2-(Naphthalene-2'-sulphonylamino)-benzoic acid

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1 - 30 June 1992

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Version / remarks:

An update has been made to the OECD Guideline since the publication of the report.

GLP compliance:

not specified

Specific details on test material used for the study:

Test material: NSABZ (2-(Naphthalene-2'-sulphonylamino)-benzoic acid)
Date of receipt: 20 December 1991.
Description: Very light brown powder.
Storage: In original container at room temperature.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Inoculum: A mixed population of activated sewage sludge microorganisms.
Source: Activated sewage was prepared by sampling 10 different sites around the UK in accordance with OECD Guideline No. 302C.
Preparation: The mixed sludge was fed daily with a 0.1% synthetic sewage and maintained on a constant aeration at 25 ± 1°C.
Usage rate: Equivalent to 100 mg dry weight/l.

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 30 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Duration: 28 days.
Criteria: Oxygen consumption measured by direct manometer reading.
Agitation: By magnetic stirrers.
Temperature: 25 ± 1°C.
Lighting: The test was carried out in darkness.
Observations: Manometer volumes were recorded daily.
Test concentrations: NSABZ: 30 mg/L.
Aniline: 100 mg/L.

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

ca. 28

Sampling time:

28 d

Details on results:

NSABZ attained 28% degradation after 28 days calculated from oxygen uptake.
Aniline attained 49% biodegradation after 7 days and 75% after 14 days thereby confirming the suitability of the inoculum and culture conditions.

Total organic carbon analysis of the test media at Day 0 and Day 28 showed that aniline attained 97% degradation after 28 days. TOC analysis of NSABZ was not possible due to the insoluble nature of the test material. Similarly a reliable COD value could not be obtained.

For the % Biodegradation calculation a ThOD of 2.05 mg O2/mg was used based on the following approximate values for this polymer:
Molecular formula: C17H13NO4S.
Molecular weight: 327.36 g/mol.

Results with reference substance:

Aniline attained 49% biodegradation after 7 days and 75% after 14 days thereby confirming the suitability of the inoculum and culture conditions.

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

NSABZ attained 28% degradation after 28 days calculated from oxygen uptake (% of ThOD) and so, therefore, cannot be considered as inherently biodegradable under the strict terms and conditions of the OECD Guidelines.

Executive summary:

The inherent biodegradation of 2-(Naphthalene-2'-sulphonylamino)-benzoic acid (NSABZ) was assessed by modified MITI method (II) (OECD Guideline 302C).

NSABZ attained 28% degradation after 28 days calculated from oxygen uptake (% of ThOD) and so, therefore, cannot be considered as inherently biodegradable under the strict terms and conditions of the OECD Guidelines.

Description of key information

The inherent biodegradation of 2-(Naphthalene-2'-sulphonylamino)-benzoic acid (NSABZ) was assessed by modified MITI method (II) (OECD Guideline 302C).

NSABZ attained 28% degradation after 28 days calculated from oxygen uptake (% of ThOD) and so, therefore, cannot be considered as inherently biodegradable under the strict terms and conditions of the OECD Guidelines.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed