Fatty acids, C8-18 and C18-unsatd., reaction products with diethanolamine and propylene oxide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure (0 h) samples from vessels without daphnids and at the end of the exposure (48 h) samples from vessels with daphnids were analysed.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Fresh stock solutions were prepared daily and each concentration prepared separately by directly adding test substance to test medium and stirring for approximately 1 hour at 20 ± 2 °C.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Clone: Daphnia magna STRAUS 1820
- Source: supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978. From this date on this clone was cultured and bred continuously in the Laboratory of Ecotoxicology of the Experimental Toxicology and Ecology of BASF SE in Ludwigshafen.
- Age at study initiation: < 24 hours (at least 3rd brood progeny)
- Feeding during test: none

CULTURE CONDITIONS
- Culture media: synthetic fresh water (Elendt M4) prepared according to OECD 202
- Diet: Unicellular algae Desmodesmus subspicatus, cultured continuously at the test facility
- Feeding: Daily
- Renewal of the culture water: Twice weekly
- Temperature: 20 ± 1 °C
- Photoperiod: 16 hours light, 8 hours dark

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

pH:

7.9 - 8.0

Dissolved oxygen:

9.0 - 9.1 mg/L

Nominal and measured concentrations:

Nominal test concentrations: control, 0.56, 1.0, 1.8, 3.2, 5.6, 10 mg/L
Measured test concentrations: (based on total organic carbon) 0, LOQ = limit of quantification (1.2 mg/L)

Details on test conditions:

TEST SYSTEM
- Test vessel: Test vessels consist of cylinders of transparent glass, 6 cm diameter, 10 cm high, with a stainless-steel grid bottom of 0.2 mm x 0.2 mm mesh. The test vessels were suspended in overflow chambers and were filled with test solution to a height of 5 cm.
- Type of flow-through (e.g. peristaltic or proportional diluter): peristaltic pump
- Renewal rate of test solution (frequency/flow rate): The flow rate per replicate was 0.6 mL/min.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic freshwater (Elendt M4)
- Alkalinity: 0.8 - 1.0 mmol/L
- Conductivity: 550 - 650 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: Measurement of the pH and oxygen content at the start of the exposure and at the end of the exposure in each replicate of all test concentrations and the control. Measurement of temperature continuously during the whole period in a separate vessel filled with water proximal to the test vessels.

EFFECT PARAMETERS MEASURED: Immobilisation was recorded after 24 and 48h exposure time.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.25 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 2.12 – 14.32 mg/L

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

< 1.9 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

3.2 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.49 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No additional adverse effects or abnormal behaviour were observed in any of the test treatments.
- Mortality of control: no
- Other adverse effects control: no

Results with reference substance (positive control):

EC50 (24 h) = 1.13 mg/L
(Experiment from 12 Feb 2009)

DOC analysis:

The analytically determined concentrations of the test substance in the test water were 88 – 107% of the overall mean measured concentration in samples from the start of exposure and 93 - 112% of the overall mean measured concentration in samples from the end of exposure (48 h). The variability between measured replicates at each time point was generally ≤ 25%, however variability was greater in one case where the concentration was near the LOQ: 55.9% at 1.8 mg/L (48h). The test substance is a complex mixture that forms an emulsion in water. Additional samples were also sent for analysis by LC/MS as this was the only specific method available to analyze such a complex mixture at the concentrations tested. The amounts of all individual components were not determined by LC/MS analysis, but rather the mass spectra of 19 representative signals selected from a calibration mixture were evaluated. The individual components of the test substance have different characteristics and it is unlikely that all the components in the mixture will have identical behavior in solution over time. As described in the analytical report, samples of 10 mg/L (nominal) had a qualitatively similar composition according to the mass spectra. However there was a shift in signal intensity from less polar to more polar components compared to the calibration mixturewhich was greater at lower nominal concentrations. It is possible that this shift was due to binding of the less polar compounds to surfaces of the test system and thus a net shift to more polar compounds in solution. Since there was a shift in the relative composition of the mixture, the calibration procedure used for the analytical determination by LC/MS was inappropriate for a quantitative assessment. Therefore TOC values were used to calculate mean measured concentrations over the exposure period. Overall the analyses confirm that the test substance was present in the test vessels over the exposure period.

Validity criteria fulfilled:

yes

Description of key information

EC50 (48h) = 2.25 mg/L (measured) for Daphnia magna (OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

2.25 mg/L

Additional information

On study investigating the short-term toxicity of Fatty acids, C8-18 and C18-unsatd., reaction products with diethanolamine and propylene oxide (CAS 1000817-22-0) to aquatic invertebrates is available. The study was performed according to GLP and OECD guideline 202 using Daphnia magna as test organism (BASF 2009). After 48 hours of exposure under flow-through conditions the EC50 is determined to be 2.25 mg/L based on measured concentrations.