6,6',6''-(1,3,5-triazine-2,4,6-triyltriimino)trihexanoic acid

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 nov 2012 - 31 Jan 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: wastewater treatment plant COV Spisska Nova Ves
- Preparation of inoculum for exposure: Sludge collected five days before test start. 15 min settling, upper layer decanted and then aerated.
- Initial cell/biomass concentration: 10.8 mg/L suspended solids, 1.8x10exp7 CFU

Duration of test (contact time):

42 d

Initial conc.:

16.47 mg/L

Based on:

DOC

Initial conc.:

28 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Test temperature: 20.7 - 21.9°C
- pH: 7.43 - 7.51
- pH adjusted to 7.4 with NaOH

TEST SYSTEM
- Culturing apparatus: 3 L glass flasks

SAMPLING
- Sampling frequency: during first ten days analysis done every third day, then at days 14, 21, 28, 35, 43.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 flasks
- Reference: 1 flask
- Abiotic sterile control: 1 flask
- Toxicity control: 1 flask

Reference substance:

other: D+ glucose monohydrate

Remarks:

41.0 mg/L

Key result

Parameter:

% degradation (CO2 evolution)

Value:

56.47

Sampling time:

28 d

Parameter:

% degradation (DOC removal)

Value:

48.04

Sampling time:

28 d

Degradation results of CO₂Evolution

Day	Degradation CO2Evolution [%]
1	1.05
3	3.85
6	5.56
8	5.96
10	7.21
14	25.90
21	52.31
28	56.47
35	54.39
43	66.19

 

 Degradation DOC [%]:

48.04% after 28 days

63.97% after 42 days

 

The abiotic control revealed that the test substance was not degraded by an abiotic way.

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test article was tested in a Modified Sturm Test according to OECD 301 B observing CO2 evolution and DOC removal. The CO2 evolution was 56.47% after 28 days and 66.19% after 42 days. Degradation values for DOC removal were 48.04% after 28 days and 63.97% after 42 days.
Under the conditions of the test the substance is regarded as not readily biodegradable. As biodegradation was >20% within 28 days, the substance is considered as inherently biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1983-11-23 to 1983-12-21

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non GLP study. Deviations from the updated OECD-guideline (adopted 1992): Filter was 0.45 instead of 0.20 micrometer.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Deviations:

yes

Remarks:

Filter was 0.45 instead of 0.20 micrometer.

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge:
Mixture of polyvalent bacteria collected on 23/11/1983
a) Secondary effluent from the sewage treatment plant of CH~4310 Rheinfelden
b) In the river Rhine" (Basle-city)
c) From a suspension of garden soil from CH-1896 Vouvry

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: in accordance to the guideline
- Test temperature: 23 +/- 2 °C
- Continuous darkness: indirect daylight

TEST SYSTEM
- Culturing apparatus: 2000ml erlenmeyer flasks
- Number of culture flasks/concentration: duplicates

CONTROL AND BLANK SYSTEM
- Inoculum blank: one blank control

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

68

Sampling time:

28 d

Details on results:

Biodegradation measured as mg DOC/L and corrected by the blank control was calculated as 68 % in 28 days.

Results with reference substance:

Biodegradation corrected by the blank control and measured as DOC (mg/L) is 86 % in 14 days.

After 28 days 64 -73% removal of DOC was observed.

Days	mean DOC removal minus blanks
7	32
14	30
21	66
27	68
28	68

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Executive summary:

The test article was tested in a modified screening test observing DOC removal. The DOC removal was 68% after 28 days, thus the pass level was not reached. As biodegradation was >20% within the test period, the substance is considered as inherently biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

14 Jul 2012 - 10 Oct 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Details on inoculum:

- Source of inoculum/activated sludge: wastewater treatment plant COV Spisska Nova Ves receiving predominantly domestic sewage, sludge from sludge fields, surface water from 3 streams and one lake, 4 soils
- Preparation of inoculum for exposure: inoculum samples from 10 sites allowing to stand, pH adjusted to 7.0 with NaOH, aerated for 23.5 hours
- Initial cell/biomass concentration: 30 mg/L suspended solids

Duration of test (contact time):

47 d

Initial conc.:

100 mg/L

Based on:

test mat.

Remarks:

Test substance concentration was measured by UV spectrometry before beginning and after end of test

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Sörenson's buffer
- pH: 7.96 - 8.03
- pH adjusted to pH 8.0

CONTROL AND BLANK SYSTEM
- Inoculum blank: 3 bottles
- Reference: 1 bottle
- Other: 1 bottle mineral medium only

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

17.14

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

17.57

Sampling time:

47 d

Results with reference substance:

53.75% after 7 days
73.50% after 14 days
99.75% after 47 days

Primary degradation (measuted by UV analysis): ca. 16% after 47 days

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

The test article was tested in a MITI (I) Test according to OECD 301 C observing O2 consumption. The biodegradation was ca. 17% after 28 days. Under the conditions of the test the substance is regarded as not readily biodegradable.

Description of key information

A Modified Sturm Test according to OECD 301 B observing CO₂ evolution and DOC removal is considered as the key study. The CO₂ evolution was 56.47% and the DOC removal was 48.04% after 28 days.

Under the conditions of the test the substance is regarded as not readily biodegradable. As biodegradation was >20% within 28 days, the substance is considered as inherently biodegradable.

Results of the prolongation of the test up to 42 days indicate that the test substance is completely mineralizable.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater

Additional information

The results of the key study are supported by further tests according to OECD 301 E ( Modified OECD Screening Test) and OECD 301 C ( Modified MITI Test (I)) .