1-naphthol

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

Not all validity criteria of OECD 203 can be thoroughly verified as there are to little detail on the test conditions. Flow-through conditions were applied and the test set up was according to "committee on methods of toxicity tests with aquatic organisms (Anon 1975)". Test conditions are stated but without any description of the variation over time. There were no mortalities in the controls and the dissolved oxygen concentrations were above 60%.

Principles of method if other than guideline:

- Principle of test: Fish (3 x n= 10) were exposed for 96 hours to five concentrations of 1 naphthol, plus controls and 96 hour LC50 were derived
- Short description of test conditions: Fish were exposed in a flow through system folowing the guidelines in the report "Commitee on methods of toxicity tests with aquatic organism (Anon, 1975)"
- Parameters analysed / observed: Lethality

GLP compliance:

no

Analytical monitoring:

no

Remarks:

Concentrations in the dosing reservoirs were confirmed at thefirst 6 hours of the exposure with a colorimetric analysis.

Vehicle:

yes

Remarks:

acetone

Details on test solutions:

Standard solutions of the toxicants (100 mg/ml and 10 mg/ml) were prepared in acetone. The control fish received an equal quantity of acetone.

Test organisms (species):

other: Catla catla, Mystus vittatus, M. cavasius and Anabas testudineus

Details on test organisms:

Four species of fish were tested

TEST ORGANISMS
- Latin names: Catla catla, Mystus vittatus, M. cavasius, Anabas testudineus
- Common name: Major (Indian) carp, Striped dwarf catfish, NA, climbing perch
- Length at study initiation (length definition, mean, range and SD):1-1.25, 4.5-6, 5-5.6, 4-5.5
- Weight at study initiation (mean and range, SD): 0.3, 3.5, 4, 8

ACCLIMATION
- Acclimation stated but period not specified
- Acclimation conditions (same as test or not): same as test
- Type and amount of food during acclimation: None
- Health during acclimation (any mortality observed):< 5% mortality


FEEDING DURING TEST
None

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

152 mg/L

Test temperature:

28+- 2C

pH:

8.4

Dissolved oxygen:

8-10 ppm

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.33 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

M. cavasius

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

4.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

C. catla

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

M. vittatus

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks:

A. testutus

Details on results:

No mortality in the controls

Sublethal observations / clinical signs:

Species	LC50	95% Confidence limits
Catla catla	4.3	4.2 -4.4
Mystus vittatus	1.1	0.9 -1.4
Mystus cavasius	0.33	0.25 -0.4
Anabas testutus	3	2.7 -3.4

Validity criteria fulfilled:

yes

Conclusions:

The test procedure follows an older report from the Environmental Protection Agency (Anonymous (1976) Committee on methods of toxicity tests with fish, macroinvertebrates and amphibians. Environmental Protection Agency, Oregon, 61 pp.

Not all validity criteria of OECD 203 can be thoroughly verified as there are to little detail on test conditions. However it is clearly stated that there were no mortalities in the controls and the dissolved oxygen concentrations were above 60%. Flow-through conditions were applied and the test conditions are described but without any description of the variation.

Executive summary:

The acute toxicity of 1-naphthol, to four species of fish was studied. The calculated 96 h LC50 values of 1-naphthol for Catla catla, Anabas testudineus, Mystus cavasius and Mystus vittatus were 4.3, 3, 0.33 and 1.1 mg/L respectively.

Description of key information

Three reliable (Klimish rating 2) studies are available for the short-term toxicity of 1-naphthol to fish. The catfish Mystus cavasius had a 96 hour LC50 of 0.33 mg/L ( 95% confidence limits 0.25 -0.4 mg/L) as measured by a flow-through exposure study (Tilak et al 1981) is noted as key. The 96 hour LC50 for the additional four fish species ranged from 1.1 – 4.63 mg/L (Geiger et al 1984, Holcombe et al 1984, Tilak et al 1981) are noted as supporting.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.33 mg/L