Alkanes, C16-47, branched and linear

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Determined test concentration was 0.09 mg/l as TOC.

Details on results:

Physicochemical measurements:
The determined results of pH value, dissolved oxygen and temperature were 7.94-8.16, 7.7-8.8mg/L and 22.4-23.TC, respectively. The allowed range of the pH value is 6.0-8.5, the temperature is 21-25°C, and dissolved oxygen is at least 60 percent of the air saturation value throughout the test.

Toxic signs:
There was no significant difference between the control and the test group.
The fish treated with the test media showed no abnormalities or deaths during the test period.

Verification of Test Concentrations:
The results showed that there was no significant difference between the control and test material samples (due to the poorly water solubility of the test substance), and there was no significant difference between fresh and the expired solutions. Because the test substance was added to the test water at 1000 mg/L, the test concentration expressed with TOC was 0.09 mg/L (i.e mean of TOC 1000 mg/l - TOC ck).

Approximate LL50:
According to the results of the test, the determined test concentration was 0.09 mg/L as TOC, and the 96-hours LLso to zebra fish (Brachydanio rerio) was greater than 1000 mg/L as WAF (0.09 mg/L as TOC).

Results with reference substance (positive control):

Not applicable.

Sublethal observations / clinical signs:

Cumulative Mortality:

Nominal concentration (mg/l)	Initial population	Time (hr)	Cumulative mortality	Abnormalities
Control	10	3	0	No observed toxic signs
		6	0
		24	0
		48	0
		72	0
		96	0
1000	10	3	0	No observed toxic signs
		6	0
		24	0
		48	0
		72	0
		96	0

 

Validity criteria fulfilled:

yes

Conclusions:

According to the results of the test, the determined test concentration was 0.09 mg/L as TOC, and the 96-hours LLso to zebra fish (Brachydanio rerio) was greater than 1000 mg/L as WAF (0.09 mg/L as TOC).

Executive summary:

Introduction.

An acute toxicity study of 'Distillates (Fischer - Tropsch), heavy, C18 -50 - branched, cyclic and linear' was conducted with the freshwater to zebra fish (Brachydanio rerio).

Methods.

Based on the results of the preliminary test, a definitive test was conducted using a limit test concentration of l000 mg/L as WAF (nominal concentration). Groups of ten zebra fish were exposed to the test media. A concurrent water control group was performed in parallel. The test was performed with a semi-static water renewal system. The pH value, dissolved oxygen and temperature were determined at the beginning of the test and at 24-hour intervals during the 96-hours exposure period. Water hardness and total alkalinity were measured at the beginning of the test in the control tank. The fish were observed daily. The abnormalities or deaths were recorded at 3, 6, 24, 48, 72 and 96 hours after exposure. During the 96-hours exposure period, no abnormalities or deaths were observed in either the control or exposure fish.

Samples of test media were taken from the control and test material vessel at the beginning and the end of the first and the third 24 hours of the 96-hours period, concentrations of total organic carbon (TOe) were determined in the samples.

Results.

The results showed that there was no significant difference between the control and test material samples (due to the poorly water solubility of the test substance), and there was no significant difference between fresh and the expired solutions. Because the test

substance was added to the test water at 1000 mg/L, the test concentration expressed with TOC was 0.09 mg/L (i.e. mean of TOC 1000 mg/L - TOCck).

According to the results of the test, the determined test concentration was 0.09 mg/L as TOC, and the 96-hours LLso to zebra fish (Brachydanio rerio) was greater than 1000 mg/L as WAF (0.09 mg/L as TOC).

Description of key information

The 96 -hour LL₅₀ for the read across substance GTL Base Oil Distillates was determined to be >1000 mg/L (Brachydanio rerio).

This data is used for read across to Alkanes, C16 -47, branched and linear.

Additional information

The short-term toxicity of the read across substance GTL Base Oil Distillates to freshwater fish Brachydanio rerio (zebra fish) has been determined; the test was conducted in accordance with OECD Test Guideline 203.

Water-accommodated fractions (WAFs) of the sample were prepared in jars, by stirring for approximately 24 hours. The contents of the vessels were left to stand for 2 hours before drawing off the aqueous phase – the WAF – for testing. Semi-static exposures were then carried out.

The test was conducted in accordance with GLP and the TOC of test media were analysed for stability and exposure concentration. Total Organic Carbon (TOC) analysis of the freshly prepared test preparations showed amount of carbon present within the 1000 mg/l loading rate WAF test vessels to range from 1.71 mg C/l to 1.79 mg C/l. TOC analysis of the old test media showed amount of carbon present to range from 1.56 mg C/l to 1.64 mg C/l. There was no significant difference in TOC content between control and exposure vessels. This was expected by the authors due to the low water solubility of the test substance. 

The test results, expressed as the LL₅₀ value, showed that GTL Base Oil Distillates was not hazardous to fish at a loading rate of 1000 mg/l WAFs.