Fatty acids, tall-oil, 1-methyl-1,2-ethanediyl esters

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)

Version / remarks:

(2004)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

(2008)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: nominal 100 mg/L and control
- Sampling intervals: start and end of the renewal periods
- Sampling method: Four samples (50 mL) were taken from the freshly prepared control and test media. The expired media from each group were pooled and further samples were taken for analysis.
- Sample storage conditions before analysis: no storage prior to analysis

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: water accommodated fractions (WAFs)
500 mg test material was dispersed in 5 L dilution medium (Elendt M4 medium) in an aspirator. The bulk preparation was stirred for approximately 24 hours in the dark, after which a syphon was added to the mid-vessel portion of the aspirator; the bulk was then left to stand for approximately 24 hours in the dark. An aliquot (1 L) of the mid-vessel portion was siphoned from the preparation vessel and discarded, after which a further 1 L was removed mid-vessel to provide the Water Accommodated Fraction (WAF); this medium was used as test medium with a nominal loading rate of 100 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: in-house culture originating from a strain supplied by the National Institute for Applied Chemical Research (IRCHA), France
- Age at study initiation: < 24 h
- Method of breeding: Stock cultures of Daphnia magna were maintained in glass vessels containing approximately 0.5 to 0.8 litres of Elendt M4 culture medium in a temperature-controlled laboratory at nominally 20 ± 2°C. A photoperiod of 16 hours light : 8 hours dark was maintained, with periods of subdued lighting at the beginning and end of each light phase. The culture medium was renewed three times each week.
Cultures were fed daily with a suspension of the unicellular green algae, Pseudokirchneriella subcapitata, to provide nominally 0.1 to 0.2 mg carbon per daphnid, per day, except during the initial three days when a slightly lower ration was given. Culture conditions ensure that the stock animals reproduce by parthenogenesis.
The day before the start of the study, all juvenile Daphnia were removed from the laboratory cultures. The following morning, juveniles produced by the gravid (egg-bearing) adult Daphnia were removed from the culture vessels and held in a separate holding vessel.
- Feeding during test: none

ACCLIMATION
- Acclimation period: not relevant, conditions were the same for maintenance and testing

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

268 and 248 mg/L as CaCO3 for the two batches of Elendt M4 medium used

Test temperature:

21 ± 1 °C

pH:

7.4-7.7

Dissolved oxygen:

86-90 % air saturation value

Nominal and measured concentrations:

nominal loading rate: 100 mg test material/L as WAF
mean measured TOC levels (after background correction):
in freshly prepared media: 6.2 and 7.8 mg C/L
in expired media (24 h): 5.4 and 7.7 mg C/L (>80% of the respective starting values)
overall geometric mean measured TOC level: 6.7 mg C/L (96% of the mean starting value)

Details on test conditions:

TEST SYSTEM
- Test vessel: covered glass jars containing approx. 100 mL of medium
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: ca. 20 mL medium per organism

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionised, reverse osmosis water
- Total organic carbon: 1.5 mg C/L
- Alkalinity: 64 and 41 mg /L as CaCO3 for the two batches of Elendt M4 medium used
- Ca/Mg ratio: 3.7:1
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours light : 8 hours dark with periods of subdued lighting at the beginning and end of each light phase

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : numbers of mobile, immobile and floating Daphnia counted approx. 24 and 48 hours after the start of the study

RANGE FINDING STUDY
- Test concentrations: nominal loading rates of 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: no immobility after 48 hours.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: results are expressed in terms of loading rates

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: results are expressed in terms of loading rates

Details on results:

- Behavioural abnormalities: none
- Mortality of control: none
- Other adverse effects control: none
- Abnormal responses: none

The test medium was colourless.

Results with reference substance (positive control):

- 48-hour EC50: 0.5 mg/L (within the range typically obtained in this laboratory)

Reported statistics and error estimates:

The “no observed effect loading rate” (NOELR) was derived by direct inspection of the data on the immobility of the animals. An incidence rate of more than 10% was considered to be significant.

Validity criteria fulfilled:

yes

Remarks:

The number of floating and/or immobile Daphnia in the control group did not exceed 10% and the concentration of dissolved oxygen was > 3 mg/L (≥60% of the air saturation value at the temperature used) at the end of the test.

Description of key information

48-h EL50 (based on loading rates) >100 mg/L for Daphnia magna (OECD TG 202, EU C.2)

Additional information

EL50 >100 mg/L for Daphnia magna.

The results indicate that the test material is not toxic to daphnia up to the limits of its water solubility (<1 mg/L) and a NOEC and thus a PNEC cannot be determined.