4H-Pyrazino[2,1-a]isoquinolin-4-one, 2-acetyl-1,2,3,6,7,11b-hexahydro-

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-12-14 to 2005-04-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations:
test concentration (limit test)

- Sampling method:
Duplicate samples from the freshly prepared test media were taken at the first treatment and after 72 h.

- Sample storage conditions before analysis:
All samples were stored under the same conditions as the vessels with Daphnia magna and afterwards sent to analysis.

Vehicle:

no

Details on test solutions:

The test medium (reconstituted water and test material) was freshly prepared. Therefore, the calibrated flask with test material and vehicle, reconstituted water, was shaken. The solution was used for the study.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

The test system used for this study was a green unicellular algae species, Desmodesmus subspicatus, strain No. SAG 86.81, supplied by the "Sammlung von Algenkulturen, Pflanzenphysiologisches Institut der Universitat Göttingen". This strain is recommended by international guidelines.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Hardness:

250 mg CaCO3

Test temperature:

22-23 °C

pH:

8

Nominal and measured concentrations:

LOQ = 0.5 mg/L
analytical concentration (initial): 96 % of nominal concentration
analytical concentration (end of treatment): 98 % of nominal concentration

Details on test conditions:

The test medium (reconstituted water and test material) was freshly prepared. The light intensity was approximately 7500 to 9500 Lux. The experimental part was started by inoculation of algae to the different groups so that the flasks contained about 10,000 cells/mL. The algae were taken from an exponentially growing pre-culture (growth rate 26.7) which was set up 3 days prior to the experimental part under the same conditions as in the final study.

Details on composition of the reconstituted water:

Macro-nutrients:
50.00 mg/L NaHCO3
18.00 mg/L CaCl2 x 2 H2O
15.00 mg/L NH4Cl
15.00 mg/L MgSO4 x 7 H2O
12.00 mg/L MgCl2 x 6 H2O
1.60 mg/L KH2PO4

Trace elements:
100.00 µg/L Na2EDTA x 2 H2O
80.00 µg/L FeCl3 x 6 H2O
415.00 µg/L MnCl2 x 4 H2O
185.00 µg/L H3BO3
7.00 µg/L Na2MoO4 x 2 H2O
3.00 µg/L ZnCl2
1.50 µg/L CoCl2 x 6 H2O
0.01 µg/L CuCl2 x 2 H2O

The pH of the reconstituted water after aeration is approximately 8.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Pretest
In a pretest under static conditions, inhibition of the growth rate of the algae, Desmodesmus subspicatus, was not observed at a concentration of 100 mg/L.

Main study
In the control group, the factor of cell growth was approx. 105.
The algae increased from 10,000 cells/mL at the start to 1,052,838 cells/mL after 72 hours.

The nominal test material concentrations and the growth inhibition data after 72 hours exposure are given below:

Results with reference substance (positive control):

Regularly, a positive control test to check the test system is carried out with potassium dichromate (no results provided in the study report).

	cell density per mL					Growth inhibition (0 - 72 h)
nominal		0 hours	24 hours	48 hours	72 hours	IA	Iµt
0		10000	59463	153731	1007397
0		10000	63090	191811	1048707
0		10000	62280	213860	1102410
	mean	10000	61611	186467	1052838
100		10000	66150	218960	1040607
100		10000	66213	217039	1031697
100		10000	60570	226559	1145097
	mean	10000	64311	220853	1072467
Inhibition IA			-5.2	-16.3	-4.4	-6.3	-0.4

I_A: inhibition of cell growth in %
I_µt. inhibition of growth rate in %

Validity criteria fulfilled:

yes

Conclusions:

An aqueous solution of 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 72 hours EC50 to Desmodesmus subspicatus was > 100 mg/L (limit test) and, thus, could not be determined in this test.

Executive summary:

The purpose of this assay was to identify the aquatic toxicity potential of the test item in algea according to OECD TG 201, to provide a rational basis for hazard estimation for the test item in aquatic environments.
The influence of the test material on the growth and growth rate of the green algae species Scenedesmus subspicatus was tested. The study design included one control and one test material group with three replicates, each containing about 100 mL reconstituted water or test medium and 10000 cells/mL at the start of the experimental phase. The algae were exposed to a solution of nominal 100 mg/L and the study was performed as a limit test in an open static test system. The growth was calculated after 24, 48, and 72 hours exposure in the test medium. The limit of quantification of the analytical method was about 0.5 mg/L. At the start, the analytically determined concentration was about 96 % of the nominal concentration. At the end of the experimental part, the analytically determined test material concentration was 98 % of the nominal concentration. The test material concentration could be maintained at > 80 % of the initial concentration and the nominal value was regarded as equivalent to the analytical value. For the test material the following nominal and analytical EC50 values and no effect concentration for Desmodesmus subspicatus were determined:

72h EC50 (biomass)    > 0.1 g/L
72 h EC50 (growth rate reduction)     > 0.1 g/L
NOEC    >=0.1 g/L

In conclusion, an aqueous solution of 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 72 hours EC50 to Desmodesmus subspicatus was > 100 mg/L (limit test) and, thus, could not be determined in this test.

Description of key information

Toxicity to aquatic algae was assessed in an OECD TG 201 compliant study and 72 h EC50 was greater than 100 mg/L (reference 6.1.5-1).

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

100 mg/L

Additional information

The purpose of this assay was to identify the aquatic toxicity potential of the test item in algea according to OECD TG 201, to provide a rational basis for hazard estimation for the test item in aquatic environments.
The influence of the test material on the growth and growth rate of the green algae species Scenedesmus subspicatus was tested. The study design included one control and one test material group with three replicates, each containing about 100 mL reconstituted water or test medium and 10000 cells/mL at the start of the experimental phase. The algae were exposed to a solution of nominal 100 mg/L and the study was performed as a limit test in an open static test system. The growth was calculated after 24, 48, and 72 hours exposure in the test medium. The limit of quantification of the analytical method was about 0.5 mg/L. At the start, the analytically determined concentration was about 96 % of the nominal concentration. At the end of the experimental part, the analytically determined test material concentration was 98 % of the nominal concentration. The test material concentration could be maintained at > 80 % of the initial concentration and the nominal value was regarded as equivalent to the analytical value. For the test material the following nominal and analytical EC50 values and no effect concentration for Desmodesmus subspicatus were determined:

72h EC50 (biomass)    > 0.1 g/L
72 h EC50 (growth rate reduction)     > 0.1 g/L
NOEC    >=0.1 g/L

In conclusion, an aqueous solution of 100 mg/L of the test item revealed no aquatic toxicity in the test system. The 72 hours EC50 to Desmodesmus subspicatus was > 100 mg/L (limit test) and, thus, could not be determined in this test.