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:
17 Feb - 21 Feb, 1997
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Done under GLP and OECD methods

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report date:
1997

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method C.3 (Algal Inhibition test)
Version / remarks:
Method C3, Directive 92/69/EEC
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
424-660-8
EC Name:
-
Cas Number:
224631-15-6
Molecular formula:
Hill formula: C18H26N4O5S CAS formula: C18H26N4O5S
IUPAC Name:
(S)-2,5-dioxopyrrolidin-1-yl 2-(3-((2-isopropylthiazol-4-yl)methyl)-3-methylureido)-3-methylbutanoate

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
Nominal test concentrations: 100mg/l

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Strain: 278/4
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa (CCAP), Ambleside, Cumbria, UK.

Study design

Test type:
semi-static
Total exposure duration:
72 h

Test conditions

Test temperature:
21 - 23°C
Nominal and measured concentrations:
Nominal test concentration:100mg/l
Details on test conditions:
Algae were provided with continuous uniform illumination, in the range 400 - 700nm at 7,500 lux.
Algal cultures were rotated orbitally at 100r.p.m.

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Remarks:
average specific growth rates and areas under growth curves.
Details on results:
Hydrolysis studies show that A-133816 degrades rapidly (t½ < 1 hour) in water to form2,4, wing acid and N-hydroxysuccinamide.
Chemical analysis was conducted on the "aged" solutions to confirm that A133816.0 had degraded to 2,4 wing acid.

Any other information on results incl. tables

The average growth rate was measured for each replicate flask over the experimental period using daily cell counts. Growth curves were calculated and the area under each curve was determined.

Test material examined in triplicate. Duplicate samples of algal medium were used as controls.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The results indicate that "aged" A-133816 at 100mg/l nominal has no inhibitory effect on the growth of Selanastrum capricornutum under the conditions of the test.
Executive summary:

There was no significant difference between growth rates and areas under the curve for test and control flasks.