2-Naphthalenol, 1-[2-[2-ethyl-4-[2-(2-ethylphenyl)diazenyl]phenyl]diazenyl]-, ar-heptyl derivs.

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:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

GLP compliance:

yes

Test material

Test material information

1

Reference substance name:

Reaction products of 2-Ethylaniline with heptyl naphthalen-2-ol

Cas Number:

1401000-07-4

Molecular formula:

Not applicable (UVCB Substance)

IUPAC Name:

Reaction products of 2-Ethylaniline with heptyl naphthalen-2-ol

Test material form:

solid

Specific details on test material used for the study:

Batch number: 80-47-16

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 test substance concentration 1

Initial conc.:

100 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

87 other: COD/L

Based on:

COD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

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).

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Remarks:

Mean value

Value:

5.2

Sampling time:

28 d

BOD5 / COD results

BOD5 / COD

Parameter:

COD

Value:

0.87 mg O2/g test mat.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test item RED 2735 was found to be not ready and completely biodegradable under the conditions applied in a manometric respirometry test, having showed a maximum biodegradation of 5.2% at the end the test (mean percentage values between two replicates).

No significant degradation was observed in the abiotic control.

The test item showed no inhibitory effects on the microorganism activity at the tested concentration, as demonstrated by the biodegradation percentage in the toxicity control exceeding the 25% pass level after four days of exposure (30.0%).

Executive summary:

A study to evaluate the ready biodegradability of the test item RED 2735, following the “Manometric Respirometry” method, was performed.

 

The tested concentration was 100 mg/L (corresponding to 87 mg COD/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 ThOD_NH3value (Theoretical Oxygen Demand without nitrification process) was calculated to be equal to 1.67 mg O₂/mg for reference item, Sodium Benzoate. while COD value (Chemical Oxygen Demand) was assessed to be 0.87 mg O₂/mg for the test item.

 

These values,1.67 mg O₂/mg for reference item and 0.87 mg O₂/mg for the test item,were used to calculate per % biodegradation.

Nitrate and nitrite concentration was measured at the start and at the test end.

At the start no nitrite nor nitrate were present. At test end no nitrite formation was observed, while nitrate concentration increased.

 

At test end nitrate concentration in the test item bottles (8.59 mg/L as mean value) was slightly higher than nitrate concentration found in blank bottles (8.04 mg/L as mean value), therefore a limited nitrification related to the test item seemed to occur during the test period (corresponding to 0.628 mg total oxygen equivalent).

 

The test item, RED 2735, was found to be not ready and completely biodegradable under the conditions applied in a manometric respirometry test, having showed a maximum biodegradation of 5.2% at the end of the test (mean percentage values between two replicates).

 

No significant degradation was observed in the abiotic control (equal to 0% 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 after four days of exposure (30.0%).

 

The reference item exceeded the biodegradation pass level (60%) on the sixth day (63.5 %), within the range fixed by OECD Guideline (first 14 days).