Registration Dossier

Diss Factsheets

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
other: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
From May 15, 1995 to August 16, 1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
The test was conducted by means of Read Across approach. The reliability of the source study report is 1. Further information was attached at section 13
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
1984
Qualifier:
according to guideline
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Version / remarks:
1992
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
yes
Details on sampling:
All test medium samples for the analytical determinations were taken from the approximate center of the test vessels (after mixing the medium) and kept at -18 °C to -25 °C until analysis.
Vehicle:
yes
Details on test solutions:
Stock solution 0.5 g test substance were mixed with 200 ml test medium in a beaker, was homogenized for 5 minutes by ultrasonic treatment and filled up to 500 ml with test medium.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: Product Ecology Division of Ciba-Geigy Ltd.,Basel
- Breeding :- Cultures of Daphnia magna are held in glass vessels containing approx. 3.0 litre of reconstituted water at 18 - 22°C. The water is renewed partially three times per week.
The Daphnia are fed with a suspension of green algae (Scenedesmus subspicatus) supplemented by a TETRAMIN-extract in such quantités that the food will be consumedwithin 24 hours.
Pretreatment : 24 hours before the start of the exposure reproductive Daphnia were separated from the young Daphnia by sieving all individuals through a 1000 µm sieve. For each test concentration 20 Daphnia divided in two groups of 10 animals were used.

Experimental conditions
48 hours at nominal 18-22 °C (during the test max. ± 1°C), 12 hours light /12 hours dark.
The Daphnia were exposed to the test substance in 250 ml beakers containing 80-100 ml test medium with 10 animals per beaker. All tests were run in duplicate.
Test type:
static
Water media type:
not specified
Limit test:
no
Total exposure duration:
48 h
Hardness:
231 mg/l CaCO3
Test temperature:
Start: 21 °C, End: 21.6 - 22.0 °C
pH:
Start: 5.8 (in the highest test concentration), End: 6.8 - 7.8
Dissolved oxygen:
Start: 99 %, End: 95 - 96 %
Nominal and measured concentrations:
45, 100 and 220 mg test article/l (nominal concentrations)
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (periodically checks to evaluate the functionality of the test systems have been performed only)
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
ca. 173 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other:
Remarks:
95 % confidence limit after 48 hours: 145-201 mg/l (Spearman-Kaerber's Method).
Details on results:
In all test concentrations no alteration of the test substance was observed after 48 hours. During the test the actual test concentrations in the analysed test media were in the range of 115-118 % of the nominal values. Therefore, the test substance was sufficiently stable in the test medium and the reported results are related to the nominal test concentrations. No immobilization and abnormal behaviour of the Daphnia was observed in the controls and in the test concentrations up to 100 mg/l. Thus, the NOEC and EC0 value after 48 hours were determined to be 100 mg/l. The EC100 value could not be determined, but was clearly higher than 220 mg/l. The EC50 value after 48 hours was calculated as 173 mg/l.
Results with reference substance (positive control):
The quality of the Daphnia was checked by determining the EC50 value (24 h) for potassium dichromate (March 29, 1995); EC50: 0.96 mg/l.
Validity criteria fulfilled:
yes
Conclusions:
The EC50 value after 48 hours was calculated as 173 mg/l.
Executive summary:

Method

The acute toxicity of the test substance to Daphnia magna was determined in a 48 hours static test according to the OECD Guideline 202 and EU Method C.2. The study was performed under Good Laboratory Practice (GLP) conditions in Switzerland. Due to the results of a pretest the nominal concentrations for the main test were selected as 45, 100 and 220 mg test article/l, a vehicle and a blank control without any additions. The test concentrations were prepared from a 1.0 g/l stock solution.

Observation

In all test concentrations no alteration of the test substance was observed after 48 hours. During the test, the actual test concentrations in the analysed test media were in the range of 115-118 % of the nominal values. Therefore, the test substance was sufficiently stable in the test medium and the reported results are related to the nominal test concentrations. No immobilization and abnormal behaviour of the Daphnia was observed in the controls and in the test concentrations up to 100 mg/l.

Results

The NOEC and EC0 value after 48 hours were determined to be 100 mg/l. The EC100 could not be determined, but was clearly higher than 220 mg/l.

The EC50 value after 48 hours was calculated as 173 mg/l.

Description of key information

EC50 (48h) = 173 mg/l

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
173 mg/L

Additional information

There is no experimental available data of the target substance, thus the information on the Similar Substance 01 was taken into account. The structural differences occurring between the target substance and Similar Substance 01 are not expected to significantly impact the toxicity to aquatic invertebrates, thus the read across approach can be considered as representavive and appropriate (details in the document attached to the IUCLID section 13).

The acute toxicity of the Similar Substance 01 to Daphnia magna was determined in a 48 hours static test according to the OECD Guideline 202 and EU Method C.2. The study was performed under Good Laboratory Practice (GLP) conditions in Switzerland. Due to the results of a pretest the nominal concentrations for the main test were selected as 45, 100 and 220 mg test article/l, a vehicle and a blank control without any additions. The test concentrations were prepared from a 1.0 g/l stock solution.

In all test concentrations no alteration of the test substance was observed after 48 hours. During the test, the actual test concentrations in the analysed test media were in the range of 115-118 % of the nominal values. Therefore, the test substance was sufficiently stable in the test medium and the reported results are related to the nominal test concentrations. No immobilization and abnormal behaviour of the Daphnia was observed in the controls and in the test concentrations up to 100 mg/l.

The NOEC and EC0 value after 48 hours were determined to be 100 mg/l. The EC100 could not be determined, but was clearly higher than 220 mg/l.

The EC50 value after 48 hours was calculated as 173 mg/l.

Categories Display