Reaction products of diazotized 2-amino-4-(methylsulfonyl)-phenol with 2-(3-Chlorophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one and Methyl-7-hydroxy-1-naphthylcarbamate – and chromium (III) 2:1, salted by ammonium, sodium and acid

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 according to OECD 201 including analytical monitoring

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

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:

other: OECD series, no. 23.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction products of diazotized 2-amino-4-(methylsulfonyl)-phenol with 2-(3-Chlorophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one and Methyl-7-hydroxy-1-naphthylcarbamate – and chromium (III) 2:1, salted by ammonium, sodium and acid

EC Number:

936-609-1

Molecular formula:

C40H32CrN4O12S2-R+] . [C36H28ClCrN7O10S2-R+] . [C34H26Cl2CrN8O8S2-R+]; R+ = NH4+, Na+ or H+

IUPAC Name:

Reaction products of diazotized 2-amino-4-(methylsulfonyl)-phenol with 2-(3-Chlorophenyl)-2,4-dihydro-5-methyl-3H-pyrazol-3-one and Methyl-7-hydroxy-1-naphthylcarbamate – and chromium (III) 2:1, salted by ammonium, sodium and acid

Details on test material:

- Physical state: Brown powder
- Storage condition of test material: Room temperature, protected from light, in original container.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The concentrations of the test item were analytically determined from all test concentrations at the start (0 hours) and the end of exposure (72 hours ). Samples at the start of exposure were taken from an additional replicate without algae. At the end of exposure, test samples of the nominal concentration Ieveis 10 to 100 mg/L were taken directly from the pooled test replicates. Separate samples of the nominal concentration Ieveis 1.0, 3.2 mg/Land the control were prepared with algae and incubated under test conditions for sampling at the end of exposure.
All original samples were stored at 6 ± 2 oc until sample preparation, if necessary. Prepared samples were stored in the auto sampler until analysis.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The stock solution was stirred for 2 hours at 11 00 rpm with a magnetic stirrer at room temperature. Thereafter, the stock solution
was centrifuged for 10 min at 3000 rpm for separating unsolved test item. The suitability of this procedure was confirmed by a matching
Chromatographie profile between an analytical standard and a test item solution. This fact indicates that there is no shift in the chemical composition between the complete dissolved test item in the calibration standards and the test item solution obtained by the described dispersion treatment.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Desmodesmus subspicatus
- Strain: CHODAT SAG 86.81
- Source (laboratory, culture collection): Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Nikolausberger Weg 18, D-37073 Göttingen.
- Age of inoculum (at test initiation): A three day old preculture, prepared in dilution water, was used as inoculum. For the start of the test, the preculture was directly pipetted into each test concentration and the control.
- Method of cultivation: Fresh stocks are prepared every month on Z-Agar. Light intensity amounts to 35-70 µE/ m^2 * s for 24 h per day.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

0.24 mmol Ca+Mg/L

Test temperature:

21 - 24 °C, controlled at ± 2 °C.

pH:

8.1 ± 0.2

Details on test conditions:

Nominal: 1.00 - 3.20 - 10.0- 32.0 - 100 mg/L
Geometric mean measured: 0.348 - 1.08 - 2.89 - 11.0 - 39.2 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 39.2 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

16.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

25.8 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

14.1 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: yield

Details on results:

Microscopic evaluation of the cells at start and end of the incubation period revealed no morphological abnormalities.
The environmental conditions (pH-value, room temperature, light intensity) were determined tobe within the acceptable Iimits.

Results with reference substance (positive control):

The toxicity of potassium dichromate (SIGMA, batch number 1450864V, purity 100.3 %, CAS RN 7778-50-9) to the unicellular freshwater green alga Desmodesmus subspicatus was determined over a period of 72 hours from April 10 to 13, 2012. The reference item toxicity is in the valid range following test facility SOPs:
ErC50 (0 - 72h) = 0.54 mg/L
EyC50 (0 - 72h)= 0.342 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes