4-pentylcyclohexanone

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:

April - July 1990

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)

Version / remarks:

adopted April 4, 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

25th April, 1984

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance is directly weighed and put into the test vessels and dissolved in dilution water by rigorous stirring. Lower concentrations will be produced in stock solutions after dissolving by mechanical distribution (Ultra-Turrax).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Strauss
- Age at study initiation: less than 24 h old
- Source: not available
- Feeding during test : no

ACCLIMATION
- Acclimation period: no details available

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

19.1°d

Test temperature:

20.5 °C

pH:

7.6

Dissolved oxygen:

94 - 100 %

Nominal and measured concentrations:

Nominal concentrations: 0, 10, 20, 30, 40, 50, 60, 100 mg/L
no measured concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL glass beaker
- Material: glass
- Volume of solution: 40 mL
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: Standard dilution water according to OECD 202

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: light-dark cycle (8 hours darkness, 16 hours light)
- Light intensity: not available

EFFECT PARAMETERS MEASURED
Immobilisation of the Daphnia was recorded after 24h and 48h. The pH and oxygen concentration were measured at the beginning and the end of each test.

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

30 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

In the control experiments no animal was immobilised neither after 24 h nor after 48 hours. The pH of the test solutions (7.6), the oxygen concentrations and temperature of the test solutions were within acceptable limits (Oxygen concentration: 94 - 100 % temperature: 20.5 °C).

Reported statistics and error estimates:

The results of the immobilization test were treated in the following way: the percentage of immobilization at each concentration between EC-0 and EC-100 was transformed into a particular Probit-value. Since there is no Probit-value for 0 % and 100 % effect and - on the other hand - the values at the edges of the toxicity-range are regarded valuable for the evaluation of the results, the Probit for 0 % was said to be 3.04 (this corresponds to 2.5 %) and the Probit for 100 % was said to be 6.96 (this corresponds to 97.5 %). Thes values were chosen, bacause a result of 0 or 20 immobilized Daphnia can mean any percentage between 0 % and 5 % (or between 95 % and 100 % on the upper edge), since there were only 20 - not 100 - Daphnia tested. The mean of this inaccuracy is 2.5 % (or 97.5 %, respectively). With these values, a linear regression analysis of the Probit = f (log c) function was performed.

 Table 1: Cumulative immobilization at 24 h and 48 h, Cumulative percentage immobilization in ( )

Concentration [mg/L]	time after test start [h]
	24	48
100	20 (100)	20 (100)
60	20 (100)	20 (100)
50	14 (70)	20 (100)
40	6 (30)	11 (55)
30	3 (15)	9 (45)
20	0 (0)	1 (5)
10	0 (0)	0 (0)
0	0 (0)	0 (0)

Validity criteria fulfilled:

yes

Conclusions:

The acute immobilization study with Daphnia magna was performed according to OECD 202. Under the given conditions the 48h EC50 value was 30 mg/L.

Executive summary:

The objective of this study was to determine the acute toxicity of the test material using Daphnia magna. For this purpose, young Daphnia magna were exposed to aqueous test material concentrations under defined conditions. The study comprised of one vessels per concentration containing 20 Daphnia magna, i.e. 20 Daphnia per concentration (test medium group) and control group. The Daphnia were observed for immobilization/deaths up to 48 hours. Daphnia magna were exposed to test material concentrations of nominal 10, 20, 30, 40, 50, 60, and 100 mg/L in a static system. The nominal concentrations of 20 to 100 mg/L led to immobilized daphnia. The EC50 values and the no observed effect concentration (NOEC) were: 48 h EC50: 30 mg/L; 48 h EC100: 50 mg/L, NOEC: 10 mg/L. Under the given conditions of this study the 48 h EC50 value was 30 mg/L and the NOEC 10 mg/L.

Description of key information

The acute immobilization study with Daphnia magna was performed according to OECD 202. Under the given conditions the 48h EC50 value was 30 mg/L (reference 6.1.3-1).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

30 mg/L

Additional information

The objective of this study was to determine the acute toxicity of the test material using Daphnia magna. For this purpose, young Daphnia magna were exposed to aqueous test material concentrations under defined conditions. The study comprised of one vessel per concentration containing 20 Daphnia magna, i.e. 20 Daphnia per concentration (test medium group) and control group. The Daphnia were observed for immobilization/deaths up to 48 hours. Daphnia magna were exposed to test material concentrations of nominal 10, 20, 30, 40, 50, 60, and 100 mg/L in a static system. The nominal concentrations of 20 to 100 mg/L led to immobilized daphnia. The EC50 values and the no observed effect concentration (NOEC) were: 48 h EC50: 30 mg/L; 48 h EC100: 50 mg/L, NOEC: 10 mg/L. Under the given conditions of this study the 48 h EC50 value was 30 mg/L and the NOEC 10 mg/L (reference 6.1.3 -1).