Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12 January 1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: A guideline study performed in compliance with the GLP regulations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
The test sample of PTH-Decahydroamide (Lot No. 25927) was supplied by Battelle, Geneva Research Centres for and on behalf ofF Hoffmann-La Roche Ltd. The sample was received on 6 May 1994 and was assigned the Laboratory code AA0447. Information supplied with the test sample indicated that it had a purity of 99.8% (Analytical certificate no. 25 927, dated 25 January 1994). The test sample was a white to light yellow solid. It was stored at ambient temperature, in the container in which it was received, until required for testing when an appropriate subsample was provided for the test operator.
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
Not relevant

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples were taken for analysis at the start and end of the 96 hour exposure period. Aqueous samples were extracted into dichloromethane, blown down to dryness and taken back up in hexane.

Test solutions

Vehicle:
no
Details on test solutions:
Nominal 100 and 180 mg/1 stock solutions of the test substance were prepared by dissolving PTH-Decahydroamide in reconstituted dilution water. These were given 10 minutes ultrasonic treatment followed by 10 minutes stirring by a magnetic follower and then a further 5 minutes ultrasonic treatment. The resultant solutions were clear and colourless.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
The test organism was the freshwater crustacean, Daphnia magna Straus, obtained from continuous laboratory cultures.

The stock cultures of Daphnia were maintained in a reconstituted water medium, identical to the test dilution water, at a temperature of 20 ± zoe, and a photoperiod of 16 hours light: 8 hours dark.

The cultures were fed a defined diet of algae Chlorella vulgaris and "Frippak Booster•" (a commercially available microencapsulated diet).

Culture conditions were such that the Daphnia reproduction was by diploid parthenogenesis.

Daphnia <24 hours old were used for testing.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Post exposure observation period:
Not applicable

Test conditions

Hardness:
The hardness of the reconstituted dilution water was measured (as mg/L CaC03) before the start of the test. The hardness of the reconstituted dilution water was measured as 163 mg/L CaC03.
Test temperature:
The temperature of water in an additional test vessel containing no Daphnia was measured by thermometer at 0, 24 and 48 hours. Hourly temperature measurements were also recorded automatically in the additional test vessel. The temperatures measured by thermometer at 0, 24 and 48 hours were all 20.4°C. The hourly temperature measurements, recorded automatically, showed maximum and minimum readings of 20.68°C and 19.82°C.
pH:
At the end of the test the pH of two replicates of the control and each treatment were measured. The pH values ranged from 8.00 to 9.29.
Dissolved oxygen:
The dissolved oxygen concentration of the control (dilution water used to prepare the test solutions) was measured prior to the start of the test. The initial pH of each test solution was determined using the excess remaining after filling the test vessels. Dissolved oxygen concentrations ranged from 8.8 to 9.1 mg/1.
Salinity:
Not applicable
Nominal and measured concentrations:
Mean measured exposure concentrations were 1.4, 2.6, 6.5, 12, 19, 34, 53, 130 and 180 mg/L in the nominal 1.8, 3.2, 5.6, 10, 18, 32, 56, 100 and 180 mg/L test treatments.
Details on test conditions:
Borosilicate glass beakers of 250 ml capacity were used as test vessels, with four replicates per exposure concentration. Each vessel contained 200 ml of test solution providing a depth of approximately 60 mm. The beakers were covered with loose fitting lids.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
100 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 77-170 mg/L
Duration:
48 h
Dose descriptor:
EC100
Effect conc.:
45 mg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 33-65 mg/L
Details on results:
After 48 hours % immobility was 0, 0, 5, 5, 25, 25, 15, 90 and 100% in the nominal 1.8, 3.2, 5.6, 10, 18, 32, 56, 100 and 180 mg/L.
Results with reference substance (positive control):
Not applicable
Reported statistics and error estimates:
The EC50 values were calcuated using mean measrued concentrations and the moving average angle method.

Any other information on results incl. tables

The results obtained (based on mean measured exposure concentrations of PTH-Decahydroamide) were:

EC50 (mg/l)

95% confidence interval

Calculation method

24 hour

100

77-170 mg/l

Moving average angle

48 hour

45

33-65 mg/l

Moving average angle

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The study was conducted according to EC directive 92/69/EEC, C. 2 (1992) and OECD guideline No. 202 (1984). Under the conditions of the present study the 48h-EC50 of PTH-decahydroamide to Daphnia magna was determined to be 45 mg/L with 95% confidence limits of 33 to 65 mg/L. The highest nominal concentration causing no immobilisation was 5.6 mg/L and the lowest concentration causing 100 % immobilisation within the test period was 180 mg/L.
Executive summary:

The 24 and 48 hour EC50 values of PTH-Decahydroamide to Daphnia magna were determined under static test conditions at a temperature of 20 ± 1 °C. Mean measured exposure concentrations were 1.4, 2.6, 6.5, 12, 19, 34, 53, 130 and 180 mg/L in the nominal 1.8, 3.2, 5.6, 10, 18, 32, 56, 100 and 180 mg/L test treaments. The results were based on the mean measured exposure concentrations of PTH-Decahydroamide. The 48 hour EC50 was 45 mg PTH-Decahydroamide/litre with 95% confidence intervals of 33 to 65 mg/L. The highest nominal test concentration causing no immobility was 5.6 mg/L and the lowest that caused 100% immobility was 180 mg/L.