ParyFree Dimer

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:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Tricyclo[8.2.2.24,7]hexadeca-4,6,10,12,13,15-hexaene, 5,11,13,15-tetramethyl-

Cas Number:

205825-52-1

Molecular formula:

C20H24

IUPAC Name:

Tricyclo[8.2.2.24,7]hexadeca-4,6,10,12,13,15-hexaene, 5,11,13,15-tetramethyl-

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Batch no. 350321
Expiry date February 26, 2024

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

25 mg/L

Based on:

test mat.

Remarks:

corresponding to 78.8 mg ThOD/L (Theoretical Oxygen Demand)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Remarks:

All reported results are related to the nominal concentration of test item, since the test concentrations were not measured during the test.

Value:

7.6

Sampling time:

10 d

Details on results:

est item concentration should be 100 mg/L or a concentration giving at least 50-100 ThOD
/L.
The tested concentration was 25.0 mg/L (corresponding to 78.8 mg ThOD/L).
All reported results are related to the nominal concentration of test item, since the test
concentrations were not measured during the test.

The biodegradation was followed by measuring the oxygen uptake (mg/L) of the test item under
defined conditions by the means of a manometric method and calculating from these values
the BOD (Biochemical Oxygen Demand).

The ThODNH3 value (Theoretical Oxygen Demand without nitrification process) was calculated
to be equal to 1.67 mg O2/mg for reference item, Sodium Benzoate, while ThODNH3 value was
assessed to be 3.15 mg O2/mg for the test item.

These values, 1.67 mg O2/mg for reference item and 3.15 mg O2/mg for the test item, were
used to calculate per % biodegradation.

Nitrate and nitrite concentration were measured at the start and at the test end.
At the start and test end no nitrite and nitrate were present.

At the test end nitrate concentration in the blank bottles (6.40 mg/L as mean value) was slightly
higher than nitrate concentration found in test item bottles (4.10 mg/L as mean value), therefore
the found negative value (-2.30 mg/L) was assumed as equal to zero, so Nitrification wasn’t
occurred during test period.

At the end of the 10-day window the biodegradation was 7.6% (mean percentage values
between two replicates).
Therefore, the test item, was found to be not ready and completely biodegradable under the
conditions applied in a manometric respirometry test.

No significant degradation was observed in the abiotic control (equal to 17.8% at the test end).
The toxicity control clearly showed that the test item does not cause inhibitory effect on the
microorganisms activity at the tested concentration. Actually, the toxicity control exceeded the
25 % pass level within the 14 days of exposure (34.4%).

BOD5 / COD results

Results with reference substance:

The reference item exceeded (87.1%) the biodegradation pass level (60%) within the range
fixed by OECD Guideline 301F (first 14 days).

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

At the end of the 10-day window the biodegradation was 7.6% (mean percentage values
between two replicates).
Therefore, the test item, was found to be not ready and completely biodegradable under the
conditions applied in a manometric respirometry test.

Executive summary:

Evaluations: the percent of biodegradation of test item at the end of the test.
Test concentrations: 25 mg test item/L corresponding to 78.8 mg ThOD/L
(Theoretical Oxygen Demand).
Test duration: 28 days.
Test environment: Thermostat.
Monitoring of test medium pH: at the start and at the end of the test, in all test item flasks.
Test temperature: 20.1 – 21.0°C.
pH of test flask: 7.32 – 7.96 at the test start, 7.35 – 8.09 at the test end.
Validity criteria: Achieved, according to Guideline OECD No. 301F, 1992
Results expression: The biological results were referred to nominal concentration of test
item
Nitrate formation: None.
Nitrite formation: None.
Biological results:
Maximum biodegradation at the end of the 10-day window:
7.6% (mean percentage values between two test item replicates).
Maximum biodegradation at the end of the test period (28 days of
exposure): 10.2% (mean percentage values between two test item
replicates).