Tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: screening test, other

Remarks:

anaerobic

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08/1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OTS 796.3140 (Anaerobic Biodegradability of Organic Chemicals)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

anaerobic

Inoculum or test system:

anaerobic sludge

Details on inoculum:

- origin: sewage treatment plant cologne (Stammheim)
- digested sludge
- preatreatment: incubation for 2 weeks

Duration of test (contact time):

56 d

Initial conc.:

20 other: mg C/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CH4 evolution

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

-concentration of inoculum: 100 ml/L
-temperature during test: 35+-2°C
-incubation in darkness

Reference substance:

other: used but no further documentation

Test performance:

Tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate was incubated in a mineral medium with digested sludge for 56 days at 35+/-2°C in the dark. Biodegradation was measured on the basis of pressure increase (methanogenesis) in the test vessels. Additionally the increase of the CO2-concentration was measured at the end of the test.

Key result

Parameter:

% degradation (CH4 evolution)

Remarks:

, and CO2 evolution

Value:

0

Sampling time:

56 d

Results with reference substance:

50% biodegradation of reference substance without further specification.

Measured carbon in the gaseous phase (CH4)

Time	Blank	Test substance
	Amount carbon in the gaseous phase	Amount carbon in the gaseous phase
2d	7.4 mg	5.1 mg
5d	9.1 mg	6.3 mg
15d	10.0 mg	7.0 mg
22d	10.6 mg	7.5 mg
30d	12.6 mg	9.0 mg
37d	12.9 mg	9.4 mg
51d	12.9 mg	9.8 mg
56d	13.1 mg	9.8 mg

Measured carbon in the liquid phase (CO2)

Time	Blank	Test substance
	Amount carbon in the liquid phase	Amount carbon in the liquid phase
0d	62.5 mg	62.5 mg
56d	65.6 mg	65.9 mg
Difference	3.1 mg	3.4 mg

Validity criteria fulfilled:

yes

Remarks:

:50% biodegradation of reference substance

Interpretation of results:

other: no anaerobic biodegradation was observed

Conclusions:

Anaerobic biodegradation was determined with a method equivalent or similar to EPA OTS 796.3140 (Anaerobic Biodegradability of Organic Chemicals). As no degradation was observed within 56 daystetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered as not biodegradable under anaerobic conditions.

Executive summary:

Anaerobic biodegradation was determined with a method equivalent or similar to EPA OTS 796.3140 (Anaerobic Biodegradability of Organic Chemicals) at a defined temperature. A mineral medium containing digested sludge and a known concentration of tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate (20 mg C/l) as the sole source of organic carbon was inoculated. Degradation was measured by CH4 and CO2 evolution, and verified by DIC, TOC and TIC analysis.

As no degradation was observed within 56 days tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered as not biodegradable under anaerobic conditions.

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07/89-08/89

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: DIN 38 412 part 25

Deviations:

not specified

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

not specified

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, industrial, non-adapted

Details on inoculum:

Source of activated sludge: industrial STP Bayer AG, Buerrig, Leverkusen: aeration tank of the sewage treatment plant; predominantly industrial sewage with minor amounts of domestic effluents,

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

1 d

Parameter:

% degradation (DOC removal)

Value:

3

Sampling time:

7 d

Key result

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

14 d

Parameter:

% degradation (DOC removal)

Value:

4

Sampling time:

21 d

Key result

Parameter:

% degradation (DOC removal)

Value:

17

Sampling time:

28 d

Results with reference substance:

Kinetic of reference substance(% Degr.): 99 after 7 days

Validity criteria fulfilled:

yes

Remarks:

, removal of the reference compound by at least 70% within 14d

Interpretation of results:

not inherently biodegradable

Conclusions:

Inherent biodegradability of tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate was assessed according to the OECD TG 302 B, showing 17% degradation after 28 days. Based on this result tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered to be not inherently biodegradable.

Executive summary:

Inherent biodegradability of tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate was assessed according to the OECD TG 302 B (Inherent biodegradability: Zahn-Wellens Test) under aerobic conditions at a defined temperature.

As test suspension, a measured volume of mineral medium containing a known concentration of the test substance of 100 mg DOC/l as the nominal sole source of organic carbon is inoculated. Degradation is followed by DOC determinations at 0 h, 3 h, 7 d, 14 d, 21 d, 27 d and 28 d. The degree of biodegradation is calculated by expressing the concentration of DOC removed (corrected for that in the blank inoculum control) as a percentage of the concentration initially present.

Tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate showed 17% degradation after 28 days. Based on this result tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered to be not inherently biodegradable.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02/2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test)

Deviations:

no

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Test organisms
- Typ: mixed population of aquatic microorganisms (activated sludge)
- Origin: Expiration of a sewage treatment plant, which is operated with municipal wastewater (Wupperverband)
- Date of collection: 2000-01-31
- Concentration of inoculum: 0.5 mL/L

Pre-treatment of the inoculum
- Coarse filtration through fluted filter

Duration of test (contact time):

28 d

Initial conc.:

19.9 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

The test substance is dissolved in a Mineralmediun, inoculated with a mixed population of aquatic microorganisms and incubated for 28 days under aerobic conditions in the dark at 22 ± 2 ° C. The biodegradability of the test substance is determined during this time by the removal of Dissolved Organic Carbon (DOC).

Reference substance:

benzoic acid, sodium salt

Remarks:

(99 %, 19.9 mg/L)

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

7 d

Key result

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

14 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

21 d

Parameter:

% degradation (DOC removal)

Value:

0

Sampling time:

27 d

Key result

Parameter:

% degradation (DOC removal)

Value:

4

Sampling time:

28 d

Details on results:

The used concentrations of the test substance did not show toxic effects to bacteria.

Results with reference substance:

Kinetic of reference substance (% Degr.):
93 after 7 days
100 after 14 days
98 after 21 days
98 after 27 days
99 after 28 days

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Following the EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test) a degradation rate of 4 % within 28 days was determined for tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate. Therefore, the tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered to be "Not Readily Biodegradable". The reference compound sodium benzoate showed 100 % degradation after 14 days.

Executive summary:

To test for its biodegradation potential, 41 % solution of tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate in water was incubated for 28 days in continuously stirred 250 mL closed flask (in duplicate) in the dark with an inoculum originally collected from a local, predominantly municipal wastewater treatment plant.

In this assay, conducted according to the EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test), biodegradation was determined by dissolved oxygen carbon (DOC) over time. DOC was measured with a carbon analyzer. The incubation temperature was 22 ± 2 ° C. The concentration of inoculum and one concentration of the substance was 19.9 mg/L DOC.

The 28 day degradation was 4 % and for the positive control (with reference substance) the biodegradation was 99 %. In conclusion tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is not readily biodegradable.

Description of key information

Within 28 days, a degradation rate of 4 % was determined for tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate. Therefore tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered to be "Not Readily Biodegradable". Assessing inherent biodegradability yields a degradation rate of 17% within 28 days. Based on this result tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is considered to be not inherently biodegradable. Under anaerobic conditions no biodegradation was observed within 56 days, therefore tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate is also considered as not anaerobic biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

To test for its biodegradation potential, 41 % solution of tetrasodium hydrogen 2-phosphonatobutane-1,2,4-tricarboxylate ("PBTCNa4") in water was incubated for 28 days in continuously stirred 250 mL closed flask (in duplicate) in the dark with an inoculum originally collected from a local, predominantly municipal wastewater treatment plant. In this assay, conducted according to the EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test), biodegradation was determined by dissolved oxygen carbon (DOC) over time. DOC was measured with a carbon analyzer. The incubation temperature was 22 ± 2 ° C. The concentration of inoculum and one concentration of PBTCNa4 was 19.9 mg/L DOC. The 28 day degradation was 4 % and for the positive control (with reference substance) the biodegradation was 99 %. In conclusion PBTCNa4 is not readily biodegradable.

 

Inherent biodegradability of PBTCNa4 was assessed according to the OECD TG 302 B (Inherent biodegradability: Zahn-Wellens Test) under aerobic conditions at a defined temperature. As test suspension, a measured volume of mineral medium containing a known concentration of PBTCNa4 of 100 mg DOC/l as the nominal sole source of organic carbon is inoculated. Degradation is followed by DOC determinations at 0 h, 3 h, 7 d, 14 d, 21 d, 27 d and 28 d. The degree of biodegradation is calculated by expressing the concentration of DOC removed (corrected for that in the blank inoculum control) as a percentage of the concentration initially present. PBTCNa4 showed 17% degradation after 28 days. Based on this result PBTCNa4 is considered to be not inherently biodegradable.

 

Anaerobic biodegradation was determined with a method equivalent or similar to EPA OTS 796.3140 (Anaerobic Biodegradability of Organic Chemicals) at a defined temperature. A mineral medium containing digested sludge and a known concentration of PBTCNa4 (20 mg C/l) as the sole source of organic carbon was inoculated. Degradation was measured by CH4 and CO2 evolution, and verified by DIC, TOC and TIC analysis. As no degradation was observed within 56 days PBTCNa4 is considered as not biodegradable under anaerobic conditions.