Propanamide, N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)thio]-2-hydroxy-2-methyl-

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:

guideline study

Data source

Reference

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

bis(N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfanyl]-2-hydroxy-2-methylpropanamide)

EC Number:

618-533-8

Cas Number:

90356-78-8

Molecular formula:

C18H14F4N2O2S

IUPAC Name:

bis(N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfanyl]-2-hydroxy-2-methylpropanamide)

Test material form:

solid: crystalline

Details on test material:

Test item: B-SulphenylCAS number: 90356-78-8Batch number: 235100NPhysical state: Solid, crystalline substanceColour: Creamy whiteActive ingredient content: ca. 99%Storage: At a temperature of 15 to 30 °C, protected from light and moisture

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

The preparation of stock and test solutions was based on the preliminary non GLP range finding test. The stock solution was prepared by measuring 75.10 mg of test item into 1 500 ml OECD growth medium. The suspension was stirred for 24 hours in dark. After stirring the suspension was filtered through a 0.2 μm WhatmanTM ME24 (Mixed cellulose ester) filter. The first 100 ml filtrate was disposed. The concentration of the test item in the filtrate (stock solution) was determined by UHPLC. The measured value was 5.72 mg/L.Preparation of test solutions: Seven test solutions of different concentration were prepared by mixing appropriate volume of OECD medium and stock solution of the test item. The maximum separation factor between of test vessels was 2. Two additional replicates were prepared for controlling the abiotic degradation of the test substance. These test vessels were not inoculated with alga inoculum culture. The following table shows the preparation of test solutions. The volume of the prepared dilution levels was 300 ml except the control solution which was 600 ml.

Test organisms

Test organisms (species):

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

Details on test organisms:

Pseudokirchneriella subcapitata (Korshikov); F.Hindák (formerly known as Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

The temperature inside the incubator at the test vessels was measured and registered continuously by thermometer and datalogger. Throughout the test the temperature was nearly constant. The temperature during the test remained in the 21 ± 2 °C range.

pH:

At the beginning of the test the pH values were measured in the remaining test solution of the concurrent test vessels at each dilution level. At the end of the test the pH values were measured in each test vessel. The pH of test solutions was not adjusted at the beginning of the test.

Nominal and measured concentrations:

In the test the following nominal concentrations were applied: 0.48; 0.95; 1.43; 1.91; 2.86; 3.81 and 5.72 mg/L. The following concentrations were calculated from the measured values and were applied for the statistical evaluation in the test: 0.32; 0.60; 1.09; 1.67; 1.70; 1.44 and 2.96 mg test item/L. The test item concentrations of the abiotic controls were 3.88 (in light) and 1.82 (in darkness) mg/L.

Details on test conditions:

The test vessels were closed with silicone stoppers. For the proper mass transfer of carbon dioxide glass tubes with filter were placed through silicone stoppers. The test was maintained under static conditions for a period of 72 hours. The vessels were shaken and illuminated continuously in the incubator. The vessels were placed randomly into the incubator and were repositioned daily after sampling. One of the vessels of abiotic controls was taken into the incubator with a complete aluminium foil cover to check the stability of test item in the absence of light

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.75 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

1.36 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.25 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

The No Observed Effect Concentration and Lowest Observed Effect Concentration for the test item were calculated by ToxRat® software with Fisher’s exact binominal test with Bonferroni correction for specific growth rate and yield. The results were not conclusive or not determinable.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the Council Regulation (EC) 440/2008 B-sulphenyl is hazardous to the aquatic environment and classified into the second acute toxic hazardous category [GHS Acute aquatic hazard Category Acute II. – 72 h EC50 (for algae or other aquatic plants) > 1 mg/L but ≤ 10 mg/L]