Guerbet alcohols, C24-26, branched and cyclic

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:

other: Study conducted according to OECD guideline 202 following GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

as Limit-test

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Water Accomodated Fraction
- Limit loading rate: 100 mg/l
- Control: ISO test water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): No vehicle used.
- Concentration of vehicle in test medium (stock solution and final test solution): No vehicle used.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): None observed.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna.
- Source: In-house culture.
- Age at study initiation (range): 2-24 hours.
- Feeding during test: No.


ACCLIMATION
- Acclimation period: Min. 2 hours in test medium.
- Acclimation conditions (same as test or not): Same as test.
- Type and amount of food: Not applicable.
- Feeding frequency: Not applicable.
- Health during acclimation (any mortality observed): No.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

semi-static exposure, renewal after 24 h

Post exposure observation period:

Not applicable.

Hardness:

262-269 mg CaCO3/L

Test temperature:

20.3-20.6°C

pH:

7.76-8.00

Dissolved oxygen:

> 8.79 mg/l (at end of 24 h exposure period)

Salinity:

Not applicable.

Nominal and measured concentrations:

100 mg/l WAF (Limit-test)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers (4 (ID) x 7 (H) cm), 50 mL capacity, loosely covered with watch glasses.
- Fill volume: 20 ml
- Aeration: No.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Dilution water: ISO Test water, according to OECD 202, Annex 3.
- Intervals of water quality measurement: At end of each renewal period (0h and 24h).

OTHER TEST CONDITIONS
- Adjustment of pH: No.
- Photoperiod: 16/8 h light/dark cycle.
- Light intensity: Diffuse light, light intensity of max. 20 µEm-2 s-1 (1340 lx).

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility after 24h and 48h of exposure.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: Not applicable.
- Justification for using less concentrations than requested by guideline: Range finding study.
- Range finding study loading rates: 10 mg/l and 100 mg/l (semi static)
- Results used to determine the conditions for the definitive study: No effects observed for any of the two loading rates.

Reference substance (positive control):

yes

Remarks:

historic (monthly data) of test institute

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: Water Accommodated Fraction

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: None reported.
- Observations on body length and weight: None reported.
- Other biological observations: None reported.
- Mortality of control: No.
- Other adverse effects control: None reported.
- Abnormal responses: None reported.
- 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: Not applicable (WAF was tested).

Results with reference substance (positive control):

Historic (monthly) reference data of test institute for potassium dichromate:
EC50 (24 h): 2.00 mg/L (Cl: 1.83 - 2.19 mg/L)

Validity criteria fulfilled:

yes

Conclusions:

At the water soluble fraction (WSF) with a nominal loading of 100 mg/L of the test item Guerbet alcohols, C24-26, branched and cyclic, no effects were observed on Daphnia magna over an exposure period of 48 hours.

Executive summary:

In the acute immobilisation test with Daphnia magna (STRAUS), the effects of the Water Soluble Fraction (WSF) with a nominal loading of 100 mg/L of the test item Guerbet alcohols, C24-26, branched and cyclic were determined according to OECD 202 (2004).

The limit test was conducted under semi-static conditions over a period of 48 hours.

The test item is an UVCB substance, a colourless liquid white, which is insoluble in water. In view of the difficulties associated with the evaluation of aquatic toxicity of poorly water soluble test items, a modification of the standard method for the preparation of aqueous media was performed. An approach endorsed by several important regulatory authorities in the EU and elsewhere (ECETOC 1996 and OECD Series No. 23 (2000)), is to expose the organisms to a Water Accommodated Fraction (WAF) / Water Soluble Fraction (WSF) of the test item in cases where the test item is a complex mixture and is poorly soluble in water and in the permitted solvents (as defined in the guidelines mentioned above).

Twenty daphnids were exposed to the WSF and the control each. No analytical monitoring of the test item concentration was carried out, because the test item is insoluble in water and therefore, measured concentrations were found to be below the limit of quantification.

Since no effects on Daphnia magna were observed, the analytical results were acceptable.

The water quality parameters (i.e. pH-value and dissolved oxygen concentration), measured at the start (0 and 24 hours) and at the end of the exposure intervals (24 and 48 hours), were within the acceptable limits. The validity criteria of the test guidelines were fulfilled.

At the water soluble fraction (WSF) with a nominal loading of 100 mg/L of the test item Guerbet alcohols, C24-26, branched and cyclic, no effects were observed on Daphnia magna over an exposure period of 48 hours.

Description of key information

An acute daphnia toxicity study performed according to OECD test Guideline 202 is available for Guerbet alcohols, C24-26, branched and linear. No toxicity was observed in the water soluble fraction with a nominal loading of 100 mg/l.

Additional information

An acute dahnia toxicity study according to OECD Guideline 202

was performed in daphnia magna. In the water soluble fraction (WSF) with a nominal loading of 100 mg/L of the test item Guerbet alcohols, C24-26, branched and cyclic, no effects were observed over an exposure period of 48 hours.

These results fit to the acute daphina toxicity data of structurally related long chain Guerbet alcohols (e. g. 2 -hexyldecan-1-ol, 2 -octyldodecan-1 -ol, 2 -hexyltetradecan-1 -ol) showing no toxic efftects in daphnia up to their (even higher) limits of water solubility.