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Hydrocarbons, C9-C10, aromatics, >1% Naphthalene are a combination of Hydrocarbons, C9 Aromatics and Hydrocarbons, C10-C12 Aromatics. Read across data is available for Hydrocarbons, C9 Aromatics and Hydrocarbons, C10-C12 Aromatics and the worst case scenario for each end point has been presented.

The ecotoxicity of hydrocarbons, C9 aromatics and hydrocarbons, C10, aromatics, >1% naphthalene have been examined in a series of studies on fish, Daphnia and algae, as well as in microorganisms and birds. Petrotox has been run on the substance Hydrocarbons C9-C10, aromatics >1% Naphthalene for several species.

 

All of the studies were conducted in Water Accommodated Fraction (WAF) studies because of the limited water solubility of C9 aromatic materials. In this methodology, different loadings of the substance are added to the test medium and equilibrium between the water and the hydrocarbons is achieved according to their specific water solubility. The hydrocarbon concentrations at equilibrium will be characteristic of the loading of the substance, and therefore toxicity values from WAF studies are expressed as effect loadings or lethal loadings (EL or LL), not as concentrations. These effect loadings are used to determine environmental classifications. The WAF methodology is widely accepted for the testing of complex hydrocarbon substances and other UVCBs.

 

Additionally, a study conducted with microorganisms demonstrated no significant toxicity (EC50 >99 mg/L) of hydrocarbons, C9 aromatics, indicating that there would not be inhibition or toxicity to sewage treatment plant microorganisms.

 

Acute Fish Toxicity:

Water accommodated fractions of hydrocarbons, C9 aromatics, produced a 96-hour LL50 value of 9.2 mg/L with rainbow trout, Oncorhynchus mykiss.

 

Water accommodated fractions of hydrocarbons, C10, aromatics, >1% naphthalene, produced a 96-hour LL50 value between 2 and 5 mg/L with rainbow trout, Oncorhynchus mykiss.

 

Chronic Fish Toxicity:

The estimated freshwater fish 28-day NOELR (No Observed Effect Loading Rate) value for Hydrocarbons, C9-C10, aromatics, >1% naphthaleneis 0.69 mg/L based on growth, using Petrotox.

 

Acute Invertebrate Toxicity:

C9 aromatics hydrocarbons causes moderate acute toxicity to freshwater invertebrates at 21.3 mg/L (48-hour EL50), based on nominal loading of

the test substance in water, and 6.14 mg/L (48-hour EC50), based on measured concentrations.

 

Water accommodated fractions of hydrocarbons, C10, aromatics, >1% naphthalene, produced a 48-hour LL50value between 3 and 10 mg/L with Daphnia magna.

 

Chronic Invertebrate Toxicity:

The estimated freshwater invertebrate 21-day NOELR (No Observed Effect Loading Rate) value for Hydrocarbons, C9-C10, aromatics, >1% naphthalene is 1.2 mg/L, based on reproduction, using Petrotox.

 

Algal Toxicity:

C9 aromatic hydrocarbons produced toxicity based on inhibition of growth rate at 2.9 to ≥7.9, and reduction in biomass of Pseudokirchneriella subcapitata (formerly Selenastrum capricornutum) at a range of 2.6 to ≥3.8 mg/L, based on nominal loading of the test substance in water, and

≥0.42 mg/L and ≥0.29 mg/ L, respectively, based on measured concentrations.

 

Water accommodated fractions of hydrocarbons, C10, aromatics, >1% naphthalene, produced a freshwater 72-hr EL50 value for Pseudokirchneriella subcapitata (formerlySelenastrum capricornutum) of 1.0 to 3.0 mg/L based on both growth rate and biomass. The 72-hr NOELR (No Observed Effect Loading Rate) value for Pseudokirchneriella subcapitata is approximately 1.0 mg/L based on both growth rate and biomass.

 

Microorganisms Toxicity:

The hydrocarbons, C9-10, aromatics, estimated protozoan, Tetrahymena pyriformis, 48-hr EL50 and NOELR values are 10.11 and 2.64 mg/L, respectively, based on growth inhibition, using Petrotox.