N-1-naphthylaniline

Sediment toxicity

Link to relevant study record(s)

Reference

Endpoint:

sediment toxicity: short-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

according to guideline

Guideline:

other: Cushman, R.M and McKamey, M.I., 1981, A Chironomus tentans bioassay for testing synthetic fuel products and effluents, with data on acridine and quinoline, Bulletin of Environmental Contamination and Toxicology 26, 601-605

GLP compliance:

no

Analytical monitoring:

yes

Vehicle:

yes

Details on sediment and application:

PREPARATION OF SPIKED WATER
- Details of spiking: Chemical added in excess to well water (pH 7.8, hardness 120-140 mg CaCO3/L), stirred overnight and filtered though Whatman paper #41
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Methanol
- Concentration of vehicle in test medium (stock solution and final test solution): 1 mg/L

Test organisms (species):

Chironomus dilutus (previous name: Chironomus tentans)

Details on test organisms:

TEST ORGANISM
- Common name: midge
- Age of parental stock (mean and range, SD): fourth-instar larvae


ACCLIMATION
- Acclimation period: 24 hours

Study type:

laboratory study

Test type:

static

Water media type:

freshwater

Limit test:

no

Duration:

48 h

Exposure phase:

total exposure duration

Hardness:

140 mg CaCO3/L
Alkalinity: 120 mg CaCO3/L

Test temperature:

23-26 °C

pH:

7.8

Dissolved oxygen:

Begin: 8.5 mg/L

Ammonia:

not specified

Nominal and measured concentrations:

Nominal: four concentrations (not specified)
Measured after 48 hours: 65 to 90% of initial concentration

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 100 mL beaker covered with aluminium foil
- Overlying water volume: 100 mL
- Aeration: no

EXPOSURE REGIME
- No. of organisms per container (treatment): 7
- No. of replicates per treatment group: 4
- No. of replicates per control / vehicle control: 4

OVERLYING WATER CHARACTERISTCS
- Type of water (e.g. deionized, ground water, sea water, Elendt medium acc. to OECD 219):
- Source of water (if non-standard medium)
- Location: well water
- Alkalinity: 120 mg CaCO3/L

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality

VEHICLE CONTROL PERFORMED: yes

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

2.81 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 2.55-3.12

Reported statistics and error estimates:

Control response corrected by Abbot's formula (1925), log transformation of and probit analysis (Finney 1978), data which were pi=0 or pi=1 were approximated by Berkson's formula (1953), weighted least-squared analysis of the transformed variables was used to fit data into linear regression model (Neter and Wasserman 1974), SAS software package was used (Barr et al. 1979)

Validity criteria fulfilled:

not specified

Conclusions:

Naphthalene showed to be toxic to Chironomus tentans in a bioassay screening the acute toxicity (48h) of the test substance.

Description of key information

LC50(48h) = 2.81 mg/L (nominal, vehicle) for Chironomus tentans (read across)

Additional information

No data are available for the toxicity of N-phenyl-1-naphthylamine to sediment organisms. Therefore, information from a supporting, structurally analogue compound (naphthalene) was taken into account.

In this key study, the toxicity of naphthalene (purity not stated) to Chironomus tentans was tested according to the method described by Cushman & McKamey (1981) in an aqueous medium (Millemann et al. 1984). Four concentrations were tested, with methanol as solvent (final concentration of methanol in the test solution 1 mg/L). As a result, the LC50 (48h) was determined to be 2.81 mg/L (mortality) with confidence limits of 2.55 to 3.12 mg/L.