6-amino-4-hydroxynaphthalene-2-sulphonic acid

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: screening test, other

Remarks:

Zahn-Wellens-Test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-08-02 - 1989-08-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

no GLP

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:

other: DIN 38412 Part 25 (Zahn Wellens Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

no

GLP compliance:

no

Remarks:

study conducted before 2008

Test material

Test material information

Constituent 1

Reference substance name:

6-amino-4-hydroxynaphthalene-2-sulphonic acid

EC Number:

202-000-8

EC Name:

6-amino-4-hydroxynaphthalene-2-sulphonic acid

Cas Number:

90-51-7

Molecular formula:

C10H9NO4S

IUPAC Name:

6-amino-4-hydroxynaphthalene-2-sulphonic acid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly industrial (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): aeration tank of a sewage treatment plant (Leverkusen-Bürrig, Germany), (predominantly industrial sewage with minor amounts of domestic effluents)
- Preparation of microbial inoculum for exposure: separation of the sludge by centrifugation (10 min at 3000 rpm), drying for 2 hours at 120°C
- Concentration of sludge: 1 g dry weight / L
- Sludge amount: 83.5 mL/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

208.4 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

480 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Test apparatus: Zahn-Wells-equipment (3 - 4 L glass flask, stirrer, aeration)
- Test temperature: 20 ± 3 °C

Reference substance

Reference substance:

aniline

Results and discussion

% Degradation

Key result

Parameter:

% degradation (DOC removal)

Value:

9

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

96% degradation after 28 days has been determined with the reference substance aniline.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

The study was conducted according to DIN 38412 Part 25 (Zahn Wellens Test) and OECD 302 B on the registered substance itself. The method is to be considered scientifically reasonable and suitable for the test item with some deficiencies in documentation, but the available information allows the conclusion that the test was properly conducted. Hence, the results can be considered as reliable to assess inherent biodegradability of the test item. A degradation of 9 % was determined, hence, the test item needs to be classified as not inherently biodegradable.

Executive summary:

This report is based on a study report “Biodegradability of Gammasäure” (1989), the corresponding raw data and additional information from the executing laboratory “Institut für Umweltanalyse”, Dr. Kanne. Recent regulatory requirements necessitate this re-evaluation.

The study was conducted in accordance with DIN 38412 Part 25 (Zahn Wellens Test). This test method is in all essential parts identical with OECD Guideline 302 B.

A solution of Gammasäure in a mineral medium was inoculated with activated sludge and incubated under aerobic conditions. Degradation was followed by DOC determinations at 3h, 1d, 7 d, 14 d, 21 d, 27 d and 28 d. The reference compound Aniline showed 100 % degradation after 14 days.

Gammasäure showed:

1 % degradation after 3 hours

6 % degradation after 1 days

7 % degradation after 7 days

6 % degradation after 14 days

11 % degradation after 21 days

11 % degradation after 27 days

9 % degradation after 28 days

The result after 3 hours shows that adsorption does not play a significant role. Therefore the results describe biodegradation rather than elimination; the test item is considered to be “not inherently biodegradable“.