2-methylpropyl-(R)-2-hydroxypropanoate

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpropyl-(R)-2-hydroxypropanoate

EC Number:

407-770-0

EC Name:

2-methylpropyl-(R)-2-hydroxypropanoate

Cas Number:

61597-96-4

Molecular formula:

C7 H14 O3

IUPAC Name:

2-methylpropyl-(R)-2-hydroxypropanoate

Details on test material:

- Name of test material (as cited in study report): D-Milchsäureisobutylester
- Physical state: fluid
- Analytical purity: 99%
- Impurities: i-Butanol (< 1%)
- Batch No.: Cont. TTTU 119 618

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green alga
- Strain: SAG 86.81
- Source: Collection of algal cultures in Goettingen, Germany

METHOD OF CULTIVATION
Stock culture
- Culture vessel: 250 ml Erlenmeyer flask
- Culture volume: 100 ml
- Initial cell density: 10000 cells/ml
- Growth period: weekly passage

Pre culture
- Culture vessel: 250 ml Erlenmeyer flask
- Culture volume: 100 ml
- Initial cell density: 10000 cells/ml
- Groth period: 72 h

Test culture
- Culture vessel: glas tubes with flat bottom
- Culture volume: 8 ml
- Initial cell density: 10000 cells/ml
- Groth period: 72 h

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

pH:

uninoculated: 8.0 - 8.9
inoculated: 8.1 - 9.5

Nominal and measured concentrations:

Nominal test concentrations: control, 0.78, 1.56, 3.13, 6.25, 12.5, 25, 50, 100 mg/l

Details on test conditions:

TEST SYSTEM
_ Initial cells density: 10000 cells/ml
- No. of vessels per concentration (inoculated): 4
- No. of vessels per control (inoculated): 4

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Intervals of water quality measurement: pH after 0 h in a uninoculated replicate and after 72 h in a uninoculated and inoculated replicate

OTHER TEST CONDITIONS
- Photoperiod: permanent light
- Light intensity and quality: universal white, 120 µE/m²s

EFFECT PARAMETERS MEASURED:
- Determination of cell concentrations: Neubauer improved
- Chlorophyll measurement: fluoreszence

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

36 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

13 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 5

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 6

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass