Alkenes, C11-12, hydroformylation products, low boiling

Long-term toxicity to fish

Description of key information

The long-term toxicity in fish of components of Alchisor TAL 123 has been documented within this dossier. There was not adequate reliable measured data for the long-term toxicity to fish to components of Alchisor TAL 123 (namely, Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecan-1-ol and dodecan-1-ol).  Long-term testing with undecan-1-ol or dodecan-1ol was deemed not necessary.  Reliable predicted data for Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) existed (Redman 2010) and provides an estimated NOELR of 0.079 mg/L. Consequently this value will be taken as the long-term toxicity in fish endpoint for Alchisor TAL 123 as a protective approach.  

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.079 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. In accordance with Column 2 of REACH Annex IX, the long-term aquatic toxicity to fish study (required in Section 9.1.6) does not need to be conducted for undecan-1-ol and dodecan-1-ol. In addition, arguments exist to support evidence for waiving data requirements for this endpoint for these constituents as discussed below. Reliable predicted data have been derived for Hydrocarbons C11-C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%) which is used to represent long-term toxicity to fish for Alchisor TAL 123 in a protective approach. No reliable measured data were available for Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2-25%), undecan-1-ol and dodecan-1-ol.

 

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

Although there are no reliable measured data for long-term fish studies relating to the toxicity of Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), reliable (Klimisch 2) predicted results using a QSAR, PetroTox computer model are available. PetroTox computes toxicity based on the summation of the aqueous-phase concentrations of hydrocarbon block(s) that represent a hydrocarbon substance and membrane-water partitioning coefficients (K_MW) that describe the partitioning of the hydrocarbons between the water and organism. As per ECHA Guidance Chapter 6, the use of QSARs is acceptable for filling data gaps needed for hazard assessment. In addition, supporting information for the use of QSAR modelling is presented in the CONCAWE report (Lampi et al., 2010), which is also included in Section 13 of the CSR. The CONCAWE report states that QSAR modelling was used for assessment of persistence and bioaccumulation for the PBT assessment.Using the Petrotox model, Redman (2010) estimated the freshwater fish 28-day NOELR (No Observed Effect Loading Rate) value, based on growth, for four hydrocarbon groups. The NOELRs for C11-C14, C10-C13, C8-C12, and C9-C10are 0.079mg/L, 0.097 mg/L, 0.161 mg/L, and 0.288 mg/L, respectively. The NOELR of 0.079 mg/L for C11-C14 is the most sensitive and will be used for this assessment.    

 

Undecan-1-ol and Dodecan-1-ol

In accordance with Column 2 of REACH Annex IX, the long-term aquatic toxicity to fish study (required in Endpoint 9.1.6) does not need to be conducted for undecan-1-ol and dodecan-1-ol as the chemical safety assessment according to Annex I indicates that this is not necessary. Adequate evidence exists for a waiver. Based on information provided in Derivation of Predicted No Effect Concentration Values for Alcohols C6-C24 (Fisk Associates 2010), and the OECD SIDS Initial Assessment Report for Long Chain Alcohols (2006) it can be concluded that it is unlikely that chronic toxicity to fish will be exhibited in the environment following exposure to long chain alcohols in the C11- C13 category for the following reasons; (i) biotransformation and (ii) significant biodegradation. Therefore, the data requirement for long-term toxicity to fish is waived. Below is a summary of the supporting evidence that undecan-1-ol and dodecan-1-ol would be unlikely to cause long-term toxicity to fish based on biotransformation and rapid biodegradation. There are no reliable measured or predicted data for chronic fish studies relating to undecan-1-ol and dodecan-1-ol.

 

Biotransformation

 

It has been reported that significant evidence is available showing biotransformation of alcohols occurs in fish which results in low bioconcentration factors. Alcohols are ubiquitous in nature and are produced by all living organisms (Mudge et al., 2008). As a result, alcohol and aldehyde dehydrogenase enzymes used in the conversions of alcohols to fatty acids are also ubiquitous in the plant and animal kingdoms (de Wolf and Parkerton, 1999). The ability of organisms to metabolise alcohols will limit the potential for bioaccumulation. Mudge et al., (2008) states that generally the biotransformation processes limit environmental exposure and dispersion. Reliable short-term data for toxicity to alcohols indicate that invertebrates are slightly more sensitive fish. Therefore, it is anticipated that long-term effects of alcohols to fish will be less sensitive than invertebrates.

Biodegradation

According to the OECD SIDS SIAR for Long Chain Alcohols (2006) reliable measured data(e.g. for hexanol, octanol, decanol, dodecanol, tetradecanol, hexadecanol and octadecanol)show that alcohols with chain lengths up to C18 are readily biodegradable. At carbon chain lengths up to C16, most tests showed that pass levels for ready biodegradation were reached within the 10-day window, with removal levels up to 100% over the timescale of the test. In additional studies conducted at environmentally realistic concentrations with radio-labeled substances (C12-16), very high rates of degradation have been measured (very rapid rate constants, with ca. 75-85% removed as CO₂and metabolites). These rates accord with field data for measured concentrations in waste-water treatment plant influent and effluent showing greater than 99% removal for carbon numbers 12 to 18. This summary of degradation is applicable to both linear and branched components of substances in the category. Therefore, the whole category is considered to show very high levels of biodegradability. Rapid degradation is also indicated by the removal rates in the chronic aquatic toxicity tests for the lower solubility substances (C10 to C15), where rapid removal of the substance from the test medium was observed, most likely due to biodegradation by microorganisms.

 

Reliable studies indicate that both linear and branched alcohols with a chain length below C18 are readily biodegradable. Long chain alcohols, such as undecan-1-ol and dodecan-1-ol, with chain lengths of C9-C14, may be considered readily biodegradable. In the environment, ready biodegradability means that it is unlikely that aquatic life will be exposed to C9-C14 long chain alcohols over extended periods, with potential to exert long-term toxic effects.

 

The long-term toxicity in fish of components of Alchisor TAL 123 has been documented within this dossier. There was not adequate reliable measured data for the long-term toxicity to fish to components of Alchisor TAL 123 (namely, Hydrocarbons C11 -C14, n-alkanes, isoalkanes, cyclics, aromatics (2 -25%), undecan-1-ol and dodecan-1-ol). Long-term testing with undecan-1-ol or dodecan-1ol is deemed not necessary. Reliable (Klimisch 2) predicted data for Hydrocarbons C11 -C14, n-alkanes, isoalkanes, aromatics (2 -25%) existed (Redman, 2010) and provides an estimated NOELR of 0.079 mg/L. Following the protective approach as detailed above and in the absence of data from both dodecan-1-ol and undecan-1-ol this value will be taken as the long-term toxicity in fish endpoint for Alchisor TAL 123. Further assessment is not necessary.

References:

de Wolf, W. and Parkerton, T. (1999). Higher alcohols bioconcentration: influence of bio-transformation. In: Symposium `Persistent, Bioaccumulative, Toxic Chemicals' at the 217th ACS National Meeting,(CA,), March 21 -25, 1999.

OECD SIDS Initial Assessment Report for22 (2006). Long Chain Alcohols; Tome 1: SIAR. Organisation for Economic Cooperation and Development.

Lampi et al. 2010. An Evaluation of the Persistence, Bioaccumulation and Toxicity of PetroleumHydrocarbonsPrepared for CONCAWE March 2010.

Mudge et al. (2008). Fatty Alcohols Anthropogenic and Natural Occurrence in the Environment. RSC Publishing.,.