Diesters of alcohols, C7-9-iso-, C8-rich, 2-ethylhexyl and nonanedioic acid

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:

20 - 22 Jan 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study with acceptable restrictions: The analytical purity is only 77.2%.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Remarks:

according to the Japanese GLP Standard

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Samples were taken directly from each vessel.
- Sample storage conditions before analysis: no storage before analysis

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Test substance was measured and mixed with vehicle. Water was added bit by bit to prepare the stock solution (1000 mg/L). Stock solution was diluted with test water and stored in the dark and cool. The stability during 48 hours is confirmed.
- Controls: blank control and vehicle control
- Chemical name of vehicle: HCO-40
- Concentration of vehicle in test medium: 1000 mg/L in a stock solution, 1 mg/L in final concentration
- Evidence of undissolved material: Test water was clear and colourless after preparation.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Incorporated Administrative Agency, National Institute for Environmental Studies, Tsukuba, Japan
- Age at study initiation: ≤ 24 hours
- Feeding during test: no food

ACCLIMATION
- Acclimation period for parental animals: 13 Jan - 04 Feb 2004
- Acclimation conditions: same as test
- Type and amount of food: Chlorella vulgaris, 0.2 mg C/day/animal
- Health during acclimation: Only healthy stock was used (mortality of parental animal was < 0%).

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

248 - 250 mg/L as CaCO3

Test temperature:

19.6 - 19.9 °C

pH:

8.3 - 8.4

Dissolved oxygen:

8.6 - 8.7 mg/L

Nominal and measured concentrations:

Nominal concentration: 0.1 mg/L
Measured concentration: 0.0931 mg/L (geometric mean)

Details on test conditions:

TEST SYSTEM
- Test vessel: beaker
- Type: closed with a teflon sheet
- Material: glass; Size: 100 mL; Fill volume: 100 mL
- Renewal rate of test solution: every 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4
- No. of vessels per vehicle control: 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M4
- Culture medium different from test medium: no
- Intervals of water quality measurement: Temperature, water hardness, pH and oxygen were measured at the study inition and after 24 h exposure time.

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment
- Photoperiod: 16 hours in the light, 8 hours in the dark
- Light intensity: < 800 lux

EFFECT PARAMETERS MEASURED: General condition and immobility were observed after 24 hours and 48 hours exposure time.

TEST CONCENTRATIONS
- Justification for using less concentrations than requested by guideline: 0.1 mg/L is the maximum attainable concentration under the present test conditions and preparation methods.
- Range finding study: performed
- Test concentrations: 0.0006, 0.006, and 0.06 mg/L
- Results used to determine the conditions for the definitive study: Immobilisation was not observed in all groups.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (analytical grade)

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.093 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: No abnormality was found.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50: 0.76 ± 0.16 mg/L

Table 1: Measured concentration

Nominal Concentration [mg/L]	Measured Concentration [mg/L]; (Percent of nominal)
	0 h (new)	24 h (old)	Mean
Control	<0.0002	<0.0002	-
Solvent Control	<0.0002	<0.0002	-
0.1	0.0922 (92)	0.0940 (94)	0.0931

new: freshly prepared test solutions

old: test solutuions after 24 hours

Table 2: The number of immobilized Daphnia magna (percent immobility)

Nominal Concentration [mg/L]	Geometric measured Concentration [mg/L]	Cumulative Number of Immobilized Daphnia (Percent Immobility)
		24 h	48 h
Control	-	1 (5)	1 (5)
Solvent Control	-	0 (0)	0 (0)
0.1	0.0931	0 (0)	0 (0)

Description of key information

In a 48 hours test daphnia were exposed to bis(2-ethylhexyl) azelate at a nominal concentration of 0.1 mg/L (measured 0.093 mg/L). At this concentration, which is above the maximum water solubility of bis(2-ethylhexyl) azelate no effects on mobility were observed. Therefore it can be concluded that the EC50 is > 0.1 mg/L (MOE 2004).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.1 mg/L

Additional information

The substance tested is considered a close analogue of diesters of alcohols, C7-9-iso-, C8-rich, 2-ethylhexyl and nonanedioic acid and a worst case due to the presence of 2-ethylhexan-1-ol as part of the starting materials of both diesters of alcohols, C7-9-iso-, C8-rich, 2-ethylhexyl and nonanedioic acid and bis(2-ethylhexyl) azelate. Therefore the outcome of the study that indicates no toxicity at the water solubility level is considered representative for diesters of alcohols, C7-9-iso-, C8-rich, 2-ethylhexyl and nonanedioic acid (see rationale for read-across)