reaction mass of isomers of: C7-9-alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1999-12-01 to 2000-01-07 (experimental phase)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

406-040-9

EC Name:

-

Cas Number:

125643-61-0

Molecular formula:

C17 H25 O3 R, Where R = (C7 H15) or (C8 H17) or (C9 H19)

IUPAC Name:

C7-9-(branched)-alkyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

For the analytical measurements, duplicate samples were taken from the freshly prepared undiluted emulsion filtrate at each test medium preparation date. Since the water solubility limit of the test item was below the limit of quantification, no samples were taken from the dilutions of the filtrate.
The duplicate samples from the start of the test were analyzed immediately after preparation. The duplicate samples from the other sampling dates were deep-frozen (at about -20 °C) immediately after sampling and were analyzed after the end of the test.

Storage
Series I: The samples were analysed after the sampling procedure (treatment samples and biological control samples of sampling day 0).
Series II: The samples were stored deep frozen and protected from light until analysis was performed (treatment samples and biological control samples of sampling days 2 to 19).

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: According to a pre-experiment (without GLP) at RCC the solubility limit of the test item in water respectively test water is < 0.03 mg/l.
Therefore, a filtrate of a supersaturated emulsion of the test item and dilutions of the filtrate were prepared. The undiluted filtrate and the dilutions 1:3.2, 1:10, 1:32 and 1:100 were tested. Additionally, a control was tested in parallel (test water without test item).

Prior to each test medium renewal, the test media were freshly prepared as follows:
A supersaturated emulsion with a loading rate of 100 mg/l was prepared by weighing 250 mg (range: 250 - 251 mg) of the test item into 1000 ml test water. This mixture was treated by ultrasonification for 15 minutes and was made up to 2500 ml test water. No auxiliary solvent or emulsifier was used. Then, the mixture was stirred for 6.5 days at room temperature in the dark. The long stirring period was chosen to dissolve a maximum of the test item in the test water. After stirring, the undissolved fraction of the test item was allowed to separate from the water phase for another half a day. After separation a part of the test item was swimming at the water-surface (oily film), while a part was homogeneously distributed in the water phase. This supersaturated emulsion was separated from the oily film by sucking it of with a Teflon-tube and was filtered through a membrane filter (Schleicher & Schuell, Type NC45, pore size 0.45 µm).

The undiluted filtrate of the supersaturated emulsion with the maximum concentration of dissolved test item was used as the highest concentrated test medium. Additionally, adequate volumes of the filtrate were diluted with test water for the preparation of test media with lower test item concentrations. No additional dilution step was inserted. In this way the following treatments were prepared: the undiluted filtrate of the emulsion with a loading rate of 100 mg/l and the dilutions 1:3.2, 1:10, 1:32 and 1:100 of the filtrate (1 part of the filtrate added to 2.2, 9, 31, and 99 parts of test water, respectively).

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: in house culture, originally supplied by the University of Sheffield/UK in 1992, defined from the supplier as clone 5. Since this date, the clone is bred in the laboratories of RCC in reconstituted water of the quality identical to the water quality used in the tests (regarding pH, main ions, and total hardness) and under temperature and light conditions identical to those of the tests.
- Age at study initiation (mean and range, SD): < 24h
- Method of breeding: parthenogenetic reproduction
- Feeding during test: yes

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

21 d

Test conditions

Hardness:

250 mg/L CaCO3

Test temperature:

21-21°C

pH:

7.6-8.0

Dissolved oxygen:

test start: 8.6-8.9 mg/L
test end: 8.1-8.6 mg/L

Nominal and measured concentrations:

control, dilution 1:100; 1:32; 1:10, 1:3.2, undiluted filtrate

Details on test conditions:

TEST SYSTEM
- Test vessel: glas beaker nominal volume 100 mL, covered with glas plates
- Fill volume: approx. 80 mL
- Renewal of test solution: on Days 2, 5, 7, 9, 12, 14, 16 and 19 of the exposure period
- No. of organisms per vessel: 1 parent animal
- No. of vessels per concentration (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic medium M7
- After preparation the M7 medium was aerated until saturation with oxygen is reached.

OTHER TEST CONDITIONS
- Photoperiod: Artificial Iight, day/night-rhythm = 16 / 8 hours
- Light intensity: about 300-800 lux

EFFECT PARAMETERS MEASURED
- Reproduction and mortality on Days 2, 5, 7, 9, 12, 14, 16 and 19 of the exposure period

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

<= 0.01 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: dilution 1:3.2, NOEC calculated by assuming a water solubility of < 0.03 mg/L

Any other information on results incl. tables

At the start of the test medium renewal periods, the test item concentration in the analyzed test medium (the undiluted filtrate of the supersaturated emulsion) was below the limit of quantification of 0.03 mg/l. Therefore, all reported biological results are related to the 'undiluted filtrate' and its 'dilutions', respectively.

 

In the control and at the dilutions from 1:100 to 1:3.2 the survival rate and reproduction rate of the test animals at the end of the test was 100%.

 

Taking into account the survival rates and the reproduction rates of the test animals, the dilution 1:3.2 was the highest treatment of the test substance tested without toxic effects after the exposure period of 21 days (21 -day NOEC). Thus, the 21 -day NOEC was approximately threefold below the water solubility of the test substance. The undiluted filtrate was the lowest treatment tested with toxic effects (21 -day LOEC) due to the significant mortality rate and due to the statistically significantly reduced mean reproduction rate of Daphnia magna at the water solubility limit of the test item.

 

No remarkable observations were made concerning the appearance of the test media. All test media were clear solutions throughout the test period.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes