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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2002-05-07 - 2002-07-12
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Qualifier:
according to
Guideline:
EPA OPP 72-2 (Aquatic Invertebrate Acute Toxicity Test)
Version / remarks:
And draft version of OPPTS 850.1010
GLP compliance:
yes (incl. certificate)
Remarks:
2000-04-26

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Specific details on test material used for the study:
- Synonyms: ITC 908, vinylidenephosphonic acid tetrasodium salt (VDPA tetrasodium salt)
- Lot/batch No.of test material: 562CH/646
- Purity: 87.33%
- Storage condition of test material: Room temperature, in the dark

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
In an attempt to determine a dosing method that would achieve near nominal test concentrations a preliminary dosing trial with chemical analysis was performed at a test concentration of 100 mg/L using dynamic, continuous flow test conditions. Analysis of the 100 mg/L test concentration at 0 and 24 hours gave measured test concentrations of 110% and 97% of nominal respectively. Therefore dynamic, continuous flow test conditions were shown to be appropriate for the preparation of the test media for the definitive test.

The concentration and stability of the test material in the test preparations were verified by chemical analysis at 0, 24 and 48 hours.

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Age at study initiation (mean and range, SD): < 24 hours
- Stage and instar at study initiation: 1st instar
- Method of breeding: Parthenogenesis
- Source: in-house laboratory cultures
- Feeding during test : No

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES, INCLUDING CULTURING CONDITIONS:
Adult Daphnia were maintained in polypropylene vessels containing approximately 2 litres of dechlorinated tap water in a temperature controlled room at 21 °c. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. Each culture was fed daily with a suspension of algae (Chlorella sp.). Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing.

Study design

Test type:
flow-through
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
150 mg/L as CacO3
Test temperature:
21 °C
pH:
7.8 - 8.1
Dissolved oxygen:
8.1 - 8.2 mg O2/L
Conductivity:
522 µS
Nominal and measured concentrations:
Range-finding study: 0.10, 1.0, 10, 100 mg/L
Definitive test: 100 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 ml test vessel
- Type: closed
- Volume of solution: 200 ml
- Aeration: No
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated and softened tap water
- Total organic carbon: 2.4 mg C/L
- Particulate matter: 0.6 mg/L
- Alkalinity: 124 mg/L as CacO3
- Conductivity: 522 µS

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED:
After 24 and 48 hours the number of immobilised Daphnia magna were recorded.

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: No immobilisation was observed at the test concenrations 0.1, 1.0, 10 and 100 mg/L. Based on the results of the range-finding test a "Limit test" was conducted at a concentration of 100 mg/L to confirm that at the maximum concentration given in the OECD test guidelines, no immobilisation or adverse reactions to exposure were observed
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
There was no immobilisation in 40 daphnids exposed to a test concentration of 100 mg/L for a period of 48 hours.

Analysis of the test preparations at 24 and 48 hours showed the measured test concentrations to range from 80% to 103% of nominal. Given that all the flow rates on the dynamic, continuous flow system were observed to be near nominal at 0 horus and that the test material was shown to be stable in water, it was considered justifiable to base the results in terms of nominal test concentrations only.

Applicant's summary and conclusion

Conclusions:
The 48-hour EC50 was greater than 100 mg/L. Correspondingly, the no observed effect concentration was 100 mg/L.
Executive summary:

The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated according to OECD Test Guideline 202. It gave a 48-hour EC50 of greater than 100 mg/L. Correspondingly, the no observed effect concentration was 100 mg/L.