5,6,7-TRIMETHYLOCTA-2,5-DIEN-4-ONE

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 6 January 2004 to 22 January 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(2E,5Z)-5,6,7-trimethylocta-2,5-dien-4-one

Cas Number:

357650-26-1

Molecular formula:

C11H18O

IUPAC Name:

(2E,5Z)-5,6,7-trimethylocta-2,5-dien-4-one

Constituent 2

Reference substance name:

(2E,5E)-5,6,7-trimethylocta-2,5-dien-4-one

Cas Number:

847144-75-6

Molecular formula:

C11H18O

IUPAC Name:

(2E,5E)-5,6,7-trimethylocta-2,5-dien-4-one

Test material form:

liquid

Specific details on test material used for the study:

Aspect: Slightly yellow liquid
Purity: 96.7%
Expiry date: 12 September 2004

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 1.0, 1.8, 3.2, 5.6 and 10 mg/L
- Sampling method: 10 mL from the approximate centre of the test vessel in duplicate for all test concentration and bloak control.
- Sample storage conditions before analysis: samples were stored in a freezer until analysis

Test solutions

Vehicle:

no

Details on test solutions:

Preparation of test solution started with a stock solution of 100 mg/L applying a short period of magnetic stirring to accelerate the dissolving of the test susbtance in the test medium. The lower test concentrations were prepared by subsequent dilutions of the stock in the test medium. The final test solution were all clear and colourless

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Species: Daphnia magna (Crustacea, Cladocera) STraus 1820
- Characteristics : Young Daphnia with an age of < 24 hours

Breeding -
Start of Each Batch : With new-born animals (less than 3 days old) by placing approximately 250 of them into 5 Litres of medium in all-glass culture vessel
Maximum age of Cultures : 4 weeks
Renewal of the Cultures : After 7 days of cultivation half of the medium twice a Week
Temperature of Medium : 18 - 22 °C
Feeding : Daily, a suspension of fresh-water algae
Medium : M7

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

In accordance with OECD TG 202 guideline

Test conditions

Hardness:

The hardness of the ISO medium is 250 mg/L expressed as CaCO3 and the pH is 8.0 +/- 0.2 after aeration

Test temperature:

The temperature of the test medium was 20.0°C at the start of the test. The temperature continuously measured in a temperature control vessel varied between 20.4°C and 21.0°C during the test, and complied with the requirements as laid down in the protocol.

pH:

Measured pH remained within the limits prescribed by the protocol (6.0 -8.5; not varying by more than 1 unit)
Measures: 8.1 and 8.0

Dissolved oxygen:

Measured oxygen remained within the limits prescribed by the protocol (>7 mg/l at the start, >= 5 mg/L at the end of the test)
Measures: 9.0 and 9.1

Nominal and measured concentrations:

Blank control; 1.0; 1.8; 3.2; 5.6; 10 mg/L (Nominal) / Blank control; 0.87; 1.44; 2.78; 4.58; 8.70 mg/L (Measured at T=0h) / Blank control; 0.75; 1.31; 2.63; 4.09; 7.71 (Measured at T=48h)

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL all glass
- Material, size, headspace, fill volume: Glass
- Aeration: No aeration of the test solutions.
- No. of organisms per vessel: 5 per vessel containing 80 ml medium
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: No, ISO Medium M7, renewed by 50% twice per week.

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


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Immobility (including mortality), 24 hours and at 48 hours.

VEHICLE CONTROL PERFORMED: yes/no

RANGE-FINDING STUDY
- Test concentrations: Blank control; 0.1; 1.0; 10; 100 mg/L (nominal)
- Results used to determine the conditions for the definitive study: Yes

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

3.1 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.2 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.4 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

The actual responses in this reference test with K2Cr2O7 are within the ranges of the expected responses at the different concentrations. Hence, the sensitiity of this batch of D. magna was in agreement with the historical data collected at NOTOX.

Any other information on results incl. tables

Table 2: Acute immobilisation of Daphnia after 24 hours and 48 hours in the final EC50 test

Concentration GR-85 -2517    Nominal / Initial (mg/L)	Vessel number	Number of Daphnia exposed	Response at 24 h		Response at 48h
			Number	Total %	Number	Total %
Blank control	A B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
1.0 / 0.87	A B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
1.8 / 1.44	A B C D	5 5 5 5	0 0 0 0	0	0 0 0 0	0
3.2 / 2.78	A B C D	5 5 5 5	0 1 1 1	15	3 4 5 5	85
5.6 / 4.58	A B C D	5 5 5 5	5 5 5 5	100	5 5 5 5	100
10 / 8.70	A B C D	5 5 5 5	5 5 5 5	100	5 5 5 5	100

Table 3: Effect parameters

Parameter	Concentration GR-85 -2517 Initial (mg/L)	95% confidence interval
Observed NOEC	1.4
24h-EC50	3.1	2.8 - 3.6
48h-EC50	2.2	2.0 - 2.5

Table: Acute immobilization of Daphnia after 24 and 48 hours in the reference test with potassium dichromate

Concentration (mg/L)	Number Exposed	% immobile		Expected response (%) after 48h*
		24h	48 h	Minimal	Maximal
Blank control	10	0	0	0	10**
0.10	10	0	0	0	10
0.18	10	0	0	0	10
0.32	10	0	0	0	30
0.56	10	0	0	0	100
1.0	10	0	90	40	100
1.8	10	100	100	100	100

*Based on historical data of previous years (n>60)

** A maximum response of 10% does not invalidate the result of the test

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study GR-85-2517did not induce acute immobilisation of Daphnia magna at an initial exposure concentration of 1.4 mg/L after 48 hours of exposure

The 48h-EC50 based on initial exposure concentrations was 2.2 mg/l with a 95% confidence interval between 2.0 and 2.5 mg/L

Executive summary:

The study procedures described in this report were based on ISO International Standard 6341, 1996. In addition, the procedures were designed to meet the test methods and validity criteria of the EEC directive 92769, Part C.2, 1992 and the OECD guideline No. 202 Part I, 1984.

The batch of GR-85 -2517 tested was a slightly yellow liquid with a purity of 96.7%. GR-85 -2517 was completely soluble in test medium at the concentration tested.

The project started with a range-finding test. Ten Daphnia per concentration (In duplicate, 5 per vessel) were exposed to a range of 0.1 to 100 mg/L increasing by a factor 10 and to a blank-control. After 24 hours of exposure all organism exposed to nominally 10 and 100 mg/L became immobilised. No immobilisation was observed at the lower test concentration. The 48h-EC50 appeared to be between nominal concentration of 1.0 and 10 mg/L. Analytical results showed that measured GR-85 -2517 concentration in samples taken taken from nominally 1.0 mg/L decreased from 0.85 mg/L at the start to 0.69 mg/L after 48 hours. Hence, GR-85 -2517 concentration did not decrease by more than 20% during the test.

The project was continued with a final EC50 test exposing twenty Daphnia per test group (in quadruplicate, 5 per vessel) to a blank control and GR-85 -2517 concentrations of 1.0, 1.8, 3.2, 5.6 and 10 mg/L. Samples for analytical confirmation of actual exposure concentrations were taken from all test solutions at the start and the end f the 48 hour test period.

Analysis of the samples taken at the start of the final test showed mean measured intitial concentrations of 0.87, 1.44, 2.78, 4.58 and 8.70 mg/L at the nominal concentration of 1.0, 1.8, 3.2, 5.6 and 10 mg/L respectively. During the exposure period the measured concentrations did not decrease by more than 20% of the initial concentrations.

The study met the acceptability criteria prescribed by the protocol and was considered valid.

GR-85 -2517 did not induce acute immobilisation of Daphnia magna at an initial exposure concentration of 1.4 mg/L after 48 hours of exposure (NOEC).

The 48h-EC50 based on initial exposure concentrations was 2.2 mg/L with a 95% confidence interval between 2.0 and 2.5 mg/L.