Caramel (color)

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:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Caramel (color)

EC Number:

232-435-9

EC Name:

Caramel (color)

Cas Number:

8028-89-5

Molecular formula:

C6H12OH

IUPAC Name:

Caramel

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Activated sludge was collected from the exit of the aeration tank, or near the exit from the tank, of a well-operated wastewater treatment plant receiving predominantly domestic sewage.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 100 mg/L

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 32.9

Sampling time:

28 d

Details on results:

The study is valid since:
Based on a biodegradation rate higher than 60% in 14 days (experimental value: 86.0 and 84.4 % in 9 days) in the reference control, the test was carried out under good conditions.
At the end of the test, measurements of Biological Oxygen Demand (BOD) in two replicates of the test item solution did not show a difference of more than 20% (experimental value:6.7%).
The oxygen uptake of the control was not greater than 60 mg/l in 28 days (experimental value:27.1 mg O2/L)
Based on a biodegradation rate higher than 25% in 14 days (experimental value: 56.8% in 13 days) in the toxicity control, the test item was not toxic to micro-organisms.
Any significant Biological Oxygen Demand of the abiotic control over the test period was highlighted. The degradation of test item was not abiotic.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test substance showed a percentage of biodegradation of 32.9% at 28 days. Since the test element is a UVCB substance, the 10-day window does not apply to the "readily biodegradable" character.
Therefore, it is considered as not readily biodegradable.