2-(2-(4-methyl-3-cyclohexen-1-yl)propyl)cyclopentanone

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 April 2004 through 04 November 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

1998

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: ISO International Standard 10706 : Determination of long-term toxicity of substances to Daphnia magna Straus (Cladocera, Crustacea"

Version / remarks:

30 March 2000

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

NECTARYL :
- Batch No. : 9000550123
- Purity : 96.7% (sum of 3 peaks)
- Expiry Date : 23 February 2006

Analytical monitoring:

yes

Remarks:

GC-MSD

Details on sampling:

A semi-static renewal set-up was employed (renewal every 48 hours).

During the study samples for analyses were taken from freshly prepared solutions on Days 0, 6 and 14, and from 48-hour aged solutions on Days 2, 8 and 16.

Vehicle:

yes

Remarks:

Acetone

Details on test solutions:

In the definitive reproduction test, the following nominal exposure concentrations employed were :

Solvent Control
0.22 mg/L
0.46 mg/L
1.0 mg/L
2.2 mg/L
4.6 mg/L

Test organisms (species):

Daphnia magna

Details on test organisms:

The Daphnia magna employed in this study are continually bred at NOTOX B.V..
- Start of each batch : With newborn animals, i.e. less than 3 days old, by placing them individually in 50 mL of M7 medium
- Medium : M7 medium
- Maximum age of cultures : 4 weeks
- Temperature of Medium : 18 - 22 °C
- Feeding : Fed daily with a suspension of freshwater algae (Chlorella pyrenoidosa)

Test type:

semi-static

Water media type:

freshwater

Remarks:

M7 medium

Limit test:

no

Total exposure duration:

21 d

Hardness:

Range during study :
Solvent Control 250 - 286 mg CaCO3/L
1.0 mg/L 268 - 304 mg CaCO3/L

Test temperature:

Temperature range : 19.1 to 20.3 °C

pH:

pH range : 6.8 to 9.0

Dissolved oxygen:

The range of dissolved oxygen concentration measured in Fresh and Aged samples ranged from 7.7 to 10.3 mg O2/L.

Nominal and measured concentrations:

Measured concentrations in the freshly prepared solutions were, generally, in agreement with nominal and the preparation proved to be reproducible.

The analytical results obtained from the aged Day 2 sample demonstrated that the actual concentrations had decreased by 50 to 70%. Therefore, from Day 5, all vessels were individually closed with caps instead of covering them with a perspex plate. Upon renewal on Day 6, the vessels were filled-up to the brim to minimise headspace, then individually closed with caps. Analyses of samples taken on Day 6 and 8 illustrated that the vessels with air-tight caps improved the stability of the solutions. A high decrease in actual measured concentrations was observed during the third sampling interval, i.e. between Days 14 and 16. One hypothesis for the decrease in Nectaryl could be the high consumption rate of algae, which may have adsorbed the test substance, by the parental daphnia and their young offspring.

Samples were analysed upon sampling.

Details on test conditions:

Test Type : Semi-static
Renewal of the Test Media : Every 48 hours
Test Duration : 21 days
Test Vessels : Volume 100 mL, dimensions 8 x 4 cm (i.d.), all glass and air-tight closed
Test Medium : M7
Experimental Design : The daphnids were exposed individually from the start of the 21-day exposure period. Ten neonate (< 24 hour old) daphnids were studied per test concentration, while the Solvent Control consisted of 20 daphnids.
Light / Dark Cycle : 16 hours light / 8 hours dark
Feeding : Twice daily, 0.10 mL of Chlorella pyrenoidosa suspension containing 2 x 10 to the power of 8 cells was added during the first week of exposure. Thereafter, twice daily, 0.125 mL was fed.

MEASUREMENTS and RECORDINGS :

Parental Daphnia -
Immobility and mortality were observed every workday and at renewals during the weekend. The number of living, immobile and dead parental daphnids were recorded. Dead daphnids were removed when observed.
Presence of eggs in the brrod pouch - observed every workday and at renewals during the weekend.
Body length - Measured at the end of the test.

F1 Generation -
Apperance of first brood - Noted when observed.
Newborn daphnids - Observed for every workday and at renewals during the weekend. The number of newborn young was counted and the condition of the young recorded. Thereafter, the young were removed.
Presence of unhatched eggs - Noted when observed
Incidence of immobility - Noted when observed.

Key result

Duration:

21 d

Dose descriptor:

NOEC

Remarks:

Overall NOEC

Effect conc.:

0.17 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: This is the Overall NOEC, which is related to the most sensitive parameters - reproduction and body length.

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

0.55 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

Mortality of parental daphnids

Duration:

21 d

Dose descriptor:

LOEC

Remarks:

Overall LOEC

Effect conc.:

0.37 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: Overall LOEC

Details on results:

Reproduction :
The reproduction curve recorded at the lowest test concentration (0.22 mg/L nominal, 0.17 mg/L measured) was similar to the reproduction curve of the Solvent Control. The reproduction curve of the 0.46 mg/L (nominal) exposure level stayed behind the reproduction curves recorded for the solvent control.

Body Length :
The mean body length of the parental daphnids was statistically siginficantly reduced at 0.46 mg/L (nominal) when compared to the solvent control. No effect was observed at the 0.22 mg/L (nominal) exposure level.

Validity Criteria :
- Mortality and development of parental daphnids in the solvent control did not exceed 20% at the end of the test;
- The mean number of living offspring at the end of the test was > or = to 60 (actual 100.9).

EC Values and Respective Parameters :

Prameter Nominal Concn. Avg. Exposure Concn.
(mg/L) (mg/L)

Observed 21-day EC100 for Parental survival 1.0 0.81
LC50 for Parental Survival 0.68 0.55
Observed 21-day EC0 for Parental Survival 0.22 0.17
21-day EC50 for Reproduction 0.57 0.47
21-day LOEC for Reproduction 0.46 0.37
21-day LOEC for Body Length 0.46 0.37
21-day NOEC for Body Length 0.22 0.17
Overall LOEC 0.46 0.37
Overall NOEC 0.22 0.17

Validity criteria fulfilled:

yes

Conclusions:

Parameter Nominal Concn. Avg. Exposure Concn.
(mg/L) (mg/L)

Observed 21-day EC100 for Parental survival 1.0 0.81
LC50 for Parental Survival 0.68 0.55
Observed 21-day EC0 for Parental Survival 0.22 0.17
21-day EC50 for Reproduction 0.57 0.47
21-day LOEC for Reproduction 0.46 0.37
21-day LOEC for Body Length 0.46 0.37
21-day NOEC for Body Length 0.22 0.17
Overall LOEC 0.46 0.37
Overall NOEC 0.22 0.17

Executive summary:

Parameter                                                        Nominal Concn.              Avg. Exposure Concn.

                                                                            (mg/L)                                   (mg/L)

Observed 21-day EC100 for Parental survival              1.0                                  0.81

LC50 for Parental Survival                                          0.68                                  0.55

Observed 21-day EC0 for Parental Survival                0.22                                   0.17

21-day EC50 for Reproduction                                   0.57                                   0.47

21-day LOEC for Reproduction                                   0.46                                   0.37

21-day LOEC for Body Length                                    0.46                                   0.37

21-day NOEC for Body Length                                   0.22                                   0.17

Overall LOEC                                                               0.46                                 0.37

Overall NOEC                                                              0.22                                 0.17

Description of key information

Parameter                                                 Nominal Concn.              Avg. Exposure Concn.

                                                                         (mg/L)                            (mg/L)

Observed 21-day EC100 for Parental survival       1.0                     0.81

LC50 for Parental Survival                                   0.68                     0.55

Observed 21-day EC0 for Parental Survival         0.22                     0.17

21-day EC50 for Reproduction                            0.57                     0.47

21-day LOEC for Reproduction                            0.46                     0.37

21-day LOEC for Body Length                            0.46                     0.37

21-day NOEC for Body Length                            0.22                     0.17

Overall LOEC                                                        0.46                     0.37

Overall NOEC                                                        0.22                     0.17

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.17 mg/L