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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

The toxicity to aquatic algae of components of Alchisor TAL 145 has been documented within this dossier. Adequate reliable measured and estimated data exists for toxicity to microorganisms to the components of Alchisor TAL 145 (Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) and dodecan-1-ol, only). Testing was deemed not necessary for tetradecan-1-ol.   In a protective approach the most sensitive study result from across Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) and dodecan-1-ol has been identified and used to address the hazard endpoint in question.  The most sensitive study result from across the two substances has been identified as a reliable predicted study with Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%).  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 will be taken as the toxicity to microorganisms endpoint for Alchisor TAL 145. 

Key value for chemical safety assessment

EC50 for microorganisms:
12.18 mg/L
EC10 or NOEC for microorganisms:
1.12 mg/L

Additional information

Alchisor TAL 145 can be characterised according to three constituents: Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), tetradecan-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 145 (namely, Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), tetradecan-1-ol and dodecan-1-ol) and are included in this dossier. The reliable studies included for each Alchisor TAL 145 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. However, all but two studies (CONCAWE 2010 and Kirch, 1994) was deemed unreliable (Klimisch 3 or 4). Although the Kirch (1994) study was deemed reliable (Klimisch 1), the study was considered supporting only. Therefore, the predicted results using a computer model are considered Key.

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.

 

Tetradecan-1-ol

There are no reliable measured or predicted data available for toxicity to microorganisms for tetradecan-1-ol. In accordance with Column 2 of REACH Annex VIII, the activated sludge respiration inhibition study (required in Section 9.1.4) does not need to be conducted due to the predicted ready biodegradability, as described in Section5.2 of this dossier, at test concentrations in the range that can be expected in the influent to a sewage treatment plant. Date deemed unreliable, either because study was deemed not valid or was from a secondary source, is included in this dossier. NOECs ranged from >13.7 mg/L for a 144 hr test withMycoplasma gallisepticum(Fletcher et al. 1981) to 10,000 mg/L for a study with six different fungi (Gershon & Shanks 1980). Minimum inhibitory concentrations (MIC) ranged from 0.6 mg/L for a test withClostridium botulinum(Huhtanen 1980) to 1.56 mg/L for a test withStreptococcus mutans(Hattori 1987). Although these data have been deemed unreliable (Klimisch 3 or 4) they provide support to the argument that levels of test substances would likely not be at concentrations near the MIC in the influent of a STP. No further assessment is necessary.

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 putidawere exposed to test concentrations for 30 minutes and oxygen consumption was measured. The NOEC is >10,000 mg/L. This study is considered supporting.

 

The toxicity to aquatic algae of components of Alchisor TAL 145 has been documented within this dossier. Adequate reliable measured and estimated data exists for toxicity to microorganisms to the components of Alchisor TAL 145 (Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) and dodecan-1 -ol, only). Testing was deemed not necessary for tetradecan-1-ol.  In a protective approach the most sensitive study result from across Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) and dodecan-1-ol has been identified and used to address the hazard endpoint in question. The most sensitive study result from across the two substances has been identified as a reliable predicted study with Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%). 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 will be taken as the toxicity to microorganisms endpoint for Alchisor TAL 145.