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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
Study period:
Feb -Mar 2001
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD guideline under GLP
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other 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 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Principles of method if other than guideline:
not relevant
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
17-Hydroxy-1,4,6-pregnatriene-3,20-dione
EC Number:
613-906-1
Cas Number:
66212-25-7
Molecular formula:
C21 H26 O3
IUPAC Name:
17-Hydroxy-1,4,6-pregnatriene-3,20-dione
Details on test material:
Name of test material (as cited in study report): AD-Dyanhydrin
- Analytical purity: 96%
- Lot/batch No.: 14610801

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
10 mg/L
Based on:
COD

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
82
Sampling time:
28 d
Details on results:
The test compound ZK 5668 was degraded to 82% on day 29 (28 days of incubation).

Any other information on results incl. tables

Table 1: Amounts of C02 produced (cumulative), in mg (values for ZK 5668, sodium acetate and toxicity control corrected for blank CO,: production)

      Day
      4 6 8 11 14 19 22 27 29
 Control/blank (mean of 3 vessels)    Concentration of carbon   2,9 5 6,50 8,6 10,6 12,7 15,5 17,7 22,6
 ZK 5668 (mean of 3 vessels)    0 mg/L   2,8 33 49,90 64 74,6 82,6 85,3 88,3 90,2
 Reference (sodium acetate)    10 mg/L   42,5 65,7 75,00 85,5 93 99,5 101 103,8 105,3
 Toxicity control (ZK 5668 + sodium acetate)    10 mg/L + 10 mg/L   39,8 92 117,90 141,7 157,9 170,3 176,1 181,7 185,2

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
According to the results of the test it can be concludied that AD-Cyanhydrin is readily biodegradable
under the conditions of the test.
Executive summary:

The purpose of this study was to determine the ready biodegradability of 1,4,6-Trienol (ZK 5668), which is an intermediate of the synthesis of cyproteroneacetate,. The study was conducted in agreement with the OECD test guideline no. 301 B.

The test substance was incubated in an aqueous solution including nutrients with microorganisms from a municipal sewage treatment plant for 28 days (start of treatment = day 1). The nutrient solutions were made up of phosphates, magnesium sulphate, iron chloride, ammonium chloride and calcium chloide. The test substance was incubated at a concentration of 10 mg carbon/L in triplicate. Additionally, a reference substance (sodium acetate) was tested in a single set according to the same procedure, in order to verify the viability and activity of the degrading microorganisms. One further set was incubated with sodium acetate at 10 mg carbon/L (reference substance) plus test substance at 10 mg carbon/L representing a toxicity control. Furthermore, a blank control was tested in triplicate without any test or refeference substance. The biological degradation of the test and reference substances was evaluated by measurement of the carbon dioxide (C02) produced during the test period. CO2 production was determined on days 4, 6, 8, 11, 14, 19, 22, 27 and :29. On day 28 the solutions were acidified in order to expel all dissolved CO2 and CO2 was determined on day 29. The CO2 production was calculated as the percentage of total CO2 that the testmaterial could theoretically have produced, based on carbon content. The blank CO2 production was subtracted for correction.

The test compound 1,4,6 -Trienol was degraded to 68% on day 14 and 82% on day 29 (28 days of incubation). The reference compound sodium acetate was degraded to 60% on day 6 and 96% on day 29 (28 days of incubation). In the toxicity control, the reference compound (sodium acetate) plus the test compound, was degraded to 84% on day 29 (28 days of incubation), reflecting the degradation in the individual sets.