Methyl 3-α,7-α-diacetoxy-12-α-hydroxy-5-β-cholan-24-oate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study is recent and has been carried out according to OECD TG 301F, OPPTS 835.3110. and method C.4-D, Part V of 440/2008/EC. It is in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-B (Determination of the "Ready" Biodegradability - Modified OECD Screening Test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Ursodeoxycholic acid

EC Number:

204-879-3

EC Name:

Ursodeoxycholic acid

Cas Number:

128-13-2

IUPAC Name:

3,7-dihydroxycholan-24-oic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

>= 1 - <= 28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

other: BOD

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

other: ThOD

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

% Degradation 1

Parameter:

other: BOD

Value:

53.4

Sampling time:

12 d

Remarks on result:

other: end of the 10-d window

% Degradation 2

Parameter:

other: BOD

Value:

82

Sampling time:

28 d

Remarks on result:

other: Maximum value of biodegradation

Details on results:

The test item Ursodeoxycholic Acid, has showed to be not ready biodegradable under the conditions applied in a Manometric Respirometry test, having not reached the pass level (60% biodegradation) during the 10-days window, but showing a maximum value of degradation of 53.4% during this period.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

The susbtance is considered to be readily biodegradable although the pass level of the 10-d window has not been respected, because ursodeoxycholic acid is a surfactant. After 28 days, ursodeoxycholic acid reached 82% of biodegradation.

Executive summary:

The test item, although it is not used in a detergent, can be considered a surfactant as defined in Regulation 648/2004/EC: “any organic substance and/or mixture used in detergent, which has surface-active properties and which consist of one or more hydrophilic and one or more hydrophobic groups of such a nature and size that is capable of reducing the surface tension of water, and of forming spreading or adsorption monolayers at the water-air interface, and of forming emulsions and /or microemulsions and/or micelles, and of adsorption at water-solid interfaces”. Therefore, a surfactant shall be considered as biodegradable if the level of biodegradability is at least 60% within 28 days, irrespectively from 10-day window principle.In this test carried out according to OECD TG 301F, ursodeoxycholic acid reached 53.4% of degradation after the 10-d window, and 82% after 28 days. Therefore the substance is considered readily biodegradable.