N-1-naphthylaniline

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented publication which meets basic scientific principles

Qualifier:

no guideline followed

Principles of method if other than guideline:

determination of cytotoxicity measured as growth inhibition

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

- Concentrations: 0.1, 1, 10, 100 and 1000 µg/mL

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: dilution in acetone or water (stock solutions at 100 mg/mL), serial dilutions at 10-fold decrements from 100 mg/mL to 0.01 mg/mL (freshly made for each assay)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone or water (not further specified)

Test organisms (species):

Tetrahymena pyriformis

Details on inoculum:

- Laboratory culture: yes
- Preparation of inoculum for exposure: maintained at 28°C, stock cultures were subcultured daily, inocula from 3-d old cultures (containing ca. 6 x 10e5 cells/mL) were diluted with sterile medium
- Initial biomass concentration: 1 x 10e4 cells/mL, diluted to final concentrations in the test tubes of 2 x 10e3 cells/mL

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

2 d

Post exposure observation period:

no

Hardness:

no data

Test temperature:

28 °C

pH:

no data

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

0.1, 1, 10, 100 and 1000 µg/mL (nominal conc.)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: screw-capped Pyrex tubes (125 x 20 mm), 5mL volume
- Aeration: no
- No. of organisms per vessel: 2 x 10e3 cells/mL
- No. of vessels per concentration (replicates): min. 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: 1.5% w/v Proteose peptone no. 3 (Difco) and 0.15% w/v yeast hydrolysate (Nutritional Biochemicals Corp.) with volatile preservative added (chlorobenzen 1 vol., 1,2-dichloroethane 1 vol., 1-chlorobutane 2 vols.), pH adjusted to 6.8
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Photoperiod: in the dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : cytotoxicity (microscopical examination of growth; classification as 100%, 50%, 25%, 12.5%)

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10

Reference substance (positive control):

not specified

Duration:

2 d

Dose descriptor:

IC50

Effect conc.:

2 mg/L

Nominal / measured:

nominal

Basis for effect:

growth inhibition

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05.12.1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

- Concentrations: 0, 100, 1000 and 10000 mg/L

Vehicle:

not specified

Test organisms (species):

activated sludge

Details on inoculum:

- Laboratory culture: yes
- Method of cultivation: 3L laboratory (OECD)
- Pretreatment: no
- Initial biomass concentration: 6 g/L (dry wt)

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Hardness:

no data

Test temperature:

19.7-20.6 °C

pH:

7.4-7.9

Dissolved oxygen:

no data

Salinity:

no data

Nominal and measured concentrations:

no data

Details on test conditions:

TEST SYSTEM
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Total volume in test vessels: 250 mL

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic nutrient solution (peptone 16 g/L, meat extract 11 g/L, NH2-CO-NH2 3 g/L, NaCl 0.7 g/L, CaCl2*2H2O 0.4 g/L, MgSO4*7H2O 0.2 g/L, K2HPO4 2.8 g/L)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): activated sludge respiration rate

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10

Reference substance (positive control):

yes

Remarks:

3,5-dichlorphenol

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

- Results with reference substance valid: yes

Respiration rate [mg/L*h] Inhibition [%] Test substance 100 mg/L 33 0 Test substance 1000 mg/L 27 5 Test substance 10000 mg/L 24 16 Reference substance 1 mg/L 24 16 Reference substance 20 mg/L 6 79 Negative control 28.5 - Autoxidation control 0 0

Description of key information

EC50(3h) > 10000 mg/L (nominal) for activated sludge (OECD 209)

Key value for chemical safety assessment

EC50 for microorganisms:

10 000 mg/L

Additional information

One study investigating the toxicity of the test substance to aquatic microorganisms is available. The study was performed according to OECD guideline 209 using non-adapted activated sludge as inoculum (Kanne 1989). Nominal concentrations of 0, 100, 1000 and 10000 mg/L were tested, and an EC50 value (3h) of > 10000 mg/L was obtained for the inhibition of the respiration rate.

Another study reports on the toxicity of Neozone A (a mixture containing N-phenyl-1-naphtylamine, not further specified) to Tetrahymena pyrifomis, yielding an IC50 value (2d) of 2 mg/L for growth inhibition, following no guideline.