bis(hydrogenated tallow C16-18-alkyl)hydroxylamine

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

Study period:

1996-05-24 to 1996-06-25

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

92/69/EEC

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted April 4, 1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all concentrations tested
- Sampling method:
During the test duplicate samples were taken from the control (0 mg/L) and the saturated test substance solution (100%-filtrate) and one dilution (25%-fiItrate) for analysis on the two major compounds.
Sampling:
Frequency: at t= 0 h and at t= 48 h.
Volume: 10 ml from the approximate centre of the test vessel.
- Sample storage conditions before analysis: stored in deep-freeze

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method:
The test substance is a mixture of eight compounds, which are all hardly soluble in water (< 0.0005 g/L). Initially, test solutions were prepared at 100 mg/L using Tween 80 as a dispersent. These solutions were stirred for ca. 68 hours. Subsequently, the water phase of one solution was separated from the undissolved
fraction of the test substance by filtration through a paper filter (Schleicher and Schuell 604, ca. 5 µm). The filtrate was tested together with the unfiltered solution.
The test solutions used in the test originated from those prepared for the fish toxicity test (please refer to section 6.1.1). In addition to the filtrate prepared at 100 mg/L (100%), dilutions of the filtrate were prepared containing 25% and 50% of the filtrate. Also, a non filtered supersaturated solution of 100 mg/L was included in the test.
- Differential loading: 100 mg/L
- Evidence of undissolved material: In the unfiltered dispersion, the major part of the undissolved test substance was observed floating at the surface.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Straus, 1820
- Age at study initiation: For the test selection of young daphnia with an age of < 24 hours.
- Method of breeding:
Start of each batch: With newborn animals, i.e. less than 3 days old, by placing about 250 of them into 10 litres of medium in an all-glass culture vessel.
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

250 mg/L expressed as CaCO3

Test temperature:

20.4 to 20.6 °C

pH:

7.4 to 8.0

Dissolved oxygen:

8.9 to 9.4 mg O2/L

Nominal and measured concentrations:

Nominal:
The final test was a limit study exposing daphnia to a supersaturated solution of 100 mg/L and the water phase of a supersaturated solution of 100 mg/L (100%) and two dilutions containing 25% and 50% of the filtrate.

Measured:
The actual concentrations were based on measurement of two compounds with molecular masses (M) of 510.7 and 522.6. The concentration of both components were just above the maximum detection level of 0.4 mg/L in the samples taken from 100 % filtrate at the start of the test, i.e. 0.54 mg/L of the compound with M= 522.6 and 0.61 mg/L of the compound with M= 510.7. The recoveries found in the samples taken at the end of the test showed that the concentration of the compound with M= 522.6 had decreased by 20%, whereas the concentration of the compound with M= 510.7 had decreased by 30%.
Hence, these results showed that it was not possible to prepare solutions which contained test concentrations at levels largely exceeding 0.5 mg/L (maximum solubility) even when starting from a supersaturated solution with a nominal concentration of 100 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL, all glass
- Aeration: No aeration of the test solution.
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 10 organisms per vessel containing 80 ml medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to EU and OECD guidelines

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hours photoperiod daily

EFFECT PARAMETERS MEASURED:
Immobility (including mortality): At 24 hours and 48 hours.
pH and oxygen: At the beginning and at the end of the test, for all concentrations and the control.
Temperature of medium: Daily in one control vessel, beginning at the start of the test.

TEST CONCENTRATIONS
- Range finding study:
Ten daphnids per vessel were exposed to either the water phase of a test substance solution prepared at a concentration of 100 mg/L or the unfiltered dispersion at nominal 100 mg/L. Both test solutions contained Tween 80 at 100 mg/L. Also a negative control and an additive control were tested.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none
- Other biological observations: none
- Immobilisation of control: 0 organisms
- Other adverse effects control: none
- Abnormal responses: none
- Any observations that might cause a difference between measured and nominal values: Substance deposits were observed in the vessels containing the unfiltered solution of 100 mg/L

Results with reference substance (positive control):

- Results with reference substance valid: yes
The 48h-EC50 was 0.65 mg/lLwith 95 % confidencial limits of 0.56 - 0.83 mg/L.

Description of key information

A GLP guideline study according to OECD 202 was conducted (NOTOX 166837, 1996). Due to the low water solubility of this UVCB, two test solutions were prepared by stirring 100 mg/L (nominal concentration) for ca. 68 hours. The water phase of one solution was separated from the undissolved fraction of the test substance by filtration through a paper filter while the second solution was tested unfiltered. In addition, dilutions of the filtrate were prepared containing 25% and 50% of the filtrate.

Due to this procedure it can be assumed that the daphnids were exposed to the maximal concentration possible in the medium used.

No significant effects concerning mobility and toxicity were observable in all test solutions after a test duration of 48 hours. Therefore, the tested UVCB is considered to be acutely not harmful to daphnids in the range of its water solubility.

Additional information

With high probability acutely not harmful to daphnids, no toxic effects occur in the range of water solubility.