6-[[(4-methylphenyl)sulphonyl]amino]hexanoic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Sampling method: algae separated by centrifugation

Vehicle:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: G. Brinkmann 1953/SAG86,81
- Source: Institute of Botany, Slovak Academy of Sciences, Bratislava, Slovak Republic
- Method of cultivation: inoculum culture prepared 3 days before test start. Conditions same as under test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.4 - 23.1°C

pH:

7.92 - 8.10

Nominal and measured concentrations:

Initial concentrations 64.0, 128.0, 256.0, 512.0, 1024.0 mg/L (nominal)
Measured concentrations: between -9.53% and +1.47% of nominal

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 mL volume in 150 mL flasks
- Type: closed with air-permeable stoppers
- Materia: glass or other chemically inert material
- Initial cells density: 4566 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes, according to OECD

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Sörensen buffer
- Intervals of water quality measurement: pH measured at beginning and end of test

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: stock solution adjusted with 1 N NaOH to pH 8.02
- Photoperiod: continuous illumination
- Light intensity and quality: 8450 - 8620 lux, cool white light, effective wavelength 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

120 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 63-228 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

626 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 328-1195 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

201 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI: 83-490 mg/L

Results with reference substance (positive control):

- 72 h-ECr10: 0.32 mg/L (mean of 3 determinations)
- 72 h-ECr50: 0.81 mg/L (mean of 3 determinations)

Reported statistics and error estimates:

A weighted linear regression analysis was used for determination of EC values

Growth data:

Nominal concentration [mg/L]	Inhibition of growth rate [%]	Inhibition of biomass [%]
64.0	0.97	5.3
128.0	4.67	27.1
256.0	25.30	72.3
512.0	47.17	92.2
1024.0	63.60	97.4

 

Validity criteria fulfilled:

yes

Executive summary:

A growth inhibition test of ASC Plus to the algae Desmodesmus subspicatus was performed according to OECD 201. After 72 h of exposure, the E_rC10 was determined to be 120 mg/L and the E_rC50 to be 626 mg/L.

Description of key information

A growth inhibition test of ASC Plus to the algae Desmodesmus subspicatus was performed according to OECD 201.

Key value for chemical safety assessment

EC50 for freshwater algae:

626 mg/L

EC10 or NOEC for freshwater algae:

120 mg/L

Additional information

The EC_b50 was determined to be 201 mg/L.