Alcohols, C9-11-branched

Endpoint summary

Description of key information

Hydrolysis:

Aliphatic alcohols are resistant to hydrolysis because they lack a functional group that is hydrolytically reactive.Therefore, this fate process will not contribute to a measurable degradative loss of this substance from the environment.

Phototransformation in air:

The photodegradation half-life of this substance as mediated by OH-attack is estimated as0.62days or 7.4 hours based on a 12-hour sunlight day.

Phototransformation in water and soil:

Aliphatic alcohols will not undergo direct photolysis and this fate process will not contribute to a measurable degradative loss of this substance from the environment.

Biodegradation:

Alcohols, C9 -C11-branched is readily biodegradable and hasbeen shown to biodegrade to a significant extent in a test of ready biodegradability (71% in 28 days) using standard OECD test guidelines. Therefore, biotic degradation will significantly contribute to the loss of this substancefrom the environment.

Bioaccumulation:

Experimental data along with the biochemical evidence suggest that this substance has a very low potential for bioconcentration in aquatic species and is not expected to bioaccumulate.

Adsorption / desorption:

The soil adsorption partition coefficient Koc of 687 (log Koc = 2.84) was estimated for Alcohols, C9-C11-branched using a log Kow method and the measured log Kow.

Distribution modelling:

Alcohols, C9 -C11, branched will partition largely to the soil compartment, followed by the water, air, and minimally to the sediment compartments, based on all available measured data. Volatilization from water and soil is expected to occur at a moderate rate.

Additional information

Hydrolysis:

Hydrolysis of an organic molecule occurs when a molecule (R-X) reacts with water (H2O) to form a new carbon-oxygen bond after the carbon-X bond is cleaved. Mechanistically, this reaction is referred to as a nucleophilic substitution reaction, where X is the leaving group being replaced by the incoming nucleophilic oxygen from the water molecule.

Chemicals that are susceptible to hydrolysis contain functional groups that can be displaced by a nucleophilic substitution reaction. Substances that have the potential to hydrolyze include alkyl halides, amides, carbamates, carboxylic acid esters and lactones, epoxides, phosphate esters, and sulfonic acid esters. The lack of a leaving group renders a compound resistant to hydrolysis.

Aliphatic alcohols are resistant to hydrolysis because they lack a functional group that is hydrolytically reactive.Therefore, this fate process will not contribute to a measurable degradative loss of this substance from the environment.

Phototransformation in air:

Alcohols, C9 -C11, branched has the potential to degrade in the atmosphere from hydroxyl radical attack and photodegradation can be a predominant daylight atmospheric degradation process for this substance. The photodegradation half-life of this substance as mediated by OH-attack is estimated as0.62days or 7.4 hours based on a 12-hour sunlight day. The half-life is calculated for a 12 -hr day because it normalizes degradation to standard day-light period during which hydroxyl radicals needed for degradation are generated.

Phototransformation in water and soil:

A conservative approach to estimating a photochemical degradation rate is to assume that degradation will occur in proportion to the amount of light with wavelengths >290 nm absorbed by the molecule. Alkyl alcohols contain molecules that are oxygenated aliphatic compounds, which absorb UV light below 220 nm, a range of UV light that does not reach the earth's surface. Therefore, aliphatic alcohols will not undergo direct photolysis and this fate process will not contribute to a measurable degradative loss of this substance from the environment.