Cyclopentane, methoxy-

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:

From 2013-02-25 to 2013-06-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Batch No.: 2820249
Purity: ≥99.9%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.102, 0.256, 0.640, 1.60, 4.00, 10.0 and 25.0 mg/L
- Sampling method: The test substance concentrations in all test concentrations were analyzed when freshly prepared and at the time of renewal on one occasion during the first week of the test and were analyzed when freshly prepared and at the time of renewal on one occasion in weeks 2 and 3 of the test. In all cases, determination of test substance concentrations prior to renewal need only be performed on one replicate vessel at each test concentration. The replicate without food and animal was analyzed before and after the renewal and imitated the process of opening and closing the vessel.
- Sample storage conditions before analysis: analyzed directly without storage

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 310 mg/L stock solutions were prepared by dissolving test substance to a glass container with 130 mL Elendt M4 medium in each and without headspace. The solutions of the test substance were prepared in lidded containers. The other treatment groups were prepared by diluting the stock solutions with Elendt M4 media by a Diluter. The process of dilution were done in a closed system

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Justification for species other than prescribed by test guideline: recommended in "SEPA" and "OECD Guidelines
- Source: MicroBioTests Inc
- Age of parental stock (mean and range, SD): less than 24 hours and not first brood progeny
- Feeding during test
- Food type: concentrated freshwater suspensions of unicellular green algae Desmodesmus Subspicatus and Pseudokirchneriella subcapitata
- Amount: 0.19-0.20 mg of organic carbon per adult
- Frequency: daily
- Culture:
Adult Daphnia magna are bred in the lab in the Elendt M4 medium. The culture conditions is similar to test conditions. Cultures of adult Daphnia magna were fed concentrated freshwater suspensions of unicellular green algae Desmodesmus Subspicatus and Pseudokirchneriella subcapitata at a rate equivalent to 0.1-0.2 mg of organic carbon per adult per day.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

145-155 mg/L (as CaCO3)

Test temperature:

20.10-21 .40 °C

pH:

7.90-8.75

Dissolved oxygen:

8.27-11.0 mg/L

Nominal and measured concentrations:

Nominal: 0.102, 0.256, 0.640, 1.60, 4.00, 10.0 and 25.0 mg/L
Measured: 0.15, 0.24, 0.53, 1.24, 3.01, 7.51 and 21.2 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 75 mL airtight glass bottles
- Type: closed
- Material, size, headspace, fill volume: with 75 mL of medium in each vessel without headspace
- Aeration: not aerated
- Renewal rate of test solution: 24 hours
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: AII sorts of analytical grade salt were dissolved in deionised water to obtain separate alga medium stock solutíons. The alga medium were prepared by diluting the stock solutions in deionised water shorIy before beginning of the test
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: Light : Dark=16 hours : 8 hours;
- Light intensity: 1200 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
The offspring produced by each parent animal were removed and counted from the appearance of the first brood. The numbers of living offspring were counted and the presence of aborted eggs or dead offspring were recorded. Mortality among the parent animals was recorded at the same tímes as offsprings were counted.
Oxygen concentration, temperature, hardness and pH values were measured twice a week, in fresh and old medium, in the control(s) and in the highest test substance concentration.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.5
- Range finding study
- Test concentrations: 0.150, 0.320, 0.720, 1.58, 3.50, 5.31, 11.1, 23.0, 48.0 and 100.0 mg/L
- Results used to determine the conditions for the definitive study: the mortality of the parent animals was irrelevant to the concentrations. The production inhibition rate was between 21.9-75.4%.

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1.24 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

3.01 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

10.8 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Results with reference substance (positive control):

The mortality of the parent animals in the control group was 10 %. The mortalities of the parent animals in the treatment groups were varied from 10 % to 20 % and the accidental or inadvertent mortalities were varied from 10 % to 20 %. No aborted eggs and dead offspring were observed during the test. The mean number of live offspring produced per parent animal surviving at the end of the test in the control group was 72. The coefficient of variation was 10.2 %.

Reported statistics and error estimates:

The estimation of the 21 days LOEC and NOEC was analyzed by the Bartlett's Test.
For the estimation of the concentration which would cause a 50 % reduction in reproductive output (i.e. the EC50) and 95 % confidence limits using the method of Maximum Likelihood Probit.
Statistical analysis of the data was accomplished with Toxcalc v5.0.26.

Validity criteria fulfilled:

yes

Conclusions:

Expressed as the time-weighted mean measured concentrations of the test substance, the lethal effect of test item on Daphnia magna is as following:
The 21 days NOEC value was 1.24 mg/L;
The 21 days LOEC value was 3.01 mg/L;
The 21 days EC50 value was 10.8 mg/L(95% confídence limits was 6.57-20.1 mg/L).

Executive summary:

The influence of the test substance to Daphnia magna was determined in a 21 days reproduction test with a frequency of 24 hours renewal according to OECD 211. Seven treatment groups and one control group were included in definitive test. The nominal concentrations of the treatment group were 0.102, 0.256, 0.640, 1.60, 4.00, 10.0 and 25.0 mg/L respectively. The time-weighted mean measured concentrations of the treatment group were 0.150, 0.240, 0.530, 1.24, 3.01, 7.51 and 21.2 mg/L respectively. The mortality of the parent animals in control group was 10% and the accidental or inadvertent mortalities of the parent animals in each treatment groups were varied from 10% to 20% at the end of the test. The mean number of live offspring produced per parent animal surviving at the end of the test in control group was 72. The test is valid.

The measured concentration of the test substance varied more than 20% of the nominal concentration. The results were expressed as time-weighted mean measured concentrations.

Results showed that under the testing conditions, for Daphnia magna reproductions, the No Observed Effect Concentration (NOEC) was 1.24 mg/L, the Lowest Observed Effect Concentration (LOEC) was 3.01 mg/L, and 50% reduction in reproductive output (EC50) was 10.8 mg/L (95% confidence limit was 6.57-20.1 mg/L).

Description of key information

For Daphnia magna reproductions, the No Observed Effect Concentration (NOEC) was 1.24 mg/L, the Lowest Observed Effect Concentration (LOEC) was 3.01 mg/L, and 50% reduction in reproductive output (EC50) was 10.8 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1.24 mg/L

Additional information

The influence of the test substance to Daphnia magna was determined in a 21 days reproduction test with a frequency of 24 hours renewal according to OECD 211. Seven treatment groups and one control group were included in definitive test. The nominal concentrations of the treatment group were 0.102, 0.256, 0.640, 1.60, 4.00, 10.0 and 25.0 mg/L respectively. The time-weighted mean measured concentrations of the treatment group were 0.150, 0.240, 0.530, 1.24, 3.01, 7.51 and 21.2 mg/L respectively. The mortality of the parent animals in control group was 10% and the accidental or inadvertent mortalities of the parent animals in each treatment groups were varied from 10% to 20% at the end of the test. The mean number of live offspring produced per parent animal surviving at the end of the test in control group was 72. The test is valid.

The measured concentration of the test substance varied more than 20% of the nominal concentration. The results were expressed as time-weighted mean measured concentrations.

Results showed that under the testing conditions, for Daphnia magna reproductions, the No Observed Effect Concentration (NOEC) was 1.24 mg/L, the Lowest Observed Effect Concentration (LOEC) was 3.01 mg/L, and 50% reduction in reproductive output (EC50) was 10.8 mg/L (95% confidence limit was 6.57-20.1 mg/L).