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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:
July 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
Tert-butyl 3-oxoazetidine-1-carboxylate
EC Number:
627-725-0
Cas Number:
398489-26-4
Molecular formula:
C8H13NO3
IUPAC Name:
Tert-butyl 3-oxoazetidine-1-carboxylate
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Batch Nr. : 10050008
Purity : 99.4% (w/w)
Stability : stable under storage conditions
Expiry date : 22 June 2013

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

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

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 37 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

The median growth inhibiting concentration (ErC50/EyC50) and the low-effect concentrations (ErC10/EyC10, ErC20/EyC20), based on the average specific growth rate and the yield (algal biomass production) within 3 days, of PAM-Azetidinone to the green alga Desmodesmus subspicatus, were investigated over a period of 72 h.

The test was performed at the following nominal concentrations: 12.5, 25.0, 50.0, 100 and 200 mg/l. Three parallel test vessels were used for each concentration of the test substance.

Since PAM-Azetidinone is a soluble test substance, the nominal concentrations were prepared by dilution of a stock solution in aerated algal medium.

HPLC analyses of PAM-Azetidinone were performed at the beginning, after 24 and 48 h, and at the end of the exposure (72 h). The measured concentrations at the beginning of the exposure were 11.1, 21.1, 38.8, 75.1 and 151 mg/l. The concentrations were satisfactorily maintained over the whole exposure period. Geometric mean concentrations over a period of 72 h (GM0-72h) were 10.8, 19.5, 37.0, 72.6 and 147 mg/l (97, 93, 95, 97 and 97% of the initial concentration, respectively). The effective concentrations of PAM-Azetidinone were assessed based on the geometric mean (GM0-72h) concentrations.

The results of the growth (r) and yield (y) inhibition of PAM-Azetidinone to green algae are summarized in the following table showing EC-values and 95% confidence limits (cl) based on the geometric mean (GM0-72h) concentrations:

Parameter ErC10 ErC20 ErC50 NOErC

GM0-72h (mg/l) 61.8 88.9 165

Lower 95%-cl 57.1 84.8 160 37.0

Upper 95%-cl 66.1 92.7 172

r2 0.977 Regression model: Logit

Intercept a -11.41

Slope b 5.14

Parameter EyC10 EyC20 EyC50 NOECy

GM0-72h (mg/l) 38.2 48.4 73

Lower 95%-cl 33.1 43.8 69 37.0

Upper 95%-cl 42.4 52.2 77

r2 0.923 Regression model: Logit

Intercept a -14.61

Slope b 7.85