2-methyl-p-phenylenediamine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2004-04-30 to 2004-05-28

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Closely followed OECD301 D guideline, GLP but on analog substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal sewage treatment plant, D-31137 Hildesheim- Laboratory culture: Not available - Storage conditions: Not available - Pretreatment: The activated sludge was filtered with a folded filter. The first 200 ml of the filtrate were not used. The second filtrate effluent from the domestic waste water was used to initiate inoculation.- Concentration of sludge: Not available- Initial cell/biomass concentration: 10(+4) to 10(+6) CFU/L- Water filtered: Not available- Type and size of filter used: Folded filter

Duration of test (contact time):

28 d

Initial conc.:

6 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS- Composition of medium: Mineral nutrient medium prepared according to the OECD Guideline 301 D- Solubilising agent: Not used- Test temperature: 21 +/- 1 degree C- pH: ranged 7.22 to 7.25- pH adjusted: No- CEC (meq/100 g): Not available- Aeration of dilution water: Aerated- Suspended solids concentration: Not available- Continuous darkness: YesTEST SYSTEM- Culturing apparatus: BOD bottles with glass stoppers (300 ml).- Number of culture flasks/concentration: Duplicate test, blanks and reference treatment- Method used to create aerobic conditions: One day before the test started the demineralized water for the test medium was aerated until oxygen saturation, and then left at room temperature for at least 20 h.- Measuring equipment: Oximeter, "WTW" Oxi 530- Test performed in closed vessels: Yes. Incubation vessels were closed without air bladders.SAMPLING- Sampling frequency: Day 0, 7, 14, 21, 28.- Sampling method: Duplicate incubation vessels taken.- Sample storage before analysis: Not availableCONTROL AND BLANK SYSTEM- Inoculum blank: 10 bottles containing only inoculum and nutrient medium- Toxicity control: 3.0 mg/L test item + 5.0 mg/L reference item + nutrient solution and inoculumSTATISTICAL METHODS: Concerning the OECD-guideline 301 D the index of the atoms of the item CcHhClclNnNanaOoPpSs was used for the calculation of the ThODNO3 and ThOD, respectively.

Reference substance:

acetic acid, sodium salt

Remarks:

CAS no: 127-09-3, 100.9% Pure, Concentration: 10 mg/L

Test performance:

Not available

Parameter:

% degradation (O2 consumption)

Value:

3

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

12

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

18

Sampling time:

21 d

Parameter:

% degradation (O2 consumption)

Value:

17

Sampling time:

28 d

Details on results:

Test substance was not readily biodegradable, in 10 day window and after 28 days. See Table below.

Results with reference substance:

The reference material, sodium acetate, reached 10% biodegradation within 2 days and >60% within 7 days. It met the validity criteria established in the guideline for a reference material.

Biodegradation of the Test Substance in the Ready Test (study # AFW94571)

Day	Biodegradation %
	Test item (6 mg/L)	Reference Material (10 mg/L)	Toxicity Control (3.0 + 5.0 mg/L)
7	3	79	41
14	12	85	46
21	18	79	49
28	17	86	54

Biodegradation based on oxygen consumption (OECD 301D test).

Validity criteria fulfilled:

yes

Remarks:

All criteria for guideline OECD 301 D were fullfilled.

Interpretation of results:

other: Not readily biodegradable.

Conclusions:

The test substance, 2-methyl-p-phenylenediaminesulfate, is not readily biodegradable. Biodegradation through Oxygen consumption after 28 days was determined to be 17%.

Executive summary:

An OECD 301 D Ready Test was conducted on 2 -methyl-p-phenylenediaminesulfate (CAS # 615 -50 -9). The test concentration was 6 mg/L, and the inoculum concentration was 10(+4)-10(+6) CFU/L. The test treatment, controls, reference, and blank were conducted in duplicate. Biodegradation was monitored by oxygen consumption.

The biodegradation of the test substance reached 17% on the 28th day. Hence the test material was not readily biodegradable.

The reference material, sodium acetate, reached >60% after day 6 and met 10 day window. It met the validity criteria established in the guideline for a reference material.

Description of key information

An OECD 301 D Ready Test was conducted on a structured related substance: 2 -methyl-p-phenylenediaminesulfate (CAS # 615 -50 -9). The test concentration was 6 mg/L, and the inoculum concentration was 10(+4)-10(+6) CFU/L. The test treatment, controls, reference, and blank were conducted in duplicate. Biodegradation was monitored by oxygen consumption. The biodegradation of the test substance reached 17% on the 28th day. Hence the test material was not readily biodegradable. The reference material, sodium acetate, reached >60% after day 6 and met 10 day window. It met the validity criteria established in the guideline for a reference material.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable, not fulfilling specific criteria