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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:
1992-04-07 until 1992-04-10
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report date:
1992

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
Dodecylphenol T
IUPAC Name:
Dodecylphenol T
Constituent 2
Chemical structure
Reference substance name:
Phenol, dodecyl-, branched
EC Number:
310-154-3
EC Name:
Phenol, dodecyl-, branched
Cas Number:
121158-58-5
Molecular formula:
C18H30O
IUPAC Name:
4-(3,4,5-trimethylheptyl)phenol
Details on test material:
- Name of test material (as cited in study report): Dodecylphenol T
- Substance type: technical product
- Physical state: liquid
- Analytical purity: 100%
- Impurities (identity and concentrations): not mentioned
- Composition of test material, percentage of components: not mentioned
- Purity test date: not mentioned
- Lot/batch No.: continuously production; 3630/81325
- Date of production: 1991-04-25
- Stability under test conditions: 1 year
- Storage condition of test material: not mentioned

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
1 g test substance was mixed with 1l deionized water, stirred for 18 h and subsequently filtrated

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: Green algae
- Strain: Scenedesmus subspicatus (CHODAT (86.81 SAG))
- Source (laboratory, culture collection): Institut für Wasser-, Boden- und Lufthygiene, Berlin; subsequently in-house breeding
- Method of cultivation: in sterile-aerated Erlenmeyer flasks on light benches

ACCLIMATION
- Acclimation period: A preculture is withdrawn from a stock culture by tranfer 3 days prior to the beginning of the test from which preculture the test cultures are inoculated at a cell density of approximately 20 000 cells/ml.
- Culturing media and conditions (same as test or not): not mentioned
- Any deformed or abnormal cells observed: not mentioned

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
none

Test conditions

Hardness:
Growth/test medium chemistry as described in guideline 92/69/EEC (C.3.), no further details mentioned
Test temperature:
22 °C
pH:
8.5 - 8.7 at the beginning of the test; 9.6 ¿ 9.7 at the end of the test
Dissolved oxygen:
not mentioned
Salinity:
not mentioned
Nominal and measured concentrations:
Stock solution: 0.85 mg/l (WAF)
Details on test conditions:
TEST SYSTEM
- Test vessel: sterile-aerated Erlenmeyes flasks
- Initial cells density: 2x10E4 cells/ml
- Control end cells density: 2x10E4 cells/ml
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 8
- No. of vessels per vehicle control (replicates): not applicable

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
no details mentioned

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: not adjusted
- Photoperiod: not specified
- Light intensity and quality: approx. 8000 lux, white

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Cell numbers for exposure times of 24, 48, 72 h
- Determination of cell concentrations: The cell numbers were determined photometrically at a wavelenght of 685 nm
- Chlorophyll measurement: no
- Other: none

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not mentioned
- Range finding study: not mentioned
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.442 mg/L
Nominal / measured:
nominal
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
ca. 0.53 mg/L
Nominal / measured:
nominal
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 0.765 mg/L
Nominal / measured:
nominal
Basis for effect:
biomass
Remarks on result:
other: water solubility under test conditions
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 0.765 mg/L
Nominal / measured:
nominal
Basis for effect:
growth rate
Remarks on result:
other: water solubility under test conditions
Details on results:
- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no observations made
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Effective concentrations [mg/l] on the basis of cell growth:
EbC50 (72 h) > 0.765 *
EbC10 (72 h) approx. 0.53
EbC90 (72 h) > 0.765 *
Effective concentrations [mg/l] based on the specific growth rate µ:
ErC50 (0-72 h) > 0.765 *
ErC10 (0-72 h) > 0.765 *
ErC90 (0-72 h) > 0.765 *

* water solubility under test conditions
Results with reference substance (positive control):
no reference substance tested
Reported statistics and error estimates:
no statistical evaluation performed

Any other information on results incl. tables

Table #1: Cell density data:

 concentration

[mg/L]

 cell number (x 10E4 cells/ml) after        
  0 h   24 h  48 h  72 h
 control 2 4 17 79
0.051 2 4 16 77
0.085 2 4 17 76
0.153 2 3 16 76
0.255 2 4 15 74
0.442 2 4 15 74
0.765 2 4 13 70

Table #2: Growth curves:

concentration [mg/L]   biomass (area under the growth curve) inhibition of biomass [%]   growth rate µ (0 - 72 h)  inhibition of growth rate [%]
 control 55.5  - 1.492 -
0.051 53.5 3.6 1.479 0.9
0.085 54  2.7 1.472 1.3
0.153 52 6.3 1.616 - 8.3
0.255 51 8.1 1.459 2.2
0.442 51 8.1 1.459 2.2
0.765 47 15.3 1.431 4.1

Applicant's summary and conclusion

Validity criteria fulfilled:
yes

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