isostearic acid monoisopropanolamide

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From March 06, 2003 to August 06, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC-system

Details on sampling:

Analytical report 798142 (Biedermann, 2003)
One sample was taken from the freshly prepared stock solution and three samples were taken from the freshly prepared test media of each test concentration and the control, at first treatment period (Day 0), at a treatment period in the second week (Day 12) and at a treatment period in the last week (Day 16). To determine the maintenance of the test substance concentrations during the test medium renewal periods (2 or 3 days), two stability control samples (with and without food particles) were taken at the end of two treatment periods (on Days 14 and 19). Immediately after sampling, the test substance was extracted from the water phase of the samples by dichloromethane. These organic test substance solutions were stored until analysis in a refrigerator. Based on a pre-experiment, the test substance was stable under these storage conditions.

Vehicle:

no

Details on test solutions:

Prior to the start of the test, an aliquot of the test substance was carefully melted for ca. 30 min in a water bath at 40°Cto increase fluidity and homogeneity. After that, a stock dispersion of nominal 100 mg/L was freshly prepared by dispersing nominal 100 mg of the test substance homogeneously in 1000 mL test water by intensive stirring for 2 x 10 min and ultrasonic treatment for 2 x 15 min. Immediately after, this stock dispersion was diluted in relation 1:10 with test water. Then, adequate volumes of the intensively stirred diluted stock dispersion were mixed into test water to obtain the desired test concentrations.
The media with treatment as well as the control were renewed on Days 2, 5, 7, 9, 12, 14, 16 and 19.

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed with females from a clone of of the species of Daphnia magna Straus, supplied originally by the university of Sheffield, UK.
Number of animals: 15-20 per beaker
Age: <24h
Temperature: 18-20°C
Artificial light-dark cycle of 16 to 8 hours with a 30 min transition period
Feeding during test: algae (Desmodesmus subspicatus) (the carbon content of the algae and fish food suspensions were determined using a Shimadzu TOC 5000 Analyser)

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

2.5 mmol/L (250 mg/L) as CaCO3

Test temperature:

18-20°C

pH:

7.6-8.3

Dissolved oxygen:

at least 8.3 mg/L

Nominal and measured concentrations:

0.00, 0.01, 0.032, 0.10, 0.32 and 1.00 mg/L (nominal) (based on a first test)

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

ca. 0.6 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

ca. 0.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction and survival rates

Remarks on result:

other: 0.22 mg/L (measured)

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

ca. 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: 0.79 mg/L (measured)

Details on results:

- Analytical results:
In test media: 86-99% of nominal 0.32 and 1.0 mg/L (meaning a correct preparation)
Stability control samples. Without food particles: 25-64% of the nominal values and with food particles: 11-41% of the nominal values (a part of the test substance could be absorbed onto the food particles. Since filter feeding test animals as Daphnia may take up the test substance also from ingested food, the decrease of the test substance concentration was not taken into account).
Therefore, the biological results werre based on the concentrations in the test media without food. The mean measured concentrations were 0.22 mg/L (0.32 mg/L nominal) and 0.79 mg/L (1.0 mg/L nominal).
- Biological results:
In the control and all doses tested, the survival rate of the animals at the end of the test was al least 80% or higher. The 20% rate left was not considered significant since it was not dose dependent and tolerated by the test guideline.
The first young offspring released from their parent animals were recorded in the control and at all test doses up to 0.22 mg/L (nominal 0.32 mg/L) on Day 9. At the highest test concentration of 0.79 mg/L (1.0 mg/L nominal), first offspring were recorded on Day 12. The reproduction rates calculated for each individual test animal in the control was 122.1 +/- 18.7 alive offspring per adult at the end of the test. No significant toxic effect of the test substance on this parameter was observed up to and including the test concentration of 0.22 mg/L (nominal 0.32 mg/L). At the concentration of 0.79 mg/L (1.0 mg/L nominal), the mean reproduction rate of surviving daphnids was statistically reduced of about 20.2% compared to the control. The 21d EC50 for the reproduction rate of Daphnia magna was estimated to be 0.6 mg/L.
NB. No abnormalities was observed.
In conclusion, the 21d NOEC was 0.22 mg/L (0.32 mg/L nominal) and the 21d LOEC was 0.79 mg/L (1.0 mg/L).
No remarkable observations were made concerning the appearance of the test media.

Reported statistics and error estimates:

The NOEC and the LOEC of the reproduction rate were statistically evaluated by testing the mean reproduction rate at the test concentrations for statistically significant differences to the control value by the multiple Williams-test after a one-way analysis of variance (ANOVA). The EC50 of the reproduction rate after 21 d was estimated by linear interpolation.

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the 21 d nominal NOEC of the test substance for reproduction rate of Daphnia magna was estimated to be 0.32 mg/L (0.22 mg/L measured).

Executive summary:

A long term toxicity study was conducted in Daphnia magna with the test substance, isoC18 MIPA (96% active), according to OECD Guideline 204, in compliance with GLP. Based on a pre-test, daphnids were exposed to a blank control and to test substance concentrations of 0, 0.01, 0.032, 0.10, 0.32 and 1.00 mg/L (nominal) for 21 d, applying a semi-static design. Test substance concentrations were verified analytically with HPLC and MS detection. In the test media, 86-99% of the nominal concentrations were found. The stability of control samples were without food particles: 25-64% of the nominal values and with food particles: 11-41% of the nominal values. A part of the test substance could be absorbed onto the food particles. Since filter feeding test animals such as Daphnia may take up the test substance also from ingested food, the decrease of the test substance concentration was not taken into account. Therefore, the biological results were based on the concentrations in the test media without food. The mean measured concentrations were 0.22 mg/L (0.32 mg/L nominal) and 0.79 mg/L (1.0 mg/L nominal). In the control and all doses tested, the survival rate of the animals at the end of the test was 80% or higher. The first young offspring released from their parent animals were recorded in the control and at all test doses up to 0.22 mg/L (nominal 0.32 mg/L) on Day 9. At the highest test concentration of 0.79 mg/L (1.0 mg/L nominal), first offspring were recorded on Day 12. The reproduction rates calculated for each individual test animal in the control was 122.1 +/- 18.7 alive offspring per adult at the end of the test. No significant toxic effect of the test substance on this parameter was observed up to and including the concentration 0.22 mg/L (nominal 0.32 mg/L). At 0.79 mg/L (1.0 mg/L nominal), the mean reproduction rate of surviving daphnids was statistically reduced about 20.2% compared to the control. Moreover, no abnormalities were observed. Under the study conditions, the nominal 21 d NOEC of the test substance was 0.32 mg/L (0.22 mg/L measured) (Peither, 2003).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.22 mg/L

Additional information

A long term toxicity study was conducted in Daphnia magna with the test substance, isoC18 MIPA (96% active), according to OECD Guideline 204, in compliance with GLP. Based on a pre-test, daphnids were exposed to a blank control and to test substance concentrations of 0, 0.01, 0.032, 0.10, 0.32 and 1.00 mg/L (nominal) for 21 d, applying a semi-static design. Test substance concentrations were verified analytically with HPLC and MS detection. In the test media, 86-99% of the nominal concentrations were found. The stability of control samples were without food particles: 25-64% of the nominal values and with food particles: 11-41% of the nominal values. A part of the test substance could be absorbed onto the food particles. Since filter feeding test animals such as Daphnia may take up the test substance also from ingested food, the decrease of the test substance concentration was not taken into account. Therefore, the biological results were based on the concentrations in the test media without food. The mean measured concentrations were 0.22 mg/L (0.32 mg/L nominal) and 0.79 mg/L (1.0 mg/L nominal). In the control and all doses tested, the survival rate of the animals at the end of the test was 80% or higher. The first young offspring released from their parent animals were recorded in the control and at all test doses up to 0.22 mg/L (nominal 0.32 mg/L) on Day 9. At the highest test concentration of 0.79 mg/L (1.0 mg/L nominal), first offspring were recorded on Day 12. The reproduction rates calculated for each individual test animal in the control was 122.1 +/- 18.7 alive offspring per adult at the end of the test. No significant toxic effect of the test substance on this parameter was observed up to and including the concentration 0.22 mg/L (nominal 0.32 mg/L). At 0.79 mg/L (1.0 mg/L nominal), the mean reproduction rate of surviving daphnids was statistically reduced about 20.2% compared to the control. Moreover, no abnormalities were observed. Under the study conditions, the nominal 21 d NOEC of the test substance was 0.32 mg/L (0.22 mg/L measured) (Peither, 2003).