Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study under GLP conditions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Batch No GST 7-18099

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
sampling was done at 0, 24, 48 and 72 h

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Study design

Test type:
static
Water media type:
freshwater
Total exposure duration:
72 h

Test conditions

Test temperature:
23°C
pH:
7-7.5 pH
Nominal and measured concentrations:
cell conentration at test start 10exp 4 cells / ml
Substance nominal concentrations: 1, 1.8, 3.2, 5.6, and 10 mg/l
Details on test conditions:
test vessel was a 100 ml flask

Results and discussion

Effect concentrationsopen allclose all
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
2.04 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Remarks on result:
other: 95% CL
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
2.43 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 95% cl
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
5.33 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 95% CL

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
growth inhibition occurs under influence of Pyrazole DHE
Executive summary:

The results from this algal growth study in which the unicellular green algae Selenastrum capricornutum were treated with the test substance Pyrazole DHE at the nominal concentrations of 1, 1.8, 3.2, 5.6, and 10 mg/l are given below.

The calculation of EbC50, ErC50, NOEC (b) and NOEC (R) was made using the nominal concentrations

The algae were treated for 72 hours and counted at 24, 48 and 72 hours.

The EbC50at 24 hours was 2.04, at 48 hours was 2.43 and at 72 hours was 5.33 mg/L.

The ErC50at 24 hours was 4.23, while at 48 and 72 hours was > 10 mg/L.

The NOEC (b) at 24 hours was 1.8 and was found to be < 1 mg/L at both 48 and 72 hours.

The NOEC (r) at 24, 48 and 72 hours was 3.2, 1 and 1.8 mg/L, respectively.