Isopropyl 2-bromo-2-methylpropionate

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

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Isopropyl 2-bromo-2-methylpropionate

EC Number:

257-158-0

EC Name:

Isopropyl 2-bromo-2-methylpropionate

Cas Number:

51368-55-9

Molecular formula:

C7H13BrO2

IUPAC Name:

isopropyl 2-bromo-2-methylpropionate

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

Standard dilution water (according to ISO 14442)

Test temperature:

Maintained at 23°C

pH:

Start : 7.18 - 7.24
End : 7.32 - 7.61

Dissolved oxygen:

Start : 8.7 - 9.1 mg/L
End : 8.6 - 10 mg/L

Salinity:

Not stated

Nominal and measured concentrations:

The ratio final/initial concentrations of Isopropyl 2-bromoisobutyrate has been measured. The average of final concentration of Isopropyl 2-bromoisobutyrate was within the designated limit of 80% of the average of initial concentrations.

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

8.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Range from 3.5 to 16 mg/L (with confident interval 95%)

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Range from 0.51 to 5.6 mg/L (with confident interval 95%)

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

23 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Range from 15 to 41 mg/L (with confident interval 95%)

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

5.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Range from 2.9 to 8.8 mg/L (with confident interval 95%)

Effect concentrations 6

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Experimental tests show an average of inhibition concentration EC50 of 8.6 mg/L of isopropyl 2-bromoisobutyrate on algae.
Thus, isopropyl 2-bromoisobutyrate has to be considered Toxic to aquatic life.