6,6',6''-(1,3,5-triazine-2,4,6-triyltriimino)trihexanoic 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 (incl. QA statement)

Remarks:

EL

Analytical monitoring:

yes

Details on sampling:

- Sampling method: algae separated by centrifugation before analysis

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 - 24 °C

pH:

7.98 - 8.16

Nominal and measured concentrations:

Initial concentrations: 64, 128, 256, 512, 1024, 2048, 3000 mg/L (nominal)
Measured concentrations at start and end of the test: between -0.27% and +9.91% 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: 4160 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 8.04
- Photoperiod: continuous illumination
- Light intensity and quality: 8470 - 8590 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.:

145 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 115-181 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3 285 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CI: 2619-4119 mg/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

452 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 95% CI: 247-825 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:

y

Growth data:

Nominal concentration [mg/L]	Inhibition of growth rate [%]	Inhibition of biomass [%]
64	1.00	4.4
128	6.71	21.2
256	18.11	42.3
512	25.66	60.8
1024	34.24	72.3
2048	43.65	76.9
3000	50.03	83.9

 

Validity criteria fulfilled:

yes

Executive summary:

A growth inhibition test of TC to the algae Desmodesmus subspicatus was performed according to OECD 201. After 72 h of exposure, the EC_r10 was determined to be 145 mg/L and the EC_r50 to be 3285 mg/L.

Description of key information

A 72 h growth inhibition test of TC to the algae Desmodesmus subspicatus was performed according to OECD 201.

Key value for chemical safety assessment

EC50 for freshwater algae:

3 285 mg/L

EC10 or NOEC for freshwater algae:

145 mg/L

Additional information

The EC50 (effect: growth rate) was determined to be 3285 mg/L.

The EC50 (effect: biomass) was determined to be 452 mg/L.