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:
experimental study
Adequacy of study:
key study
Study period:
1998-05-25 to 1998-05-28
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study without restrictions. The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
yes
Details on sampling:
- Concentrations: Concentrations of total organic carbon (TOC) were determined at the start of the test and after 24 hours exposure in the 10000 mg/L WAF.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: The test substance was a poorly soluble complex mixture and therefore the test media were water-accommodated fractions (WAF) prepared by stirring for 23 hours with a vortex depth not exceeding 10% of the liquid depth. The media were then allowed to stand for 1 hour before drawing off the WAFs for testing.

WAFs were prepared at nominal loading rates of 625, 1250, 2500, 5000 and 10000 mg/L. The WAFs were renewed after each successive 24 hour exposure period.

- Controls: Dilution water
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM

- Strain: Clone 5

- Source: Daphnia magna (Clone 5) originally obtained from the German Environment Ministry

- Age at study initiation (mean and range, SD): <24 hours

- Method of breeding: Laboratory stock culture

- Feeding during test: none

ACCLIMATION

- Acclimation conditions: same as test

- Type and amount of food: The daphnia were fed 2-3 times daily with algae (Scenedesmus subspicatus)
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Hardness:
2.5 mmol/L
Test temperature:
20+/-2.0ºC
pH:
5.8-7.2
Dissolved oxygen:
7.9-8.6 mg/L
Salinity:
not applicable
Nominal and measured concentrations:
Nominal loading rates: 0 (Control), 625, 1250, 2500, 5000 and 10000 mg/L.

Concentrations of total organic carbon (TOC) were determined at the start of the test and after 24 hours exposure in the 10000 mg/l WAF. The measured concentrations were 31 and 36 mg/L respectively (Table 2).

The test results are reported with reference to nominal loading rates.
Details on test conditions:
TEST SYSTEM

- Test vessel:

- Type (delete if not applicable): open beakers

- Material, size, fill volume: glass, 50 ml with 20 ml of test medium

- Aeration: none

- Renewal rate of test solution (frequency/flow rate): static test

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4

- Biomass loading rate: 1 daphni/4 ml

TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: demineralized water with added salts, macro-nutrients and trace elements. Comparable to that described in OECD Guideline 202.

- Alkalinity: 0.8 mmol/l

- Ca/mg ratio: 4:1

- Culture medium different from test medium: no

- Intervals of water quality measurement: Start of test and then after 24 and 48 hours

OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: 14 h light, 10 h dark

- Light intensity: not reported

EFFECT PARAMETERS MEASURED: Observations of immobilised daphnids, daphnids trapped at the surface, weak daphnids and carapace moults were made at least three times per day throughout the test.

TEST CONCENTRATIONS

- Spacing factor for test concentrations: 2
Reference substance (positive control):
no
Duration:
48 h
Dose descriptor:
NOELR
Effect conc.:
5 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
water-accommodated fraction loading rate
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 5 000 - < 10 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
water-accommodated fraction loading rate
Basis for effect:
mobility
Details on results:
- Immobilisation of control: 0

- Other adverse effects control: none

- Abnormal responses: none

- Effect concentrations exceeding solubility of substance in test medium: The tested loading rates exceeded the aqueous solubility of the substance.
Reported statistics and error estimates:
The test results were not subjected to statistical analysis

Table 1. Test results - cumulative percentage immobilisation in each treatment over the course of the test

 Time (h)  Control  625 mg/L  1250 mg/L  2500 mg/L  5000 mg/L  10000 mg/L
24 0 0
48 0 85 

Table 2. Results of analysis of test media - concentrations of Total Organic Carbon (TOC, mg/L) at the start and end of the first 24 hour exposure period in the 10000 mg/L nominal treatment

 Time (h)  10000 mg/L treatment
 0  31.3
 24  36.2
Validity criteria fulfilled:
yes
Conclusions:
A 48 h EL50 of between 5000 and 10000 mg/L and a NOELR of 5000 mg/L have been determined for the effects of the test substance on mobility of Daphnia magna.

Description of key information

The results for short-term toxicity to aquatic invertebrates are summarised in Table 7.2. A 48h EL50 of between 5000 and 10000 mg/L and a NOELR of 5000 mg/L have been determined for the effects of DTO on mobility of Daphnia magna. These values are the lowest of those obtained in three reliable tests conducted on different samples of DTO.

The test organisms were exposed to water-accommodated fractions of the substance. The values are supported by similar results from two other reliable studies.

Calculation of PNECs for the aquatic compartment will be based on data for the blocks of constituents rather than on data for the whole substance.

Key value for chemical safety assessment

Additional information