1,3,5-Triazine-2,4-diamine, N2-[(1R,2S)-2,3-dihydro-2,6-dimethyl-1H-inden-1-yl]-6-(1-fluoroethyl)-

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 (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item was added to about 130 mL deionized water and stirred overnight before testing (equilibration phase).

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Laboratory culture: no, aeration tank of a domestic sewage treatment plant (Municipal STP Cologne-Stammheim)
- Pretreatment: aeration of the activated sludge. daily fed with synthetic medium

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

20 ± 2° C

pH:

7.5

Nominal and measured concentrations:

Nominal test concentrations (mg/L) : 10, 100, 1000 (Test item concentration in physico-chemical oxygen consumption control (mg/L) : 1000)

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 2

OTHER TEST CONDITIONS
- Type of application : direct weighing into Erlenmeyer flasks (incubation vessel)
- Test concentration of the activated sludge : 960 mg/L suspended solids
- Test temperature : 20 ± 2° C
- Stirring period of test item before start of incubation time : 16 hours
- Incubation time : 3 hours with permanent aeration


TEST MEDIUM / WATER PARAMETERS
Synthetic sewage feed : A synthetic sewage feed is made by dissolving
the following amounts of substance in 1 litre of
water.
- 16.0 g peptone
- 11.0 g meat extract
- 3.0 g urea
- 0.7 g NaCl
- 0.4 g CaCl2 · 2H2O
- 0.2 g MgSO4 · 7H2O
- 2.8 g K2HPO4
pH of the synthetic sewage feed : 7.5 ± 0.5


EFFECT PARAMETERS MEASURED: Respiration rate

Reference substance (positive control):

yes

Remarks:

3.5-dichlorophenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Oxygen content temperature, and pH values during exposure phase (test item):

	Test concen-tration [mg/L]	O2start [mg O2/L]	O2end [mg O2/L]	Time (start-end) [min.]	Temp. [°C]	pH
Test item	10	4.5	2.8	4	19.4	7.7
	100	4.7	2.7	5	19.3	7.7
	1000	4.7	2.6	6	19.3	7.7
Control 1		5.3	2.9	6	19.3	7.9
Control 2		5.4	2.6	7	19.3	7.9
Physico-chemical oxygen consumption control	1000	7.0	7,0	9	19.5	7.3

Results for test item:

Test concentration	Respiratory ratetest item	Phys.-chem. O2consumption	Respiratory rate - phys.-chem. O2consumption	Inhibition
[mg/L]	[mg/L⋅h]	[mg/L⋅h]	[mg/L⋅h]	[%]
10	25.5	*0.0	25.5	0.0
100	24.0	*0.0	24.0	0.0
1000	21.0	0.0	21.0	12.5
Control. mean	24.0
Control 1	24.0
Control 2	24.0

AE 1170437 TECHNICAL showed 12.5 % respiration inhibition of activated sludge at a test item concentration of 1000 mg/L.

EC50 > 1000 mg/L

Description of key information

The inhibition of the degradation activity of activated sludge is not anticipated. 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

1 000 mg/L

Additional information

The respiration inhibition of the substance was tested in an OECD Guideline 209 -Activated Sludge, Respiration Inhibition Test.

The 3h EC50 and EC20 of the test item for respiratory inhibition of activated sludge fed with synthetic sewage was > 1000 mg/L. The test item is therefore of low-toxic to activated sludge microorganisms and the inhibition of the degradation activity of activated sludge is not anticipated.