Decene, hydroformylation products, low boiling

Toxicity to microorganisms

Description of key information

The toxicity to aquatic algae of components of Alchisor TAL 111 has been documented within this dossier. Adequate reliable measured and estimated data exists for toxicity to microorganisms to the constituent categories of Alchisor TAL 111, namely C9 -C14 aliphatics (2 -25% aromatics). In a conservative approach the most sensitive study result from across the C9-C14 aliphatics (2-25% aromatics) data sets has been identified and used to address the hazard endpoint in question.  The most sensitive study result from the Category 3 hydrocarbon solvent substances is a reliable predicted study with C9 -C14 aliphatics (2 -25% aromatics).  CONCAWE (2010) provided predicted results of a 48-hr NOELR for toxicity to microorganisms of 1.12 mg/L. Consequently this value is taken as the toxicity microorganisms endpoint for Alchisor TAL 111. 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

1.12 mg/L

Additional information

Alchisor TAL 111 is decene, hydroformylation product, low boiling and can be characterised as a UVCB substance. As defined in the ‘Read-Across Justification Document’ section 13, data provided for the analogue substance Alchisor TAL 123 and the Alchisor TAL 111 consitutent category substances, Category 3 hydrocarbon solvents, are representative of Alchisor TAL 111 and suitable for assessment purposes. Study data for each analogue/constituent category has been evaluated and considered together.Four reliable (Klimisch 2) toxicity studies in microorganisms have been conducted for constituent categories of Alchisor TAL 111 (namely, C9 -C14 aliphatics (2 -25% aromatics)) and are included in this dossier. The studies are all predicted results using a QSAR approach. In a conservative approach the most sensitive study result from across the hydrocarbon studies (CONCAWE, 2010) is used to address the hazard endpoint in question.

C9-C14 Aliphatics (2-25% Aromatics)

Predicted toxicity values are included in the dossier, although no reliable measured data were available for toxicity to microorganism for C9 -C14 aliphatics (2 -25% aromatics). CONCAWE (2010) predicted the toxicity of C9 -C14 aliphatics (2 -25% aromatics) to microorganisms using PetroTox in a QSAR approach. This method maintains consistency with common experimental protocols where the test media is first in contact with the hydrocarbon phase to prepare the water accommodated fraction (WAF) that is subsequently siphoned off and used in the toxicity test. Dissolved hydrocarbons in the WAF can interact with the other components in the exposure chamber (e.g., particulate matter) thereby reducing their intrinsic bioavailability. Only the dissolved fraction of any given hydrocarbon solvent is used to calculate toxicity in PetroTox.The estimated 48-hr EL50 values, based on growth inhibition, for the protozoan,Tetrahymena pyriformis, for C11-C14, C9-C10, C8-C12, and C10-C13 hydrocarbons are 185.1 mg/L,12.18 mg/L, 34.69 mg/L, and 63.75 mg/L, respectively. The estimated 48-hr NOELR (No Observed Effect Loading Rate), based on growth inhibition for C11-C14, C9-C10, C8-C12, and C10-C13 hydrocarbons are 1.71 mg/L, 1.53 mg/L, 1.12 mg/L, and 1.59 mg/L, respectively. The most sensitive NOELR of 1.12 mg/L for C8-C12 will be used in this assessment.

 

The toxicity to microorganisms of components of Alchisor TAL 111 has been documented within this dossier. Adequate reliable measured and estimated data exists for toxicity to microorganisms to the components of Alchisor TAL, namely C9 -C14 aliphatics (2 -25% aromatics).  In a conservative approach the most sensitive study result from the constituents (i.e., C9-C14 hydrocarbons) has been identified and used to address the hazard endpoint in question. The most sensitive study result is a reliable predicted study with C9 -C14 aliphatics (2 -25% aromatics) from a 48-hr NOELR for toxicity to microorganisms of 1.12 mg/L (CONCAWE, 2010). Consequently this value is taken as the toxicity microorganisms endpoint for Alchisor TAL 111.