N,N'-diphenyl-p-phenylenediamine

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

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:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

N,N'-diphenyl-p-phenylenediamine

EC Number:

200-806-4

EC Name:

N,N'-diphenyl-p-phenylenediamine

Cas Number:

74-31-7

Molecular formula:

C18H16N2

IUPAC Name:

N,N'-diphenyl-p-phenylenediamine

Test material form:

solid

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Laboratory culture: Activated sludge from the municipal wastewater treatment plant of Mannheim, Germany was collected from the aeration tank of the plant
- Preparation of inoculum for exposure: The activated sludge suspension was sieved with a fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. At the next day the sludge suspension was washed once with tap water and the suspension was adjusted to 7.5 g/L dry matter.
- Pretreatment: None
- Initial biomass concentration: 1.5 g/L dry mass

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

180 min

Test conditions

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer-flasks (nominal volume 250 mL)
- Type (delete if not applicable): closed
- Aeration: incubation was started by aeration of the test vessels with pressure air
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates):2
- No. of vessels per vehicle control (replicates):0

OTHER TEST CONDITIONS
- Adjustment of pH: no

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline:
- Test concentrations: 62.5, 125, 250, 500, 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

180 min

Dose descriptor:

EC10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

180 min

Dose descriptor:

other: EC20

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 3

Duration:

180 min

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

The EC50 of 3,5-dichlorophenol is in the range of 5 - 30 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes