Bromobenzene

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

The study was conducted at least in part following OECD 202.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A range of different concentrations of exposure solutions of the test substance was prepared before use directly in the culture media, sonciated for 30 min and sterilized by filtration through a 0.22 µm filter (Millipore).
- Controls: yes, without test item

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: CISA, Spain
- Age at test begin: neonates

CULTURE CONDITIONS
- Temperature: 20 °C
- Food: C. vulgaris

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Nominal and measured concentrations:

control, 0.01, - 0.5 mM

Details on test conditions:

TEST SYSTEM
- Test vessel: flasks (Costar, Cambridge, MA, USA)
- Material, size, headspace, fill volume: Material: polystyrene; Size: 70 mL; Fill volume: 25 mL
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): at least in duplicate
- No. of vessels per control (replicates): at least in duplicate
- Other: all experiments were performed at least three times

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: standard reference water according to OECD guideline

EFFECT PARAMETERS MEASURED:
- Immobilization: 24, 48, and 72 h

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

15.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: re-calculated from 0.10 mM

Reported statistics and error estimates:

Statistical analysis was carried out using analysis of variance (ANOVA), followed by Dunnett´s multiple comparison test.
Mean effective concentration (EC50) values were determined by probit analysis.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, and each concentration
- Sampling method: Toxicant concentration was measured at the beginning and the end of the test, on one vessel of each concentration and the control. To reduce loss due to volatilization during sampling, exposure water was siphoned into volumetric flasks or volumetrically pipetted into reagent bottles containing a known volume of hexane.

Test organisms (species):

other: Ceriodaphnia dubia

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: EPA Environmental Research Laboratory, Duluth culture
- Age at test initiation: < 24 h
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

45.5 ± 1 mg/L CaCO3 (dilution water)

Test temperature:

25 ± 1 °C (dilution water)

pH:

7.6 ± 0.6 (dilution water)

Dissolved oxygen:

7.3 ± mg/L (dilution water)

Conductivity:

111 ± 9 µΩ^-1 cm (dilution water)

Details on test conditions:

TEST SYSTEM
- Test vessel: cup
- Type (delete if not applicable): tightly closed
- Material, size, headspace, fill volume: Material: plastic; size: 25 mL; Fill volume: 25 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: sand-filtered, aerated natural water from Lake Superior
- Alkalinity: 41 ± 5 mg/L (as CaCO3)
- Conductivity: 111 ± 9 µΩ^-1 cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: at the beginning and end of the test

OTHER TEST CONDITIONS
- Photoperiod: 18 h light, 6 h dark

EFFECT PARAMETERS MEASURED:
- Mortality: after 24 h

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

5.8 mg/L

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 4.8 - 7.1 mg/L 95% confidence limits

Reported statistics and error estimates:

The trimmed Spearman-Karber method (Hamilton et al., 1977) was used to estimated the LC50 values and their confidence limits. A trimming of 10% was judged appropriate for most of the data sets. In those cases when the highest percentage of affected animals was less than 80%, the LC50 was estimated by linear interpolation.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

- Concentrations: test solutions
- Sampling method: at the beginning and end of the experiment

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solutions were prepared by adding the chemicals to the dilution water under mechanical stirring. Test solutions were obtained by diluting the stock solutions.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house laboratory culture
- Age at test start: < 24 h

LABORATORY CULTURE
- Food type: yeast and Selenastrum capricornutum

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

24 h

Hardness:

130 mg/L CaCO3

Test temperature:

20 ± 1 °C

pH:

8.2 ± 0.5

Conductivity:

400 ± 25 µS/cm

Nominal and measured concentrations:

control, and a minimum of five test concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: bottles
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: Size: 150 mL; Headspace: 0 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dilution water was prepared by mixing Milli-Q and tap water in a 1:1 ratio, which was adjusted to a hardness of 150 mg/L (CaCO3); total hardness 130 mg/L (expressed as CaCO3)
- Conductivity: 400 ± 25 µS/cm
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: yes
- Photoperiod: 16 h light, 8 h dark

EFFECT PARAMETERS MEASURED:
- Immobilization: after 24 h

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

1.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Confidence limits = 1.04 - 2.46

Reported statistics and error estimates:

The 24 h - EC(50) value was estimated by the Litchfield and Wilcoxon method.

Description of key information

EC50 (48 h): 15.7 mg/L (nominal, OECD 202, D. magna)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

15.7 mg/L

Additional information

Three published studies are available investigating the acute toxicity towards aquatic invertebrates. None of them were conducted according to GLP or strictly followed OECD guideline 202 or similar.

The most reliable is the study by Zurita et al (2007). Not all details are provided, but this study followed in part OECD guideline 202. D. magna were exposed to concentrations of the test substance ranging from 1.57 to 78.5 mg/L (nominal) (given as 0.01 - 05.mM). The test solutions were prepared before use directly in the culture media, sonciated for 30 min and sterilized by filtration through a 0.22 µm filter. No analytics were performed. For 48 h an EC50 mg/L of 15.7 mg/L was determined (re-calculated from 0.10 mM).

Two further publications available (Marchini et al., 1993; Tosato et al., 1991) provide less detailed information and report only 24 h EC50 values of 5.8 mg/L and 1.6 mg/L, respectively. Nevertheless, with regard to classification these two studies were also considered, thus classification is based on a worst case assumption.