Terpene Dimers

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 2018 to August 2018

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 (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Terpene Dimers

EC Number:

948-032-2

IUPAC Name:

Terpene Dimers

Test material form:

liquid

Details on test material:

Batch no. DF1710011

Study design

Inoculum or test system:

sewage, predominantly domestic (adaptation not specified)

Details on inoculum:

The sludge was taken from the activation basin of the sewage treatment plant, In den Seewiesen, 67435 Edenkoben. Date of collection: 09. May 2018, batch no: 20180509. The sludge was filtrated, washed with medium 2x, and re-suspended in test medium. It was then aerated. The dry matter was determined as 3880 mg suspended solids/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

30 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

A measured volume of inoculated mineral medium, containing a known concentration of test item as the nominal sole source of organic carbon, is stirred in a closed flask at a constant temperature for up to 28 days. The consumption of oxygen is determined from the change in pressure in the apparatus. Evolved carbon dioxide is absorbed in soda lime (mixture of sodium hydroxide and calcium hydroxide). The amount of oxygen taken up by the microbial population during biodegradation of the test item (corrected for uptake by blank inoculum, run in parallel) is expressed as a percentage of ThOD (Theoretical Oxygen Demand).

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Test performance:

No observations were made which might cause doubts concerning the validity of the study outcome. The result of the test can be considered valid.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Details on results:

The degree of biodegradation reached 0 % after 28 days. The 10-day-window could not be detected. No degradation and no lag phase was observed. For the test item Terpene Dimers no biodegradation was observed after 28 days. The 10-
day window could not be determined. The criterion of reaching 60% of degradation after 28 days is not met. Terpene Dimers is therefore considered as “not readily biodegradable” following OECD 301F/EU C.4-D.

BOD5 / COD results

Results with reference substance:

Parameter Criterion Found Assessment
Degradation of positive control > 60% < 14 days 3 days valid
Mean O2 demand of the controls < 60 mg/L 24.5 mg/L valid
Degradation in the toxicity flask on day 14 > 25% 43.9 % non - toxic
pH at the end of the test 6.0 – 8.5 7.3 – 7.8 valid

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

All validity criteria were met. Oxygen consumption in the blank controls and in the positive controls was normal, indicating that the test system has worked properly. The ThOD of the test item was calculated based on a theoretical formula of the test item,
calculated as C7.32H11.78O0.02. The formula was based on elemental analysis. The sum of analysed elements (87.98 % C, 11.87 % H, 0.32 % O) was 100.17 %. For the test item Terpene Dimers no biodegradation was observed after 28 days. The 10-
day window could not be determined. The criterion of reaching 60% of degradation after 28 days is not met. Terpene Dimers is therefore considered as “not readily biodegradable” following OECD 301F/EU C.4-D. No observations were made which might cause doubts concerning the validity of the study outcome. The result of the test can be considered valid.

Executive summary:

The test item Terpene Dimers was tested using a concentration of 30 mg test item/L (equivalent to a theoretical oxygen demand of 99.65 mg O2/L). Activated sludge was used as inoculum. The test was left running for 28 days. All validity criteria were met. The positive control reached the pass level of 60% on day 3 (criterion: <= 14).

The following data could be determined for the test item Terpene Dimers:

10-day-window:                                             not detected

Degradation phase:                                          none

degradation at the end of 10-day-window:       none

degradation at the end of the test:                     0 %

For the test item Terpene Dimers no biodegradation was observed after 28 days. The 10 - day window could not be determined. The criterion of reaching 60% of degradation after 28 days was not met. Terpene Dimers is therefore considered as “not readily biodegradable” following OECD 301F/EU C.4-D.