Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reason / purpose:
read-across source
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
15.6 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: Recalculated for target
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
14.8 mg/L
Nominal / measured:
nominal
Conc. based on:
other: expressed as solid content
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
ca. 4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: Recalculated for target
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
ca. 3.8 mg/L
Nominal / measured:
nominal
Conc. based on:
other: expressed as solid content
Basis for effect:
growth rate
Details on results:
- Observation of abnormalities (for algal test): no data
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no data
- Effect concentrations exceeding solubility of substance in test medium: not applicable
Results with reference substance (positive control):
No data

 Average Growth rates and Yield (Y):

Nominal test item concentration (mg/L; aqueous solution)

Average growth rateµ (day-1) and inhibition of µ (Ir)

Yield Y and inhibition of Y (Iy)

0-72 h

0-72 h

µ

Ir (%)

Y

Iy (%)

Control

1.57

0.0

55.0

0.0

1.0

1.60

-2.0

60.5

-10.1

10

1.40*

10.6

34.6*

37.0

100

0.22*

86.0

0.5*

99.2

263 (100 mg solids/L)

0.34*

78.1

0.9*

98.3

EC50

39 mg/L (aqueous solution)

13 mg/L (aqueous solution)

95% Confidence Interval

Not determined

12-17 mg/L

*Mean value significantly lower than in the control (according to a Dunnett’s-test, one-sided,α= 0.05)

Validity criteria fulfilled:
yes
Remarks:
1) Multiplication in the control: 111 (should be >16); 2) Coefficient of variation of average specific growth rate in controls: 0.013% (should be <7%); 3) Mean coefficient of variation for section-by-section growth rates in the control:can not be verified
Conclusions:
In a 72h Algal growth Screening test with Miranol Ultra L-32 (Amphoacetates C12), an EC50 (growth rate) of 14.8 mg/L (expressed as solid content) was determined. This result is read across to Amphoacetates C8.
Executive summary:

In a screening test for algal growth inhibition with Miranol Ultra L-32 (Amphoacetates C12), concentrations of 0, 1.0, 10, 100 and 263 mg/L (aqueous solution) were tested on Desmodesmus subspicatus. For each concentration and for the control, there were 3 replicates. There was no analytical monitoring. The algal biomass was determined by measurement of the algal cell density using an electronic particle counter (Coulter Counter, Model ZM), at t=72h only. The measurements were performed in duplicate. An 72h-ErC50 (growth rate) of 14.8 mg/L (expressed as solid content) and an 72h-ErC10 (growth rate) of approximately 3.8 mg/L (expressed as solid content) were determined from the results of this study. One of the validity criteria can not be verified (the other 2 are fulfilled). This result is read across to Amphoacetates C8.

Description of key information

 In a 72h Algal growth Screening test with Miranol Ultra L-32 (Amphoacetates C12), an 72h-ErC50 (growth rate) of 14.8 mg/L was determined (based on solid content). This result is read across to Amphoacetates C8.

Key value for chemical safety assessment

EC50 for freshwater algae:
14.8 mg/L
EC10 or NOEC for freshwater algae:
3.8 mg/L

Additional information

In a screening test for algal growth inhibition with Miranol Ultra L-32 (Amphoacetates C12), concentrations of 0, 1.0, 10, 100 and 263 mg/L (aqueous solution) were tested on Desmodesmus subspicatus. For each concentration and for the control, there were 3 replicates. There was no analytical monitoring. The algal biomass was determined by measurement of the algal cell density using an electronic particle counter (Coulter Counter, Model ZM), at t=72h and not at t=24h and t=48h. The measurements were performed in duplicate. An 72h-ErC50 (growth rate) of 14.8 mg/L (expressed as solid content) was determined. One of the validity criteria can not be verified (the other 2 are fulfilled). This result is read across to Amphoacetates C8.