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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Reference
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reason / purpose for cross-reference:
read-across source
Key result
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
11 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 8.4 - 13 mg/L WAF
Duration:
48 h
Dose descriptor:
NOELR
Effect conc.:
1.8 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: NDA
- Observations on body length and weight: NDA
- Other biological observations: NDA
- Mortality of control: 0
- Other adverse effects control: None noted
- Abnormal responses: NDA
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None noted
- Effect concentrations exceeding solubility of substance in test medium: N/A
Results with reference substance (positive control):
- Results with reference substance valid? Yes.

- Mortality: mortality was observed at concentration ≥ 0.56 mg/L

- EC50/LC50:
Time (h) 3

EC50 (mg/l) > 3.2
95% Confidence limits (mg/l) - no data

Time (h) 24
EC50 (mg/l) = 1.0
95% Confidence limits (mg/l) = 0.90 – 1.2

Time (h) 48
EC50 (mg/l) = 0.78
95% Confidence limits (mg/l) = 0.68 - 0.88
Reported statistics and error estimates:
No data available

Cumulative Immobilisation data in the Range Finding Test

Nominal Loading Rate (mg/l)

Cumulative ImmobilisedDaphnia(Initial Population: 10 Per Replicate)

24 Hours

48 Hours

Control

0

0

1.0

0

0

10

0

2

100

0

4

Cumulative Immobilisation Data in the Definitive Test

Nominal Loading Rate (mg/l)

Cumulative Immobilised Daphnia (Initial Population: 10 Per Replicate)

24 Hours

48 Hours

R1

R2

Total

%

R1

R2

Total

%

Control

0

0

0

0

0

0

0

0

1.0

0

0

0

0

0

0

0

0

1.8

0

0

0

0

0

0

0

0

3.2

0

0

0

0

0

2

2

10

5.6

0

0

0

0

3

3

6

30

10

0

0

0

0

5

4

9

45

18

0

0

0

0

6

7

13

65

32

0

0

0

0

9

9

18

90

56

0

0

0

0

10

10

20

100

100

10

10

20

100

10

10

20

100

Chemical analysis of test loading rates

Chemical analysis of the test preparations (see Appendix 3) at 0 (fresh media), 24 (old and fresh media) and 48 (old media) hours showed measured test concentrations to range from 0.015 mg/l to 0.265 mg/l. A concentration dependant general trend was consistently observed (with increasing loading rate) in both the fresh and old media at both media renewal periods, and a slight decline in measured concentration was consistently observed over each media renewal period.

The control test sample at 0 hours showed a measured concentration of 0.0030 mg/l. Analysis of a frozen duplicate sample showed a measured concentration of less than the limit of quantification (LOQ) which confirmed the original analysis to be erroneous.

The results of the chemical analysis showed measured concentrations in the definitive test that were lower than the measured Total Organic Carbon (TOC) levels observed in the pre-study validation of mixing period work. This was considered to be due to the analytical method employed only detecting the 399 ion whereas TOC analysis detected the total dissolved test material present in the WAF.

Validity criteria fulfilled:
yes
Conclusions:
The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EL*50 value of 11 mg/l loading rate WAF with 95% confidence limits of 8.4 - 13 mg/l loading rate WAF. The No Observed Effect Loading rate at 48 hours was 1.8 mg/l loading rate WAF.
Executive summary:

Introduction.A study was performed to assess the acute toxicity of the test material to daphnia magna followed that described in the OECD 202.

Methods.Following a preliminary range-finding test, twenty daphnids (2 replicates of

10 animals) were exposed to Water Accommodated Fractions (WAFs) of the test material over a range of nominal loading rates of 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/l for 48 hours at a temperature of 21ºC to 22ºC under semi-static test conditions. The number of immobilised Daphnia and any adverse reactions to exposure were recorded after 24 and 48 hours.

A positive control conducted approximately every six months used potassium dichromate as the reference material. Daphnia magna was exposed to an aqueous solution of the reference material at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/l for 48 hours at a temperature of 21°C to 22°C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 3, 24 and 48 hours.

Results.The 48-Hour EL*50 for the test material to Daphnia magna based on nominal loading rates was 11 mg/l loading rate WAF with 95% confidence limits of 8.4 - 13 mg/l loading rate WAF. The No Observed Effect Loading rate was 1.8 mg/l loading rate WAF.

Chemical analysis of the test preparations at 0 (fresh media), 24 (old and fresh media) and 48 (old media) hours showed measured test concentrations to range from 0.015 mg/l to 0.265 mg/l. A concentration dependant general trend was consistently observed (with increasing loading rate) in both the fresh and old media at both media renewal periods, and a slight decline in measured concentration was consistently observed over each media renewal period.

The control test sample at 0 hours showed a measured concentration of 0.0030 mg/l.

Analysis of a frozen duplicate sample showed a measured concentration of less than the limit of quantification (LOQ) which confirmed the original analysis to be erroneous.

The dissolved test material may have been one or several components of the test material. Given that toxicity cannot be attributed to a single component or a mixture of components but to the test material as a whole, the results were based on nominal loading rates only.

The 48-Hour EC50 for the reference material to Daphnia magna based on nominal concentrations was 0.78 mg/l with 95% confidence limits of 0.68 – 0.88 mg/l. The No Observed Effect Concentration was 0.32 mg/l.

Description of key information

The acute toxicity of the test material to the freshwater invertebrate Daphnia magna has been investigated and gave a 48-Hour EL*50 value of 11 mg/l loading rate WAF with 95% confidence limits of 8.4 - 13 mg/l loading rate WAF. The No Observed Effect Loading rate at 48 hours was 1.8 mg/l loading rate WAF.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
11 mg/L

Additional information

A study was performed to assess the acute toxicity of the test material to daphnia magna followed that described in the OECD 202.

Following a preliminary range-finding test, twenty daphnids (2 replicates of

10 animals) were exposed to Water Accommodated Fractions (WAFs) of the test material over a range of nominal loading rates of 1.0, 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg/l for 48 hours at a temperature of 21ºC to 22ºC under semi-static test conditions. The number of immobilised Daphnia and any adverse reactions to exposure were recorded after 24 and 48 hours.

A positive control conducted approximately every six months used potassium dichromate as the reference material. Daphnia magna was exposed to an aqueous solution of the reference material at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/l for 48 hours at a temperature of 21°C to 22°C under static test conditions. Immobilisation and any adverse reactions to exposure were recorded after 3, 24 and 48 hours.

The 48-Hour EL*50 for the test material to Daphnia magna based on nominal loading rates was 11 mg/l loading rate WAF with 95% confidence limits of 8.4 - 13 mg/l loading rate WAF. The No Observed Effect Loading rate was 1.8 mg/l loading rate WAF.

Chemical analysis of the test preparations at 0 (fresh media), 24 (old and fresh media) and 48 (old media) hours showed measured test concentrations to range from 0.015 mg/l to 0.265 mg/l. A concentration dependant general trend was consistently observed (with increasing loading rate) in both the fresh and old media at both media renewal periods, and a slight decline in measured concentration was consistently observed over each media renewal period.

The control test sample at 0 hours showed a measured concentration of 0.0030 mg/l.

Analysis of a frozen duplicate sample showed a measured concentration of less than the limit of quantification (LOQ) which confirmed the original analysis to be erroneous.

The dissolved test material may have been one or several components of the test material. Given that toxicity cannot be attributed to a single component or a mixture of components but to the test material as a whole, the results were based on nominal loading rates only.

The 48-Hour EC50 for the reference material to Daphnia magna based on nominal concentrations was 0.78 mg/l with 95% confidence limits of 0.68 – 0.88 mg/l. The No Observed Effect Concentration was 0.32 mg/l.