N-(4-{[3-(dimethylamino)propyl]sulfamoyl}phenyl)-2-[(2-methoxy-4-nitrophenyl)diazenyl]-3-oxobutanamide

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

ISO 8692 (Water Quality - Fresh Water Algal Growth Inhibition Test with Scenedesmus subspicatus and Selenastrum capricornutum)

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Guidance document on aquatic toxicity testing of difficult substances and mixtures, OECD series on testing and assessment number 23 (2000)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N-(4-{[3-(dimethylamino)propyl]sulfamoyl}phenyl)-2-[(2-methoxy-4-nitrophenyl)diazenyl]-3-oxobutanamide

EC Number:

700-222-4

Cas Number:

1065519-44-9

Molecular formula:

C22H28N6O7S

IUPAC Name:

N-(4-{[3-(dimethylamino)propyl]sulfamoyl}phenyl)-2-[(2-methoxy-4-nitrophenyl)diazenyl]-3-oxobutanamide

Details on test material:

- Name of test material (as cited in study report): NO.408 YELLOW
- Physical state: powder
- Analytical purity: 98.6%
- Lot/batch No.: 081105-1
- Expiration date of the lot/batch: 04. November 2009
- Storage condition of test material: at room temperature in the dark
- Other: solubility in water: 0.38 mg/l

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with a stock solution prepared at a loading rate of 100 mg/l. A 15-minute treatment period with ultrasonic waves was followed by a magnetic stirring period of 47 h to accelerate the dissolving of the test substance in the test medium. This resulted in a solution that still contained some undissolved material, which was consequently removed by filtration through a 0.45 μm membrane filter (Whatman, RC55).
- Controls: Test medium without test substance or other additives

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Strain: NIVA CHL 1
- Source (laboratory, culture collection): In-house laboratory culture
- Method of cultivation: Algae stock cultures were started by inoculating growth medium with algal cells from a pure culture on agar. The suspensions were continuously aerated and exposed to light in a climate room at a temperature of 21 - 24 °C.
ACCLIMATION
- Culturing media and conditions (same as test or not): Pre-culture medium was M2, according to the OECD 201 Guideline, formulated using Milli-Q water (tap water purified by reverse osmosis (milli-RO) and subsequently passed over activated carbon and ion-exchange cartridges (Milli-Q water, Millipore Corp., Bedford, Mass., USA). Test medium was the same as pre-culture medium.
- Any deformed or abnormal cells observed: deformation of test cells were not observed when compared to the control

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

24 mg CaCO3/l

Test temperature:

22.1 °C at the start of the test
22.5 - 23.6 °C during the exposure period

pH:

8.3 - 8.4 at test start
8.2 - 8.3 at test end

Nominal and measured concentrations:

10, 18, 32, 56 and 100% of a 0.45 μm filtered solution prepared at 100 mg/l (nominal)
3.54, 8.44, 14.4, 26.0 and 47.7 μg/l (measured at test start)
The measured concentrations decreased significantly during the first 24-h test period (i.e. by 70 - 90%) and remained fairly stable during the remaining test period. Based on these results, the Time Weight Average concentrations were calculated to correspond to 1.3, 1.6, 2.2, 4.6 and 8.8 μg/l, respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 100 ml, all-glass, containing 50 ml of test solution
- Initial cells density: 1 x 10^4 cells/ml
- Control end cells density: 119.3 x 10^4 cells/ml
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6


GROWTH MEDIUM
- Standard medium used: yes (OECD medium)


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water purified by reverse osmosis (milli-RO) and subsequently passed over activated carbon and ion-exchange cartridge (Milli-Q water; Millipore Corp., Bedford, Mass., USA)
- Culture medium different from test medium: no (pre-culture medium was the same as test medium, however, stock culture medium (medium M1 according to the NPR 6505) differed from test medium)


OTHER TEST CONDITIONS
- Photoperiod: continuously lighting
- Light intensity and quality: light intensity within the range of 77 to 82 μE/m2/s emitted from TLD-lamps of the type 'cool-white' of 30 Watt


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: at the beginning, cells were counted using counting chamber and microscope, thereafter, cell densities were determined by spectrophotometric measurement of samples at 720 nm using a Varian Cary 50 single beam spectrophotometer with a cuvette (pathlength = 10 mm)


TEST CONCENTRATIONS
- Spacing factor for test concentrations: ca. 1.8
- Range finding study
- Test concentrations: 1.0, 10 and 100% of the 0.45 μm filtrate prepared at a loading rate of 100 mg/l
- Results used to determine the conditions for the definitive study: mean growth rate was reduced by 17.8% at the highest filtrate compared to control

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

2.2 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

4.9 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 1.9 - 13 μg/l

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 8.8 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.3 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

1.7 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 0.75 - 3.8 μg/l

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

8.5 µg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: yield

Remarks on result:

other: 3.6 - 20 μg/l

Results with reference substance (positive control):

- EC50: 1.6 mg/l (95% confidence interval: 1.2 - 2.1 mg/l) (growth rate)
0.73 mg/l (95% confidence interval: 0.51 - 1.1 mg/l) (yield)

Any other information on results incl. tables

Mean cell densities (x 10^4 cells/ml) during the test

TWA concentration NO.408 YELLOW (μg/l)	Exposure time (hours)
	0	24	48	72
control	1.0	4.9	22.2	119.3
1.3	1.0	4.8	22.1	118.9
1.6	1.0	4.5	19.1	100.3
2.2	1.0	4.6	20.2	100.7
4.6	1.0	4.0	16.8	88.1
8.8	1.0	3.2	8.7	53.4