry weight was 5.4 mg in the water control and 5.5 mg in the solvent control. In the treatment the mean individual dry weight was calculated to be 5.4 mg in test item concentration of 10 mg Propanediol dicaprylate/L.
Statistical analysis did not show any significant differences in individual dry weight between control and treatments (STUDENT t-test, α = 0.05, two-sided).
Behaviour
No abnormal behavior of the fish was observed during the study.

Conclusion
Statistical evaluation revealed no significant effect of Propanediol dicaprylate on hatchability, post hatch survival or growth in terms of individual total length and dry weight.

For all parameters, under the test conditions applied, the EC10, 20, 50 are estimated to be above the highest concentration.

All effect concentrations obtained from the study are shown in the following Table

Parameter	NOEC / LOEC Mean measured initial concentration Propanediol dicaprylate [µg/L]	NOEC / LOEC Nominal concentration Propanediol dicaprylate [mg/L]
Hatching success	≥15.83 / >15.83	≥10 / >10
Post hatch survival at day 21 pf *)	≥15.83 / >15.83	≥10 / >10
Post hatch survival at day 35 pf *)	≥15.83 / >15.83	≥10 / >10
Individual total length at day 35 pf *)	≥15.83 / >15.83	≥10 / >10
Individual dry weight at day 35 pf *)	≥15.83 / >15.83	≥10 / >10

 

Description of key information

Statistical evaluation revealed no significant effect of Propanediol dicaprylate on hatchability, post hatch survival or growth in terms of individual total length and dry weight.

For all parameters, under the test conditions applied, the EC10, 20, 50 and NOEC were estimated to be above the highest nominal concentration which correspond to 10 mg/L and above 15.83 µg Propanediol dicaprylate /L based on the mean measured initial concentration.

 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Remarks:

Relevant endpoint: hatchability, post hatch survival or growth in terms of individual total length and dry weight.

Effect concentration:

>= 10 mg/L