[No public or meaningful name is available]

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

effects on growth of green algae

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

7-hydroxycitronellal

EC Number:

203-518-7

EC Name:

7-hydroxycitronellal

Cas Number:

107-75-5

Molecular formula:

C10H20O2

IUPAC Name:

7-hydroxy-3,7-dimethyloctanal

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test medium of the highest test concentration of nominal 500 mg/l was prepared. Then, this test medium was serially diluted with test water to obtain the desired test concentrations.
- Test concentration separation factor: 2-fold

Test organisms

Test organisms (species):

Scenedesmus sp.

Details on test organisms:

TEST ORGANISM
- Strain: SAG 86.1
- Source (laboratory, culture collection): Sammlung für Algenkulturen, University of Göttingen

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

19.85 degrees C

pH:

7.6-9.5

Nominal and measured concentrations:

0, 3.9, 7.8, 15.625, 31.25, 62.5, 125, 250, 500 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer
- Material, size, headspace, fill volume: 250 mL
- Initial cells density: 10,000 cells/mL
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 2

GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to OECD 201


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: Fluorometric measurement of cell density after 0, 24, 48 and 72 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2-fold

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

123.32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

42.36 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

235.05 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Colour differences: No

Reported statistics and error estimates:

EC50 values were determined with appropriate statistical methods (according to Tallarida & Jacob, 1
979).

Any other information on results incl. tables

Concentration	Fluorometer Value - Inoculated	Fluorometer Value – Non-inoculated	Difference	% of Control
0	1684	0	N/A	N/A
3.9	1665	2	1663	98.77
7.8	1525	1	1524	90.52
15.625	1499	1	1498	88.97
31.25	1320	0	1320	78.40
62.5	894	1	893	53.04
125	307	0	307	18.23
250	79	1	78	4.63
500	68	0	68	4.04

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 72-hr EC50 for algae based on growth rate is 123.32 mg/L.

Executive summary:

The toxicity of the test substance to algae was determined.  Concentrations of 0, 3.9, 7.8, 15.625, 31.25, 62.5, 125, 250, and 500 mg/L were tested.  Algal growth was monitored using a fluorometer.  The 72-hr EC50 based on growth rate was determined to be 123.32 mg/L.