Tris(2-hydroxyethyl)-1,3,5-triazinetrione

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

April 1984

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Version / remarks:

Commission Directive 88/302/EEC

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Version / remarks:

1986

Deviations:

no

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge, domestic

Details on inoculum:

activated sludge from a lab-scale waste-water treatment system operated with municipal waste water

Test type:

static

Water media type:

freshwater

Total exposure duration:

30 min

Remarks on exposure duration:

The contact time of 30 minutes is regarded as sufficient since the test material has a high water solubility (> 500 g/L)

Nominal and measured concentrations:

nominal: 1000, 500 and 100 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Key result

Duration:

30 min

Dose descriptor:

EC10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Duration:

30 min

Dose descriptor:

EC0

Effect conc.:

>= 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Details on results:

The test material had no effect on the respiration of domestic activated sludge after an incubation time of 30 minutes.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels: EC50 = 14 mg/L

Validity criteria fulfilled:

not applicable

Conclusions:

The test material was not toxic to activated sludge bacteria ( EC10 > 1000 mg/L).

Reference 2

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable study report which meets basic scientific principles

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test was performed according to the specification described in Liu, D. (1989): A rapid and simple method for direct determination of chemical toxicity; Toxicity Assessment 4:399-404.
Principle of the method: determination of microbial dehydrogenase activity by photometric mesurement of the reduction of resazurin at 601 nm

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

activated sludge, domestic

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

180 min

Test temperature:

room temperature

pH:

7.0

Nominal and measured concentrations:

nominal: 0 (control), 100, 500, and 1000 mg/L

Details on test conditions:

- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per abiotic control /replicates): 2


OTHER TEST CONDITIONS
- Adjustment of pH: yes (pH 7.0), at test start

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : dehydrogenase activity, 0, 10, 20 and 30 min

Reference substance (positive control):

no

Key result

Duration:

180 min

Dose descriptor:

IC10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: dehydrogenase activity

Extinction (601 nm)

Time (min)	BW	PK1	PK2	PC1	PC2	TA1	TA4	TA2	TA5	TA3	TA6
0	1.585	1.014	0.998	1.575	1.560	1.162	1.102	0.983	0.986	0.973	0.884
10	1.598	0.654	0.624	1.569	1.561	0.832	0.805	0.642	0.628	0.620	0.574
20	1.597	0.416	0.382	1.569	1.562	0.642	0.609	0.426	0.413	0.391	0.349
30	1.601	0.279	0.257	1.572	1.564	0.474	0.439	0.295	0.295	0.264	0.243
Activity (mU/mg dry weight)	--	512	516	--	--	479	461	480	481	494	446
Inhibition (%)						8.6		6.5		8.6

BW = blank control, PK = control (0 mg/L), PC = abiotic control (physical-chemical reduction), TA1+TA4 = 1000 mg /L, TA2+TA5 = 500 mg/L, TA3 + TA6 = 100 mg/L

Validity criteria fulfilled:

not specified

Description of key information

Toxicity to microorganisms: not toxic to microorganisms: EC10 >1000 mg/L (OECD 209, activated sludge respiration inhibition test; dehydrogenase test), EC10 > 10000 mg/L (DIN 38412, Pseudomonas putida test)

Additional information

Value used for CSA: EC10/LC10 or NOEC for microorganisms: >1000 mg/L