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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:
21 Jul - 24 Aug 1995
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: control, 1000 mg/L
- Sampling method: Samples were removed from the test solutions on day 0 and at termination.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Individual treatment solutions (WAF) were prepared by adding the appropriate amount of the test substance to 1 L of dilution water in 1 L size glass aspirator bottles. The vessels were closed with cotton-gauze stoppers to minimize evaporation and/or volatilazition. The solutions were mixed at <10% vortex on magnetic stirplates with Teflon® coated stirbars for approximately 24 hours. All treatment levels appeared clear with test substance floating on the surface. After mixing, the solutions were allowed to settle for approximately one hour before the WAFs were removed through the outlet at the bottom of the aspirator bottle.
- Evidence of undissolved material: No test substance insolubility was observed in any of the test chambers.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Source: in-house culture
- Age at study initiation: < 24 hold, taken from 16 d old parents
- Method of breeding: Daphnids are kept in 1 L glass culture vessels with dilution water (BW3 at 20 ± 2 °C) supplemented with vitamin B12 and selenium.
- Feeding during test: none

ACCLIMATION
- Acclimation period: not specified
- Acclimation conditions: same as test
- Type and amount of food: Selenastrum capricornutum and a 6 µL/mL yeast/ salmon starter/ cereal leaves mixture
- Feeding frequency: daily

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
190 mg/L as CaCO3
Test temperature:
21.2 - 22.0 °C
pH:
7.6 - 8.0
Dissolved oxygen:
7.0 - 8.3 mg/L
Nominal and measured concentrations:
Nominal: 62.5, 125, 250, 500 and 1000 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Erlenmeyer flask sealed with ground glass stoppers
- Material: glass; Size: 125 mL; Fill volume: 140 mL of solution
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory dilution water, a mixture of carbon filtered well water and water dialyzed by reverse osmosis supplemented with 1 µg/L vitamin B12 and 2 µg/L selenium, aged and aerated ≥ 24 h prior to introduction of the test substance
- Total organic carbon: 1.528 ppm
- Alkalinity: 57 mg/L as CaCO3
- Conductivity: 370 µmhos
- Culture medium different from test medium: no
- Intervals of water quality measurement: Water quality measurements (pH, dissolved oxygen and temperature) were performed on a subsample of each treatment on Day 0 and a composite of the replicates at termination.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark with a gradual intensity conversion between periods
- Light intensity: 640.56 - 642.82 lux during full daylight periods

EFFECT PARAMETERS MEASURED: Immobilisation was recorded after 24 and 48 h test duration.
Reference substance (positive control):
no

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
(WAF)
Basis for effect:
mobility
Details on results:
- Immobility of control: No immobility observed.

Any other information on results incl. tables

The quality of the dilution water used in culture and testing is monitored at weekly, monthly and semi-annual intervals. There are no known contaminants in the feed or water believed to be at levels high enough to interfere with this study based on contaminant analysis and/or historical data.

The TOC analysis indicates that the level of test substance in the WAF was at or near the level of organic carbon in the control. This result confirms the low solubility of the test substance in water and the unsuitability to use the measured concentrations for the determination of the effect value. Thus, the effect value is related to the nominal concentration.

Table 1: Measuremnt of the test concentration

Loading level [mg/L]

Total organic carbon [mg/L]*

Day 0

 “fresh”

Day 2

“old”

Control

19 ± 0.3

10 ± 0.8

1000

6.6 ± 0.3

16 ± 1.0

*: triplicate TOC measurements on each sample

Table 2: Immobilisation of Daphnia

Loading level [mg/L]

Percent immobilisation

24 h

48 h

Control

0

0

62.5

0

5

125

0

0

250

0

0

500

0

0

1000

0

5

Applicant's summary and conclusion