Bis(2,4-dichloro-5-nitrophenyl) carbonate

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

Study period:

From 27 June 2005 (beginning of the study) to 30 June 2005 (end of the study)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study was performed according to EU Method C.3 (equivalent to the OECD Guideline 201) with GLP statement. All validity criteria were fulfilled but pH deviation of more than 1.5 unit was observed in the test item vessel throughout the test and no explanation was provided.

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Version / remarks:

, 1992

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

version of 1984

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Bis(2,4-dichloro-5-nitrophenyl) carbonate

EC Number:

254-471-4

EC Name:

Bis(2,4-dichloro-5-nitrophenyl) carbonate

Cas Number:

39489-75-3

Molecular formula:

C13H4Cl4N2O7

IUPAC Name:

bis(2,4-dichloro-5-nitrophenyl) carbonate

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Bis(2,4-dichloro-5-nitrophenyl)carbonat
- Substance type: no data
- Physical state: no data
- Expiration date of the lot/batch: no data
- Stability under test conditions: stable. Verified by chemical analysis (HPLC) at 0 and 72 hours.
- Storage condition of test material: no data

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
None

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Aliquots of the samples from the biological test were directly analysed.
- Sample storage conditions before analysis: The samples are analysed immediately. Only in exceptional cases, samples are stored overnight deeply frozen and protected from light.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Before start of the test, the test item was pulverized. To accelerate the solution procedure, a 69 amount of the water solubility of the test item underexposure conditions (1.8 mg/L) was taken (125 mg/L) and added directly to 1L of dilution water and treated for 1 hour in an ultrasonic bath and afterwards stirring for 21 hours on a magnetic stirrer. Finally undissolved particles of the test item were removed by filtration.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: Desmodesmus subspicatus
- Strain: no data
- Source (laboratory, culture collection): Non-axenic strain of the test species obtaine from "The Collection of Algal Cultures" of the Institute of Plant Physiology at the University of Göttingen (Germany). Exponentially-growing stock cultures are maintained in the test facility under constant temperature conditions (23 +/- 2°C) at a light intensity in the range 60-120 µE. x m-2 x s-1 (measured in the range 400 to 700 nm using a spherical quantum flux meter). The nutrient medium is renewed once a week. Cell density measurements are made using a microcell counter.
- Age of inoculum (at test initiation): no data
- Method of cultivation: Pre-cultures are set up three days before the start of a test. They are grown under identical exposure conditions as the stock cultures, except from the use of a different nutrient medium (medium recommended by the guideline).

ACCLIMATION
no data

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

none

Post exposure observation period:

None

Test conditions

Hardness:

No data

Test temperature:

No data

pH:

Control: 8.0-8.6
At 1.8 mg/L: 6.0-9.4

Dissolved oxygen:

No data

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentration: 1.8 mg/L
Measured concentrations: See table 6.1.5/1 in "Any other information on results incl. tables" section.

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- Type (delete if not applicable): closed (with cotton stoppers)
- Material, size, headspace, fill volume: 300 mL
- Aeration: no data
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): not applicable
- Initial cells density: 10000 cells/mL
- Control end cells density: mean of 833889 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): not applicable

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: no data

OTHER TEST CONDITIONS
- Sterile test conditions: no data
- Adjustment of pH: no
- Photoperiod: constant illumination
- Light intensity and quality: 4000 to 8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting chamber
- Chlorophyll measurement: no

TEST CONCENTRATIONS
- Spacing factor for test concentrations: limit test (1.8 mg/L)
- Range finding study: no data

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC0

Effect conc.:

>= 1.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

and biomass

Details on results:

- Exponential growth in the control (for algal test): yes
See table 6.1.5/2 in "Any other information on results incl. tables" section.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not relevant

Any other information on results incl. tables

Table 6.1.5/1: Analytical monitoring

Nominal concentrations (mg/L)	Measured concentrations (mg/L)
	0h	72h
Control	<0.025 / <0.025	<0.025 / <0.025
1.8 (with algal inoculum)	1.637 / 1.643 (90.9 to 91.3% of nominal)	1.7 / 1.693 (94.1 to 94.4% of nominal)
1.8 (without algal inoculum)	1.659 / 1.666 (92.2 to 92.6% of nominal)	1.917 / 1.925 (106.5 to 106.9% of nominal)

Table 6.1.5/2: Results

Nominal concentration (mg/L)	Replicate	Cell density (cells/mL)				Growth (b)	Percentage increase of cell growth (%)	Growth rate (r)	Percentage increase of cell growth rate (%)
		0h	24h	48h	72h
Control	1 2 3 4 5 6	10000 10000 10000 10000 10000 10000	30000 40000 40000 40000 33333 40000	173333 180000 173333 163333 183333 170000	826667 846667 820000 843333 850000 816667	591667 618333 598333 600000 616667 593333	-	1.47 1.48 1.47 1.48 1.48 1.47	-
	Mean	10000	37222	173889	833889	603056		1.47
1.8	1 2 3	10000 10000 10000	36667 40000 40000	206667 196667 206667	940000 1030000 920000	688333 726667 681667	-15.9	1.51 1.54 1.51	-3.3
	Mean	10000	38889	203333	963333	698889		1.52

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

OECD validity criteria of the testing guideline 201 (version of 1984) : the cell concentration in the control cultures have increased by a factor of more than 16 within 3 days.

Conclusions:

Based on the absence of inhibition of growh and growth rate at the limit test concentration, the 72h-EC0 was greater or equal to 1.8 mg/L.

Executive summary:

This study was performed according to EU Method C.3 (equivalent to the OECD Guideline 201) with GLP statement, to assess adverse effects of the test substance on the growth and the growth rate of the planktonic freshwater algal species Desmodesmus subspicatus over several generations.

Exponentially growing algal cells were exposed for a period of 72 hours to a limit test concentration of nominally 1.8 mg/L of test item dissolved in water. Auxiliaries used to prepare the test media were an ultrasonic bath, a magnetic stirrer and a folder filter.

The cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction of growth and growth rate, relative to control cultures grown under identical conditions.

Based on the absence of inhibition of growh and growth rate at the limit test concentration, the 72h-EC0 was greater or equal to 1.8 mg/L. All results are expressed in terms of nominal concentrations. Recovery rates ranged from 90.9 to 92.6% of nominal values at 0 hours, and from 94.1 to 106.9% of nominal values at 72 hours, respectively.

All validity criteria were fulfilled but pH deviation of more than 1.5 unit was observed in the test item vessel throughout the test and no explanation was provided.