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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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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: The study has been performed according to OECD and EC guidelines and according to GLP principles.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report Date:
2007

Materials and methods

Test guideline
Qualifier:
according to
Principles of method if other than guideline:
OECD guideline for Testing of Chemicals, guideline No. 201:
"Algae, Growth Inhibition Test", Adopted March 23, 2006. In
addition, the procedures were designed to meet the test
methods prescribed by the Guidance document on aquatic
toxicity testing of difficult substances and mixtures, OECD
series on testing and assessment number 23, December 14,
2000.
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): TC4ASO2
- Substance type: multi-constituent
- Physical state: white powder
- Analytical purity: 97.8%
- Composition of test material, percentage of components: 92.9% 4-tert-Butylsulfonylcalix(4)arene (CAS 204190-49-8)
4.9% 4-tert-Butylsulfonylcalix(8)arene
- Lot/batch No.: AYUI-1Y
- Expiration date of the lot/batch: 07 October 2007
- Stability under storage conditions: Stable
- Storage condition of test material: At room temperature in the dark

Test solutions

Details on test solutions:
Identity and concentration of auxiliary solvent for dispersal: Test concentrations were prepared by stirring a dispersion
of the test substance in test medium (100 mg/l) for 72 hours
and subsequently filtering this mixture through a 0.45 mm
filter to obtain the soluble fraction. Two additional test
solutions were prepared containing 1 and 10% of this
filtrate, respectively. The final test solutions were all
clear and colourless.

After preparation, volumes of 50 ml were added to each
replicate of the respective test concentration.
Subsequently, 1 ml of an algal suspension was added to each
replicate providing a cell density of 10E4 cells/ml.

Test organisms

Test organisms (species):
other: Pseudokirchneriella subcapitata, strain: NIVA CHL 1

Study design

Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
24 mg CaCO3/L

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.07 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
%Concentration loss over test: 61 ...

Any other information on results incl. tables

Comments:
Analysis of the samples taken at the start of the test, at
24 h and at 48 h showed a measured concentration of 0.12
mg/l, 0.04 mg/l and 0.062 mg/l, respectively. The overall
mean concentration was 0.07 mg/l.

Under the conditions of the test, no reduction of growth
rate was recorded at the maximum level of solubility of the
test substance in test medium (NOEC). Due to the very low
solubility of the test substance in water, concentration
levels that might be toxic for algae could not be reached.
The EC50 for growth rate reduction (ErC50:0-48h) was > 0.07
mg/l.

Applicant's summary and conclusion