Ethyl 4-methyl-2-oxocyclohexanecarboxylate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Sept 23, 2016 to March 23, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Batch PDJ 378-68
Purity 93.2%
Expiration 2018/06

Details on sampling:

10.0 mL water samples were taken (at least in duplicate) before and after renewal from each concentration during the definitive test at 0, 24, 48, 72 and 96 h. On each occasion, one sample was analysed after certain pre-treatments; the remaining samples were retained in case further analysis would be required.

Vehicle:

no

Details on test solutions:

In the test, the test solution was prepared by directly adding appropriate amounts of FRET 13-0545 (93.2%) in dilution water and then facilitating its dispersion by string for 30 min. The test substance dissolved in water and the solutions were colourless and clear. Each test chamber contained 3L of test solution covered by inert lids with zero headspace and solutions were renewed every 24 h.

Test organisms (species):

other: Gobiocypris rarus

Details on test organisms:

The Rare minnow, Gobiocypris rarus was used in the test on the basis of such important practical criteria as, for example, their ready availability throughout the year, ease of maintenance, convenience for testing and any relevant economic, biological or ecological factors. The test species of Rare minnow, Gobiocypris rarus (Batch No.: F20161025G), were bred by the testing lab. A population of a single stock was used in the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

166-174 mg (CaCo3)/L

Test temperature:

23-23.1C

pH:

7.76-7.89

Dissolved oxygen:

85-96% of the air saturation

Nominal and measured concentrations:

The measured concentrations of 10.0, 20.0, 40.0, 60.0, 80.0 and 100 mg/L were 10.3, 20.3, 39.9, 59.3, 80.0 and 97.5 mg/L, respectively.

Details on test conditions:

During the test, the following conditions were maintained:
-Light: 12 hours photoperiod daily;
-Temperature: 23.0ºC to 23.1ºC;
-pH: 7.76~7.89
-Oxygen concentration: 85% ~ 96% of the air saturation; No aeration.
-Feeding: none.

Reference substance (positive control):

yes

Remarks:

under the same test condition the resulting 24 h-LC50 was 291 mg/L for K2Cr2O7

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 46 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The results showed that under valid semi-static (24 h renewal) conditions, the 96 h-LC50 of the test substance to fish (Rare minnow, Gobiocypris rarus) was 46.0 mg/L, with 95% confidence limit of 38.2 mg/L ~ 55.5 mg/L (based on the measured concentration). The maximum tested concentration causing no mortality (96 h-LC0) was 20.0 mg/L (measured concentration 20.3 mg/L). The minimum concentration causing 100% mortality (96 h-LC100) is 80.0 mg/L (measured concentration 80.0 mg/L), i.e.:
96 h-LC50 = 46.0 mg/L, 95% CI 38.2 ~ 55.3 mg/L (based on measured concentration);
96 h-LC0 = 20.0 mg/L (measured concentration 20.3 mg/L);
96 h-LC100 = 80.0 mg/L (measured concentration 80.0 mg/L).

Results with reference substance (positive control):

K2Cr2O7was used as the positive control substance, and the resulting 24 h-LC50 was 291mg/L

Reported statistics and error estimates:

Trimmed Spearman-Karber Method (Version 1.5, USEPA) can be used to calculate the LC50 and 95% confidence limits.

Validity criteria fulfilled:

yes

Conclusions:

The results showed that under valid semi-static (24 h renewal) conditions, the 96 h-LC50 of the test substance to fish (Rare minnow, Gobiocypris rarus) was 46.0 mg/L, with 95% confidence limit of 38.2 mg/L ~ 55.3 mg/L (based on the arithmetic mean of measured concentration), according to OECD TG 203.

Executive summary:

The results showed that under valid semi-static (24 h renewal) conditions, the 96 h-LC50 of the test substance to fish (Rare minnow, Gobiocypris rarus) was 46.0 mg/L, with 95% confidence limit of 38.2 mg/L ~ 55.3 mg/L  (based on the arithmetic mean of measured concentration), according to OECD TG 203.

The duration of test was 96 hours in a semi-static exposure system with renewed test solution every 24 hours. The analytical results showed that the concentration of the test substance is consistent in the test medium throughout the 96-hour test period (deviation within 20%). Results were calculated based on the measured concentrations (arithmetic mean).

Description of key information

The results showed that under valid semi-static (24 h renewal) conditions, the 96 h-LC50 of the test substance to fish (Rare minnow, Gobiocypris rarus) was 46.0 mg/L, with 95% confidence limit of 38.2 mg/L ~ 55.3 mg/L  (based on the arithmetic mean of measured concentration), according to OECD TG 203.

The duration of test was 96 hours in a semi-static exposure system with renewed test solution every 24 hours.The analytical results showed that the concentration of the test substance is consistent in the test medium throughout the 96-hour test period (deviation within 20%). Results were calculated based on the measured concentrations (arithmetic mean).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

46 mg/L