8-Chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1300 (Daphnid Chronic Toxicity Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

1

Reference substance name:

8-chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid

Cas Number:

353258-35-2

Molecular formula:

C9H4ClF3N2O2

IUPAC Name:

8-chloro-6-(trifluoromethyl)imidazo[1,2-a]pyridine-2-carboxylic acid

Specific details on test material used for the study:

Test substance: IN-QEK31-011
Batch No.: SG0312574
Purity: 98.2%

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Remarks:

Dilution water

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

21 d

Test conditions

Hardness:

The total hardness ranged from 140 to 146 mg CaCO3/L in control solution samples and from 132 to 150 mg CaCO3/L in the treatment solution samples

Test temperature:

20.2 - 21.0°C

pH:

7.4 - 8.6

Dissolved oxygen:

7.6 - 9.1 mg/L (87 to 103% saturation)

Salinity:

The total alkalinity ranged from 148 to 162 mg CaCO3/L in control solution samples and from 124 to 184 mg CaCO3/L in the treatment solution samples

Conductivity:

The total conductivity ranged from 332 to 364 μS/cm in control samples, and from 326 to 351 μS/cm in the treatment samples

Nominal and measured concentrations:

Nominal: 1.5, 4.4, 13, 40, and 120 mg/L
Measured: 1.40, 4.06, 12.2, 37.7, and 111 mg/L

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

111 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: Adult Survival, Reproduction, Adult Length, Adult Dry Weight

Effect concentrations 2

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 111 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: Adult Survival, Reproduction, Adult Length, Adult Dry Weight

Effect concentrations 3

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 111 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

other: Adult Survival

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

21-day NOEC (Daphnia, Adult Survival, Reproduction, Adult Length, Adult Dry Weight): 111 mg/L
21-day LOEC (Daphnia, Adult Survival, Reproduction, Adult Length, Adult Dry Weight): >111 mg/L
21-day EC50 (Daphnia, Adult Survival): >111 mg/L

Executive summary:

The chronic toxicity of the test item to the cladoceran, Daphnia magna, was determined in a 21-day static renewal test. The test was conducted in accordance with OECD Guideline No. 211 and U.S. EPA OPPTS 850.1300 test guidelines. The study was conducted with five target nominal concentrations (1.5, 4.4, 13, 40, and 120 mg/L) and a dilution water control, at a temperature range of 20.2 to 21.0°C. One daphnid was used per replicate with ten replicates per treatment, for a total of 10 organisms per treatment.

The concentration of the test item was measured at initiation, in fresh test solutions on days 9, 14, and 19, and in spent test solutions on days 2, 12, 16, and 21 of the definitive test. Measured concentrations of the test item at initiation were 1.46, 3.97, 12.4, 38.1, and 111 mg/L, or 90 to 97% of nominal. The mean measured concentrations of the test item during the 21-day exposure were 1.40, 4.06, 12.2, 37.7, and 111 mg/L or 92 to 94% of nominal. No residues of the test item were detected in the dilution water control solution above the LOD of 0.0133 mg/L. Recoveries from the QC fortifications ranged from 93 to 106% of the nominal concentrations during the exposure. The biological response results are based on the mean measured concentrations.

Based on survival and mean measured concentrations, the 21-day NOEC and LOEC were 111 and >111 mg/L, respectively, the highest concentration tested. The MATC, based on the survival, could not be calculated. The 21-day EC50 based on immobilization of the first generation daphnids was estimated to be >111 mg/L, the highest concentration tested.

The NOEC and LOEC, based on mean number of live young per surviving adult and mean measured concentrations, were 111 and >111 mg/L, respectively. The MATC, based on the mean number of young per live adult produced during the course of the test, could not be calculated. The 21-day EC10 and EC20, based on number of live young per surviving adult and mean measured concentrations, were estimated to be 114 mg/L (95% CL: 94 and 134 mg/L) and 118 mg/L (95% CL: 110 and 127 mg/L), respectively.

The NOEC and LOEC values, based on mean measured concentrations and adult length, were 111 and >111 mg/L, respectively. The MATC, based on adult length, could not be calculated. The 21-day EC10 and EC20, based on adult body length and mean measured concentrations, were not statistically sound values.

The NOEC and LOEC values, based on mean measured concentrations and adult dry weights, were 111 and >111 mg/L. The MATC, based on adult weight, could not be calculated. The 21-day EC10, based on adult dry weight and mean measured concentrations, was not statistically sound. The 21-day EC20, based on adult dry weight and mean measured concentrations, was estimated to be 116 mg/L (95% CL: 107 and 125 mg/L).