N,N'-(2-chloro-1,4-phenylene)bis(3-oxobutaneamide)

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

Study period:

1999-12-03 to 2000-05-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

443-010-4

EC Name:

-

Cas Number:

53641-10-4

Molecular formula:

C14H15ClN2O4

IUPAC Name:

N-[3-chloro-4-(3-oxobutanamido)phenyl]-3-oxobutanamide

Test material form:

solid

Sampling and analysis

Analytical monitoring:

yes

Remarks:

Test item concentrations have been analytically verified at test initiation and test end

Details on sampling:

Separate replicates for the test item analysis after 0 and 72 h were prepared (test beginning provided without alga and test end with same density of alga as the test replicates) and incubated under test conditions.

Test solutions

Vehicle:

no

Remarks:

No vehicle was used to dissolve the test item. The test item was completely dissolved in all test replicates throughout the test period.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

Scenedesmus subspicatus CHODAT SAG 86.81
Reason for selection: According to the guideline Scenedesmus subspicatus CHODAT SAG 86.81 is suitable for this kind of study.
Origin: Collection of algae cultures (SAG). Pflanzenphysiologisches Institut der Universität, Nikolausberger Weg 18, 0-37073 Göttingen
Method of cultivation: Fresh stocks were prepared every month on Z-Agar. Light intensity amounted 35-70 pE/m2 s for 24 h per day.
Culture medium: Nutrient medium Z according to LÜTTGE et al. (1994).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

Mean: 23.8 °C

pH:

7.47 - 8.11

Nominal and measured concentrations:

Nominal: 15.625, 31.25, 62.5, 125. 250, 500, 1000 mg/L
a.i. nominal: 15.40625, 30.8125, 61.625, 123.25, 246.5, 493, 986 mg/L

Measured: 80-93% of nominal

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

219 mg/L

95% CI:

195 - 246

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

450 mg/L

95% CI:

396 - 512

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

15.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

15.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

Microscopic evaluation of the cells at the start of the incubation period revealed no morphological abnormalities. At the end of the test cells at concentration levels 500 and 1000 mg/L were lighter green and at concentration level 1000 mg/L cells were smaller than in the control. Water quality parameters of pH-value, measured at 0 and 72 h, and room temperature, measured continuously, met the guideline requirements.

Reported statistics and error estimates:

Calculations were carried out using software
- SigmaPlot rel. 5.0 (1986-1995), JANDEL CORPORATION
- SigmaStat rel. 2.03 (1992-1997), SPSS INC.
- Excel rel. 5.0a (1985 - 1993), MICROSOFT CORPORATION

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this study CL-DAEP was found to inhibit the growth of the freshwater green alga
Scenedesrnus subspicatus at concentrations > 15.625 mg/L (biomass and growth rate).
The EC50-values for inhibition of biomass growth (E,C„) and specific growth rate (E,C50) after
72 h were 219 (195 - 246) and 450 (396 - 512) mg/L, respectively.

Executive summary:

The acute toxicity of CL-DAEP batch no. 90003 CCL to the unicellular freshwater green alga Scenedesmus subspicatus was determined according to the principles of OECD-Guideline 201 at DR.U.NOACK-LABORATORIUM FÜR ANGEWANDTE BIOLOGIE in 31157 Sarstedt, Germany from February 29 to March 3, 2000.

The study was conducted under static conditions over a duration of 72 hours with an initial cell density of nominally 104 cells/mL. 7 concentration levels were tested in a geometrical series with a dilution factor of 2:
15.625 - 31.25 - 62.5 - 125 - 250 - 500- 1000 mg/L.

3 replicates were tested for each concentration and 6 replicates for control.
No vehicle was used to dissolve the test item. The test item was completely dissolved in all test replicates throughout the test period.
Microscopic evaluation of the cells at the start of the incubation period revealed no morphological abnormalities. At the end of the test cells at concentration levels 500 and 1000 mg/L were lighter green and at concentration level 1000 mg/L cells were smaller than in the control. Water quality parameters of pH-value, measured at 0 and 72 h, and room temperature, measured continuously, were determined to be within the acceptable limits.
The concentrations of the active ingredient 2-Chlor-bis-(N-acetoacetyI)-p-phenylendiamin were determined at all concentration levels at test start and test end. The overall mean values of recovery rates of the active ingredient at the beginning and the end of the test were > 80 % (except one dosage level with 79 %). Therefore all effect concentrations are based on nominal concentrations of the test item. 

The effects of CL-DAEP, based on the nominal concentrations are:

Biomass:

72h EC50 = 219 mg/L (CI: 195-246 mg/L)

72h NOEC = 15.625 mg/L

Growth rate:

72h EC50 = 450 mg/L (CI = 396-512 mg/L)

72h NOEC = 15.625 mg/L