2,6-dibromo-4-cyanophenyl octanoate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 Aug - 23 Sept, 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

version from 1984

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Remarks:

from: THE DEPARTMENT OF HEALTH OF THE GOVERNMENT OF THE UNITED KINGDOM

Analytical monitoring:

yes

Details on sampling:

The concentration of the test substance in the test solutions was measured at the start. At the end of the test one replicate of each test concentration was sampled.
(excess solution)

Vehicle:

yes

Remarks:

dimethylformamide

Details on test solutions:

A 10000 mg/L stock solution of the test substance was prepared by dissolving 0.1 g of test substance in 10 ml of dimethylformamide. A 1000 mg/L stock solution of the test substance was prepared by dissolving 0.1 g of test substance in 100 ml of dimethylformamide.
One litre of each test solution was prepared by the addition of aliquots of stock solutions to dilution water. The additions were made gradually by microlitre syringe while stirring with a magnetic follower. Equalising additions of dimethylformamide were made in the same way, such that all test substanceconcentrations and the solvent control contained 0.1 ml of dimethylformamide per litre. The control consisted of dilution water only.

Test organisms (species):

Daphnia magna

Details on test organisms:

Daphnia < 24 hours old obtained from a single culture vessel, were used for testing.
The test organisms and the culture from which they were obtained showed no evidence of disease before the test period; therefore, no treatments were necessary.
Five Daphnia, in < 2.0 ml of dilution water were added to each test vessel in sequence across the treatment rows. Each treatment contained a total of 20 Daphnia.
The Daphnia were not fed during the course of the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

According to the report: test item hydrolyses readily at pH >9 in highly molar solutions, thus giving some explanation of the relatively low measured concentrations during the test.

Hardness:

166 mg/L

Test temperature:

20.3 - 20.5 °C

pH:

8.32 - 8.49

Dissolved oxygen:

9.0 - 9.4 mg/L

Salinity:

Not specified

Conductivity:

549 µS/cm

Nominal and measured concentrations:

Nominal concentrations: 18, 32, 56, 100, 180, and 320 µg a.i./L
Mean measured concentrations: 9, 17, 29, 43, 83 and 190 µg a.i./L

Details on test conditions:

Borosilicate glass beakers of 250 ml nominal capacity were used as test vessels, with four replicates per exposure concentration. Each vessel contained 200 ml of test solution providing a depth of approximately 60 mm.
The nominal test solution temperature was 20 ± 1°C, maintained by control of the room temperature and a photoperiod of 16 hours light:8 hours dark with a 15 minute transition period, was provided. The test solutions were not aerated.
Observations on immobility were done after 24 and 48 hours.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.03 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Remarks on result:

other: re_calculated

Remarks:

based on mean measured concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

60 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % C.I.: 54 - 70 µg a.i./L

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.046 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Remarks on result:

other: re-calculated

Remarks:

Based on intial measured concentrations

Please refer to "overall remark/ attached background material" field for result tables.

Validity criteria for OECD 202 (2004) table

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	0% immobilization at the end	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	Values ranged from 9.0 to 9.4 mg /L	yes

Validity criteria fulfilled:

yes

Remarks:

Not specified in the report but for further details please refer to “Any other information on results incl. tables”.

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, the acute EC50 48h for Daphnia magna was 0.060 mg test item/L (based on nominal), equivalent to 0.030 mg a.i./L (based on mean measured).

Description of key information

From short-term key study, the 48-hour EC50 for aquatic invertebrates exposed to the present test material was 0.03 mg a.i./L in freshwater.

From short-term supporting study, the 96-hour LC50 for aquatic invertebrates exposed to the present test material was 0.087 mg a.i./L in saltwater.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

ca. 0.03 mg/L

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

LC50

Effect concentration:

ca. 0.087 mg/L

Additional information

Four GLP-studies are available for short-term toxicity testing to aquatic invertebrates and one of them was identified as key study.

In the key study (1992), the acute toxicity of test substance to daphnia was investigated in a 48-hours static test with Daphnia magna according to guideline OECD 202. Five daphnia per replicate and four replicate per concentration were exposed for 48 hours under static conditions to nominal concentrations of 0.018, 0.032, 0.056, 0.100, 0.180, and 0.320 mg a.i./L, alongside with a control and a solvent control. The 48-hour EC₅₀was re-calculated and resulted in EC₅₀ of 0.03 mg a.i./L.

There are three additional studies available, conducted with Daphnia magna, Mysidopsis bahia and Crassostrea virginica; the resulting LC₅₀/EC₅₀values ranged between 0.087 and > 0.13 mg a.i./L. These studies were considered suitable for supporting purpose.

 

In the first supporting study (1998), the acute toxicity of test material to Daphnia magna was

determined in a 48-h-static test according to guideline OECD 202.The 48-hour EC50 of the technical active ingredient was determined to be > 0.13 mg/L based on the nominal concentrations.

 

In the second supporting study (1992), the acute toxicity of test material to M. bahia was determined in a 96-h flow-through test according to US EPA-72.3 guideline.The 96-hour LC50 of the technical active ingredient was determined to be 0.087 mg a.i./L, based on the mean measured concentration.

 

In the third supporting study (1992), the acute toxicity of test material to C. virginica was determined in a 96-h flow-through test according to US EPA-72.3 guideline.The 96-hour EC50of the technical active ingredient was determined to be 0.17 mg a.i./L, based on the mean measured concentration.