Hydrocarbons, C9-C10, n-alkanes, isoalkanes, cyclics, <2% aromatics

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

Study period:

August - December 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This robust summary has a reliability rating of 1 because the study followed a standard guideline, followed GLP guidelines, and was conducted without deviations that would invalidate the study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Samples for analysis of new and old test solutions were taken new at 0 hours (test initiation), new and old at 24, 48, and 72 hours, and old at 96 hours.

Vehicle:

no

Details on test solutions:

The water accommodated fractions of the test material were prepared by stirring the test material at each loading level in the exposure solution for 21 to 24.5 hours with a 1.5 to 2 hour settling period, after which each aqueous phase was removed and added to a test system. An equilibration study was conducted over a period of 72 hours prior to the definitive study to determine the approximate length of time needed to stir the test substance in the test media to acheive a saturated solution. Results suggested that a stirring period of 20 to 28 hours would be sufficient to reach equilibrium.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Fish were obtained from Brow Well Fisheries Ltd, Hebden, Yorkshire, UK, and acclimated to the test conditions for more than nine days before use. The seven control fish at test termination had a mean length of 4.0 cm and a mean weight of 0.53 g.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

None

Hardness:

149 to 164 mg/L CaCO3

Test temperature:

14.7 to 16.3 degrees C

pH:

7.3 to 8.2

Dissolved oxygen:

5.5 to 9.2 mg/L

Nominal and measured concentrations:

Nominal loading rates were 0.3, 1, 3, 10, 30, and 100 mg/L. A control was also included. Based on analyses of new and old test solution samples taken new at 0 hours (test initiation), new and old at 24, 48, and 72 hours, and old at 96 hours (test termination), the nominal/measured (mean) concentration values were: control/<0.01 mg/L; 0.3/0.03 mg/L; 1/0.08 mg/L; 3/0.23 mg/L; 10/0.30 mg/L; 30/0.42 mg/L; and 100/0.36 mg/L.

Details on test conditions:

The study was conducted in closed test systems that were renewed daily with fresh treatment solution. The test systems used were 1L glass bottles. One control and six treatment test systems were filled with media and sealed without a headspace. Seven fish were exposed to each of the control and treatment solutions and were not fed during the study.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

24 h

Dose descriptor:

LL0

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LL0

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LL50

Effect conc.:

> 10 - < 30 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LL0

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 10 - < 30 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LL0

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Seven fish were added to the control and each treatment solution. Mortality results are as follows:

Loading Rate Mortality
(mg/L) 24 hr 48 hr 72 hr 96 hr
Control 0 0 0 1
0.3 0 0 0 0
1 0 0 0 0
3 0 0 1 1
10 0 0 1 1
30 0 3 5 7
100 0 0 1 3

Reported statistics and error estimates:

Effect levels were estimated by visual inspection of the data, which is thought to be more appropriate than interpolative statistical analysis if the data are based on water accommodated fractions of a complex test substance with low water solubility.

Validity criteria fulfilled:

yes

Conclusions:

Water accommodated fractions of the test substance produced a 96-hour LL50 range of >10 to <30 mg/L and LL0 value of 1 mg/L with rainbow trout, Oncorhynchus mykiss.

Executive summary:

Water accommodated fractions of the test substance produced a 96-hour LL50 range of >10 to <30 mg/L and LL0 value of 1 mg/L with rainbow trout, Oncorhynchus mykiss.

Description of key information

Water accommodated fractions of hydrocarbons, C9-C10, n-alkanes, isoalkanes, cyclics, <2% aromatics, produced a 96-hour LL₅₀ value of >10-<30 mg/L with rainbow trout, Oncorhynchus mykiss.

Additional information

Water accommodated fractions of hydrocarbons, C9-C10, n-alkanes, isoalkanes, cyclics, <2% aromatics, produced a 96-hour LL₅₀ value of >10 -<30 mg/L with rainbow trout, Oncorhynchus mykiss.