N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide]

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

For the detailed read across justification please refer to the attached pdf file.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

48 h

Dose descriptor:

EC50

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

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-05-10 to 2002-05-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study performed according to OECD and according to GLP. No analytical determination performed (undiluted filtrate of a supersaturated dispersion).

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted 1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test medium was prepared as follows: Due to the low water solubility of the test item, a supersaturated dispersion with a loading rate of 100 mg/L was prepared by weighing 30 mg of the test item into 300 mL test water. No auxiliary solvent or emulsifier was used. The test item was mixed into the test water as homogeneously as possible by ultrasonic treatment for 15 minutes and by intense stirring for 96 hours at room temperature to dissolve a maximum concentration of the test item in the dispersion.
Then, the supersaturated dispersion of the test item was filtered through a membrane filter (Schleicher & Schuell, Type NC45, pore size 0.45 pm) just before the start of the test.

Test organisms (species):

Daphnia magna

Details on test organisms:

Common Name: Water Flea - Daphnia magna Straus
A clone of this species was originally supplied by the University of Sheffield/UK in 1992, defined from the supplier as clone 5.
Age at study initiation: 6-24 h
Method of breeding: in RCC laboratories in reconstituted water of the quality identical to the water quality used i the tests (regarding pH, main ions and total hardness) and under temperature and light conditions identical to those of the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (=250.0 mg/L) as CaCO3

Test temperature:

20 °C (the test was performed in a temperature-controlled room)

pH:

7.8-8.0
start: pH = 8.0 for control and 7.8 for the loading rate; end: pH = 7.9 for both

Dissolved oxygen:

8.5-9.1
start: 8.7 for the control and 8.5 for the loading rate; end: 9.0 for the control and 9.1 for the loading rate

Nominal and measured concentrations:

Loading rate of 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: the beakers were covered with glass plates to reduce the loss of water and to avoid the entry of dust
- Material, size, headspace, fill volume: 100 mL glass beakers
- Aeration: non
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: < 1 daphnia per 2 ml of test solution

TEST MEDIUM / WATER PARAMETERS
Test water:
- Reconstituted test water: analytical grade salts were dissolved in purified water in accordance with Guideline:
- Alkalinity: 0.8 mmol/L
- Ratio of Ca:Mg = 4:1 (based on molarity)
- Ratio of Na:K = 10:1 (based on molarity)
- Culture medium different from test medium: no
- Intervals of water quality measurement: 24h

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: a 16-hour light to 8-hour dark photoperiod with a 30-minute transition period
- Light intensity: between approximately 520-685 Lux

EFFECT PARAMETERS MEASURED: Immobilization (every 24h)

TEST CONCENTRATIONS
Loading rate of 100 mg/L (nominal)

Reference substance (positive control):

yes

Remarks:

potassium dichromate (tested at least once a year)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

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:

Mortality of control: none
No remarkable observations were made concerning the appearance of the test medium. The test medium was a clear solution throughout the whole test duration.

Description of key information

With high probability acutely not harmful to aquatic invertebrates. 

Additional information

According to regulation (EC) No 1907/2006, Annex XI, paragraph 1.5., substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity may be considered as a group, or "category" of substances. Environmental effects or environmental fate may be predicted from data for reference substance(s) within the group by interpolation to other substances in the group (read-across approach). The detailed read across justification is attached to the endpoint.

The toxicity of Daphnia magna of a structural analogue (EC No 255 -392 -8) was studied in a 48 h static test according to OECD 202. A supersaturated dispersion of the test item with a loading rate of 100 mg/L continuously stirred at room temperature in the dark over 96 h and a control was used in the test. No immobilized test organisms were determined during the test period of 48 hours. Thus, the 48 -h EC50 were determined to be at the loading rate of 100 mg/L.

In addition, the toxicity of the test item was determined in a disregarded static 24 -h acute toxicty test to Daphnia magna according to OECD 202. Since the test item is poorly water soluble, an emulsifier was used as test vehicle. Nominal concentrations were 10, 18, 32, 58 and 100 mg/L. No toxic effects in the range of water solubility were observed after 24 hours.