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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
August-November 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study has been conducted according to OECD guideline No. 201 and under GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): Pentanerythritol (EO)n tetraacrylate
- Substance type: UVCB
- Physical state: clear liquid
- Analytical purity: 100%
- Lot/batch No.: 10028446
- Expiration date of the lot/batch: 30 June, 2011
- Storage condition of test material: room temperature

Sampling and analysis

Analytical monitoring:
no
Details on sampling:
Water samples were taken from the controls and 12.0, 20.4, 34.6 and 100 mg/l loading rate WAT at the start (0 hours) and at the end (72 hours) of the test for DOC analysis. At 72 hours, the algae were removed by centrifugation. DOC analysis was performed by TOC (Total Organic Carbon).

Test solutions

Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The solubility test was conducted at the nominal concentration of 100 mg/L. About 200 mg of the test substance was added to 2 liter of OECD medium and mixed for 96 hours. Afrter a 30 min settling of the aqueous phase, WAFs were drawn off by siphoning from the middle of the test solution for analyzing for 96 hours. Dissolved organic carbon (DOC) analyis was provided to demonstrate attainment of equilibrium time and stability of WAFs. Undissolved test substance was not observed after 24 hours of stirring and the DOC value was not increased during 96 hours.

The stability of the test substance was conducted at a nominal concentration of 100 mg/L. Dissolved organi carbon was analyzed to monitor any losses of the test substance from the test medium. The DOC value was stable during 72 hours.

300 mg of the test substance was added to 3 L OECD medium to prepare 100 mg/L (nominal) of the test solution. This solution was stirred for 24 hours to dissolve the test substance. WAFs (about 2 L) were drawn off by siphoning from the middle of the test solution for testing. From this highest conconcentration, test solutions at 58.8, 34.6. 20.4 and 12 mg/L were prepared by serial dilution with OECD medium.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: UTEX 1648
- Source (laboratory, culture collection: orignially purchase from UTEX, the Culture Collection of Algae, The University of Texas at Austin, USA
- Age of inoculum (at test initiation) and method of cultivation: two to four days before the the test, sterile OECD nutrient medium was inoculated with about 5.0 x 10-3 cells/mL from a stock culture and incubated in a shaking incubator under continuous illumination at 21-24 °C to give an algal suspension in log phase growth.
- Culturing media and conditions (same as test or not): sterile OECD nutrient medium

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
No

Test conditions

Hardness:
No data
Test temperature:
22.4 ± 3 °C
pH:
7.80-8.54 during the test period
Salinity:
No data
Nominal and measured concentrations:
0. 12., 20.4, 34.6, 58.8 and 100 mg/L loading rate WAF
Details on test conditions:
TEST SYSTEM
- Test vessel: 250 ml Erlenmeyer flaks
- Renewal rate of test solution (frequency/flow rate): no renewal during 72-hour test period
- Initial cells density: 5.0 x 10-3 cells/mL
- Control end cells density: cell densities were determined at 0, 24, 28 and 72 hours

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: the pH was recorder daily
- Photoperiod: test was conducted under continuous illumination

TEST CONCENTRATIONS
- Range finding study: conducted at 0.1, 1, 10 and 100 mg/L loading rate WAFs

- Results used to determine the conditions for the definitive study:
Growth inhibition above 50% was not observed at 0.1, 1, 10 or 100 mg/L loading WAFs in average growth rate. However, 79.2% inhibtion was observed at 100 mg/L loading rate WAFs in yield. Therefore, the definitive test was conducted at control, 12.0, 20.4, 34.6, 58.8 and 100 mg/L loading rate WAF with three replicates.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
76.3 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 56.5-84.8
Duration:
72 h
Dose descriptor:
NOELR
Effect conc.:
58.8 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOELR
Effect conc.:
58.8 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
biomass
Details on results:
- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no
- Unusual cell shape: no

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72-h EL50 valuse expressed in terms of the nominal loading rate WAF of the test substance to Pseudokirchneriella subcapitata were determined to be > 100 mg/L loading rate WAF for growth rate and 76.3 mg/L for yield. The 72-h NOELR (No-observed effect loading rate) was expressed as 58.8 mg/L loading rate WAF for growth inhibtion and yield.
Executive summary:

The study was performed to assess the inhibitory effect of the test substance on the growth of the unicellar green alga Pseudokirchneriella subcapita. The study was conducted according to OECD Guideline No. 201 and under GLP.

Water Accomodated Fractions (WAFs) of the test substance were used for the test. The concentration of the test solutions was expressed as original loading rate. The toxicity ive test was conducted at control, 12.0, 20.4, 34.6, 58.8 and 100 mg/L loading rate WAF, each in three replicates during 72 hours. Cultures were incubated on a shaking incubator under continuous illumination at 22.4

± 3 °C for 72 hours. Growth was monitored daily by determinig the cell density of each culture by direct counts using an optical microscope.

The 72-h EL50 valuse expressed in terms of the nominal loading rate WAF of the test substance to Pseudokirchneriella subcapitata were determined to be > 100 mg/L loading rate WAF for growth rate and 76.3 mg/L for yield. The 72-h NOELR (No-observed effect loading rate) was expressed as 58.8 mg/L loading rate WAF for growth inhibtion and yield.

 

 

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