Castor oil, dehydrated

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:

May - June 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to EC Method C.4-D and OECD 301 F in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

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-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Castor oil, dehydrated

EC Number:

264-705-7

EC Name:

Castor oil, dehydrated

Cas Number:

64147-40-6

Molecular formula:

Not applicable for this UVCB.

IUPAC Name:

Castor oil, dehydrated

Details on test material:

- Storage condition of test material: at room temperature (15 - 25°C), under dark and dry conditions
- Theoretical oxygen demand:
ThOD NH4: 3.578 mg oxygen par mg test substance
ThOD NO3: 3.628 mg oxygen per mg test substance

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.:

103 mg/L

Based on:

formulation

Reference substance

Reference substance:

other: sodium benzoate

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

ca. 40

Sampling time:

28 d

Remarks on result:

other: No 10-day-window was passed

Details on results:

ThOD NH4:
Under the test conditions the percentage of biodegradation of the test substance reached 10% after 3 days of incubation and continuoulsy increased in the 10 days window to 30%. After 28 days the biodegradation was 40%.

ThOD NO3:
According to the test suigeline, nitrification has to be considered if nitrogen is part of the molecule. BASed on ThOD NO3 the mean percentage biodegradation based at the end of the study was 39% (mean value).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: not readily biodegradable

Conclusions:

Under the test conditions, the degradation rate of the test substance did not reach 60% within the 10-day window or after 28 days of incubation. Therefore, the test substance is not considered to be readily biodegradable.

Executive summary:

A study was conducted to determine the ready biodegradability of castor oil, dehydrated according to EC Method C.4-D and OECD Guideline 301 F (manometric respirometry test).

Biodegradation was followed via oxygen uptake of microorganims from non-adapted domestic sludge over a period of 28 days.

Under the test conditions, the degradation rate of the test substance did not reach 60% within the 10-day window and after 28 days of incubation. Therefore, the test substance is not considered to be readily biodegradable.