2-sec-butylcyclohexan-1-one

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:

March 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

FRESKOMENTHE
Lot No. VE00426966
Purity 99.2%
Expiry Date 19 February 2018.

Analytical monitoring:

yes

Details on sampling:

All concentration levels and the control were analytically verified via GC-FID at the start of the exposure (0 hours) and at the end of the exposure (48 hours).
The method was validated prior to this study according to SANCO 3029/99 rev.4 (2000).
At the start of the exposure (0 hours), sampling was carried out after preparation of the test item concentrations.
At the end of the exposure (48 hours), samples were taken directly from the test vessels and analyzed.

Vehicle:

no

Details on test solutions:

Five test item concentrations in a geometric series with a separation factor of 2, prepared by dilution of the stock solution 100 mg/L with dilution water (Elendt M4), were tested as follows:
6.25 - 12.5 - 25.0 - 50.0 - 100 mg/L
The test item concentrations were selected based on the results of a non-GLP preliminary range finding test.

Test organisms (species):

Daphnia magna

Details on test organisms:

Origin - Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany

Less than 24 hours old daphnids from a healthy stock were used for the study. Juvenile daphnids were removed from the culture vessels at the latest 24 hours before the start of the exposure and discarded. The juveniles born within the following period of max. 24 hours preceding the exposure were used for the test. No first brood progeny was used for the test.

Test type:

static

Water media type:

freshwater

Remarks:

Elendt M4

Limit test:

no

Total exposure duration:

48 h

Hardness:

171 mg/L CaCO3

Test temperature:

18 - 19 °C

pH:

Control : 7.84 - 8.13
6.25 mg/L (nominal) :7.99 - 8.60
12.5 mg/L (nominal) : 8.69 - 8.80
25.0 mg/L (nominal) : 8.73 - 8.89
50.0 mg/L (nominal) : 8.80 - 8.99
100 mg/L (nominal) : 8.83 - 8.99

Dissolved oxygen:

Control : 7.55 - 8.87 mg O2/L
6.25 mg/L (nominal) :7.79 - 8.90 mg O2/L
12.5 mg/L (nominal) : 7.98 - 8.54 mg O2/L
25.0 mg/L (nominal) : 8.13 - 8.81 mg O2/L
50.0 mg/L (nominal) : 8.05 - 8.87 mg O2/L
100 mg/L (nominal) : 8.45 - 8.77 mg O2/L

Conductivity:

441 microS/cm

Nominal and measured concentrations:

The measured concentrations of the test item were in the range of 106 to 118% of the nominal values at the start of the exposure (0 hours) and 99 to 109% at the end of the exposure (48 hours) representing 91.5 to 95.8% of time 0 measured test item concentrations.

Since the test item demonstrated stability over the duration of the exposure period, the end-point results are presented based on Nominal test concentrations.

Details on test conditions:

Dose Preparation - The stock solution (100 mg/L of the test item were weighed out) was freshly prepared with dilution water (daphnia medium) prior to the exposure (0 hours). The stock solution was stirred with a magnetic stirrer at approximately 1100 rpm for 30 min at room temperature;

Test Concentrations - 5 test item concentrations in a geometric series with a separation factor of 2, prepared by dilution of the stock solution 100 mg/L with dilution water (daphnia medium), were tested as follows:
6.25 - 12.5 - 25.0 - 50.0 - 100 mg/L
The test item concentrations were selected based on the results of a non-GLP preliminary range finding test;

Control - Dilution water (daphnia medium) without test item incubated under the same conditions as the test groups;

Test Method - Due to the high vapor pressure of the test item, a closed system (closed test vessels without headspace) was chosen for testing to reduce contact with air and losses of the test item by evaporation. Since the test item concentrations were stable over an exposure period of 48 hours during the non-GLP preliminary range finding test, the study was performed with a static test design under diffuse light conditions.

Test Duration - 48 hours

Test Vessels - Sealed glass flasks (4.5 (ID) x 9.5 (H) cm) with screw caps (made from polypropylene) were used. A test volume of approximately 130 mL was provided in each test vessel.

Number of Daphnids and Replicates - 20 daphnids, divided into 4 replicates, each with 5 daphnids, were used for each concentration level and the control.

Age of Daphnids - Less than 24 hours old daphnids from a healthy stock were used for the study. Juvenile daphnids were removed from the culture vessels at the latest 24 hours before the start of the exposure and discarded. The juveniles born within the following period of max. 24 hours preceding the exposure were used for the test. No first brood progeny was used for the test.

Test Temperature - 18-22 °C, constant within ± 1 °C;

Lighting - Diffuse light, light intensity of max. 1500 lx, 16 hr / 8 hr light / dark cycle;

Feeding - The daphnids were not fed during the study.

Reference substance (positive control):

yes

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Test Item stable over exposure duration (Nominal = Measured)

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Test Item stable over exposure duration (Nominal = Measured)

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

Test Item stable over exposure duration (Nominal = Measured)

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

12.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other:

Remarks:

Sub-lethal effects - physical and behavioural observations

Remarks on result:

other:

Remarks:

Test Item stable over exposure duration (Nominal = Measured)

Results with reference substance (positive control):

Potassium Dichromate (99.0 %), 24 hr EC50 = 1.01 mg/L (95% CI = 0.767 - 1.24 mg/L).

Validity criteria fulfilled:

yes

Conclusions:

The following end-points were determined for Daphnia exposed to FRESKOMENTHE in a valid OECD 202 study :
48 hr EC50 = 25.0 mg/L
48 hr EC0 = 12.5 mg/L
48 hr EC100 = 50.0 mg/L
48 hr NOEC = 12.5 mg/L

Executive summary:

The following end-points were determined for Daphnia exposed to FRESKOMENTHE in a valid OECD 202 study :

48 hr EC50 = 25.0 mg/L

48 hr EC0 = 12.5 mg/L

48 hr EC100 = 50.0 mg/L

48 hr NOEC = 12.5 mg/L

Description of key information

The following end-points were determined for Daphnia exposed to FRESKOMENTHE in a valid OECD 202 study :

48 hr EC50 = 25.0 mg/L

48 hr EC0 = 12.5 mg/L

48 hr EC100 = 50.0 mg/L

48 hr NOEC = 12.5 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

25 mg/L