3-methyl-1-phenylpyrazol-5-ylamine

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

Objective of this study was to observe the action of test chemical when it exposed with the Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) for 72 hrs. Test conducted in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test).

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material :3-methyl-1-phenyl-1H-pyrazol-5-amine
- Molecular formula: C10H11N3
- Molecular weight : 173.2179 g/mol
- Smiles notation : Cc1cc(n(n1)c2ccccc2)N
- InChl:1S/C10H11N3/c1-8-7-10(11)13(12-8)9-5-3-2-4-6-9/h2-7H,11H2,1H3
- Substance type:Organic
- Physical state:Solid

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The stock solution 160 mg/l was prepared by dissolving white powder in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name:
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of botany of the ASCR
- Initial biomass concentration: 5x10(3) cells /ml
- Method of cultivation: No data available

ACCLIMATION - No data available
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test temperature:

23±2°C

pH:

Test at highest concentration 160 mg/l: 8 change to 7.8 during test
Control: 8 change to 7.8 during test

Nominal and measured concentrations:

0, 10, 20, 40, 80 and 160 mg/l

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

100.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95 % CI was 76.2 to 131.7 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- ErC50: 0.77 mg/L (24 hours)

Reported statistics and error estimates:

ErC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical the ErC50 was determine to be 100.2 mg/l.

Executive summary:

Objective of this study was to observe the action of test chemical when it exposed with the Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) for 72 hrs. Test conducted in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 160 mg/l was prepared by dissolving white powder in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. 0, 10, 20, 40, 80 and 160 mg/l concentrations were used. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration ErC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs.

The median effective concentration (ErC50) for the test substance 3-methyl-1-phenyl-1H-pyrazol-5-amine, in algae was determined to be 100.2 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the ErC50 value, which indicates that the substance is likely to be non-hazardous to aquatic algae and cannot classified as per the CLP classification criteria.

Description of key information

Objective of this study was to observe the action of test chemical when it exposed with the Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) for 72 hrs. Test conducted in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 160 mg/l was prepared by dissolving white powder in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. 0, 10, 20, 40, 80 and 160 mg/l concentrations were used. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration ErC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determined after an exposure period of 72 hrs. The median effective concentration (ErC50) for the test substance 3-methyl-1-phenyl-1H-pyrazol-5-amine, in algae was determined to be 100.2 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the ErC50 value, which indicates that the substance is likely to be non-hazardous to aquatic algae and cannot classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

100.2 mg/L

Additional information

Objective of this study was to observe the action of test chemical when it exposed with the Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) for 72 hrs. Test conducted in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 160 mg/l was prepared by dissolving white powder in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. 0, 10, 20, 40, 80 and 160 mg/l concentrations were used. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration ErC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determined after an exposure period of 72 hrs. The median effective concentration (ErC50) for the test substance 3-methyl-1-phenyl-1H-pyrazol-5-amine, in algae was determined to be 100.2 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the ErC50 value, which indicates that the substance is likely to be non-hazardous to aquatic algae and cannot classified as per the CLP classification criteria.