2,2'-dibromobiphenyl

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:

June 18 - October 19, 2015

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure and at the renewal (0 and 24 h), samples of the freshly prepared test item concentrations were taken and analyzed.
At renewal and at the end of the exposure (24 and 48 h), sampled of the 24 h old media were taken directly fron the test vessels and analyzed.

Vehicle:

yes

Remarks:

dilution water

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS (Clone 5)
- Source: Institut für Wasser-, Boden und Lufthygiene (WaBoLu), Berlin, Germany
- Age: < 24 h

FEEDING DURING TEST
- Food type: 5 x per week ad libitum with a mix of unicellular green algae

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

263 (0 h) and 267 (24 h) mg CaCO3/L

Test temperature:

20.7 - 20.9 °C

pH:

7.68 - 7.69

Dissolved oxygen:

10.0 - 8.75 mg/L

Conductivity:

640 - 660 µS/cm

Nominal and measured concentrations:

100 mg/L (nominal) = 0.236 mg/L (geometric mean analytical)

Details on test conditions:

Test vessels:
Glass beakers, 50 mL capacity, loosely covered with watch glasses
Test volume: 20 mL
Number of daphnids and replicates: 20 daphnids, divided into 2 replicates, each with 10 daphnids were used for the test material concentration level and control.
Application: 20 g test solution per replicate was weighed out into each test vessel. This corresponds to 20 mL per test vessel. The daphnids were inserted with a small amount of dilution water (start of the exposure) or test solution (water renewal) by pipette.
Renewal of the test solutions: The test solutions were renewed after 24 h. For this purpose, a second set of test vessels was filled with the freshly prepared test solutions and the daphnids were transferred by pipette.

Reference substance (positive control):

no

Remarks:

A reference test is conducted once per month to prove the validity of the test item.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.236 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: limit of water solubility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No effects were observed on Daphnia magna at the saturated solution with a nominal loading rate of 100 mg/L (= 0.236 mg/L geometric mean measured concentration).

Results with reference substance (positive control):

EC50 (24 h) = 1.88 mg/L
valid range: 1.62 - 2.19 mg/L, acc. to AQS P 9/2 (02/2000)

1) Immobilization Rates after 24 and 48 hours of Exposure in the Definitive Test of the saturated solution with a loading rate of 100 mg/L

Geometric mean measured test item concentration [µg/L]	IMMOBILIZATION [%]
	24 hours					48 hours
	Replicates					Replicates
	1	2	3	4	MV	1	2	3	4	MV
0.236	0	0	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0	0	0

2) Measured Concentrations during the Definitive Test

Sampling date	Fresh media, 0 hours	Old media, 24 hours		Fresh media, 24 hours	Old media, 48 hours		Geometric mean* measured concentration of the test item   [mg/L]
Nominal loading rate of the saturated solution of the test item [%]	Test Item
	Meas. conc. [mg/L]	Meas. conc. [mg/L]	%	Meas. conc. [mg/L]	Meas. conc. [mg/L]	%
100	0.310	0.225	73	0.277	0.160	58	0.236
Control	< LOQ	< LOQ		< LOQ	< LOQ		< LOQ

Meas. conc. = measured concentration of the test item, enrichment and dilution factors taken into account

%                = percentage of the initially measured concentration of the test item

LOQ           = limit of quantification of the analytical method (3 µg test item/L)

Validity criteria fulfilled:

yes

Conclusions:

Based on the geometric mean measured concentrations of the test item, the 48 hour-EC50 for Daphnia magna was > 0.236 mg/L thus exceeding the saturation limit at the nominal loading of 100 mg/L.

Executive summary:

The information for this endpoint study record was obtained from an experimental study. The OECD GLP criteria were met and the methods applied are fully compliant with OECD TG 202. No adverse effects on the mobility of daphnia magna were observed up to the water solubility of the test item. Based on the geometric mean measured concentrations of the test item, the 48 hour-EC50 for Daphnia magna was > 0.236 mg/L thus exceeding the saturation limit at the nominal loading of 100 mg/L.

Description of key information

Based on the geometric mean measured concentrations of the test item, the 48 hour-EC50 for Daphnia magna was > 0.236 mg/L (eq. nominal 100 mg/L). No adverse effects were observed up to the water soulibity of the test item.