Distillates (coal tar), benzole fraction

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (see deviations from recommendations of standard guideline: worst-case condition)

Data source

Reference

Reference Type:

publication

Title:

Effects of Naphthalene and Benzene on Fathead Minnows and Rainbow Trout

Author:

De Graeve GM, Elder RG, Woods DC, and Bergman HL

Year:

1982

Bibliographic source:

Arch Environ Contam Toxicol 11, 487-490

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

; mean fish length: ca. 1 cm rather than 5 cm

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Benzene

EC Number:

200-753-7

EC Name:

Benzene

Cas Number:

71-43-2

Molecular formula:

C6H6

IUPAC Name:

benzene

Details on test material:

- Name of test material (as cited in study report): benzene
- no further information on test substance

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
--

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Benzene was pumped undiluted to a toxicant head tank and mixed with a predetermined flow of well water to achieve the highest test concentration. Lower concentrations were obtained within the diluter by dilution of the head tank concentration with dilution water.
- Controls: well water
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout
- Source: State of Wyoming Game and Fishery Department
- Age at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): mean length 1.06 cm
- Weight at study initiation (mean and range, SD): mean weight 13.9 g
- Feeding during test: no

ACCLIMATION
- Acclimation period: at least 10 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: no data
- Health during acclimation (any mortality observed): no data

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

535 - 596 mg/L as CaCO3

Test temperature:

15 ± 2°C

pH:

7.9 - 8.0

Dissolved oxygen:

ca. 7 mg/L

Nominal and measured concentrations:

Seven separate test solutions were used. Each concentration was half/double of the next higher/lower test concentration. Individual test concentrations are not reported.

Details on test conditions:

TEST SYSTEM
- Test vessels: four tanks, two 28 L and two 14 L in size
- Type (delete if not applicable): no data
- Aeration: no data
- Type of flow-through (e.g. peristaltic or proportional diluter): solutions/dilution water were delivered by peristaltic pumps to the diluters.
- Renewal rate of test solution (frequency/flow rate): 6.2 tank volumes within every 24 h
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- Biomass loading rate: < 1 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: well water from site of facility
- Alkalinity: 147 - 165 mg/L (CaCO3)
- Conductivity: 910 - 1051 µmhos/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: once per test

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 / 8 h light / dark
- Light intensity: no data

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

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

5.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

The LC50 determination was made using the graphical method given in Standard Methods (American Public Health Association, 1975).

Any other information on results incl. tables

Sublethal observations / clinical signs:

For fathead minnow 30% mortality were observed at a test substance concentration of 15.1 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

(But no data on mortality in controls is reported.)

Conclusions:

In an acute fish toxicity test with rainbow trout using a flow-through test system, the 96-h LC50 of benzene was determined to be 5.3 mg/L. The test complies with guideline requirements except that the fish used in this test were very young/small (mean size 1.06 cm, mean weight 13.9 g).