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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to the O.E.C.D. test guideline 301D with GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: Liquid at room temperature.
Details on test material:
As per IUCLID5 Sections 1.1. 1.2. and 4.1.

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
The Activated sludge, Lot No. Q110237.01 was acquired from the Brazos River Valley Sewer Authority, Sugar Land, Texas as a grab sample on 01 Dec 2011. The sludge sample was maintained under ambient conditions (approximately 22°C.).
Duration of test (contact time):
ca. 28 d
Initial test substance concentration
Initial conc.:
ca. 5 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
A mineral salts medium was used for the incubation with the activated sludge. The mineral salts medium was aerated for 2-3 hours in Biological Oxygen Demand (BOD) bottles before use.

Approximately 1.5 mg of the test substance was applied to aluminum foil and placed in each replicate, resulting in a dose rate of approximately 5 mg/L. The BOD bottles were then filled to a total volume of 300 mL with the prepared mineral salts media. The mineral salts media was used as the blank. Distilled Aniline at 2.0 mg/L served as the Reference Substance (positive control). The Toxicity Reference Solutions had approximately 5 mg/L test substance and 2.0 mg/L of the Reference Substance, distilled Aniline.

Ten labeled BOD bottles were prepared for the blank, 5 mg/L test substance and reference solutions (up to 5 sampling periods). Only six bottles were prepared for the toxicity reference solution. The Day 0 samples were examined for dissolved oxygen and the remaining bottles were stored in the dark and incubated at 22° C.

Two BOD bottles for each solution were removed at each sampling interval (0, 7, 14, 21 and 28 days). The oxygen in each duplicate set of solutions was measured using an YSI Model 5100 Dissolved Oxygen Meter and recorded at each interval.

Reference substance
Reference substance:
aniline
Remarks:
2.0 mg/L.

Results and discussion

Test performance:
The toxicity reference standard showed sufficient oxygen depletion, indicating that the test substance was not toxic to the microbes in the activated sludge.
% Degradation
Parameter:
% degradation (O2 consumption)
Value:
ca. 20
Sampling time:
7 d
Remarks on result:
other: The percent test substance biodegradation was approximately 20% during the 7-28 day contact interval.
Details on results:
Test Substance Percent Biodegradation
_________________________________________________________________________________________________________________________________
Sampling Time Days: 7 14 21 28

% Biodegradation: 20.2 20.3 20.1 19.3

BOD5 / COD results

Results with reference substance:
The positive control Reference Substance, 2.0 mg/L Distilled Aniline demonstrated 84.7% biodegradation after seven days of sludge contact and reached a maximum biodegradation of 96.6% after 28 days of activated sludge contact time.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: Not readily biodegradable, but may be inherently biodegradable.
Conclusions:
The test substance is not readily biodegradable under the conditions of the O.E.C.D. no. 301D study method. However, the test substance may be inherently biodegradable in an appropriate test.
Executive summary:

The test substance, Formaldehyde, polymer with 1,3 -benzenedimethanamine and phenol was accessed for ready biodegradation in an O.E.C.D. no. 301D Closed Bottle study. A maximum of approximately 20% biodegradation was observed. Therefore, the test substance is not readily biodegradable under the conditions of the O.E.C.D. no. 301D study method. However, the test substance may be inherently biodegradable in an appropriate test.