3-methyl-1-phenyl-5-pyrazolone

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:

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)

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:

3-methyl-1-phenyl-5-pyrazolone

EC Number:

201-891-0

EC Name:

3-methyl-1-phenyl-5-pyrazolone

Cas Number:

89-25-8

Molecular formula:

C10H10N2O

IUPAC Name:

5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one

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.:

ca. 102.3 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test item Pyrazol was investigated for its ready biodegradability in a manometric respirometry test over a period of 28 days. The biodegradation was fol- lowed by the oxygen uptake of the microorganisms during exposure. As a reference item sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.
Test conditions: 22°C ± 1°C, darkness, climatised chamber, pH of 7.4 to 7.6 (measured at the start of the test) and 7.4 to 7.5 (measured at the end of the test)

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 2.5

Sampling time:

28 d

Remarks on result:

other: based on ThOD(NH4)

% Degradation 2

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 2

Sampling time:

28 d

Remarks on result:

other: based on ThOD(NO3)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item did never reach 10% degradation during incubation time. The mean biodegradation at test end after 28 days was 2.5% (ThODNH4) and 2% (ThODNO3).
Therefore, Pyrazol is considered to be not readily bio- degradable based on ThODNH4 / ThODNO3.