Hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, >5% n-hexane

Endpoint summary

Additional information

No studies are available on the acute toxicity for hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, > 5% n-hexane. Based on a category approach data are read-across to hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane. A number of studies are available on the ecotoxicity of hydrocarbons, C6-C7, n-alkanes, isoalkanes, cyclics, <5% n-hexane to fish, Daphnia and algae. All studies were conducted using Water Accomodated Fractions (WAFs). Acute toxicity to fish ranged between LL50 values from 11.4 to 46 mg/L. EL50 values for Daphnia were found to range between 3 – 22 mg/L. Toxicity to algae measured as inhibition to biomass (ELb50) and growth rate (ELr50) ranged from 10 – 30 mg/L and from 30 – 100 mg/L, respectively. A study is available on the chronic toxicity to Daphnia for hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics. Based on a category approach data are read-across to this substance. The chronic toxicity, as measured by survival, sublethal effects, reproduction, and length of first generation adults resulted in a NOELR of 1 mg/L. Further, short-term and chronic aquatic toxicity were estimated using the Petrotox computer model (v. 3.04), which combines a partitioning model used to calculate the aqueous concentration of hydrocarbon components as a function of substance loading with the Target Lipid Model used to calculate acute and chronic toxicity of non-polar narcotic chemicals. The estimated freshwater fish 28-day NOELR (No Observed Effect Loading Rate) value is 2.028 mg/L based on growth. The estimated EL50 value for the protozoan, Tetrahymena pyriformis, as a representative for microorganisms, is 35.29 mg/L based on growth inhibition.