Hydrocarbons, C12-C16, 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:

January 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This robust summary has a reliability rating of 2 because the study did not follow GLP and the test containers were open to the air, which allowed for some volatile loss of the test substance. The study followed a standard guideline and was conducted without deviations that would invalidate the study.

Qualifier:

according to guideline

Guideline:

other: Unpublished Environment Canada Guideline: Environmental Protection Service 1985; Laboratory for determining the acute lethality of a water-soluble fraction of mineral oil to rainbow trout. Environment Canada, Dartmouth, N.S. June 17.

GLP compliance:

no

Analytical monitoring:

yes

Details on sampling:

Samples for analyses were taken at test initiation and termination.

Vehicle:

no

Details on test solutions:

The treatment solution was prepared by adding one part of the test substance to nine parts dechlorinated tap water for a total volume of 100 L in 120 L cylindrical fiberglass tanks. The tanks were covered with a sheet of polyethylene, and the stock solution was mixed for 20 hours at room temperature with a vortex of approximately 25%. Mixing was performed using a magnetic stir plate and stir bar. After mixing, the solutions were allowed to separate for four hours and the Water Accommodated Fraction (WAF) was then siphoned from the bottom of the mixing vessel and added to the test vessels. Siphons were placed in the tanks prior to adding the test material. Analytical measurements confirmed components of the test material were present in the test solution.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

Reported as former name, Salmo gairdneri. Juvenile trout were obtained from Loch Bras d'Or Salmon Farms in Baddeck, Nova Scotia, Canada. The fish had been maintained at a temperature of approximately 5 degrees C at the hatchery. The fish were kept in the testing laboratory in dechlorinated tap water. Prior to the start of the test, the holding water was increased in temperature to approximately 15 degrees C in 2 degrees C/day increments. Fish were fed daily until 24 hours prior to test initiation. The mean length of the fish was 45.9 mm, mean weight was 0.85 gm, and test loading was approximately 0.125 g fish/L. Fish were not fed during the exposure period.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Post exposure observation period:

None

Test temperature:

15.5 to 19.2 degrees C for the test substance.
15.5 to 17.0 degrees C for the control.

pH:

6.4 to 6.8 for the test substance.
6.7 to 7.3 for the control.

Dissolved oxygen:

8.1 to 9.2 mg/L for the test substance.
7.6 to 10.5 mg/L for the control.

Salinity:

Freshwater

Nominal and measured concentrations:

Water accomodated fractions were prepared by adding one part of the test substance to nine parts dechlorinated tap water for a total volume of 100 L in 120 L cylindrical fiberglass tanks. The nominal loading was 788,000 mg/L. The test substance concentration was 200 ppb at test initiation and 120 ppb at termination. The control measured 40 ppb at test initiation.

Details on test conditions:

Test vessels were 60 L circular polyethylene containers with 2 L of test solution per gram of fish per 24 hours of exposure, for approximately 60 L of solution open to the air. One replicate for the concentration and one replicate for the control were tested, each containing 10 fish.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LL0

Effect conc.:

788 000 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.:

> 788 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

No mortality was observed from a water soluble fraction of the test substance prepared at a loading of 788,000 mg/L.

Reported statistics and error estimates:

None were needed as there was no mortality.

Validity criteria fulfilled:

yes

Conclusions:

A water soluble fraction of the test substance prepared at a loading of 788,000 mg/L did not produce mortality to the fish, Oncorhynchus mykiss, during a 96-hour exposure period.

Executive summary:

A water soluble fraction of the test substance prepared at a loading of 788,000 mg/L did not produce mortality to the fish, Oncorhynchus mykiss, during a 96-hour exposure period. Test systems were not covered during the exposure period, but analytical results showed that constituents of the test substance were present at test initiation and termination.

Description of key information

A water accommodated fraction of hydrocarbons, C12-C16, isoalkanes, cyclics, <2% aromatics, produced a 96-hour LL₅₀ value of >88,444 mg/L and LL0 value of 88,444 mg/L with rainbow trout, Oncorhynchus mykiss. No mortality was observed in the treatment test system.

The water accommodated fraction of hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics, produced a 96-hour LL₅₀ value of >1000 mg/L and LL0 value of 1000 mg/L with rainbow trout, Oncorhynchus mykiss. No mortality was observed in either the control or treatment test systems.

The data from the latter study are used as supporting, read-across data to hydrocarbons, C12-C16, isoalkanes, cyclics, <2% aromatics.

Additional information

A water accommodated fraction of hydrocarbons, C12-C16, isoalkanes, cyclics, <2% aromatics, produced a 96-hour LL50 value of >88,444 mg/L and LL0 value of 88,444 mg/L with rainbow trout, Oncorhynchus mykiss. No mortality was observed in the treatment test system. The water accommodated fraction of hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics, produced a 96-hour LL50 value of >1000 mg/L and LL0 value of 1000 mg/L with rainbow trout, Oncorhynchus mykiss. No mortality was observed in either the control or treatment test systems. The data from the latter study are used as supporting, read-across data to hydrocarbons, C12-C16, isoalkanes, cyclics, <2% aromatics.