5'-chloro-3-hydroxy-2'-methyl-2-naphthanilide

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:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: according to OECD 301F; experimental part equivalent to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

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:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

GLP compliance:

no

Remarks:

experimental part acc. to GLP standards but no quality control, sample storage and GLP certificate

Test material

Test material information

Constituent 1

Reference substance name:

5'-chloro-3-hydroxy-2'-methyl-2-naphthanilide

EC Number:

205-207-1

EC Name:

5'-chloro-3-hydroxy-2'-methyl-2-naphthanilide

Cas Number:

135-63-7

Molecular formula:

C18H14ClNO2

IUPAC Name:

N-(5-chloro-2-methylphenyl)-3-hydroxy-2-naphthamide

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Origin of inoculum: municipal sewage treatment plant Frankfurt- Sindlingen, Germany
Source: washed activated sludge of municipal sewage treatment
Preparation of suspension: activated sludge sediment centrifugated twice and resuspended in de-ionized water
Used quantity of inoculum: 10 ml/L suspended sludge
Pretreatment: acc. to guideline; pre-aeration of supernatant for 8 days to deactivate carbon dissolved in activated sludge
Preconditions: not pre-adapted to the test substance and the reference material

Duration of test (contact time):

27 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

49.75 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

50.5 mg/L

Based on:

test mat.

Initial test substance concentration 3

Initial conc.:

49.25 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Due to the low solubility of the tested substance no stock solution was prepared. The tested substance was added directly to the test flasks.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (O2 consumption)

Value:

31

Sampling time:

27 d

Details on results:

The value %Degr. is the mean value of 3 different initial concentrations of the test substance;
The %Degr. value is based on the ratio of determined O2 consumption and the theoretical O2 consumption (CSB).
Determinded values were corrected by control values from a blank test performed without any testing substance.
The O2-consumption of the blank test was below 60 mg/L [O2] after 27 days.

BOD5 / COD results

Results with reference substance:

The reference test using benzoic acid sodium salt as reference substance provided a O2 consumption of more than 60% within 14 days (mean value of 3 tests). The %Degr. value is based on the ratio of determined O2 consumption and the theoretical O2 consumption.
The O2 consumption of the blank test was below 60 mg/L [O2] after 27 days.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

other: the tested substance is not readily biodegradable (60% biodegradation level not achieved after adaption time (10% degradation) of 11 days)

Conclusions:

The test item must be regarded as not readily biodegradable in the 10 d-window and after 28 days.