Isopropyl 2-methylbutyrate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 October to 02 November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Toyo Gosei Ltd., H4-K-27
- Expiration date of the lot/batch: 17 August 2019
- Purity test date:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient (15±10°C)
- Stability under test conditions: Stable
- Solubility and stability of the test substance in the solvent/vehicle: Stable
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: CCAP 278/4
- Source (laboratory, culture collection): Culture Collection of Algae and Protozoa, SAMS Ltd, Scottish Marine Institute, OBAN, Argyll PA37 1QA, Scotland, United Kingdom
- Age of inoculum (at test initiation):
- Method of cultivation:

ACCLIMATION
- Acclimation period: noi
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

Standard for OECD 201

Post exposure observation period:

None

Hardness:

No data

Test temperature:

20°C

pH:

8 to 9.6

Dissolved oxygen:

No data

Salinity:

No data

Conductivity:

No data

Nominal and measured concentrations:

0 amd 100 mg/L
0 and 44.317 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL flask
- Type: closed; Each flask was sealed immediately after the introduction of the inoculated
test media and sealed with parafilm to prevent volatilisation of the test material. The flask was given a single perforation using a 5μl syringe to allow the control and test media to maintain a stable pH.
- Material, size, headspace, fill volume:
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Renewal rate of test solution (frequency/flow rate):
- Initial cells density:
- Control end cells density:
- No. of organisms per vessel:
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6
- No. of vessels per vehicle control (replicates): not applicable

GROWTH MEDIUM
- Standard medium used: yes
- Detailed composition if non-standard medium was used:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- Total organic carbon:
- Particulate matter:
- Metals:
- Pesticides:
- Chlorine:
- Alkalinity:
- Ca/mg ratio:
- Conductivity:
- Culture medium different from test medium:
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Sterile test conditions: yes/no
- Adjustment of pH:
- Photoperiod:
- Light intensity and quality: 5900 to 9590 Lux
- Salinity (for marine algae):

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: [counting chamber; electronic particle counter; fluorimeter; spectrophotometer; colorimeter]
- Chlorophyll measurement:
- Other:

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Justification for using less concentrations than requested by guideline:
- Range finding study
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 44.317 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Confidence limits not possible to determine.

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 44.317 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

44.317 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): no
- Observation of abnormalities (for algal test): no
- Unusual cell shape: no
- Colour differences: no
- Flocculation: no
- Adherence to test vessels: no data
- Aggregation of algal cells:
- Other:
- Any stimulation of growth found in any treatment:
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
- Effect concentrations exceeding solubility of substance in test medium:

Validity criteria fulfilled:

yes

Conclusions:

The 72 hour EC(r)50 of Isopropyl 2-methylbutyrate to Pseudokirchneriella subcapitata was >44.317mg/L

Description of key information

The 72 hour EC(r)50 of Isopropyl 2-methylbutyrate to Pseudokirchneriella subcapitata was >44.317mg/L.

The 0 to 72-hour NOEC(r) was <44.317mg/L and the 0-72 hour LOEC was 44.317mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:

44.317 mg/L

EC10 or NOEC for freshwater algae:

44.317 mg/L