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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17 Aug - 14 Sep 2001
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP - Guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report date:
2001

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
GLP compliance:
yes (incl. QA statement)
Remarks:
The Department of health of the Government of the United Kingdom

Test material

Constituent 1
Chemical structure
Reference substance name:
Potassium 3-sulphonatopropyl acrylate
EC Number:
250-465-0
EC Name:
Potassium 3-sulphonatopropyl acrylate
Cas Number:
31098-20-1
Molecular formula:
C6H10O5S.K
IUPAC Name:
potassium 3-(acryloyloxy)propane-1-sulfonate
Details on test material:
- Name of test material (as cited in study report): SPA (sulfopropyl acrylate)
- Physical state: powder
- Analytical purity: no data
- Lot/batch No.: 0200014/001
- Storage condition of test material: at room temperature in the dark

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: Final effluent of Severn Trent Water Plc sewage treatment plant at Loughborough, Leicestershire, United Kingdom, obtained on 17 Aug 2001
- Pretreatment: The effluent was filtered through coarse filter paper, while approx. the first 200 mL were discarded. The filtrate was maintained on continuous aeration in a temperature controlled room at 21 °C.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
5 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Composition of medium: 100 mg test substance were directly added to the culture medium (according to OECD 301D) and dissolved with the aid of ultrasonication (5 min). The volume was adjusted to 100 mL to give a 1000 mg/L stock solution which was inverted several times to ensure adequate mixing and homogeneity. An aliquot of 30 mL was dispersed into the final volume of 6 L to give a concentration of 5 mg/L. 1 drop inoculum per litre was added to each test flask.
- Test temperature: 20 °C
- pH adjusted: no

TEST SYSTEM
- Culturing apparatus: 250 - 300 mL darkened glass bottles (BOD bottles), stoppered
- Number of culture flasks/concentration: 2
- Measuring equipment: Yellow Springs oxygen meter and BOD Probe

SAMPLING
- Sampling frequency: after 0. 3, 6, 9, 12, 15, 18, 21, 24 and 28 d

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: -
- Toxicity control: yes, containing 5 mg/L test substance and 1.5 mg/L reference substance
Reference substance
Reference substance:
benzoic acid, sodium salt
Remarks:
3 mg/L

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Value:
28
Sampling time:
28 d
Details on results:
The test substance was degraded by 28% within 28 d and thus, can not be considered to be readily biodegradable.
The toxicity control was degraded by 27% within 15 d. Since the biodegradation was > 25 % the test substance is not considered to be inhibitory to the inoculum.

BOD5 / COD results

Results with reference substance:
The reference substance is degraded by 74% within the 14-day window, confirming the inoculum and the test set-up to be appropriate.

Any other information on results incl. tables

Table 1: Biodegradation of the test substance, control, reference und toxic control after 28 d

days mean biodegradation [%]
test substance inoculum blank reference substance  toxicity control 
3 5 0.450 41 10
6 7 0.575 56 10
9 10 0.625 57 11
12 29 0.675 65 29
15 28 0.825 65 27
18 27 0.850 73 28
21 27 0.850 74 29
24 27 0.950 75 29
28 28 1.050 74 29

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: not readily biodegradable