Hydrocarbons, C16-C22, n-alkanes, isoalkanes, <2% aromatics

Short-term toxicity to aquatic invertebrates

Description of key information

(48-h) EL50 >100 mg/l D. magna (read-across, reliability 2).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 000 mg/L

Additional information

Measured acute (short-term) toxicity data are available for Hydrocarbons, C18-C24, isoalkanes, <2% aromatics to the freshwater invertebrate Daphnia magna (Sacker, 2014). The test was conducted under static conditions (no renewal of the test media) in accordance with OECD Test Guideline 202. Appropriate modifications to the test and media preparation procedures were made to take account of the test substance containing multiple constituents, having low solubility in water and being potentially volatile. No effects on mobility of D. magna were observed after 48 hours exposure to the test medium prepared as a water-accommodated fraction (WAF) at a loading rate of 100 mg/l; 48-hour EL50 >100 mg/l, NOELR ≥100 mg/l. Samples of the control and the 10 and 100 mg/l loading rate WAFs were taken at 0 and 48 hours for Total Organic Carbon (TOC) analysis. Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantification of the analytical method. The results of the test are considered to be reliable.

Measured acute (short-term) toxicity data are available for Shell GTL Solvent GS270 (Hydrocarbons, C15-C19, n-alkanes, isoalkanes, <2% aromatics) to the freshwater invertebrateDaphnia magna(Harris, 2014). The test was conducted under static (no renewal of the test media) conditions in accordance with OECD Test Guideline 202 and method C2 of EC Regulation No. EC 440/2008. Appropriate modifications to the test and media preparation procedures were made to take account of the test substance containing multiple constituents, having low solubility in water and being potentially volatile. No effects on mobility ofD. magnawere observed after 48 hours exposure to the test medium prepared as a water-accommodated fraction (WAF) at loading rates up to 100 mg/l; 48-hour EL₅₀>100 mg/l, NOELR ≥100 mg/l. Samples of the control and the 10 and 100 mg/l loading rate WAFs were taken at 0 and 48 hours for Total Organic Carbon (TOC) analysis. Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantification of the analytical method. The results of the test are considered to be reliable.

 

The acute toxicity of a sample of GTL Gasoil has been determined by Palmer (2001) in tests with the freshwater invertebrateDaphnia magna (water flea). The test was conducted in accordance with OECD 202 methodology.

WAFs of the sample were prepared in sealed vessels with minimum headspace by stirring for approximately 72 hours. The contents of the vessels were left to stand for 1-2 hours before drawing off the aqueous phase – the WAF – for testing. Static exposures were then carried out in completely full, sealed vessels. The tests were not subject to GLP and the test media were not analysed for stability or for exposure concentration of the test substance. However in other respects they were considered to fulfil the requirements of current best practice.

The test results, expressed as the EL₅₀value, showed that the sample was not acutely toxic to Daphnia magna at a loading rate of 1000 mg/l.

Albertus and Phillips (2005) have reported results for anacute toxicity test carried out ona second sample of the substance with the freshwater invertebrate Daphnia magna (water flea). The test was conducted in accordance with OECD Test Guidelines 202. The test media were water-accommodated fractions of the test sample that were prepared in sealed vessels with a small headspace according to the CONCAWE methodology for the ecotoxicological testing of petroleum products (CONCAWE report, 1993).

The test results, expressed as the EL₅₀value, showed that the sample was not acutely toxic to Daphnia magna at a loading rate of 1000 mg/l.

The short-term toxicity of GTL Base Oil Distillates with the freshwater invertebrate Daphnia magna (water flea) has been determined by Harlan (Priestly, 2009) in a study conducted in accordance with OECD Test Guideline 202. 

WAFs of the sample were prepared by stirring for approximately 23 hours and left to stand for 1 hour before drawing off the aqueous phase – the WAF – for testing. Static exposures were then carried out according to GLP.

Total Organic Carbon (TOC) analysis of the freshly prepared test preparations showed amount of carbon present within the control and the 100 mg/l loading rate WAF test vessels to be less than the limit of quantitation (LOQ) for the method within fresh and old media. Therefore the results from the TOC analysis did not provide definitive evidence of the stability of the test preparations.

The test results, expressed as the EL₅₀value, showed that the sample was not hazardous to Daphnia magna at a loading rate of 100 mg/l.

Conclusion

Short-term daphnia toxicity tests are available for several substances in the relevant carbon number range for the registration substance. In the absence of adverse effects in these studies it can be concluded that, based on weight of evidence, the ELR₅₀(freshwater invertebrates) for Hydrocarbons, C16-C22, n-alkanes, isoalkanes, <2% aromatics is >1000 mg/l.