(1,2-dimethylpropyl)-5-methyl-pyrazole-4-carboxylic acid

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

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:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(1,2-dimethylpropyl)-5-methyl-pyrazole-4-carboxylic acid

EC Number:

846-828-3

Cas Number:

1872341-39-3

Molecular formula:

C10H16N2O2

IUPAC Name:

(1,2-dimethylpropyl)-5-methyl-pyrazole-4-carboxylic acid

Specific details on test material used for the study:

- Source and lot/batch No.of test material:
L2018-005
- Expiration date of the lot/batch:
01 Apr 2020
- Purity: 99.8 %

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Analysis of the test media samples was conducted on fresh media at 0 hours and on
corresponding old media at 72 hours

Test solutions

Vehicle:

no

Details on test solutions:

The necessary amount of test item for preparing the stock solution S1 was weighed on a weighing
scoop and transferred to a volumetric flask. Test medium (was added up to the
bench mark and the stock solution was shaken, treated with 10 minutes ultrasound and stirred for
24 hours at 600 rpm with a magnetic stirrer. Afterwards the stock solution was filtered and
appeared clear and transparent. Lower test solutions were prepared by dilution of the stock
solution with test medium

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

The test organism Pseudokirchneriella subcapitata (Korshikov) Hindák (Sphaeropleales:
Selenastraceae), strain: SAG 61.81, was purchased from a commercial supplier, MBM
Sciencebridge GmbH, Hans-Adolf-Krebs-Weg 1, D-37077 Göttingen, Germany.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

Temperature Range (°C)
22.0 – 23.0°C

pH:

7.03 – 7.33

Nominal and measured concentrations:

The measured initial concentrations of analyte ranged from 94 % to 105 % of nominal. In the aged
samples the measured concentrations were between 96 % and 113 % of nominal. Therefore
toxicological endpoints were evaluated using the nominal concentrations of the test item.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

26.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

49.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes