hexasodium (R)-carboxy(phosphono)methanolate (S)-carboxy(phosphono)methanolate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: conducted to OECD/EC guidelines with GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Principles of method if other than guideline:

Deviations: the volume of the test solution was reduced from 3.0 to 1.5 litres. The sludge was aerated for 24 hours, centrifuged at 300 rpm and the supernatant was filled into the test solutions as inoculum.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Details on test material:

Test materal is 50% aqueous hydroxyphosphonic acid
- Name of test material (as cited in study report): TK 13061
- Physical state: aqueous solution
- Analytical purity: ca. 50% in water
- Lot/batch No.: 1
- Storage condition of test material: room temperature

Study design

Oxygen conditions:

aerobic

Remarks:

50 ml/min air free of CO2

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Bacteria collected from activated sludge of the sewage treatment plant of CH-4153 Reinach on 01/07/85.
- Preparation of inoculum for exposure: aerated for 24 hours, centrifuged at 1300rpm and the supernatant was filled into the test solutions as inoculum.
- Storage conditions: room temperature

Duration of test (contact time):

36 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

10 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

20 mg/L

Based on:

test mat.

Reference substance

Reference substance:

aniline

Remarks:

MERCK No.1261

Results and discussion

Test performance:

The biodegradation was calculated as:
10 mg/L test substance: 23% biodegradation in 36 days.
20 mg/L test substance: 56% in 36 days.

% Degradation

% Degradation 1

Parameter:

% degradation (CO2 evolution)

Value:

23

Sampling time:

36 d

Remarks on result:

other: 10 mg/l

% Degradation 2

Parameter:

% degradation (CO2 evolution)

Value:

56

Sampling time:

36 d

Remarks on result:

other: 20 mg/l

BOD5 / COD results

Results with reference substance:

See table below.

Any other information on results incl. tables

Carbon dioxide values and percentage biodegradation.

	Days	5	9	16	23	27	28	33	36
10 mg/L	mg CO2	0.0	0.0	0.0	0.0	2.0	1.0	1.5	0.0
	% degradation	0.0	0.0	0.0	0.0	10.0	15.0	23.0	23.0
20 mg/L	mg CO2	0.1	0.0	0.0	0.3	13.5	5.4	3.0	0.0
	% degradation	0.0	0.0	0.0	1.0	35.0	49.0	56.0	56.0
Reference substrate	mg CO2	49.3	16.3	7.7	1.7	0.9	0.5	-	-
	% degradation	58.0	77.0	86.0	88.0	89.0	90.0	-	-

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Conclusions:

Trisodium [carboxy(oxido)methyl]phosphonate is biodegradable to some extent but not readily biodegradable in this test.