L 165

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:

14 -16 July 2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted according with OECD Guideline No. 202 (draft 2000) and in accordance with GLP principles. The study is considered to be reliable with restrictions since the measured Zn concentrations in this study are in the same range of the LOQ, which shows a too high recovery (155%). The high recovery is probably the result of Zn contamination of water samples during laboratorial handling. Therefore, an underestimation of the test substance toxicity could be occurring. However, as no mortality occurred at the at the maximum solubility of the test substance, this constraint is deemed acceptable.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

(draft 2000)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): Leuchtstoff L 165
- Physical state: Solid (powder)
- Stability under test conditions: Not available
- Storage condition of test material: room temperature, dark and dry
- Expiration date of the lot/batch: not applicable (according to the sponsor unlimited storable, when protected from humidity)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control) and 100 mg/L (loading rate)
- Sampling method: Not reported
- Sample storage conditions before analysis: The samples were stored at a temperature of ≤-18 °C until the beginning of analysis.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A total of 0.100 g L 165 were added to 1 L of dilution water. This stock solution was shaken for 48 hours and then filtered (0.45 µm). The resulting filtrate was the final solution used to expose daphnids.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): Not reported

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water fleas
- Source: Landesanstalt für Umweltschutz Baden-Württemberg Griesbachstr. 1, D-76185 Karlsruhe
- Age at study initiation: <24 h
- Method of breeding: under standardised laboratory conditions
- Feeding during test: None

ACCLIMATION
- Acclimation period: Not specified
- Acclimation conditions (same as test or not): Yes
- Food type: Alga Desmodesmus subspicatus origin: Albrecht-v.-HalLer-Institut für Pflanzenwissenschaften, Niklausberger Weg 18, D-37073 Gottingen
- Amount: Daphnia of different age were fed with a defined suspension of algae:
1 day old: 0.5 ml/50 ml M4; 3 to 10 days old: 1.0 ml/50 ml M4; > 10 days old: 1.5 ml/50 ml M4
- Feeding frequency: daily
- Health during acclimation (any mortality observed): Not reported

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

200 mg/L CaCO3

Test temperature:

19.9 - 20.3 °C

pH:

7.77 - 7.85

Dissolved oxygen:

8.50 - 9.08 mg/L

Nominal and measured concentrations:

- Nominal: 0 (blank control) and 100 mg/L (loading rate)
- Average measured (Zn content): <0.012 (blank control) and 0.023 mg Zn/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beaker with a capacity of 150 ml and filled with 100 ml of test solution
- Aeration: None
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Loading: 1 daphnid per 20 ml of test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dilution water according to ISO 6341
- Conductivity: 0.656 µS/cm
- Culture medium different from test medium: yes
- Intervals of water quality measurement: At 0 and 48 h the pH, dissolved oxygen and test temperature were measured.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): At 24 and 48 h the number of immobilised Daphnia per vessel (including discoloration, anomalies) were determined.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.023 other: mg Zn/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

element

Remarks:

total measured amount of Zinc (Zn)

Basis for effect:

mobility

Remarks on result:

other: Obtained at a loading rate of 100 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Basis for effect:

mobility

Remarks on result:

other: > than the maximum soluble concentration in the test medium

Details on results:

- Measured concentrations: At 48 h the test concentration corresponded to 32% of the initial measured concentration. Therefore, the EC50 was expressed as analysed mean measured concentrations.

- Biological results: No mortality or any visible signs of abnormality were observed during the entire test period.

- Validity criteria
Immobilised daphnids: ≤10% in the control
Oxygen concentration at the end of the test: ≥3 mg/L in control and test vessels

Results with reference substance (positive control):

- The 48 h EC50 for potassium dichromate was 1.25 mg/L.

Reported statistics and error estimates:

- No statistical evaluation was performed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under laboratory conditions no effects of the test item L 165 on immobilisation of daphnids were determined. The 48 h EC50 referred to Zn content was >0.023 mg Zn/L.

Executive summary:

In a 48 h acute toxicity limit test conducted according to OECD guideline 202 (draft 2000), water fleas (Daphia magna) were exposed to L 165 under static conditions at loading rate of 100 mg/L. The test substance did not induce significant acute immobilisation of Daphnia magna at 0.023 mg Zn/L after 48 hours of exposure. The 48 h EC50 was >0.023 mg Zn/L based on the average measured concentrations.

The study is considered to be reliable with restrictions since the measured Zn concentrations in this study are in the same range of the LOQ, which shows a too high recovery (155%). The high recovery is probably the result of Zn contamination of water samples during laboratorial handling. Therefore, an underestimation of the test substance toxicity could be occurring. However, as no mortality occurred at the at the maximum solubility of the test substance, this constraint is deemed acceptable.