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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 was conducted acccording to O.E.C.D. Test Guideline No. 201 with GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
not specified
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
As per IUCLID5 Sections 1.1 -1.4.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Sampling to confirm test substance concentration and stability was conducted at 0 hr and 72 hr of exposure.

Test solutions

Details on test solutions:
Direct weighings were prepared to give the desired series of test substance concentrations. Appropriate amounts of the test substance were added each to 1 litre of dilution water and treated for 1 h in an ultrasonic bath and stirred for 21 h on a magnetic stirrer. To produce the different test substance concentrations 80 mL of the prepared solutions were taken and 10 mL of nutrient medium and 10 mL of algal inoculum with a cell density of 5000 cells/mL were added resulting in the final nominal concentrations of : 4.3, 9.4, 20.7, 45.5 and 100 mg/L.

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
The algal species Desmodesmus subspicatus (formerly Scene-desmus subspicatus) Strain No. 86.81 SAG was obtained from 'The Collection of Algal Cultures' of the Institute of Plant Physiology at the University of Göttingen (Germany). Exponentially-growing stock cultures were maintained in the test facility under constant temperature conditions (21-24°C with a maximum fluctuation of +/- 2°C) at a light intensity in the range 60 – 120 μE. x m-2 x s-1 (measured in the range 400 to 700 nm using a spherical quantum flux meter). The nutrient medium (according to BRINGMANN & KÜHN (1977) was renewed once a week.

Study design

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

Test conditions

Hardness:
No data
Test temperature:
21°C to 24°C was maintained at +/- 2°C
pH:
8.0 - 8.7
Dissolved oxygen:
No data
Salinity:
No data, freschwater
Nominal and measured concentrations:
The nominal concentrations were: 4.3, 9.4, 20.7, 45.5 and 100 mg/L. The measured concentrations were reduced in a dose-dependent manner from 36.5% at 4.3 mg/L to 9.26% at the high nominal concentration of 100 mg/L.
Details on test conditions:
The algal inocula for the test were taken from an exponentially-growing pre-culture and were mixed with the nutrient salts medium to make up to a final cell density of about 5000 cells per millilitre in the test medium. The cultures for exposure were maintained in 300 mL Erlenmeyer flasks with cotton stoppers in a Light chamber in which a temperature in the range 21°C to 24°C was maintained at +/- 2°C, with continuous uniform illumination was provided in the spectral range 400 to 700 nm. There were three algal cultures per treatment condition. Exposure was for 72 hr. Cell densities were measured in a microcell counter (Sysmex F300, Digitana).
Reference substance (positive control):
no

Results and discussion

Effect concentrations
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: The actual ECr50 valued appeared to be approximately 1000 mg/L.
Details on results:
ErC 50 (0-72 h) : > 100 mg/L, ErC 10 (0-72 h) : 10.3 mg/L, EyC 50 (0-72 h) : 15.6 mg/L, EyC 10 (0-72 h) : 2.7 mg/L NOEC [r] (tα 0.05) : 2.15 mg/L and NOEC [y] (tα 0.05) : 2.15 mg/L The EC 50 growth rate could not be calculated with sufficient precision. However, a value of ca. 1000 mg/L was extrapolated, thus the EC 50 is clearly > 100 mg/L.
Results with reference substance (positive control):
No data
Reported statistics and error estimates:
Not determined.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Based on algal growth rate the estimated 72 hr EC50 value for 2-Acetone polymer with phenol (BPA-Tars) was > 100 mg/L. The actual value appeared to be approximately 1000 mg/L. The 72 hr EC50 value based on cell yield was approximately 15.6 mg/L. These data suggest that BPA-Tars maty be harmful to algal species.
Executive summary:

2 -Acetone polymer with phenol (BPA-Tars) was assessed for acute toxicity to algae by an O.E.C.D. Test Guideline No. 201 study conducted with GLP compliance. Based on algal growth rate the estimated 72 hr EC50 value for BPA-Tars was > 100 mg/L. The actual value appeared to be approximately 1000 mg/L. The 72 hr EC50 value based on cell yield was approximately 15.6 mg/L. These data suggest that BPA-Tars maty be harmful to algal species.