2,2',2''-(hexahydro-1,3,5-triazine-1,3,5-triyl)triethanol

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Activated sludge from laboratory wastewater plant treating municipal sewage.
- The inoculum was washed, brought to a concentration of 5 g/L dry substance and aerated during the night.
- 50 mL were added to a total volume of 250 mL to obtain a concentration of 1 g/L dry substance in the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test temperature:

20+/-2°C

Dissolved oxygen:

- During aeration: >2.5 mg/L
- Immediately before measurement: >6.5 mg/L

Nominal and measured concentrations:

- Nominal concentrations of test substance (mg/L): 10, 100, 248, 496, 1000

Details on test conditions:

- Test vessels: Erlenmeyer-vessels (nominal volume 250 mL)
- Test volume: 250 mL
- Synthetic medium: 8 mL/vessel 100-fold concentrated OECD

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

ca. 170 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Key result

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

ca. 550 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

30 min

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

- EC50 of 3,5-dichlorophenol in the range of 5-30 mg/L
- Deviation of blank controls < 15%

Description of key information

The test substance was tested in an OECD guideline study. The EC50 was determined to be 550 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:

550 mg/L

Additional information

Freshwater

Key

The test substance was tested in an OECD guideline 209 study. The nominal concentrations tested were 10, 100, 248, 496, 1000 mg/L.The test was conducted under static conditions. Domestic activated sludge was used as inoculum. The total exposure duration was 30 min. The EC50 was determined to be 550 mg/L.

Supporting

The toxicity to microorganisms was tested in a study according to DIN 38412-8. The nominal concentration (mg/L) used were: 39.06, 78.13, 156.25, 312.5, 625, 1250, 2500, 5000, 10000. The EC50 value was determined to be 55.4 mg/L and the EC10 value was determined to be 41.3 mg/L. Both values based on growth inhibition.

The toxicity to microorganisms was tested in this OECD guideline study. The test substance was tested under static conditions with a total exposure duration of 30 min. The EC50 value was determined to be 560 mg/l.

The toxicity to microorganisms was tested in this OECD guideline study. Only few data were available for this study. The EC50 value was determined to be 370 mg/L and the EC10 value was determined to be 140 mg/L.

Conclusion: 4 different studies were available. 3 OECD guideline studies were available one study according to DIN 38412 -8. The results of the guideline studies lay all in the same range. As a result the EC50 value of 550 mg/L was chosen as key result.