Ethyl 2-cyclohexylpropionate

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 14 to 16 January 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to the OECD Guideline and it is GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Ethyl 2-cyclohexylpropionate

EC Number:

412-280-5

EC Name:

Ethyl 2-cyclohexylpropionate

Cas Number:

2511-00-4

Molecular formula:

C11H20O2

IUPAC Name:

ethyl 2-cyclohexylpropanoate

Details on test material:

- Physical state: clear liquid
- Stability under test conditions: verified by chemical analysis. Water samples were taken from the control and all test concentrations at 0 hours and from the control and all relevant test concentrations at 48 hours and sent to HRC Departmenet of anlytical Chemistry for analysis.
- Storage condition of test material: in darkness at 4ºC

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Straus)
- Source: Laboratory culture originating from a strain supplied by IRChA, France

Study design

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

150-200 mg/L as CaCO3

Test temperature:

21ºC

pH:

7.6

Dissolved oxygen:

8.6 mgO2/L

Nominal and measured concentrations:

Nominal test concentrations: 0.10, 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6 and 10 mg/L.
Relevant measured test concentrations: 0.30, 0.94, 1.6, 2.9 and 5.9 mg/l.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass jars each containing 200 ml test solution. The jars covered with aluminium foil with minimim headspace.
- Experimental design: 9 test concentrations plus 1 control, each in duplicate. 20 animals per test concnetrations.

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Details on results:

All calculations are based on mean measured concentrations. Values obtained ranged from 64-75% of nominal (mean value 70%) at 0 hours (fresh media) and from 35 to 43% of nominal (mean value 39% at 48 hours (expired media). Despite the use of covered vessels with minimum headspace, stable concentrations could not be maintained due to the volatility of the test substance. The low values measured at 0 hours suggest that much of the maintained due to the volatility of the test substance. The low values measured at 0 hours suggest that much of the losses occur during sampling and handling of the test media.
Data for the 1 mg/l treatment have not been included in these calculations due to a suspected sampling/analytical error at 48 hours. This is not considered to have any significant effect on the overall results of the tes, however, since there are sufficient data remaining to define adequately the EC50 value (as indicated by the narrow 95% confidence limits) and the "no effect" levels.

Any other information on results incl. tables

Table 1

Cumulative immobilisation data for Daphnia magna exposed for 48 hours to the test substance

Nominal concentration mg/l	Measured concentration mg/l	Cumulative immobilised Daphnia magna (initial population:20)
		24 hours				48 hours
		R1	R2	Total	%	R1	R2	Total	%
Control	Control	0	0	0	0	0	1	1	5
0,1	-	0	0	0	0	1	0	1	5
0,18	-	1	0	1	5	1	0	1	5
0,32	-	0	0	0	0	0	1	1	5
0,56	0,3	0	0	0	0	0	0	0	0
1	-	1	0	1	5	3	3	6	30
1,8	0,94	0	0	0	0	4	3	7	35
3,2	1,6	0	1	1	5	3	6	9	45
5,6	2,9	2	4	6	30	9	10	19	95
10	5,9	3	4	7	35	10	10	20	100

R1 Replicate 1

R2 Replicate 2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

At 48 hours, the EC50 is 1.1 mg/l and at 0.30 mg/l there is no effect level.

Executive summary:

The test substance was performed to obtain the Acute toxicity in Daphnia Magna 48h according to the OECD Guideline 202. All concentrations are based on mean measured concentrations. Values obtained ranged from 64 to 75% of nominal (mean value 70%) at 0 hours (fresh media) and from 35 to 43% of nominal (mean value 39%) at 48 hours (expired media).

Data for the 1 nmg/l treatment were not included in these calculation due to a suspected sampling/analytical error at 48 hours.

At 48 hours, the EC50 is 1.1 mg/l and at 0.30 mg/l there is no effect level.