1-(2-hydroxyethyl)-1H-pyrazol-4,5-diyldiammoniumsulfate

Toxicity to aquatic algae and cyanobacteria

Administrative data

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:

other: Guideline study under GLP conditions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1-(2-hydroxyethyl)-1H-pyrazol-4,5-diyldiammoniumsulfate

EC Number:

429-300-3

EC Name:

1-(2-hydroxyethyl)-1H-pyrazol-4,5-diyldiammoniumsulfate

Cas Number:

155601-30-2

Molecular formula:

C5H12N4O5S

IUPAC Name:

2-(4,5-diamino-1H-pyrazol-1-yl)ethan-1-ol; sulfuric acid

Details on test material:

Batch No GST 7-18099

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

sampling was done at 0, 24, 48 and 72 h

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test conditions

Test temperature:

23°C

pH:

7-7.5 pH

Nominal and measured concentrations:

cell conentration at test start 10exp 4 cells / ml
Substance nominal concentrations: 1, 1.8, 3.2, 5.6, and 10 mg/l

Details on test conditions:

test vessel was a 100 ml flask

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

2.04 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: 95% CL

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

2.43 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% cl

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

5.33 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

growth inhibition occurs under influence of Pyrazole DHE

Executive summary:

The results from this algal growth study in which the unicellular green algae Selenastrum capricornutum were treated with the test substance Pyrazole DHE at the nominal concentrations of 1, 1.8, 3.2, 5.6, and 10 mg/l are given below.

The calculation of EbC₅₀, ErC₅₀, NOEC (b) and NOEC (R) was made using the nominal concentrations

The algae were treated for 72 hours and counted at 24, 48 and 72 hours.

The EbC₅₀at 24 hours was 2.04, at 48 hours was 2.43 and at 72 hours was 5.33 mg/L.

The ErC₅₀at 24 hours was 4.23, while at 48 and 72 hours was > 10 mg/L.

The NOEC (b) at 24 hours was 1.8 and was found to be < 1 mg/L at both 48 and 72 hours.

The NOEC (r) at 24, 48 and 72 hours was 3.2, 1 and 1.8 mg/L, respectively.