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
Study period:
1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study and GLP

Data source

Reference
Title:
Unnamed
Year:
1992
Report date:
1992

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: Directive 87/302/EWG Algal inhibition test
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Ethyl cyanoacetate
EC Number:
203-309-0
EC Name:
Ethyl cyanoacetate
Cas Number:
105-56-6
Molecular formula:
C5H7NO2
IUPAC Name:
ethyl 2-cyanoacetate
Constituent 2
Reference substance name:
[SPEC][/SPEC][SYN][/SYN]
IUPAC Name:
[SPEC][/SPEC][SYN][/SYN]
Constituent 3
Reference substance name:
[CS]000000157834[/CS]
IUPAC Name:
[CS]000000157834[/CS]
Details on test material:
Batch no. Tank 434
ID no. 3633/81410

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Name: Scenedesmus subspicatus
- Strain: 86.81 SAG

Study design

Test type:
not specified
Water media type:
not specified
Limit test:
no
Total exposure duration:
72 h

Test conditions

Test temperature:
24 ± 2°C
pH:
at beginning of the test: 7.1 - 7.8
at the end of the test: 3.5 - 8.7
Nominal and measured concentrations:
cell concentration at test start: ca. 20000 cells/ml
substance nominal concentrations: 10, 17, 30, 50, 80 und 140 mg/l

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
72.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
17.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
294.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Remarks on result:
other: at concentration of 140 mg/l
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
141.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: at concentration of 140 mg/l
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
29.9 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC90
Effect conc.:
673
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: at concentration of 140 mg/l
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
17 mg/L
Details on results:
During the 72 h the test substance hydrolysed. At concentrations from 30 mg/l the ph-value decreased to acid. An influence on the test results cannot be excluded.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Ethyl cyanoacetate was tested according to Directive 87/302/EWG Algal inhibition test and reached after 72 hours an EbC50 of 72.4 mg/l related to cell number.
Executive summary:

The results from this algal growth study in which the unicellular green algae Scenedesmus subspicatus (new name: Desmodesmus subspicatus) were treated with the test substance Ethyl cyanoacetate at the nominal concentrations of 10, 17, 30, 50, 80 and 140 mg/l are given below.

Ethyl cyanoacetate was tested according to Directive 87/302/EWG Algal inhibition test and reached after 72 hours an EbC50of 72.4 mg/l related to cell number and an ErC50 of 140 mg/l related to growth rate.

The NOEC at 72 hours was 17 mg/l.

During the 72 h the test substance hydrolysed. At concentrations from 30 mg/l the ph-value decreased to acid. An influence on the test results cannot be excluded.