Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

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:
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. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 concentrationopen allclose all
Initial conc.:
10 mg/L
Based on:
test mat.
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.
% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
23
Sampling time:
36 d
Remarks on result:
other: 10 mg/l
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.