4-chloro-7H-pyrrolo[2,3-d]pyrimidine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From February 26, 2021 to March 08, 2021

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13th April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch number: 4419-190704
Purity: 99.3%

Analytical monitoring:

yes

Details on sampling:

Analysis frequency: in 0-hour fresh solution and 48-hour old solution.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 0.0505 g test item was weighed and dissolved in 1000 mL of test water directly. After the test item was dissolved completely by stirring for about 24 hours, the solution was used for exposure and dilution. 50, 89, 160 and 280 mL were diluted to 500 mL with test water, respectively, to get test solutions of 5.0, 8.9, 16 and 28 mg/L.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation (mean and range, SD): less than 24 hours old and not the first brood progeny.
- Source: Applied Chemistry Department Pesticide Environmental Evaluation Laboratory of China Agricultural University.

ACCLIMATION
- Acclimation period: 1d
- Acclimation conditions (same as test or not): same

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

140 to 250 mg/L (as CaCO3)

Test temperature:

18~22oC and be constant within ±1oC

pH:

within 6 - 9, normally not vary by more than 1.5 units in any one test

Dissolved oxygen:

not less than 3 mg/L during the test period

Nominal and measured concentrations:

Nominal 5.0, 8.9, 16, 28 and 50 mg/L;
Measured 4.159, 7.810, 13.978, 24.782 and 44.307 mg/L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 200 mL glass beakers
- Type (delete if not applicable): open
- Material, size, headspace, fill volume:
- Volume of solution: 100 mL per vessel
- Aeration: no aeration to vessels
- No. of organisms per vessel: 5 daphnia
- No. of vessels per concentration (replicates): 4 replicates
- No. of vessels per control (replicates): 4 replicates

OTHER TEST CONDITIONS
- Adjustment of pH: During the test, there was no pH adjusting or feeding.
- Photoperiod: 16 hr light: 8 hr dark
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Biological observation: Observation intervals: 24 and 48 hours after exposure
Method: Each test vessel was checked for immobilized daphnids. In addition to immobility, any abnormal behavior or appearance were recorded. Those animals that are not able to swim within 15 seconds, after gentle agitation of the test vessel are considered to be immobilized (even if they can still move their antennae).

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 1, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: During the period of 48 hours, no immobilization or any toxic signs were observed in the control group and the test groups of 1 mg/L. 1 or 2 daphnia were immobilized in the test group of 10 mg/L and 5 daphnia were immobilized in each replicate of 100 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate as reference item was tested for EC50 as a means of assuring that the test conditions are reliable four times a year in the laboratory.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

15.42 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limit was 13.05-18.23 mg/L.

Details on results:

Physicochemical Measurements in the Definitive Test:
The determined values of dissolved oxygen were 8.57 ~ 9.15 mg/L, the pH values were between 8.10 ~ 8.50 and the max difference was 0.40. Total hardness of test water was 180 mg/L (as CaCO3). The temperature was 18.5 ~ 19.5 oC, the difference was 1.0 oC. They were in the allowed range specified in Conditions of exposure.
Toxic Signs in the Definitive Test:
During the 48-hour exposure period, no immobilization and abnormal behavior or appearance was observed in the control group and the test group of 5.0 mg/L. The daphnids exposed to 8.9, 16, 28 and 50 mg/L test groups showed abnormal behavior such as immobilization, swimming slowly, 100% inhibition occurred in 50 mg/L test group.

Results with reference substance (positive control):

EC50-24 h of potassium dichromate to Daphnia magna was 1.17 mg/L, and the 95% confidence limits was 0.99 ~ 1.39 mg/L. The results met the recommended criterion in OECD Guideline No. 202: EC50-24 h of potassium dichromate is within the range of 0.6 mg/L to 2.1 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 of the test item to Daphnia magna was determined to be 15.42 mg/L.

Executive summary:

A Daphnia acute immobilisation test of the test item was conducted with Daphnia magna over a 48-hour exposure period, according to OECD Guideline 202 under GLP.

The 48-hour EC50 of the test item to Daphnia magna was determined to be 15.42 mg/L.

Description of key information

A Daphnia acute immobilisation test of the test item was conducted with Daphnia magna over a 48-hour exposure period, according to OECD Guideline 202 under GLP.

The 48-hour EC50 of the test item to Daphnia magna was determined to be 15.42 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

15.42 mg/L