Bontron E-108

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 December 2001 to 20 December 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): S178207.
- Substance type: White powder.
- Physical state: Solid.
- Composition of test material, percentage of components: 91.4% w/w total ligand, 25.9% w/w free ligand and 69.1% w/w for the strength of S178207.
- Lot/batch No.: NBZ 0155/44.
- Storage condition of test material: At ambient temperature in the dark, in the container in which it was received.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Aqueous samples were diluted with tetrahydrofuran and analysed. The excess test solutions were sampled at 0-h, and one replicate of the dilution water control, solvent control and each test concentration was sampled at 48-h.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A stock solution (0.18 g of the test substance in 10 ml of dimethylformamide (DMF). This stock solution was ultrasonicated for 3 minutes giving a white homogeneous suspension. The test solutions were prepared from the stock solution by addition of appropriate volumes to 1 litre of dilution water and stirring throughly. The nominal concentrations of the test solutions were 0.18, 0.32, 0.56, 1.0 and 1.8 mg/l. A solvent control was similarly prepared by the addition of 100 ul of DMF to 1 litre of dilution water, to give a solvent concentration of 100 ul/l. Equalising volumes of DMF were added, where applicable, to each of the test exposure solutions to give a final DMF concentration of 100 ul/l in each exposure vessel. All additions were made sub-surface, gradually, by microlitre syringe, into solutions vigorously stirred by magnetic follower.
- Controls:DMF and water.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): DMF for the preparation of a stock solution, and water as media for the test.
- Concentration of vehicle in test medium (stock solution): 100 ul/l.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The resultant solutions were clear and colourless.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea.
- Source: From continuous laboratory cultures. The parental animals were from Brixham Environmental Laboratory, Brixham, Devon, UK.
- Age at study initiation (mean and range, SD): < 24 hours old, 1st instar.
- Weight at study initiation (mean and range, SD): Weight unknown.
- Breeding: The parent animals were 27 - 29 days old and had been maintained with a twoce weekly renewal of reconstituted water medium.
- Feeding during test
- Food type: Defined diet of algae Chlorella vulgaris, strain CCAP 211/12 and commercially available microencapsulated diet Frippak Booster.


ACCLIMATION
- Health during acclimation (any mortality observed): Monitored using a reference toxicant, potassium dichromate, twice a year.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Not applicable.

Test conditions

Hardness:

202.7 mg/l of CaCo3.

Test temperature:

20 ± 1ºC.

pH:

7.89 - 7.99.

Dissolved oxygen:

8.2 - 8.6 mh/l.

Salinity:

Not applicable.

Nominal and measured concentrations:

0.18, 0.32, 0.56, 1.0 and 1.8 mg/l (nominal), and 0.21, 0.36, 0.58, 1.0 and 1.8 mg/l (measured).

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: closed
- Material, size, headspace, fill volume: Borosilicate glass beakers of 250 ml nominal capacity.
- Aeration: No.
- Renewal rate of test solution (frequency/flow rate): Not applicable, as static test conditions.
- No. of organisms per vessel: 20.
- No. of vessels per concentration (replicates): 4.
- No. of vessels per control (replicates): Unknown.
- No. of vessels per vehicle control (replicates): Unknown.
- Biomass loading rate: 25 Daphnia/l.


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt's M4 Daphnia medium.
- Particulate matter: No metal or pesticide contained.


OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: Photoperiod of 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immbilisation - macroscopic observation of whole body movement, relative to the water, within a period of 15 seconds even if movement of individual appendages was visible.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.65 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: moving average angle

Remarks on result:

other: 0.52 - 0.84 mg/l

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

There was no immobility observed in the Daphnia at the nominal concentration of 0.18 mg/l. There was no immobility observed in either the diultion water or solvent control. 24 hour EC 50 is > 1.8 mg/l (05%CI NA) based on non-statistical estimation, and 48 hour EC50 is 0.65 mg/l (95%CI 0.52 - 0.84 mg/l) based on moving average angle of Daphnia.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

Not reported.

Any other information on results incl. tables

Table Analytical results ^a

Nominal conc (mg/l)	Measured conc (mg/l)		Mean measured conc over the test duration^b (mg/l)	Mean measured conc as % of nominal
	0 hour	48 hour
Dilution water control	< 0.041	< 0.042	< 0.042	-
solvent control	< 0.041	< 0.042	< 0.042	-
0.18	0.21	0.21	0.21	117
0.32	0.36^c	0.35^d	0.36	113
0.56	0.57	0.58	0.58	104
1.0	1.0	1.0	1.0	100
1.8	1.8	1.7	1.8	100

a All measurements are quoted to two significant figures and percentages are quoted to the nearest integer.

b Calculated using the arithmetic mean of the 0 - 48 hour results

c Mean of triplicate analysis (0.36, 0.35, 0.36 mg/l)

d Mean of triplicate analysis (0.34, 0.35, 0.35 mg/l)

The highest limit of detection in the study was 0.042 mg/l.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

There was no immobility observed in the Daphnia at the nominal concentration of 0.18 mg/l. Therefore 48 hour NOEC = 0.18 mg/l.

Executive summary:

Introduction. A study was performed to assess the acute toxicity of the test material, S178207, to Daphnia magna between 18 to 20 December 2001. The method followed that described in the OECD Guidelines for Testing of Chemicals (April 1984) No 202, " Acute Immobilisation Test", also considered acceptable when compared to requirements of the relevant US Environmental Protection Agency guideline and EU guideline.

 

Methods: Daphnia magna, continuous laboratory cultures (parental stock 27 – 29 days old), was used for the test. The test conditions were dilution water control, solvent control and nominal concentrations of 0.18, 0.32, 0.56, 1.0 and 1.8 mg/l of the test material at 20 ± 1ºC. The duration of the study was 48 hours.

 

Results. The 24 hour EC 50 was > 1.8 mg/l (95%CI NA) based on non-statistical estimation, and the 48 hour EC50 was 0.65 mg/l (95%CI 0.52 - 0.84 mg/l) based on moving average angle of Daphnia. The 48 hour NOECbased on immobility was 0.18 mg/l.