N-1-naphthylaniline

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

17.01.-07.02.1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: OECD guideline 202, part II (draft 8/1995)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was treated in an ultrasonic bath for 1 h, and stirred for 48 resp. 72 h on a magnetic stirrer. Undissolved material was filtered off (pore size: 7-12 µm).
- Controls: yes

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Source: clone breed of Bundesgesundheitsamt Berlin, Germany (German Health Authority), cultured in laboratory of Bayer AG, Leverkusen, Germany
- Age of parental stock (mean and range, SD): max. 24 h
- Feeding during test
- Food type: Scenedesmus subspicatus
- Amount: 0.1 mg TOC per adult per day (days 0-7), 0.2 mg TOC per adult per day (days 8-21)
- Frequency: daily
METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES:
careful sieving

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

14.7 - 15.0 °dH

Test temperature:

19.6 - 20.5 °C

pH:

7.5 - 8.0

Dissolved oxygen:

90.3 - 110.4%

Nominal and measured concentrations:

Nominal: 0, 0.0032, 0.01, 0.032, 0.1 and 0.32 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed with watchglasses (diameter 6 cm)
- Material, size, headspace, fill volume: glass beakers (diameter 5.5 cm, height 9.5 cm), 100 mL test medium
- Aeration: no
- Renewal rate of test solution (frequency/flow rate): three times per week (monday, wednesday, friday)
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 medium (Elendt) according to BGA (1992)
- Culture medium different from test medium: no
- Intervals of water quality measurement: weekly before and after renewal of test solutions

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16 h light: 8 h darkness
- Light intensity: < 12 µE/m²s, corresponding to < 800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
immobility, reproduction (daily inspection)

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.032 mg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 0.1 - < 0.32 mg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

immobilisation

Details on results:

- Mortality of parent animals: 10% in control, 0% at 0.0032, 0.01, 0.032 and 0.1 mg/L and 90% at 0.32 mg/L
- Reproduction rate (mean, offspring per adult): 103.6 in control, 102.3 at 0.0032 mg/L, 95.2 at 0.01 mg/L, 96.6 at 0.032 mg/L, 83.9 at 0.1 mg/L and 87.0 at 0.32 mg/L; corresponding to 100% in control, 98.% at 0.0032 mg/L, 91.9% at 0.01 mg/L, 93.2% at 0.032 mg/L, 81.0% at 0.1 mg/L and 84.0% at 0.32 mg/L

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Principles of method if other than guideline:

21d chronic toxicity test using Daphnia magna (following US-EPA recommendations)

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

not applicable

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: adding ethanol stock solutions of PNA to water
- Controls: yes, blank and solvent control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): ethanol (0.2 mL/L water)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Waterflea
- Strain: Daphnia magna
- Source: biological supply house
- Age at study initiation (mean and range, SD): 12 +/- 12 hours, first instar
- Method of breeding: stock cultures with regular subculturing (method of Dewey and Parker), in 4L polyethylene separatory funnels
- Feeding during test
- Food type: food suspension (30 mg/L) of yeast, chlorophyll, trout starter feed

ACCLIMATION
- Acclimation period: stock cultures with regular subculturing
- Acclimation conditions (same as test or not): yes
- Type and amount of food: baker's yeast, chlorophyll and algae (Chlorella pyrenoidosa)

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

none

Hardness:

170 mg/L as CaCO3

Test temperature:

20 +/- 2 °C

pH:

7.2-7.6

Dissolved oxygen:

no data

Salinity:

not relevant

Nominal and measured concentrations:

0, 0.01, 0.02, 0.04, 0.08 and 0.16 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: culture dishes containing 100 mL of solution
- Aeration: no data
- Renewal rate of test solution (frequency/flow rate): three times per week (monday, wednesday, friday)
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: soft reconstituted freshwater, recommended by US EPA for culture and testing of freshwater invertebrates; reagent-grade, deionized water (> 10megohm-cm), filtered through activated carbon and a 0.2 µm particle filter in a Barnstead NANOpure water purification unit
- Alkalinity: 30-35 mg/L as CaCO3
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16 h light: 8 h darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality (lack of movement)

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.02 mg/L

Nominal / measured:

nominal

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

0.06 mg/L

Nominal / measured:

nominal

Basis for effect:

mortality

Details on results:

- Mortality of parent animals: 20% for control, 7% for ethanol control, 20% at 0.01 mg/L, 27% at 0.02 and 0.04 mg/L, 53% at 0.08 mg/L and 100% at 0.16 mg/L

Results with reference substance (positive control):

not applicable

Validity criteria fulfilled:

not applicable

Description of key information

NOEC (21d) = 0.02 mg/L (nominal, mortality) for Daphnia magna (following US-EPA recommendations)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.02 mg/L

Additional information

The available data on the long-term toxicity of N-phenyl-1-naphthylamine to Daphnia magna were taken together and considered in a weight-of-evidence approach.

In the first study, effects of Vulkanox PAN (Additin 30) on daphnid reproduction were investigated in a GLP study according to OECD guideline 202 part II (Caspers 1996). Nominal concentrations of 0, 0.0032, 0.01, 0.032, 0.1 and 0.32 mg/L were tested. This study yielded a 21-d NOEC for reproduction of 0.032 mg/L. However, due to low recovery rates in preliminary experiments, analytical monitoring of the test concentrations was not conducted. Another study reports on long-term toxicity testing of N-phenyl-1-naphthylamine following US EPA recommendations (Sikka et al. 1981), with nominal concentrations of 0, 0.01, 0.02, 0.04, 0.08 and 0.16 mg/L. As a result, a 21-d NOEC of 0.02 mg/L was obtained for Daphnia magna based on mortality. Analytical monitoring was conducted, but results not reported. Furthermore, mortality is an endpoint of minor relevance for chronic toxicity tests. However, in order to a apply a conservative apprtoach this lightly lower NOEC value of 0.02 mg/L was used for the chemical safety assessment of the test substance.