4-Methanesulfonyl-2-(trifluoromethyl)benzaldehyde

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

Study period:

Feb - Oct 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

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)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-methanesulfonyl-2-(trifluoromethyl)benzaldehyde

EC Number:

812-681-9

Cas Number:

1215310-75-0

Molecular formula:

C9H7F3O3S

IUPAC Name:

4-methanesulfonyl-2-(trifluoromethyl)benzaldehyde

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples for possible analysis were taken from all test concentrations and the control according to the schedule:
Frequency at t=0 h, t=24 h and t=72 h
Volume 3.0 mL
Storage Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

Test solutions

Vehicle:

yes

Remarks:

M2

Details on test solutions:

Preparation of test solutions started with a loading rate of 100 mg/L applying a 20-minute
treatment with ultrasonic waves followed by a 3-day period of magnetic stirring to ensure
maximum dissolution of the test item in medium. The obtained aqueous mixture was filtered
through a 0.45 μm membrane filter (RC55, Whatman) and the resulting Saturated Solution
(SS) was used as the highest test concentration. Lower test concentrations were prepared by
subsequent dilutions of the SS in test medium. All test solutions were clear and colorless at
the end of the preparation procedure.
After preparation, volumes of 50 mL were added to each replicate of the respective test
concentration. Subsequently, 1 mL of an algal suspension was added to each replicate
providing a cell density of 104 cells/mL.

Test organisms

Test organisms (species):

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

Details on test organisms:

Pseudokirchneriella subcapitata, strain: NIVA CHL 1

Study design

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

21-24°C

pH:

6.0-9.0

Reference substance (positive control):

yes

Remarks:

Test medium without test item or other additives

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

52 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:

EC10

Effect conc.:

5.8 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:

EC50

Effect conc.:

17 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Yield

Effect concentrations 5

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

< 5.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

based on statistical significance

Effect concentrations 6

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

11 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks:

based on biological relevance

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, under the conditions of the present study with Pseudokirchneriella subcapitata, QAW039-C2 reduced growth rate of this fresh water algae species significantly at a TWA concentration of 5.6 mg/L and higher.
The EC50 for growth rate inhibition (72h-ERC50) was 52 mg/L with a 95% confidence interval ranging from 50 to 53 mg/L.
The EC50 for yield inhibition (72h-EYC50) was 17 mg/L with a 95% confidence interval ranging from 17 to 18 mg/L.
The 72h-NOEC for growth rate and yield inhibition was below 5.6 mg/L based on statistical significance. The 72h-NOEC for growth rate was 11 mg/L, based on biological relevance.