Alkenes, C11-12, hydroformylation products, low boiling

Toxicity to microorganisms

Description of key information

The toxicity to aquatic algae of components of Alchisor TAL 123 has been documented within this dossier. Adequate reliable measured and estimated data exists for toxicity to microorganisms to the constituents of Alchisor TAL 123: Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) and dodecan-1-ol, only. Testing was deemed not necessary for undecan-1-ol.   In a protective approach the most sensitive study result from across the Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) and dodecan-1-ol data sets has been identified and used to address the hazard endpoint in question.  The most sensitive study result from the two substances is a reliable predicted study with Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%).  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 TAL123. 

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

1.12 mg/L

Additional information

Alchisor TAL 123 can be characterised according to three constituents: Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), undecan-1-ol and dodecan-1-ol. Study data, where available, for each constituent has been evaluated and considered together. Toxicity studies for microorganisms have been conducted for constituents of Alchisor TAL (namely, Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecan-1-ol and dodecan-1-ol) and are included in this dossier. The reliable studies included for each Alchisor TAL 123 component is briefly described below. In a protective approach the most sensitive study result from across the three constituents will be identified and used to address the hazard endpoint in question.

 

Adequate reliable measured and estimated data exist for toxicity to microorganisms to the constituents of Alchisor TAL 123: Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) and dodecan-1-ol, only. However, all but two studies (CONCAWE 2010 and Kirch, 1994) were deemed unreliable (Klimisch 3 or 4). Although the Kirch (1994) study was considered to be reliable (Klimisch 1), the study provides supporting information only. Therefore, the predicted results using a QSAR approach is considered to be the key study.Testing was deemed unnecessary for undecan-1-ol.

Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)

Predicted toxicity values are included in the dossier, although no reliable measured data were available for toxicity to microorganism for Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%). CONCAWE (2010) predicted the toxicity of Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) 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.

 

Undecan-1-ol

In accordance with Column 2 of REACH Annex VIII, the activated sludge respiration inhibition study (required for Endpoint 9.1.4) does not need to be conducted due to the predicted ready biodegradability at test concentrations in the range that can be expected in the influent to a sewage treatment plant. Although the study presented by Hattori (1987) where Streptococcus mutans was exposed to both undecan-1-ol for 48hrs was deemed unreliable, the Minimum Inhibitory Concentration (MIC) of 12.5 mg/L undecan-1-ol provides support to the argument that levels of test substances would likely not be at concentrations near the MIC in the influent of a STP.

Dodecan-1-ol

One reliable measured study was available for toxicity to microorganisms for dodecan-1-ol. Kirch (1994) conducted a reliable (Klimisch 1) GLP compliant study according to a national standard method with dodecan-1-ol. Pseudomonas putida were exposed to test concentrations for 30 minutes and oxygen consumption was measured. The NOEC is >10,000 mg/L. This study is considered supporting information.

 

The toxicity to aquatic algae of components of Alchisor TAL 123 has been documented within this dossier. Adequate reliable measured and estimated data exists for toxicity to microorganisms to the components of Alchisor TAL 123: Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) and dodecan-1-ol, only.Testing was deemed not necessary for undecan-1-ol.  In a protective approach the most sensitive study result from across the two constituents has been identified and used to address the hazard endpoint in question. The most sensitive study result is a reliable predicted study with Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) 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 123.