1,2-dihydro-2-oxoquinoline-4-carboxylic acid

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Remarks:

study is in progress

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1,2-dihydro-2-oxoquinoline-4-carboxylic acid

EC Number:

239-827-9

EC Name:

1,2-dihydro-2-oxoquinoline-4-carboxylic acid

Cas Number:

15733-89-8

Molecular formula:

C10H7NO3

IUPAC Name:

1,2-dihydro-2-oxoquinoline-4-carboxylic acid

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Remarks:

Reconstituted algal growth medium (OECD medium, according to OECD 201)

Test organisms

Test organisms (species):

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

Details on test organisms:

Strain number: 61.81 SAG (identical strains: CCAP 278/4; UTEX 1648; ATCC 22662)

Study design

Test type:

semi-static

Water media type:

other: Reconstituted algal growth medium (OECD medium, according to OECD 201)

Limit test:

yes

Total exposure duration:

72 h

Remarks on exposure duration:

The exposure time was 72 hours. The test was started (0 hours) by inoculation of a biomass of approximately 104 algal cells per mL test medium.

Test conditions

Test temperature:

Culture temperature was checked at the beginning of the experiment and each day thereafter in a flask filled with water, in the climatic chamber. In addition, water temperature was continuously measured (with a min/max thermometer) within the climate chamber. The temperature was in the range of 22.6 – 22.7 °C measured in the flask and between 21.6 and 23.3 °C measured within the climate chamber.

pH:

The pH was checked at the beginning and at the end of the test in each test vessels. The pH of the control medium was not increased by more than 1.5 units during the test. The range of the pH was 7.68 – 8.76 during the experiment.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: yield

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 5

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Results with reference substance (positive control):

The 72h ErC 50: 0.88 mg/L, (95 % confidence limits: 0.81 – 0.96 mg/L)
The 72h EbC 50: 0.63 mg/L, (95 % confidence limits: 0.58 – 0.69 mg/L)
The 72h EyC 50: 0.53 mg/L, (95 % confidence limits: 0.49 – 0.58 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this algal growth inhibition test the calculated endpoints for the effect of ACIDE HYDROXY were the following:
The 72h EbC50 value (biomass): > 100 mg/L (nominal)
The 72h ErC50 value (growth rate): > 100 mg/L (nominal)
The 72h EyC50 value (yield): > 100 mg/L (nominal)
The 72h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)
The 72h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)

Executive summary:

The effect of ACIDE HYDROXY test item was assessed on algal growth using the unicellular green alga Pseudokirchneriella subcapitata, over an exposure period of 72 hours.

Because a toxic response was not observed during the preliminary concentration range-finding test, a Limit Test was carried out using only one test concentration of 100 mg/L (nominal) and one control group.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 96.1 mg/L at the start and 92.6 mg/L at the end of the experiment.

As the analytically measured concentration deviated not more than 20 per cent from the nominal, the biological results are based on the nominal test item concentration.

The test design included six replicates at test concentration and six replicates for the untreated control.

Statistical comparisons of biomass, average specific growth rates and yield in control and in treated groups were carried out using 2 Sample t-Test (α = 0.05) by TOXSTAT software.

The ErC50, EbC50 and EyC50 values of the test item were determined directly from the raw data.

Under the conditions of this algal growth inhibition test the calculated endpoints for the effect of ACIDE HYDROXY were the following:

The 72h EbC50 value (biomass): > 100 mg/L (nominal)

The 72h ErC50 value (growth rate): > 100 mg/L (nominal)

The 72h EyC50 value (yield): > 100 mg/L (nominal)

The 72h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

The 72h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)