(6S,8S,9S,10R,11S,13S,14S,17R)-17-acetyl-11,17-dihydroxy-6,10,13-trimethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-3-one

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(6S,8S,9S,10R,11S,13S,14S,17R)-17-acetyl-11,17-dihydroxy-6,10,13-trimethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-3-one

EC Number:

615-123-0

Cas Number:

7055-53-0

Molecular formula:

C22H32O4

IUPAC Name:

(6S,8S,9S,10R,11S,13S,14S,17R)-17-acetyl-11,17-dihydroxy-6,10,13-trimethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthren-3-one

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

<= 28 d

Initial test substance concentration

Initial conc.:

ca. 15 mg/L

Based on:

other: mg organic carbon/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Test conditions: 22°C, darkness
pH of 7.01 to 7.21 (test start) and 6.51 to 7.11 (test end)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

< 10

Sampling time:

28 d

Details on results:

To be considered readily biodegradable, a test substance must achieve 60% biodegradation by the end of the test. Additionally, the test substance must biodegrade by at least 60% within 10 days of having degraded by 10%.
Medrane showed biodegradation not exceeding 10%. Medrane cannot, therefore, be considered readily biodegradable.
Percent biodegradation values at each sampling interval, for the two replicates containing Medrane did not vary by more than 10%, therefore satisfying the validity criterion of less than 20% difference.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

All validity criteria were satisfied (inorganic carbon content, degradation of reference material, CO2 production from blank controls) and the results of this study are therefore considered to be valid.
Mean carbon dioxide evolution from Medrane was <10% of the theoretical carbon dioxide yield throughout the test. The level of biodegradation did not meet the requirements for ready biodegradability and Medrane cannot, therefore, be classified as readily biodegradable.