Registration Dossier

Diss Factsheets

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
Study period:
8 January - April 22, 1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report date:
1991

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Qualifier:
according to guideline
Guideline:
other: EEC dir. 84/449, Part C: Methods for the determination of ecotoxicity, Publication No. L251, C5: "Biodegradation: modified Sturm test" , adopted Sep. 1984
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
α-trimethylsilanyl-ω-trimethylsiloxypoly[oxy(methyl-3-(2-(2-methoxypropoxy)propoxy)propylsilanediyl]-co-oxy(dimethylsilane))
EC Number:
406-420-4
EC Name:
α-trimethylsilanyl-ω-trimethylsiloxypoly[oxy(methyl-3-(2-(2-methoxypropoxy)propoxy)propylsilanediyl]-co-oxy(dimethylsilane))
Cas Number:
69430-40-6
Molecular formula:
Unspecified example: C18.3H46.8O5.8Si4.1
IUPAC Name:
α-trimethylsilanyl-ω-trimethylsiloxypoly[oxy(methyl-3-(2-(2-methoxypropoxy)propoxy)propylsilanediyl]-co-oxy(dimethylsilane))
Details on test material:
- Name of test material (as cited in study report): DC 5067
- Substance type: Reaction mass (mixture)
- Physical state: Liquid
- Analytical purity: > 99%
- Lot/batch No.: AB 090122
- Expiration date of the lot/batch: December 1, 1991
- Stability under test conditions: Stable
- Storage condition of test material: In the original container at room temperature in the dark
- Other:



Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Duration of test (contact time):
28 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.

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
34
Sampling time:
1 d
Remarks on result:
other: first 10 days, then every 5th day
Parameter:
% degradation (CO2 evolution)
Value:
39
Sampling time:
1 d
Remarks on result:
other: first 10 days, then every 5th day
Details on results:
see table above (section: Any other information on materials and methods incl. tables)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
DC 5067 was degraded significantly during the test period . However, since at least 60% biodegradation was not reached within ten days of
biodegradation exceeding 10%, the criteria for ready biodegradability were not met. Thus, under the conditions of this test DC 5067 was not
readily biodegradable.
Executive summary:

DC 5067 was tested for its ready biodegradability in the modified Sturm test at nominal concentrations of 10 and 20 mg/l.

The relative degradation values calculated from the measurements performed during the test period of 28 days revealed that at both concentrations DC 5067 was degraded significantly: 34% and 39% for 10 and 20 mg/l respectively. However,

since at least 60% biodegradation was not reached within 10 days of biodegradation exceeding 10%, the criteria for ready biodegradability were not met. Thus under the conditions of this test, DC 5067 was not readily biodegradable.

Under the same conditions sodium acetate was degraded by more than 60%.