Diethyl 4-oxopentane-1,2-dicarboxylate

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)

Rationale for reliability incl. deficiencies:

other: GLP compliant study conducted to Internation test guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Diethyl 4-oxopentane-1,2-dicarboxylate

EC Number:

413-860-0

EC Name:

Diethyl 4-oxopentane-1,2-dicarboxylate

Cas Number:

1187-74-2

Molecular formula:

C11H18O5

IUPAC Name:

1,4-diethyl 2-(2-oxopropyl)butanedioate

Details on test material:

- Name of test material (as cited in study report): CA787A (intermediate of CGA163935)
- Physical state: Liquid
- Analytical purity: 98.9%
- Purity test date: 1996-06-03
- Lot/batch No.: SKCA001
- Stability under test conditions: Stable
- Storage condition of test material: Room temperature, protected from light

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control) and 100 mg/L
- Sampling method: Direct sampliing of fresh media (study initiation) and, at study end, direct sampling of a composite of the 3 replicates after centrifugation to remove algae. Samples taken from mid-point of test vessel
- Sample storage conditions before analysis: Analysis undertaken on the day of sampling

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Dilution with test medium
- Eluate: OECD medium
- Differential loading: No
- Controls: Yes - OECD medium alone
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): None used
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None observed

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapita
- Strain:
- Source (laboratory, culture collection): Laboratory culture originally sourced from Plant Physiologic Institute Gottingen Germany
- Age of inoculum (at test initiation): 5 days
- Method of cultivation: 250 mL glass flasks containing 100 mL OECD medium, shaking at 90 rpm, constant illumination at 6026-8070 Lux, at 24.3-24.9 degrees C


ACCLIMATION
- Acclimation period: 5 days
- Culturing media and conditions (same as test or not): Same as test conditions
- Any deformed or abnormal cells observed: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Post exposure observation period:

None

Test conditions

Hardness:

Not reported

Test temperature:

24.3-24.8 degrees c

pH:

Control: 8.02 at test start, 9.81 at test termination
Test: 7.96 at test start, 9.34 at test termination

Dissolved oxygen:

Not reported

Salinity:

Not relevant for fresh water tests

Nominal and measured concentrations:

Nominal: 0 mg/L (control) and 100 mg/L (limit test)
Measured at test start: <5.345 mg/L (control) and 102 mg/L(limit test)
Measured at test termination: <4.746 mg/L (control) and 49 mg/L (Limit test)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed with stainless steel caps
- Material, size, headspace, fill volume: Glass 250 mL flasks, filled with 100 mL medium
- Aeration: none
- Initial cells density: 1E4 cells/mL
- Control end cells density: 137.8E4 cells/mL
- No. of organisms per vessel: 1E6 cells
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3


GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Sterile deionised water
- Total organic carbon: Not reported
- Particulate matter: Not reported
- Metals: Meets ASTM E729-88
- Pesticides: Meets ASTM E729-88
- Chlorine: Not reported
- Alkalinity: Not reported
- Ca/mg ratio: 5.3
- Conductivity: Not repoted
- Culture medium different from test medium: No
- Intervals of water quality measurement: Annual


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: Yes
- Photoperiod: Continuous
- Light intensity and quality: 6241-7747 lux, cool white fluorescent lamps


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting chamber


TEST CONCENTRATIONS
- Spacing factor for test concentrations: None (study conducted as a limit test)
- Justification for using less concentrations than requested by guideline: Expected lack of toxicity at limit concentration
- Range finding study
- Test concentrations: 0.01 - 100 mg/L
- Results used to determine the conditions for the definitive study: Lack oif growth inhibition at 100 mg/L

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 3

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 75.26 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 75.26 mg/L

Nominal / measured:

meas. (arithm. mean)

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:

growth rate

Effect concentrations 6

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 7

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 75.26 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 8

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 75.26 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test):
- Unusual cell shape: Bloated appearance
- Colour differences:
- Any stimulation of growth found in any treatment: Yes
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The substance tested does not inhibit the growth of aquatic algae

Executive summary:

The substance tested does not inhibit the growth of aquatic algae