Reaction mass of (2R,5R)-2-isopropyl-5-methylcyclohexanone and (2S,5R)-2-isopropyl-5-methylcyclohexanone

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:

2000-05-09 to 2000-05-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Valid guideline study under GLP, limited level of detail but sufficient for assessment

Data source

Reference

Reference 1

Reference Type:

secondary source

Title:

Unnamed

Year:

2000

Report date:

2000

Reference 2

Reference Type:

secondary source

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

Test conducted under closed-bottle conditions, i.e. “Karlsruher Flaschen”

GLP compliance:

yes

Remarks:

as specified in Annex I of Law on Hazardous Substances (German Chemicals Law - according to the respective valid issue)

Test material

Test material information

Constituent 1

Reference substance name:

L-menthan-3-one

EC Number:

237-926-1

EC Name:

L-menthan-3-one

Cas Number:

14073-97-3

Molecular formula:

C10H18O

IUPAC Name:

2-isopropyl-5-methylcyclohexanone, (2S,5R)-

Details on test material:

- Name of test material (as cited in study report): Menthone L/Isomenthone D

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: All test concentrations plus a control
- Sampling method: At test start and after 48 hours of exposure
- Sample storage conditions before analysis: Shipment for TOC determination at Dr. Dullau, Institute of Environmental Analysis, Germany

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
To produce the test concentrations, the test substance were weighed into water, treated for 60 seconds at 8000 rpm with an ultra turrax and afterwards stirred for 24 hours with a magnetic stirrer. To remove undissolved particles the resulting suspensions were filtered using folded filters of the pore size 7-12 µm.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Federal Health Office (BGA) in Berlin, Germany (laboratory bred of the parthenogenetic females at Bayer AG Leverkusen)
- Age at study initiation: 0 - 24 hours

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

15.5 ° dH

Test temperature:

20.2, 20.0, 20.0, 20.1, 20.1 and 20.1 °C were measured in the control and the 6.3, 12.5, 25, 50 and 100 mg/L treatments, respectively

pH:

7.9, 7.8, 7.8, 7.8, 7.8 and 7.8 were measured in the control and the 6.3, 12.5, 25, 50 and 100 mg/L treatments, respectively

Dissolved oxygen:

8.9, 7.9, 8.0, 8.0, 7.8 and 7.8 mg/L were measured in the control and the 6.3, 12.5, 25, 50 and 100 mg/L treatments, respectively

Nominal and measured concentrations:

Nominal: 0, 6.3, 12.5, 25, 50 and 100 mg/L
Measured at 0 hours: <2, 5, 9, 14, 27 and 61 mg TOC/L, which equals to <2.6, 6.5, 11.7, 18.2, 35.1 and 79.3 mg/L of the test item
Measured at 48 hours: <2, 5, 9, 13, 26 and 62 mg TOC/L, which equals to <2.6, 6.5, 11.7, 16.9, 33.8 and 80.6 mg/L of the test item
In consequence the test results were assigned to the measured concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel: so called “Karlsruher bottles” with stoppers
- Type: Closed
- Fill volume: 250 to 300 mL with head space
- Aeration: Not ventilated
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4-Medium according to Elendt and BGA (1992)
- Culture medium different from test medium: No, M4-Medium according to Elendt and BGA (1992) was used for culture and dilution

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light/8 hours dark

EFFECT PARAMETERS MEASURED
Oxygen [mg/L], pH and water temperature [°C] after 48 hours and the number of immobile daphnids after 24 hours and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2 (thus below the maximum of 2.2 according to the guidance)

Reference substance (positive control):

no

Remarks:

historical control data of the laboratory used

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

30.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Calculated as geometric mean of EC0 and EC100

Details on results:

24 h LC values on the basis of nominal concentrations calculated by Probit analysis were:
EC05=13 mg/L, EC10=18 mg/L, EC50=55 mg/L, EC90=170 mg/L and EC95=230 mg/L

Reported statistics and error estimates:

The effect concentratios were determined by Probit analysis (see picture below). The correlation coefficient was 0.965.

Any other information on results incl. tables

Results after 24 and 48 hours

Nominal test item concentrations [mg/L]	Immobile daphnids, cumulated
	after 24 h	after 48 h
Control	0	0
6.3	0	0
12.5	0	0
25	5	11
50	5	14
100	17	20

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 to daphids is 30.6 mg/L.

Executive summary:

The effects of the test item L-menthan-3-one to daphnids (Daphnia magna) were investigated according to the EU Method C.2 (1992) under GLP conditions. The test organisms were exposed during 48 hours under static conditions in closed vessels to nominal concentrations of 0, 6.3, 12.5, 25, 50 and 100 mg/L. The dose was verified as Total Organic Carbon (TOC analysis) and found sufficiently constant under the test conditions. As the recovery was below 80 % the effects were assigned to measured concentrations.

The daphnid 48 h LC50 was calculated to be 30.6 mg/L.